thesis carnivore attrition of the kaplan-hoover bison ... · chrissina coleen burke anthropology...
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THESIS
CARNIVORE ATTRITION OF THE KAPLAN-HOOVER BISON BONEBED: LATE
HOLOCENE PREDATORY ECOLOGY OF THE CACHE LA POUDRE BASIN,
COLORADO PIEDMONT
Submitted by
Chrissina C. Burke
Department of Anthropology
In partial fulfillment of the requirements
For the degree of Master of Arts
Colorado State University
Fort Collins, Colorado
Summer 2008
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COLORADO STATE UNIVERSITY
May 9th, 2008
WE HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER
OUR SUPERVISON BY CHRISSINA COLEEN BURKE ENTITLED CARNIVORE
ATTRITION OF THE KAPLAN–HOOVER BISON BONEBED: LATE
HOLOCENE PREDATORY ECOLOGY OF THE CACHE LA POUDRE BASIN,
COLORADO PIEDMONT BE ACCEPTED AS FULFILLING IN PART
REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS.
Committee on Graduate Work
__________________________________________________
Kenneth J. Berry
__________________________________________________
Jason M. LaBelle
__________________________________________________
Advisor: Lawrence C. Todd
__________________________________________________
Anthropology Department Chair: Kathleen A. Galvin
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ABSTRACT OF THESIS
CARNIVORE ATTRITION OF THE KAPLAN–HOOVER BISON BONEBED:
LATE HOLOCENE PREDATORY ECOLOGY OF THE CACHE LA POUDRE
BASIN, COLORADO PIEDMONT
This thesis presents the results of zooarchaeological, taphonomic, and
ethological investigations of carnivore modification at the Kaplan–Hoover bison
bonebed (5LR3953) in Windsor, Colorado. Kaplan–Hoover is a Late Archaic
Yonkee bison bonebed dated to approximately 2724+/-35 RCYBP. Prehistoric
hunters used an arroyo to trap approximately 200+ bison. After the kill, limited
use of the carcasses by hunters left a surplus of bison meat available for non-
human scavengers and predators. Carnivore attrition is present on over 40% of
the limb bones included in this study. Taphonomic analysis indicates that the
Kaplan–Hoover collection was modified and used by a range of non-human
scavengers. Using an interdisciplinary approach to methodology as well as
identifying key patterns relevant to a variety of fields of research, including
conservation biology is done. This thesis demonstrates how biogenic factors
influence the taphonomy of a faunal assemblage. In addition, this project is a
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part of the push to integrate zooarchaeological research and conservation
management decisions currently occurring in the field of archaeology. This
assessment suggests that in order to understand human interactions with present
and future environments, a researcher must first understand the prior behaviors
that assisted in the development of those events.
Chrissina Coleen Burke
Anthropology Department
Colorado State University
Fort Collins, CO 80523
Summer 2008
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ACKNOWLEDGEMENTS
This thesis is the culmination of a lot of lab time, tears, and excitement. I would have
never completed it, let alone even began it without the encouragement and help from a good
many people. First of all I could not have done this thesis without my advisor Dr. Larry Todd.
Not only has he been instrumental in my success here at CSU, but he is a major reason I was able
to preserver in all of the difficult situations I have encountered during my stay. I cannot say
enough wonderful things about Dr. Todd. He is an amazing mentor, teacher, friend, and
supporter. I have never felt respect from another faculty member as I have from Dr. Todd. His
ability to discuss every interest a student has in archaeology and help push them along to greater
and greater heights is one of amazement. I appreciate his willingness to take me on as a student
and I will always strive to be a mentor to my future students as he was with me.
Dr. Jason LaBelle also deserves a great deal of credit for helping me discover my path in
archaeology. His encouragement has always been of the utmost importance and his willingness
to sit and talk every research topic, obstacle, and success out thoroughly with me has been
extremely helpful. When I was frustrated and worried I couldn’t finish, Dr. LaBelle managed to
keep me going and help me realize that the whole process of graduate school is difficult for
everyone and that the ability to keep going was a trait that was developed and learned from
understanding set backs and problems. Dr. LaBelle is a great professor and mentor and has been
an important influence for the type of mentor I would like to be in the future.
Dr. Kenneth Berry was an important addition to my committee and helped ensure that my
statistics were correct and spent a number of hours discussing graduate school and life with me.
His encouragement and willingness to join my committee has been greatly appreciated and his
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advice for future research and instruction on proper formatting was very helpful for the
completion of this thesis.
I could not have finished writing this thesis without the support of my friends. Bethany
Mizushima and Benjamin Jewell (nerd corp!) have been incredibly supportive in every facet of
the writing process. Without them I would not have completed let alone stayed sane the entire
time. When I thought I couldn’t keep writing, I knew I could always talk to either one of them
and they would help me get back on track, even if they were “culturals” and didn’t know what I
was talking about. Erik Otárola-Castillo has also been an important friend for and mentor in my
pursuits with archaeological research. His willingness to include me in research projects has not
only been very helpful for my future, but has also increased my understanding of working with
colleagues on presentations and papers. Lastly, Robin Roberts has been an important part of this
support network. Her ability to encourage and support my every decision and ability to always
push me to have fun has increased my sanity as well.
Finally, Abe Thompson deserves an award for living with me while I was writing my
thesis and not killing me during the many times I unloaded my stress and frustration on him. I
can not imagine living with me while I was panicking and he magically did so without moving
out or running away! My sister Michelle was and always has been my biggest supporter. No
matter how much doubt I have had about myself she has always told me that she knew I could do
it. She also saved my thesis by editing the 100 or so pages, while taking care of her own family.
To everyone above, you are greatly appreciated and without you this thesis would have
never been done. I appreciate your influence in my life every single day and hope that in the
future, I will be able to repay your thoughtfulness and I promise to always support your dreams
and goals.
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TABLE OF CONTENTS
ABSTRACT OF THESIS ................................................................................................. iii ACKNOWLEDGEMENTS.............................................................................................. v TABLE OF CONTENTS ................................................................................................ vii LIST OF FIGURES........................................................................................................... ix LIST OF TABLES............................................................................................................. xi CHAPTER 1: INTRODUCTION .................................................................................... 1
Questions for Research................................................................................................ 1 Site Description and Information .............................................................................. 4 Kaplan–Hoover and Other Yonkee Bison Kill Sites................................................ 8 Summary of Chapters................................................................................................ 13
CHAPTER 2: FOUNDATIONS FOR RESEARCH .................................................... 15 Methodological Changes to Understanding Biogenic Factors ............................ 16 FAUNMAP: Choosing Non-Human Scavengers to Explore............................... 20 Ethological Research: Understanding Scavenging Behaviors ............................. 27 Conservation Research.............................................................................................. 41 Summary of Chapter ................................................................................................. 50
CHAPTER 3: AN INTERDISCIPLINARY APPROACH TO METHODS .............. 53 Data Collection Procedures ...................................................................................... 54 Extant Non-human Scavengers: Ethological Methods ......................................... 75 Summary of Chapter ................................................................................................. 76
CHAPTER 4: RESULTS OF DATA ANALYSIS......................................................... 78 Herd Characteristics Analysis.................................................................................. 79 Differential Destruction Analysis ............................................................................ 90 Carnivore Modification Analysis .......................................................................... 104
CHAPTER 5: CONCLUSIONS AND FUTURE DIRECTIONS ............................. 124 Implications for Conservation Research............................................................... 133 Future Directions ..................................................................................................... 136
Literature Cited ............................................................................................................ 142 APPENDIX A: FAUNMAP DATA............................................................................ 155 APPENDIX B: CODING SYSTEM ............................................................................. 157
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APPENDIX C: LANDMARK AND MEASUREMENT DESCRIPTIONS AND
CODES ........................................................................................................................... 159 APPENDIX D: KAPLAN-HOOVER DATA............................................................. 165 APPENDIX E: ANALYSIS OF SEX FOR SPECIFIC SKELETAL ELEMENTS .... 188
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LIST OF FIGURES
