Determining the density of coyotes in different habitat types at the Sevilleta NWR/LTER

Damon R. LowerySevilleta 2008 REU Program

Coyote (Canis latrans)

Medium-sized canids

Various habitats throughout North and Central America

Occupy dens or burrows

Omnivorous diet

Various hunting strategies

NatureWorks. 2008

Project Objectives

Estimate coyote densities at the Sevilleta NWR– Assess habitat use by coyotes

Grassland, Shrubland, Woodland

– Assess effect of percent woody vegetation cover on coyote densities

Grassland Shrubland Woodland

Context and Significance of Study

Adds to past coyote research that has been performed at the Sevilleta NWR– Absolute density, Parmenter 2004

– Diet, Hernandez et al. 2002

Expands on the Parmenter (2004) data set

Assist in management of land and top predators

Research Question and Hypothesis

Does the relative density of coyotes differ among habitat types or change with variation in percent woody vegetation cover?– Hypothesis: Coyote densities will be higher in open,

grassland habitats with less shrub and tree cover

G S W Habitat Type

Coy

ote

Rel

ativ

e D

ensi

ty

Coy

ote

Rel

ativ

e D

ensi

ty

% Woody Cover

Support for Hypothesis

Open habitats = Higher coyote densities

Potential reasons why– Coyotes evolved in open habitats – Open habitats contain a large abundance of

preferred coyote prey species– Open habitats may be better suited to coyote

hunting strategies

Hidalgo-Mihart et al. 2006, Kamler and Gipson 2000

Study Site: Sevilleta NWR

Scat Collection MethodsScat Collection Methods

Marked 13, one mile long road-based transects– 5 grassland – 5 shrubland– 3 woodland

Collected scat weekly

Identified scat (e.g. Halfpenny 2001)

Scat Samples from Different Species

Berry filled scat. Species Unknown. 2.75 X 13cm scat. Black Bear.

1 X 7cm scat. Ringtail.

2 X 7.5cm scat. Possibly Bobcat.

2.5 X 11cm scat. Coyote.

2.5 X 12cm scat. Large taper. Coyote

Habitat Assessment Methods

Determined habitat types– ArcGIS tools and Sevilleta vegetation map

Determined percent woody vegetation cover– 100m line intercept transects

Scat Data

Scat from 8 known species and potentially ≥ 5 other species 289 total scats collected 78 coyote scats collected = 27% of all scats

Habitat Type  # of Coyote

Scats Percentage of All

Coyote Scats

Grassland 27 34.6%

Shrubland 35 44.9%

Woodland 16 20.5%

Species # of Scats

Coyote 78

Kit, Gray, Red Fox 51

Ringtail 13

Mountain Lion 11

Bobcat 8

Striped Skunk 5

Spotted Skunk 3

Black Bear 1

Unknown 52

Possibly ≥2 species 67

Percent Woody Vegetation Cover for Each Scat Transect

Initial assessment of habitat type for each scat transect confirmed by line intercept transects and ArcGIS analysis

24 total woody species Gutierrezia sarothrae (broom snakeweed) most common

and abundant

Habitat Type Avg. % Woody Cover Total # of Woody Species

Grassland 3.41 % 9

Shrubland 19.22 % 15

Woodland 37.96 % 13

Relative Density Calculation

Relative Density: – R = S/(LnD) (Webbon et al. 2004)

R = relative density S = # of feces found when collecting

Ln = length of linear features driven

D = # of days between collections

Densities for all transects within a given habitat type were averaged

Coyote Densities for Each Habitat Type

Habitat Type Average Density

Grassland 0.129

Shrubland 0.167

Woodland 0.127

Statistical Analysis

Differences in coyote density among different habitat types were assessed using an ANOVA

Coy

ote

Rel

ativ

e D

ensi

ty

G S W

Habitat Type

Results of ANOVA

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

Grassland Shrubland Woodland

Habitat Type

Co

yot

e R

ela

tiv

e D

ensi

ty

p = 0.88

Statistical Analysis

Performed a regression analysis on coyote densities vs. percent woody vegetation cover

Coy

ote

Rel

ativ

e D

ensi

ty

% Woody Vegetation Cover

Results of Regression Analysis

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 10 20 30 40 50

% Woody Vegetation Cover

Coy

ote

Rel

ativ

e D

ensi

ty

Y= 0.0002x + 0.1398 R2 = 0.0004 p = 0.95

Overview of Findings

Shrubland habitat had the highest density of coyotes However, NO statistically significant differences in

densities among habitats NO correlation between percent woody cover and

density of coyotes

Significance of Findings

Open habitats ≠ higher coyote densities

Amount of woody vegetation cover has NO effect on coyote densities

Discussion of Findings

Why were there no differences among habitats?– Densities do NOT differ among habitats – Prey in equal abundance in all habitat types– Road location and usage– Sample size: # of scat collections and transects

Future Work

DNA and dietary analysis of scats Further study of coyote habitat use Apply study results to management of

coyotes and their prey species

Acknowledgements

I’d like to thank the following for their help and support: NSF and Sevilleta REU Program UNM and US Fish and Wildlife Service Virginia Seamster Jennifer Johnson John Dewitt Terri Koontz Kelly Bowman All of the Sevilleta REU’s and Interns, especially CJ Jewell,

Dan Colman, and Emerson Tuttle

Questions?

Sevilleta 2008 REU Program

References

Halfpenny JC. 2001. Scats and Tracks of the Rocky Mountains. Guilford: The Globe Pequot Press. 144 p.

Hernández L, Parmenter RR, Dewitt JW, Lightfoot DC, Laundré JW. 2002. Coyote diets in the Chihuahuan Desert, more evidence for optimal foraging. Journal of Arid Environments, 51: 613-624.

Hidalgo-Mihart MG, Cantú-Salazar L, López-González CA, Martínez-Gutíerrez PG, Fernandez EC, and González-Romero A. 2006. Coyote habitat

use in a tropical deciduous forest of Western Mexico. Journal of Wildlife Management, 70: 216-221.

Kamler JF and Gipson PS. 2000. Space and habitat use by resident and transient coyotes. Canadian Journal of Zoology, 78: 2106-2111.

NatureWorks. 2008. Coyote- Canis latrans. Available at http://www.nhptv.org/natureworks/coyote.htm

Parmenter B. 2004. Coyote Scat Survey. Albuquerque, NM: Sevilleta Long Term Ecological Research Site Database: SEV049.

http://sev.lternet.edu/project_details.php?id=SEV049. Accessed: May 8, 2008. Webbon CC, Baker PJ, and Harris S. 2004. Faecal counting for monitoring

changes in red fox numbers in rural Britain. Journal of Applied Ecology, 41: 768-779.