Figure 1.1: Late Archaic projectile ................................................................................. 6 Figure 1.2: Plan map of the Kaplan–Hoover bison bonebed ..................................... 8 Figure 1.3: Map of Late Archaic Yonkee bison kill sites........................................... 10 Figure 2.1: Number of sites with specific non-human scavengers ......................... 24 Figure 2.2: Percentage of non-human scavengers present in sites.......................... 26 Figure 2.3: Canis lupus maxilla ..................................................................................... 29 Figure 2.4: Carnassial pair of Canis lupus ................................................................... 30 Figure 2.5: Canis latrans maxilla ................................................................................... 32 Figure 2.6: Ursus arctos maxilla .................................................................................... 35 Figure 2.7: Ursus americanus maxilla ........................................................................... 40 Figure 3.1: Chipping back ............................................................................................. 67 Figure 3.2: Crenellations ............................................................................................... 67 Figure 3.3: Furrowing .................................................................................................... 68 Figure 3.4: Pitting ........................................................................................................... 68 Figure 3.5: Punctures ..................................................................................................... 69 Figure 3.6: Scooping out................................................................................................ 69 Figure 3.7: Tooth scoring............................................................................................... 70 Figure 3.8: Light utilization .......................................................................................... 71 Figure 3.9: Light/moderate utilization ........................................................................ 71 Figure 3.10: Light/moderate utilization ...................................................................... 72 Figure 3.11: Moderate utilization................................................................................. 72 Figure 3.12: Moderate/heavy utilization..................................................................... 73 Figure 3.13: Moderate/heavy utilization..................................................................... 73 Figure 3.14: Heavy utilization ...................................................................................... 74 Figure 3.15: Extreme heavy utilization ....................................................................... 74 Figure 4.1: Scatter plot of %MAU and bone mineral densities ............................ 103 Figure 4.2: Presence or absence of modification...................................................... 105 Figure 4.3: Percentage of carnivore utilization for the humerus........................... 106 Figure 4.4: Carnivore utilization for the radius-ulna.............................................. 110 Figure 4.5: Carnivore utilization for the femur........................................................ 113 Figure 4.6: Carnivore utilization for the tibia .......................................................... 117 Figure 5.1: Bear modification Bos taurus tibia from Dr. Haynes collection ......... 132
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Figure 5.2: Probable bear modification on Bison bison ............................................ 132 Figure E.1: Sex analysis scatter plot for the humerus ............................................. 188 Figure E.2: Sex analysis scatter plot for the radius-ulna ........................................ 189 Figure E.4: Sex analysis scatter plot for the metacarpal ......................................... 190 Figure E.5: Sex analysis scatter plot for the metacarpal ......................................... 190 Figure E.6: Sex analysis scatter plot for the metacarpal ......................................... 191 Figure E.7: Sex analysis scatter plot for the metacarpal ......................................... 191 Figure E.8: Sex analysis scatter plot for the femur .................................................. 192 Figure E.9: Sex analysis scatter plot for the femur .................................................. 192 Figure E.10: Sex analysis scatter plot for the femur ................................................ 193 Figure E.11: Sex analysis scatter plot for the tibia ...................................................193 Figure E.12: Sex analysis scatter plot for the tibia ...................................................194 Figure E.13: Sex analysis scatter plot for the tibia ...................................................194 Figure E.14: Sex analysis scatter plot for tibia.......................................................... 195 Figure E.15: Sex analysis scatter plot for the tibia ...................................................195 Figure E.16: Sex analysis scatter plot for the metatarsal ........................................ 196 Figure E.17: Sex analysis scatter plot for the metatarsal ........................................ 196 Figure E.18: Sex analysis scatter plot for the metatarsal ........................................ 197 Figure E.19: Sex analysis scatter plot for the metatarsal ........................................ 197 Figure E.20: Sex analysis scatter plot for the astragalus......................................... 198 Figure E.21: Sex analysis scatter plot for the calcaneus .......................................... 198 Figure E.22: Sex analysis scatter plot for the calcaneus .......................................... 199
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LIST OF TABLES
Table 2.1: FAUNMAP age categories.......................................................................... 22 Table 2.2: FAUNMAP species codes ........................................................................... 22 Table 4.1: Cross tabulation of side and sex for MNI analysis of the humerus...... 86 Table 4.2: Cross tabulation of side and sex for MNI analysis of the radius-ulna . 86 Table 4.3: Cross tabulation of side and sex for MNI analysis of the metacarpal .. 87 Table 4.4: Cross tabulation of side and sex for MNI analysis of the femur ........... 87 Table 4.5: Cross tabulation of side and sex for MNI analysis of the tibia.............. 88 Table 4.6: Cross tabulation of side and sex for MNI analysis of the metatarsal ... 88 Table 4.7: Cross tabulation of side and sex for MNI analysis of the astragalus.... 89 Table 4.8: Cross tabulation of side and sex for MNI analysis of the calcaneus..... 89 Table 4.9: Bone mineral densities for Bison bison ..................................................... 92 Table 4.10: MNE portions for the humerus ................................................................ 93 Table 4.11: MNE portions for the radius-ulna ........................................................... 94 Table 4.12: MNE portions of the femur....................................................................... 95 Table 4.13: MNE portions of the tibia ......................................................................... 96 Table 4.14: Frequency table of landmarks on the humerus ..................................... 98 Table 4.15: Frequency table of landmarks on the radius-ulna ................................ 98 Table 4.16: Frequency table of landmarks on the femur .......................................... 99 Table 4.17: Frequency table of landmarks on the tibia ........................................... 100 Table 4.18: Minimum animal units and % MAU values for Kaplan–Hoover..... 101 Table 4.19: %MAU based on MNE portion codes for Kaplan–Hoover................ 102 Table 4.20: Spearman correlation of %MAU and bone mineral density crosses 104 Table 4.21: Chi-square analysis of sex and carnivore utilization .......................... 107 Table 4.22: Chi-square analysis of sex and modification ....................................... 107 Table 4.23: Chi-square analysis of carnivore utilization and side......................... 108 Table 4.24: Carnivore utilization and side cross-tabulation .................................. 108 Table 4.25: Chi-square analysis of carnivore utilization and portion................... 109 Table 4.26: Carnivore utilization and portion cross-tabulation ............................ 109 Table 4.27: Chi-square analysis of carnivore utilization and portion................... 111 Table 4.28: Cross-tabulation of carnivore utilization and portion ........................ 112 Table 4.29: Chi-square analysis of sex and carnivore utilization .......................... 114 Table 4.30: Chi-square analysis of sex and modification ....................................... 114
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Table 4.31: Chi-square analysis of carnivore utilization and side......................... 115 Table 4.32: Carnivore utilization and side cross-tabulation .................................. 115 Table 4.33: Chi-square analysis of carnivore utilization and portion................... 116 Table 4.34: Carnivore utilization and portion cross-tabulation ............................ 116 Table 4.35: Chi-square analysis of sex and carnivore utilization .......................... 118 Table 4.36: Chi-square analysis of sex and modification ....................................... 118 Table 4.37: Chi-square analysis of carnivore utilization and side......................... 119 Table 4.38: Chi-square analysis of carnivore utilization and portion................... 119 Table 4.39: Bone mineral densities from bison ........................................................ 120 Table 4.40: Bone mineral densities for bison ............................................................ 121
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CHAPTER 1: INTRODUCTION
Questions for Research
In any archaeological site there are specific factors that illustrate formation
processes essential to understanding the spatial and temporal aspects of
paleoecology. If the site is composed of a dense bonebed of skeletal material, it is
necessary to assess the taphonomic factors that are associated. Of particular
interest to this thesis is carnivore modification, a biogenic factor that influences
the overall destruction and formation of the bonebed as well as illuminates the
predatory and scavenging behaviors of both human and non-human scavengers.
The goals of this thesis are wide-ranging, with basal questions and
integrated questions. The basal questions are useful for setting the framework
from which the integrated questions can be asked. The integrated questions
incorporate an understanding of the basal questions so that the information
presented by this thesis is useful for other researchers at a variety of different
faunal assemblages. Finally, these questions are meant to establish a framework
for analyzing carnivore modification in faunal assemblages and how that
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information is useful for understanding human and non-human scavenger
interactions.
Basal Questions:
1. What are the herd characteristics at Kaplan–Hoover?
2. What types of carnivore modification and intensity of carnivore
utilization is present on the Kaplan–Hoover collection?
3. Where is the modification located on the appendicular skeleton and
which specific elements exhibited more destruction than others?
4. What non-human scavenger behaviors are important to understand
when discussing the taphonomy of a faunal assemblage?
Integrated Questions:
1. What relationships between prehistoric human hunters and non-
human scavengers can be observed from the faunal remains at
Kaplan–Hoover?
2. How can these same methods be used for other sites?
3. Why is the interdisciplinary approach used in this thesis beneficial for
answering all of the preceding questions?
The first question, that will build the basis for the remaining questions
asks, what are the herd characteristics? It is essential to know the demographics
of the herd to understand if carnivores were selectively scavenging the remains,
therefore analysis on size and sex of the skeletal material must be accomplished.
The second question: where is the carnivore modification located on the skeletal
elements, is important to understanding how the collection was damaged. A
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record of the types of carnivore modification present as well as where it is
located anatomically and in what abundances is relevant for comprehending
overall destruction of the material, utilization of the material, and site formation
processes. In conjunction with the remaining basal questions, ethological
literature is useful for understanding non-human scavenger behaviors,
specifically species that could be associated with the region the site is located
within.
The integrated questions for contemplation and analysis seek to
understand the interactions between human hunters and non-human scavengers
that can be observed by comparing and contrasting the answers from the basal
questions. How do the herd demographics and carnivore modification data
support inferences that specific carnivores were present at the site? Included will
be a discussion on how these data sets can be used to understand the overall
paleoecology of a region, further discussing present and future conservation
issues that may have resulted from the interactions created in the past by
humans between themselves and their environments
These questions are important for a number of reasons. First of all,
archaeologists are in a prime position to influence decision making in the natural
resources (Lyman and Cannon 2004:xv). Research done by archaeologists is
useful for understanding interactions between species through time, therefore,
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having the ability to assist in management decisions for eradication or
reintroduction of species into habitats and regions. Currently, the natural
resources and social sciences are working in parallel directions with a distinct
lack of integration and collaboration. Instead of a parallel line of thinking by
both fields, an integrated line would benefit both in their pursuits.
In general, the questions presented by this research are important to
zooarchaeology and a number of archaeological, paleontological, and ecological
sites. When answered, these questions will provide a basic description of the
Kaplan–Hoover bison bonebed as well as an understanding of four non-human
scavenger species: Canis lupus, Canis latrans, Ursus arctos, and Ursus americanus.
Finally, this research describes an interdisciplinary methodological framework to
zooarchaeological research and carnivore modification.
Site Description and Information
The Kaplan–Hoover bison bonebed located in Windsor, Colorado is a
highly non-human scavenger modified Bison bison bonebed. Therefore, it is an
important example of why it is imperative to research the behaviors of carnivore
and rodent species to assess the specific mammals that altered the skeletal
elements after prehistoric peoples had left. To test the usefulness of the
methodological questions presented in the preceding paragraphs, the Kaplan–
Hoover site was used. Excavations were undertaken by Colorado State
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University (CSU) from 1997-2001 and overseen by Dr. Lawrence C. Todd from
the CSU Anthropology Department.
Kaplan–Hoover is a late archaic (middle Holocene) bison arroyo trap and
single catastrophic event kill (Todd, et al. 2001:137). Located in Larimer County
Colorado, the site sits at an elevation of 1475 m and is located approximately 800
m north of the Cache la Poudre River (Todd, et al. 2001:126). Radiocarbon dating
was accomplished using several charcoal samples that were collected and
mapped in the bonebed (Todd, et al. 2001:132-133). Using AMS dating, two
larger chunks of charcoal were dated to 2740+/-40 and 860+/-40 radiocarbon years
before present (RCYBP) (Todd, et al. 2001:132-133). In addition, an intact
metatarsal was dated to 2690+/-60 RCYBP and when averaged with the date of
one of the charcoal chunks of 2740+/-40 RCYBP, Kaplan–Hoover is given a date
of 2724+/-35 RCYBP (Todd, et al. 2001:132-133).
The seasonality of the site has been determined as being a September-
October kill based on the eruption and wear of the bison mandibular molars
(Todd, et al. 2001:137). The site is composed of a dense accumulation (Figure 1.2)
of Bison bison skeletal material with the excavated portion measuring 4-5 m wide
and at least 1 m thick (Todd, et al. 2001:127-128). The minimum number of
individual animals (MNI) at the time of the first report was 44 based on the
crania recovered (Todd, et al. 2001:135). Additionally, 4000+ identifiable skeletal
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elements have been removed from the site and are currently housed in the
Anthropology Department at Colorado State University, with exception of a
number of elements that were left in situ and thus not available for analysis
(Todd, et al. 2001). Estimations from minimum number of skeletal elements
(MNE) and number of identified specimens (NISP) suggest that the deposit could
hold roughly 200+ bison, therefore, 150 have yet to be exhumed (Todd, et al.
2001:135). From these data, the herd composition is approximately 33-39% bulls
and 61-67% females and sub-adults (Todd, et al. 2001:137). Research presented in
this thesis, which includes analysis of materials recovered subsequent to the 2001
publication, will change these numbers slightly.
Figure 1.1: Late Archaic projectile points from the Kaplan–Hoover site (Todd et al. 2001).
The majority of the skeletal elements missing from the bonebed are ribs,
thoracic vertebrae (hump meat), and femora all of which have high food utility
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values (Todd, et al. 2001:136-137). In general the preservation of the elements is
excellent, with very little weathering cracks, which according to Todd, et al.
(2001:134) indicate burial of the remains soon after the animal’s death. However,
the site preservation is compromised due to heavy modification of the
abandoned skeletal elements by carnivores and rodents and post-depositional
deterioration.
Heavy modification due to carnivores is what separates the Kaplan–
Hoover bonebed from other sites in the prehistory of North America. During
initial examination of the skeletal elements 45 humeri were studied for degree of
carnivore damage, of those 80% had carnivore damage consuming the entire
proximal end and Todd et al. (2001:140) remark that “overall, 98% of the humeri
from the site have some carnivore damage.” These estimates surpass the Casper
site which has 37%, the Jones–Miller site with 28%, and the Bugas–Holding site
with 17% carnivore damage to the humeri (Todd, et al. 1987; Todd, 1997; Todd, et
al. 2001:140). In Chapters 4 and 5 discussions on the types of carnivore
modification and intensity of modification will clarify these numbers and give
more details pertaining to the remaining skeletal elements used for analysis in
this thesis.
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Figure 1.2: Plan map of the Kaplan–Hoover bison bonebed (Todd, et al. 2001:134, Figure 7).
Kaplan–Hoover and Other Yonkee Bison Kill Sites
The projectile points recovered from Kaplan–Hoover include Yonkee
points, described from the Powers–Yonkee site (24PR5) in southeastern Montana
(Bentzen 1961; Bentzen 1962b; Bump 1987; Frison 1978; Roll, et al. 1992). Yonkee
points (Figure 1.1) are typically side and or corner notched with a basal notch or
indention (Frison 1978:50). The type site of this technology is the Powers–
Yonkee (24PR5) site, located in southern Montana (Bentzen 1961, 1962b; Bump
1987; Frison 1978). Other sites that contain Late Archaic Yonkee points include
Kobold (24BH406) in southern Montana, Powder River (48SH312), and
Mavrakis–Bentzen–Roberts (48SH311) both of which are in northern Wyoming
(Bentzen 1962a; Bump 1987; Frison 1968; Frison 1970; Frison 1978). The last site
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to be discussed is Ayers–Frazier (24PE30), another bison trap in Montana (Clark
1981) (Figure 1.3).
Powers–Yonkee (24PR5) was initially dated to 4450+/-125 years before
present (Bentzen 1961). Several years later Bump (1987) dated bison skeletal
material to 2290+/-50 years before present. The site was excavated by the
Sheridan Chapter of the Wyoming Archaeological Society in August of 1961
(Bentzen 1961). The Powers–Yonkee bison kill is an arroyo trap that sits upon a
high terrace at about 1097 meters above sea level; the site is located on the north
bank of a small arroyo upon this terrace (Bentzen 1961). Bentzen (1961) states
that the bison were driven into the north-south branch of the arroyo and then
were shunted or trapped into the east-west branch of the arroyo. A bison kill is
represented at Powers–Yonkee, however, there are other faunal remains,
including one canid (Bump 1987:31). The remains are very well preserved and
major concentrations lie at approximately 89–104 cm below the surface sediments
(Bump 1987:33). As will be seen in most of the sites designated as Yonkee,
projectile points are usually recovered from rib skeletal elements (Bentzen 1961:7;
Frison 1968:32-33, 1978:203). Muscle stripping is evident from butchery cut
marks on specific elements as well at Yonkee sites (Frison 1968:33-34, 1978:203).
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Figure 1.3: Map of Late Archaic Yonkee bison kill sites
on the Great Plains in Montana, Wyoming, and Colorado.
The Powder River site (48SH312) located in the Powder River Basin has
not been dated. The site was excavated in 1966 and is an arroyo trap single kill
event of Bison bison, with an MNI of approximately 12 (Frison 1968:32). Of the 25
projectile points found at the site, 16 are located inside rib or vertebral column
skeletal elements (Frison 1968:32-33). Butchering marks indicate that the hunters
removed meat that was easiest to obtain (Frison 1968:33-34). The majority of the
meat removed at Powers-Yonkee was hind limbs, thus leaving most of the
forelimbs present at the site (Frison 1968:33). In addition, hunters did not
remove the brains, hides, or tongues, further reinforcing the idea that the meat
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was chosen based on easiest to access in the arroyo (Frison 1968:33). Finally, the
author makes mention that other damage to the skeletal elements is most likely
indicators of non-human scavenging behaviors, although he does not go into
detail on this topic (Frison 1968:33).
The Mavrakis–Bentzen–Roberts bison trap (48SH311) is a single kill event
located in the Powder River Basin just as the Powder River site (Bentzen 1962a;
Frison 1968, 1978). Mavrakis–Bentzen–Roberts site was excavated in 1962 and is
an arroyo trap kill with an MNI of approximately 17-26 bison (Bentzen 1962a:32).
Dated to 2600+/-200, site 48SH311 shows little evidence of marrow removal
because of few stone tools imbedded directly into shaft of the elements (Bentzen
1962a:32). Finally, 48SH311 shows butchering cut mark evidence of muscle
stripping similar to the other Yonkee sites (Frison 1978:206).
The Kobold site (24BH406) has not been dated, however, the projectile
points at the site are Yonkee points (Frison 1970b). Kobold is a multiple
component bison jump from a 7.62 meter cliff in southern Montana (Frison
1970b:7). Two of the levels at the site contain faunal remains, level two contains
badly decomposed material with some long bones broken for marrow with an
MNE of approximately 65 (Frison 1970b:15). The second level to contain faunal
materials is level four, which is mostly scapulae, humeri, radii, and metacarpals
with possible removal of marrow (Frison 1970b:22-23).
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The final site is the Ayers–Frazier site (24PE30) dated to 2180+/-150 years
before present (Clark and Wilson 1981:23). The site was excavated in 1978 and is
interpreted as being a single kill event in an arroyo trap with 700 elements
recovered from excavations and approximately 300 more from a looter’s back
dirt pile (Clark and Wilson 1981:37). There is evidence of butchering in terms of
cut marks, chop marks, and skinning marks on the skeletal remains from Ayers–
Frazier (Clark and Wilson 1981:38). Of the 700 skeletal elements analyzed from
the test excavation area, approximately 15% have carnivore modification and the
authors go into great deal discussing the bone tools of the site, which appears to
be a description of the carnivore modification types of chipping back and
salivary polishing that will be defined later in this thesis (Clark and Wilson
1981:50–51).
Yonkee complex sites are similar in more ways than just the type of
projectile points. The bison kills from the Yonkee Late Plains Archaic are
typically arroyo traps with exception of the Kobold site, which is a jump
(Bentzen 1961, 1962; Bump 1987; Clark and Wilson 1981; Frison 1968, 1970b,
1978). Faunal material at Yonkee sites typically have points lodged in the ribs
and vertebral columns and butchering evidence suggests stripping of muscle
meat as well as some removal of marrow and long bones (Bentzen 1961, 1962b;
Bump 1987; Clark and Wilson 1981; Frison 1968, 1970b, 1978). With limited
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carcass utilization, expecting non-human scavenger modification is reasonable.
The only authors discussing carnivore modification are Clark and Wilson with
the Ayers–Frazier site, which was published in 1981.
Focus on the Yonkee sites indicates that most of the sites with Yonkee
projectile points were arroyo traps and butchering patterns suggest that
prehistoric hunters did not use all of the bison meat available. At the Ayers–
Frazier site, there is a record of carnivore modification being present, suggesting
that a new analysis of the other sites may yield similar results considering that
the other publications were prior to intense taphonomic scrutiny at
archaeological sites.
Summary of Chapters
The remaining chapters will discuss a wide range of topics and end with a
synthesis of ideas. Chapter 2 discusses a number of background research
projects and methods. Chapter 2 begins by identifying the methodological
framework on carnivore attrition, then presents exploratory research using the
FAUNMAP database, and concludes with a discussion of non-human scavenger
behaviors and predator conservation issues in North America. Chapter 3
describes and explains the methods used to collect and analyze data from the
Kaplan–Hoover collection. Chapter 4 discusses the final results of analysis,
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14
specifically discussing sex analysis, herd characteristics, carnivore modification,
and overall description of carnivore destruction on the collection. Finally
Chapter 5 allows discussion of the most important results and patterns as well as
correlations between the skeletal analysis and ethological literature review.
Chapter 5 concludes with future directions for research in biogenic factors in
taphonomy, carnivore management, and future interdisciplinary approaches to
current environmental problems.
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CHAPTER 2: FOUNDATIONS FOR RESEARCH
This chapter presents information collected on carnivore modification in
zooarchaeology, presence of non-human scavengers in Great Plains
archaeological sites, and non-human scavenger ethological literature. First, it is
essential to discuss where and how the understanding of carnivore modification
on faunal remains emerged in the long history of archaeology and
zooarchaeology. Next a discussion on the use of the FAUNMAP database assists
in identifying non-human scavenger remains in Holocene archaeological and
paleontological sites. Finally, a review of the ethological literature on the species
of interest Canis lupus, Canis latrans, Ursus arctos, and Ursus americanus is
accomplished. This section serves as both part of the literature review and part of
the results section, as a means to illustrate animal behaviors that may have
contributed to the taphonomy of faunal assemblages. This chapter ends with a
discussion on conservation issues in regards to wolves, coyotes, and bears. In
view of the long relationship humans and these scavengers have had, it is
important to discuss how zooarchaeological research can contribute to long term
management decisions. Discussion of conservation can open interdisciplinary
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16
communications that can influence an understanding of how humans have an
impact on their environment.
Methodological Changes to Understanding Biogenic Factors
In the earliest archaeological research, faunal remains were typically
thrown to the side and in some early cases recorded in lists (Reitz and Wing
1999:16-17). The reaction to exclude faunal remains from archaeological
interpretation is in part due to the lack of understanding that humans and their
environments are related and interacting (Reitz and Wing 1999:15-16). Initially,
archaeologists did not believe any data or significant information could be
gathered from faunal remains, and then gradually, archaeologists began
recording what species the faunal materials exhibited and counting how many
individuals were present (Reitz and Wing 1999:15-16). Over time, archaeologists
began interpreting damage to faunal remains as bone tools, and in several cases
the modification was interpreted as indicating tool construction (Binford 1981;
Brain 1981; Dart 1953; Dart 1956; Dart 1971). An example of the most famous
misinformed assumption that bones were altered to be tools or weapons was
established by Dart and his Osteodontokeratic Culture (Binford 1981; Brain 1981;
Dart 1953, 1956; Dart and Wolberg 1971). Dart believed that in the South African
caves, the bone accumulations were indications of a violent past in human
culture and he suggested that the breaks and crenellations exhibited in the
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17
skeletal elements were created by early man (Binford 1981; Brain 1981; Dart 1953;
Dart 1956; Dart 1958; Dart 1971).
Brain (1981) took a different approach to the evidence proposed by Dart;
he studied the behaviors of African carnivores and the geology of caves and
discovered a drastically different scenario. After observing wild dogs, he found
that the types of modification Dart had been recording on bones was very similar
to the types of gnawing and crushing marks created by various carnivores
devouring a carcass (Brain 1981:22-24).
In the Great Plains, a similar situation occurred. Bison kill sites in various
settings were being excavated and skeletal elements were being analyzed. At the
Glenrock Buffalo Jump site, Frison (1970a:26-33) suggested that bone tools were
constructed as “expediency tools” and used to skin and remove meat from the
bison. At the Casper site, Frison (1974:28-31) again suggested the use of skeletal
elements as choppers and hide scrapers. Similar to Brain, Binford (1981) was
working on understanding the different processes possible to change the
dynamics of an archaeological site. In the seminal publication, “Bones: Ancient
Men and Modern Myths”, Binford illustrates the differences between bone tools
and carnivore modification of elements (Binford 1981). Moreover, he
demonstrates, with extensive actualistic research the differences between animal
and human modification to skeletal elements (Binford 1981). Finally, Binford
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(1981:81) states that while humans may be the sole agent for change in stone by
making tools; a similar correlation does not exist for human impact to skeletal
material, especially considering that numerous mammals rely completely on
other animal resources for survival.
Complementary research by Haynes (1980a, 1980b, 1981, 1982, and 1983)
also emerged in the early 1980s. Instead of Binford’s system to understand the
types of specific marks produced by scavenging predators, Haynes (1981 and
1982) sought out to understand how entire carcasses were utilized. Instead of
coding the types of modification present on the skeletal elements, Haynes
(1982:275) recorded the amount of destruction to the elements and compared this
to actualistic research of scavenging behaviors. Combining the methods
presented by Binford and Haynes, such as: ethological literature, actualistic
research, and skeletal material properties, changes have been made to how
archaeologists understand the influence of biogenic factors in site formation
processes.
Researchers in current carnivore modification studies have begun to ask
how one could identify the specific predator that left the marks on the remains
found at hominid sites in Africa (Coard 2007; Dominguez-Rodrigo and Piqueras
2003; Pickering, et al. 2004; Selvaggio and Wilder 2001). Arguments could be
made that these researchers cannot discover the specific species consuming
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19
carcass materials from faunal remains. It is difficult to assess specific carnivore
modifying assemblage by tooth marks because of the nature of carnivore
scavenging, which has been shown to be multiple marks overlapping one
another. Further it can be argued that they are not discussing the ethological
literature or doing ethological research as Binford (1981), Haynes (1980a, 1980b,
1982, and 1983), and Burgett (1990) had done. Trying to determine species from
tooth marks invariably led to the assessment (thus far) that the size class of
predators responsible could be discovered, however because of the processes of
gnawing and the plasticity and density of the skeletal material, accurate
measurements are not attained and comparison with the various African
carnivores can not be determined to any defining degree (Selvaggio and Wilder
2001). Selvaggio and Wilder (2001) specifically found that it is very difficult to
assess species of scavenger on skeletal elements based on size and shape of tooth
marks, specifically because skeletal element densities affect the resistance to force
of the skeletal material.
Appreciating how the methodological framework for studying faunal
remains developed over the course of archaeological history assists a researcher
in developing their own methods. Thus, illustrating what methods have worked
in the past and what needs to be changed to improve the field as a whole. Faunal
remains have not always been considered an important part of archaeological
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20
assemblages, however, an increasing awareness of the dynamic nature of
archaeological sites has improved the questions asked and thus the methods
needed to resolve them. One possible method used in this research to help
decide which non-human scavenger species to focus on is the use of the
FAUNMAP database of faunal remains at archaeological and paleontological
sites across North America.
FAUNMAP: Choosing Non-Human Scavengers to Explore
This part of the project was used to achieve an understanding of the
specific species of predators represented in Bison bison archaeological
assemblages and to evaluate the overall changes, through time, space, and in
terms of population numbers between various species and bison. Collection of
data from FAUNMAP assists in the increase of information on how the Kaplan–
Hoover bonebed was used and why it is used at such a high intensity by non-
human scavengers when compared to other Holocene Great Plains bison kills.
The FAUNMAP database was created in an effort to document the
mammalian species in paleontological and archaeological deposits in North
America during the Quaternary period (Graham, 1995). This database is not
exhaustive, but is fairly extensive on species within paleontological and
archaeological deposits. Initially the database was created to facilitate the
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21
information on the evolution and movement of mammalian communities, but
can be used as an important resource for archaeologists attempting to
understand the biogenic ecology of a region, such as the locality of their specific
site (Graham and Lundelius 1995).
The FAUNMAP database was used as a method for understanding what
species could have been present during the late Holocene on the Great Plains.
From FAUNMAP information has been collected on the states of Montana,
Wyoming, and Colorado (coded as MT, WY, and CO respectively). The
information collected for each site includes: site name, number, state, county,
latitude and longitude, FAUNMAP age group (Table 2.1), species and family
(Table 2.2), minimum number of individuals (MNI), number of individual
specimens per taxon (NISP), and literature citation (to seek out any information
not provided by the FAUNMAP database). The species of interest for this
research study were Canis familiaris, Canis latrans, Canis lupus, Ursus arctos, Ursus
americanus, and Bison bison. To begin, all sites containing Bison bison in Montana,
Wyoming, and Colorado were documented, followed by information on above
species, and finally collection of the rest of the information listed above.
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22
FAUNMAP Age Categories
HOLO
EHOL
EMHO
MHOL
LMHO
LHOL
HIHO
HIST
Age CategoriesHolocene 0-10,000 B.P.
Early Holocene 7,500-10,500 B.P.
Early/Middle Holocene 3,500-10,500 B.P.
Middle Holocene 3,500-8,500 B.P.
Middle/Late Holocene 0-8,500 B.P.
Late Holocene 450-4,500 B.P.
Late Holocene/Post-Columbian 0-4,500 B.P.
Post-Columbian 0-550 B.P.
FMAGE
Table 2.1: FAUNMAP age categories used for background research.
FAUNMAP Species Codes
CAN
CA
CA fa
CA lu
CA la
UR ar
UR am
BI bi
SpeciesCanidae
Canis sp.
Canis familiaris
Canis lupus
Canis latrans
Ursus arctos
Ursus americanus
Bison bison
FMSP
Table 2.2: FAUNMAP species codes used for background research.
Analysis began by assessing the overall numbers of sites in each state and
within specific latitudes and longitudes. There are 30 sites located in Montana,
46 in Wyoming, and 13 in Colorado. This disparity could be accounted for by
bison populations during the middle Holocene. An increase in numbers in the
northern plains occurred because bison thrive on the abundance of C4 grasses
which are tolerant of drought and thus typical of the warm and dry
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23
Hypsithermal period (8,000 – 4,000 B.P.), which began in the northern plains and
moved south through time (Kay 1998:25-27). This was then overlapped and
followed by the Neoglacial which began around 4,500 B.P. and lasted into
present times in the northern plains. The Neoglacial period contrastingly was
associated with higher precipitation and thus expansion of boreal forests, this
could have also increased bison population numbers and bison kills by
providing more precipitation to grasses, further this could have also expanded
Ursidae habitats (Kay 1998:27-28). Interestingly, Montana and Wyoming (Figure
2.1) have both grizzly bears and black bears present in faunal assemblages,
whereas Colorado (Figure 2.1) does not, and may have been too warm and dry to
accommodate the bears. Finally, these relationships correspond with the number
of sites containing non-human scavengers in the late Holocene.
The numbers of predators in archaeological assemblages increased in the
late Holocene (Figure 2.2), from 7% to 45%! From the time when the Neoglacial
began about 4,500 B.P. at the beginning of the FAUNMAP age group for the late
Holocene, it would be assumed that this drastic increase in predator
representation was related to moisture in the northern plains. Increasing
precipitation increases boreal forests, grasses, and other botanical species, thus
increasing amount of resources for a multitude of mammalian and ornithologic
species as well. It should be assumed that Canis familiaris, Canis latrans, Canis
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24
lupus, Ursus arctos, and Ursus americanus were not solely sustaining themselves
on Bison bison. Therefore, the increase in numbers could have come in part on
the increase in the family Lagomorpha or the variety of berries whose population
numbers could have increased as well.
0
1
2
3
4
5
6
7
8
Montana Wyoming Colorado
State
Nu
mb
er o
f S
ites Canis familiaris
Canis latrans
Canis lupus
Ursus arctos
Ursus americanus
Figure 2.1: Number of sites with specific non-human scavengers in Montana, Wyoming, and
Colorado from the FAUNMAP database.
Transitioning from the late Holocene to the Post-Columbian is an
interesting shift as well. Again, 45% of late Holocene sites contain predator
remains, whereas the late Holocene/Post-Columbian switch has 23% and then
decreases again in the Post-Columbian period to 12% (Figure 2.2). Euro-
American settlement of the Great Plains, decimation of bison populations, and
human death caused by disease, all of which limited bison kills, may have
impacted the number of bison kill sites on the Great Plains. Therefore, the
numbers of predators represented in bison faunal assemblages would have been
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25
impacted. Furthermore, as bison began to disappear, so too would have the
predators that likely used them. This could have occurred by population
movements to the east, west, or south and by reduction in number of offspring
produced.
In relation to the paleoclimatic fluctuations, there are distinct differences
in which species live in which regions. Ursidae and Canidae can live in a wide
range of environments (Fitzgerald, et al. 1994). Ursidae, are typically scavengers,
and scavenge in the spring months after their winter lethargy period has ended
(Green, et al. 1997:1040; Mattson 1997:165). If these bears were scavenging
human produced carrion, then it could be assumed that human-predator
interactions would have occurred and possibly led to domestication.
Canids account for 97% of predator remains in the sites in Montana,
Wyoming, and Colorado. To what extent did wolves and coyotes follow humans
for sustenance? Later in this chapter a discussion on coyote behaviors indicates
that coyotes follow wolves to kills and wait to scavenge the remains. It has been
suggested that dog domestication and or hybrid dog remains are present as early
as 6,500 B.P. at the Hawken Site in Wyoming and 4,300 B.P. at the Dead Indian
Creek site in Wyoming (Walker and Frison 1982:127-128). Given that dog
domestication occurred at this time it is plausible that the increase in canid
remains in the late Holocene could be related to their domestication by humans.
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26
Figure 2.2: Percentage of non-human scavengers present in sites within FAUNMAP age groups.
Use of the FAUNMAP database is important for recognizing patterns in
the archaeological and paleontological record of the Great Plains. It is evident
now from FAUNMAP research that canids are slightly more represented in
Holocene archaeological sites on the Great Plains. Additionally, it is evident that
more bison kill sites occur in Montana and Wyoming. Finally, there are more
non-human scavengers present in Montana and Wyoming. This information has
placed the Kaplan–Hoover bonebed in the context of other sites within the Great
Plains, within the Holocene, within bison sites, and within mammalian
population fluctuations. Besides placing Kaplan–Hoover in context, it is
important for questioning why this site is heavily modified and why other sites
may not be. Therefore, a discussion of non-human scavenger behaviors is
essential for understanding how scavengers used the bonebed.
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Ethological Research: Understanding Scavenging Behaviors
There are thousands of books, articles, conference proceedings, and
reports published on the behaviors of carnivore and omnivore scavengers in the
Great Plains, North America, and the world. Because of this, the research
presented in this section is not conclusive or exhaustive. This research
background gives a brief description of Canis lupus, Canis latrans, Ursus arctos,
and Ursus americanus behaviors and feeding habits to inform further questions
about interactions with bison kill remains from prehistory. Research on wolves
and grizzly bears is very expansive; including numerous books and articles
whereas research on coyotes and black bears is slightly limited. For this project,
future research could include behaviors of other mammal scavengers that utilize
faunal remains.
Canis lupus: Wolves
Wolves were at one point common all over the United States, which
indicates that they could have easily been located in various places on the Great
Plains. With the introduction of domesticated cattle, however, the species has
been eradicated from most states for livestock slaughter (Fitzgerald, et al.
1994:307). Canis lupus can occupy a wide range of environments, including high
altitudes and the species typically lives in regions where there are high
populations of large bodied ungulate species (Fitzgerald, et al. 1994:306).
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28
Documentation of kills demonstrates that the gray wolf mostly predates elk,
mule deer, bison, and mountain sheep and in some instances beavers (Fitzgerald,
et al. 1994:306; Mech 1970).
Anatomically, canids (Figure 2.3) are designed to make numerous shallow
bites while attacking to take down its prey, whereas a felid can take one deeper
bite and hold on to take their prey down (Peterson and Ciucci 2003:112-113).
Wolves having heterodont sharp high cusped teeth are able to break and chew
through a variety of gross materials, the molars are used to rip and shred meat,
while the canines and premolars are used to crush and crack bone material
(Peterson and Ciucci 2003). In addition to the dental specialization for meat
consumption, the mandibular structure of a wolf is robust with several massive
muscles that act in unison to close the jaw rapidly and efficiently (Peterson and
Ciucci 2003). Further adaptation for the lifestyle of a carnivore is the carnassial
pair (Figure 2.4), which are the upper fourth molar and the lower first molar that
act together as scissors for shearing and slicing through hide materials (Peterson
and Ciucci 2003).
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29
Figure 2.3: Canis lupus maxilla (Myers, et al. 2008).
Wolves can swallow pieces of carcasses whole; in one study two whole
caribou tongues were found in a wolf stomach (Mech 1970:169-170). Wolf
stomach contents have been known to contain anywhere from 2.40 to 5.98
kilograms of meat, bone and hair, with the largest known amount being close to
8.62 kilograms (Mech 1970:170-171). Typically wolves begin feeding on the
internal organs after tearing open the carcass, then move to hind limbs and other
parts, while avoiding the entrails and stomach contents (Mech 1970; Peterson
and Ciucci 2003). Wolves will feed until their stomachs are full and their sides
distended and in the winter, after feeding, wolves will collapse and sleep up to 5
hours, which aids in digestion after gorging (Peterson and Ciucci 2003:124). In
addition, wolves rely heavily on skeletal materials from kills, often scavenging
on them to sustain their mineral nutrient intake (Peterson and Ciucci 2003:125).
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30
Further, single wolves that have not had access to a fresh kill can sustain
themselves for long periods of time on only skeletal material and then may be
willing to eat any part of the gross tissue (Peterson and Ciucci 2003:125).
Figure 2.4: Carnassial pair of Canis lupus (Myers, et al. 2008).
Gray wolves have been recorded scavenging significantly more bison
carcasses as opposed to red deer and wild boars in Bialowieza Primeval Forest in
Poland (Selva, et al. 2005:1593). Interestingly, of all the predators monitored in
Bialowieza Primeval Forest (including: ravens, buzzards, eagles, red foxes,
raccoon dogs, pine martens, and domestic dogs), gray wolves were the only
species able to open dead bison carcasses (Selva, et al. 2005). In the winter
season, Huggard (1993) noted that wolves scavenged in shallower snow than
deep snow and would hunt more often if the snow was at great depths. Wolves
are even known to cache carcass remains for later use, specifically in the summer
to keep flies away and preserve the meat out of the summer heat (Mech 1970;
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31
Peterson and Ciucci 2003). Further this caching can be done to save food for later
after the wolf is satiated, and typically wolves will take their food for caching
long distances (up to 5 km) from the kill to avoid theft by other scavengers
(Peterson and Ciucci 2003:117).
Canis latrans: Coyotes
Canis latrans (Figure 2.5) is still considered common all across Colorado
and is easily adapted to all elevations (Fitzgerald, et al. 1994:302). In addition,
the species is well adapted to living amongst human populations and may have
thrived after the eradication of the gray wolf (Fitzgerald, et al. 1994:302).
Typically, Canis latrans is an opportunistic feeder, often preferring animal meat,
but also consuming vegetation and insects in some instances (Fitzgerald, et al.
1994:303). In most situations coyotes will eat jackrabbits, cottontail rabbits, and
rodents, likewise; they are known to scavenge carrion of cattle and big game
which has been killed by other larger predators and do often themselves kill
livestock such as sheep and goats (Fitzgerald, et al. 1994; Hilton, 2001; Kleiman,
2001; Paquet, 1992). Coyotes can and will alter their natural diet to exploit foods
introduced by humans and other scavengers to lessen the amount of energy
needed to gain food (Kleiman and Brady 2001). Coyote stomachs typically
contain large quantities are scavenged foods (indicated by large quantities of
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32
maggots) as well, suggesting that in the wild they are not necessary hunters, but
scavengers (Kleiman and Brady 2001:168-169).
Figure 2.5: Canis latrans maxilla (Myers, et al. 2008).
Canis latrans is known for defecating on their kills and carrion to mark
their property and deter other animals from consuming it (Acorn and Dorrance
1990; Acorn and Dorrance 1998; Wade and Bowns 1985). When hunting, coyotes
attack the neck/throat first of sheep and goats and attack the hind limbs in calves
of other ungulates (Wade and Bowns 1985). They primarily begin feeding in the
hind limbs or just below the ribs and choose viscera first when consuming
carcasses (Acorn and Dorrance 1990; Acorn and Dorrance 1998; Wade and Bowns
1985). In almost every case of carrion scavenging, however, the coyote will either
follow gray wolves or scavenge gray wolf kills (Paquet 1992). In some instances
it is difficult to assess the amount of material in a coyote stomach as carrion or
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33
hunted; however, the presence of maggots and fly larvae have been used as a
means to determine if the coyote hunted its meal (Kleiman and Brady 2001:168).
Comparing Wolves and Coyotes
A research study at Riding Mountain National Park in Manitoba,
documented 194 ungulate wolf kills from July 1982 through March 1986 (Paquet
1992:338). Within this same time frame Canis latrans killed 59 ungulates and
were documented to visit every wolf kill (Paquet 1992:338). On average, large
gray wolf packs consume more of the killed carcasses than do coyotes; this is
likely due to size and energy expenditure needed by each non-human scavenger
(Hilton 2001; Paquet 1992). During this research study Paquet (1992:341) found
that all wolf-killed ungulates remains (n = 194) were scavenged by coyotes and
this was evident by coyote tracks to every wolf-kill and skeletal disarticulation
and hide removal of carcasses. Moreover, Paquet (1992:341) observed coyotes
waiting 100 m from a fresh wolf kill and noticed that the coyotes moved in
quickly to consume the remains immediately following wolf departure. This of
course led to the demise of some coyotes that were impatient; however, this
danger did not deter them (Paquet, 1992; Wilmers, 2004).
Anatomically, wolves and coyotes are similar; however, the coyote is
constrained by being significantly less powerful than the wolf and much smaller
in size (Hilton 2001). In terms of scat, wolf and coyote scats are similar in
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34
appearance, contents, and can overlap in size; however, coyote scat rarely
exceeds three centimeters in diameter, while wolf scats can exceed three
centimeters and typically go beyond or up to 4 centimeters in diameter (Mech
1970). In appearance, wolf and coyote scat is arranged with the skeletal
fragments in the center while hide and hair are wrapped around the outside,
therefore protecting the intestines (Mech 1970). Unlike wolves, coyotes scavenge
and typically hunt alone, allowing more time to be dedicated to following other
hunters (Kleiman and Brady 2001).
Ursus arctos: Grizzly Bears
Ursus arctos (Figure 2.6) is known to live in a wide variety of environments
from plains grasslands to alpine tundra and is most content in a habitat of
seasonally changing food stuffs (Fitzgerald, et al. 1994; Servheen 1999). Use of
FAUNMAP to get a rough estimate of where grizzly bears were on the Great
Plains during the Holocene indicates that they were present at various
archaeological sites during all geological time periods, including Colorado
during the early and middle Holocene. Predominately, Ursus arctos consumes
vegetation; nevertheless, the species is known for scavenging carrion (especially
in the spring), and killing small mammals such as marmots, large mammals such
as elk and other ungulates, and livestock such as cattle and sheep (Craighead, et
al. 1995; Fitzgerald, et al. 1994; Wade and Bowns 1985).
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35
Figure 2.6: Ursus arctos maxilla (Myers, et al. 2008).
These mammals are incredibly efficient as omnivores, and are fairly
inefficient as carnivores, so scavenging is the main way for them to get meat
protein (Craighead and Craighead 1972:304). Winter-killed ungulate species are
of importance to grizzly bears, specifically in the spring after they have
awakened from winter lethargy; however, carrion feeding is at its peak from
March through May (Craighead, et al. 1995; Green, et al. 1997; Mattson 1997). In
Yellowstone National Park, grizzly bears consume mostly elk, bison, and moose
meat (Craighead, et al. 1995; Mattson 1997). Carrion availability can drastically
affect these behaviors by increasing the amount of time bears use carrion
(Craighead, et al. 1995:258-260). Mattson (1997:171-172), states that the frequency
in which grizzly bears used ungulate carcasses, varied during months, years, and
regions of the park. In addition, use of ungulates was related to availability of
whitebark pine seeds (Mattson 1997:169). However, if large numbers of
carcasses exist in a grizzly bear’s territory, they will forego eating other foods
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36
and just sustain themselves on carrion. Bears typically do not feed in groups or
at the site of the kill and typically remove pieces of carcasses and retreat to
concealed areas for feeding purposes (Craighead, et al. 1995). Bears are also
known for caching carcasses for future use and will return to feed numerous
times if the carcass is not located by other scavengers (Craighead, et al. 1995:259).
Moreover, Green, et al. (1997) discovered that date of death was less important in
determining if a bear would scavenger a carcass if the death occurred between
February and early March and more important between middle March to late
April. This could be due to increase in temperature and rate of decomposition of
the carcasses. Green, et al. (1997:1047) further reported that Ursus arctos typically
scavenges more Bison bison than Cervus elaphus in Yellowstone National Park.
Ursus arctos exploits carrion more frequently in higher altitudes in Yellowstone
National Park than lower altitudes during the late spring (Green, et al.
1997:1048).
Ursus arctos is an animal that, as argued by Craighead, et al. (1995) and
Craighead and Craighead (1971), is conditioned by humans for food resources.
There is a large body of literature on grizzly bears feeding in garbage dumps,
campgrounds, and boneyards (cattle carcass piles) in Montana and Yellowstone
National Park (Craighead and Craighead 1971; Craighead, et al. 1995; Rogers
1987; Wilson et al. 2005). After consumption of ungulate species in the early
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37
spring, snow decreases and tourist activity increases allowing grizzlies to stock
up on more calorie rich foods from garbage dumps, which are particularly
important to the feeding habits of Yellowstone National Park bears (Craighead,
et al. 1995:44-47). Garbage dump feeding does not have a specific seasonal time
period however, as bears use this resource continually throughout their non-
lethargy season as a consistent and stable food supply (Craighead, et al.
1995:270).
A significant research study from 1977 to 1987 suggested that grizzly
bears on the east front of the continental divide of Montana were frequenting
rancher boneyards as a secondary source of all protein (Craighead, et al. 1995;
Wilson, et al. 2005; Wilson et al. 2006). These sites are typically frequented
during the spring when bears need to gain calories and protein quickly after
winter lethargy (Mace et al. 1987; Wilson et al. 2006).
According to Craighead and Craighead (1972), grizzlies who feed at
garbage dumps, campgrounds, and boneyards exhibit less fear of humans and
human smells; however, in other areas of national parks and human landscapes
they are fearful and tend to avoid contact with humans. Within Yellowstone
National Parks campgrounds, grizzlies return for garbage foraging during spring
and fall migratory movements to gain access to another food source with limited
energy expenditures and the animals that frequent campgrounds on a regular
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38
basis become conditioned to human presence, a difference from grizzlies that
frequent isolated garbage dumps where humans move into and out of the area
on a more predictable regular basis (Craighead and Craighead 1972:309-311).
The conditioned behaviors exhibited by grizzly bears could be attributed
interactions with humans (Craighead and Craighead 1972). Given that these
interactions are occurring more frequently, due to human encroachment on
natural habitats, grizzly bears will become acclimated to human scents and
environments (Craighead and Craighead 1972). Therefore, bears become less
fearful, further causing more conflicts in homes, cars, and camp sites (Craighead
and Craighead 1972).
Understanding feeding ecocenters as defined by Craighead, et al. (1995)
assists in the general knowledge of how bears feed and the patterns that may be
observed from their feeding behaviors. Craighead, et al. (1995:321), define bears
as an ecocentered population “that congregates at a high-quality food source in a
relatively confined, predictable portion of an entire ecosystem during an
extensive, annually predictable time period.” In view of the fact that bears have
a regimented feeding pattern based on availability of food stuffs, it would be
expected that bears could have evolved behaviors that rely heavily on this
feeding style to ensure existence.
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Finally, boneyards as feeding ecocenters are important in terms of where
bear behaviors have been constant over time. Across the Great Plains and
Western United States, cattle ranchers have sometimes used boneyards or cattle
carcass dumps when their livestock have died (Craighead, et al. 1995; Mace et al.
1987; Wilson et al. 2005; Wilson; et al. 2006). Craighead et al. (1995:324–326)
compare boneyards to bison kill sites, suggesting that these were predictable and
stable events across the Great Plains, allowing bears to be conditioned further by
humans by expecting large quantities of carrion to be available throughout the
year. As stated previously, Craighead, et al. (1995:322-326) indicate that this
phenomenon of using feeding ecocenters is a biological phenomenon that has
existed in bears not necessary because of a reliance on humans, but possibly
because of the environment bears have been a part of since human hunters began
hunting large numbers of bison in the Great Plains. In the present time grizzly
bears have been shut out of garbage dumps thus increasing human-bear
conflicts.
Ursus americanus: Black Bears
Ursus americanus (Figure 2.7) is arboreal by nature and is therefore
commonly found in montane shrublands and forests and subalpine forests at
moderate elevations (Fitzgerald et al. 1994:318). Primarily, black bears are
vegetarians; however, they have been known to consume carrion and will kill elk
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calves and other wild ungulate calves, sheep, goats, and pigs (Fitzgerald et al.
1994; Wade and Bowns 1985).
Ursus americanus commonly predates in the spring and summer (Wade
and Bowns 1985). Green et al. (1997), discuss Ursus americanus use of lower
altitude carrion as opposed to Ursus arctos. Additionally, the black bear is more
likely to use carcasses during the late spring than the early spring (Green, et al.
1997:1052). In the attack, black bears typically use their paws and break the back
or neck with strong blows, eventually killing the prey by biting the neck and
shoulders (Wade and Bowns 1985). Black bears are inclined to drag their food to
a secluded area for feeding; however they will defecate on the carrion as Canis
latrans to discourage other non-human scavengers from consuming it (Wade and
Bowns 1985:10). Finally, both bears do not scatter, chew, and break up carcasses,
which is typical canid behavior (Wade and Bowns 1985).
Figure 2.7: Ursus americanus maxilla (Myer et al. 2008).
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Non-human scavenger behaviors vary between species. When discussing
canids and ursids it is important to note that they are very distinct in terms of
type of dentition, scavenging styles and patterns, and various other behaviors.
Differences in dentition are due in large part to the type of carnivore or omnivore
it is. Canids are generally hunters therefore sharp cusped teeth are necessary to
rip flesh and muscle, whereas ursids are typically omnivores and need rounded
low cusped teeth useful for eating a larger variety of food stuffs.
There are great differences in terms of how canids and ursids scavenge.
First of all canids typically scavenge and hunt in groups, therefore when there
are a number of individuals together at one carcass, fighting for food increases
the tearing, dragging, and movement of a carcass. Bears on the other hand are
solitary or with cubs, therefore individuals generally take a limb or piece of the
carcass and drag it away to a concealed location for feeding.
Conservation Research
Zooarchaeological research in the past and present is addressing the use
of faunal remains associated with human behaviors by non-human scavengers
(Reitz and Wing 1999:135). Given that research on carnivore modification lends
information to how a faunal assemblage was altered through time, this research
can be useful when applied to management decisions in animal conservation.
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Managers deciding whether to reintroduce or eradicate a particular species can
benefit from understanding the expansive time period in which a species has co-
existed with others. As stated previously, archaeologists are in a prime position
to influence management decisions by sharing their data with the natural
sciences to assist in understanding the impacts of species management changes.
The following discussion highlights the history of eradication and specific
conservation issues currently for wolves, coyotes, grizzly bears, and black bears.
Canis lupus and Canis latrans: Conservation Issues
Wolves and coyotes have always been considered a nuisance by ranchers
and hunters (Clark and Rutherford 2005; Fritts et al. 2003; Smith, Brewster, and
Bangs 1999; Wilmot and Clark 2005). Public interest is varied, with some people
believing that wolves and coyotes destroy their products (livestock) and profits
while others believe that they should be left alone, to allow them to live naturally
in the wilderness (Clark and Rutherford 2005). On another side, hunters argue
that introduction or reintroduction of non-human predators significantly reduces
population numbers for wild game hunting and eliminates the traditional
heritage of American settlers (Wilmot and Clark 2005).
While settling the west, ranchers would kill wolves and coyotes since they
were seen as decimating their livestock and adding competition to hunting wild
game (Smith, et al. 1999:108-109). After prey species populations of the wolf,
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such as bison, deer, elk, and pronghorn declined in the west, wolves began to
feed on livestock provided by the ranchers (Young 1946). The rough lifestyle of
western settlers and the depredation of their livestock caused animosity towards
the wolves, which in a short period of time led to the eradication of wolves
(Young 1946). Wolves were almost completely eradicated, with few singles and
pairs from the lower United States, except for northern parts of Minnesota by the
1930s (Smith, et al. 1999:108). In 1974, wolves were listed on the Endangered
Species Act and mandated to be reintroduced to Yellowstone National Park and
not until 1995 and 1996 were 31 individuals reintroduced (Smith, et al. 1999;
Smith, et al. 2003). After a year, 44 adult wolves and an unknown number of
litters were present in and around the park (Smith, et al. 1999). Prior to the
count, 26 had been killed from human caused deaths such as illegally or legally
being shot and hit by cars (Smith, et al. 1999). To this day, humans are the largest
cause in wolf mortality, and influence the behaviors and predatory ecology of the
species (Fritts et al. 2003). Finally, this reintroduction has changed the numbers
of coyotes drastically and changed their breeding and hunting behaviors as well
(Smith, et al. 1999).
The importance of wolves in ecosystems cannot be overstated. The
species is responsible for much of the available carcasses for scavenging species
(Mech 1970). In addition, wolves are imperative to some ungulate species
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population control; without predator-prey relationships, some species such as
elk become overpopulated, which will lead to starving and more accidents with
cars. A research project on the influence of reintroduction of wolves to Cervus
elaphus (elk) and Bison bison suggests that the elk population suffered a shift in
diet quality to low, while bison remained stable with females and calves
increasing vigilance (Hernandez and Laundre 2005; Laundre, et al. 2001).
Coyotes have been seen in a similar light throughout western settlement
and are still seen as a problematic nuisance with ranchers today (Beckoff and
Gese 2003). Livestock predation amongst coyotes is a contentious issue, with a
disparity between human belief that coyotes kill livestock or leave livestock
alone (Beckoff and Gese 2003:475). As the wolf’s habitat has decreased and
human eradication of them has occurred, coyotes have been able expand their
habitat ranges (Nowak 2001). In addition, coyotes are very efficient at adapting
to human environments such as neighborhoods, towns, and larger cities by
exploiting garbage, livestock, and pets (Beckoff and Gese 2003; Nowak 2001).
For the sheep industry, stockmen have stated that coyote depredation is the most
problematic cause of profit loss (Beckoff and Gese 2003; Sterner and Shumake
2001). Coyote population control and determent from sheep and livestock
depredation has been done using a number of non-lethal methods, including:
exclusion fences, aversive agents, and chemosterilants (Acorn and Dorrance
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1998; Acorn and Dorrance 1990; Beckoff and Gese 2003; Sterner and Shumake
2001). Of the methods to deter coyote depredation, aversive agents such as
olfactory and gustatory products have done little to decrease predation (Beckoff
and Gese 2003). In recent years, other methods, such as sheep collars that release
toxic chemicals and trapping have been somewhat productive (Beckoff and Gese
2003). Interestingly, with all of the control methods and killing of coyotes by
humans, population numbers of coyotes have remained stable (Beckoff and Gese
2003).
Ursus arctos and Ursus americanus: Conservation Issues
Human relationships with bears are a highly contentious issue in wildlife
conservation (Craighead, et al. 1995; Gilbert 1989). Bears are typically
omnivores, and easily adapt to change. They are able to adapt so well to human
surroundings, that people have been accidentally conditioning bears for a long
time (Gilbert 1989). From the opening of Yellowstone National Park, humans in
the west have been feeding and taking care of bears, to which bears have
responded by being less fearful of humans (Craighead, et al. 1995; Gilbert 1989).
Grizzly bear populations today in the lower 48 states are located in
Greater Yellowstone Ecosystem, with another smaller population located in the
northern Cascades, with approximately 1000 bears between the two (Schwartz, et
al. 2003:558). From the 1930s through the 1960s, visitors of the Park would feed
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grizzlies and did not anticipate that building a reliance and acceptance of human
presence could influence future problems, such as personal injuries to humans
and property damage (Craighead, et al. 1995:24). Early attempts to educate the
public on wildlife included lecture series, where park rangers would place food
wastes in a central location and then visitors would sit on bleachers watching the
bears feed and hear about their behavior and ecology (Craighead, et al. 1995:44-
47). The last of the lecture series food waste sites were closed by the mid-1940s
in a hope to decrease human-bear interactions; however, bears did not stop
feeding in these locations or other established tourist dumps and may have
become accustomed to including garbage into their seasonal feeding habits at
this point (Craighead, et al. 1995:270). These human induced bear interactions
led researchers to believe that the major causes of bear mortality had less to do
with habitat and more to do with their relationships with humans (Gilbert 1989).
Mortality rates in grizzly bear populations are caused mostly by human impacts
to populations through hunting, poaching, and habitat loss (Servheen 1999;
Schwartz, et al. 2003). Cause for eradication of grizzly bears was due to fear of
attack from them or destruction of campsites and livestock (Craighead, et al.
1995; Primm and Murray 2005).
Human-bear interactions are among the most important to consider when
discussing conservation, specifically for the grizzly bear, which has been
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conditioned to trust and in some instances rely on humans to provide food
(Gilbert 1989). Researchers believe that in parks, like Yellowstone National Park,
when humans began feeding bears or when lectures were centered on bear
feeding, that bears became conditioned or accepting of human smells and
therefore less fearful (Craighead, et al. 1995; Gilbert 1989). Beginning in 1968,
Yellowstone National Park personnel began reducing the amount of garbage
held in the remaining Park tourist dumps and by 1971 closed the rest of the
dumps (Primm and Murray 2005). Other researchers believed that the dumps
should not have been closed instantaneously and that the bears should have been
weaned off of human garbage as sustenance (Craighead, et al. 1995; Primm and
Murray 2005).
After the closure of the dumps, there was a dramatic decline in the
number of grizzly bears in the park. With the constant source of garbage
unavailable, the bears began going into camps, livestock areas, and surrounding
community garbage dumps outside of Yellowstone National Park, leading to
more human-bear conflicts, and more deaths caused by human shootings
(Primm and Murray 2005). After this, researchers and public relationships
declined dramatically. Finally,