Download - Chapter 1 Exploratory Behavior Profiles
What behavioral syndrome? Individual differences and multiple exploratory behavioral profiles in
prairie voles
Danielle N. Lee* & Zuleyma Tang-MartínezDepartment of Biology
University of Missouri-St. Louis
Animal personality research
Behavioral Syndromes: Suites of related behaviors across situations or contexts
– Correlation of behaviors– Behavioral plasticity limited
• Context• Stability
Behavioral Stability
• Broad– Correlations of behavior
across different contexts or functional categories
• Domain specific– Correlations of behavior
within a single context or functional behavioral category
• Trait response (Stable)– Behavioral responses that
are consistent from one situation to another
• State response (Unstable)– Behavioral responses that
occur in a specific situation (not consistent from one situation to another)
Behavioral Context
Kopp, Voge & Misslin 1999
Behavioral Stability
• Broad– Correlations of behavior
across different contexts or functional categories
• Domain specific– Correlations of behavior
within a single context or functional behavioral category
• Trait response (Stable)– Behavioral responses that
are consistent from one situation to another
• State response (Unstable)– Behavioral responses that
occur in a specific situation (not consistent from one situation to another)
Behavioral Context
Broad behavioral SyndromeCorrelations of behavior across different contexts or functional categories
• Wilson et al. 1993• Pumpkin-seed sunfish,
Lepomis gibbosus• Multiple Contexts
(Exploration & Social)Bold fish were more likely to
approach novel objects and swim in closer proximity to other fish compared to shy fish Image credit: Encyclopaedia
Brittanica
Domain-specific Behavioral SyndromeCorrelations of behavior within a single context or functional behavioral category
• Verbeek et al. 1994• Great tits, Parus major• Single Context
(Exploration)Fast novel room explorers
are also fast novel object explorers
Image credit: http://www.thebirdsofsussex.co.uk/
Behavioral Stability
• Broad– Correlations of behavior
across different contexts or functional categories
• Domain specific– Correlations of behavior
within a single context or functional behavioral category
• Trait response (Stable)– Behavioral responses that
are consistent from one situation to another
• State response (Unstable)– Behavioral responses that
occur in a specific situation (not consistent from one situation to another)
Behavioral Context
Behavioral Syndromes Hypotheses Hierarchy
• H0: no correlations of behavior responses across situations or contexts = no syndrome = STATE RESPONSE
• H1: correlations of behavior response across situations or contexts = syndrome = TRAIT RESPONSE
• H1a: correlations of behavior responses within one context = DOMAIN SPECIFIC
• H1b: correlations of behavioral responses across two or more contexts = BROAD
OBJECTIVE• To examine individual variation in a single
context – EXPLORATION
QUESTIONS• Is variation in individual behavior consistent
across different tests?• If so, then do these consistent differences in
behavior contribute to a behavioral syndrome?
Exploratory behavior
• Functional behavior category widely studied• Tendency to investigate novel environments
and/or objects• Spontaneous behavioral responses• Indicates how animals might gather
information about local environment and its resources
Microtus ochrogasterprairie vole
Methods
• Three Exploratory tests– Open-field with novel objects – Exploratory maze– Two-way novel choice apparatus
Open-field with Novel Objects TestDependent Variables:
1)Latency
2)Time in the novel environment
3)Time with novel objects
4)Returns
5)Instantaneous scan of location
a) Total squaresb) Visits to each section
Exploratory Maze Test
Dependent Variables:
1)Latency
2)Number of times each arm was entered
3)Returns to the start box
Novel Choice Test
Dependent Variables:
1)Latency
2)Time to reach the first terminal
3)Time to reach the second terminal
4)Total time to complete the test
Overall Predictions
• Lower latency • More time spent
interacting with novel stimuli
• Higher spatial scores
less exploratory more exploratory
•Higher latency •Less time spent interacting with novel stimuli•Lower spatial scores
Statistical Analysis
• PCA analysis for each exploratory test• Identified the key dependent variables
– PC1 accounted for the highest % of variance– All dependent variables that scored above .80 that
explained PC1 – called Key Dependent Variables
• Ranked each Key DV• Computed the overall Exploratory Score for each
individual in each test• Correlate Exploratory scores across tests
Exploratory Scores Continuum
• Open-field with novel objects test• Exploratory Maze test• Two-way novel choice test
lower exploratory scores higher exploratory scores
Open-field with novel objects test
1 2 3
Latency to depart start box -.353 -.243 .866
Total squares visited .638 .656 -.046
Returns -.711 .303 -.250
Time in novel environment .820 .476 .166
Time with novelties .675 .015 .235
Visits to center squares -.624 .603 .288
Visits to edge squares .945 .005 .106
Ratio of visits to center: edge squares
.553 -.573 -.105
Components
PC 1 explains 46.9% of the variancePC 2 explains 18.7 %PC 3 explains 12.5 %
N = 10258 females44 males
Exploratory maze test
PC 1 explains 58% of the variancePC 2 explains 19%
1 2
Latency to depart start box -.593 .526
Returns .306 -.857
Visits to arm 1 .787 .139
Visits to arm 2 .818 .279
Visits to arm 3 .888 .069
Sum of visits to all arms .979 .179
N = 9853 females45 males
Components
Novel choice apparatus test
1 2 3
Latency to depart start box .753 -.316 .154
Time to reach 1st terminal .860 -.316 .103
Time to reach 2nd terminal .821 -.323 -.038
Total test time (minus latency)
.906 -.347 .017
Components
PC 1 explains 54% of the variancePC 2 explains18%PC3 explains 13 %
N = 14183 females58 males
Correlations of Exploratory Scores across all three tests
Open-field testExploratory Score
Novel choice testExploratory Score
Novel choice test Exploratory Score
r = .075
p = .602------
Maze test Exploratory Score
r = -.052
p = .717
r = -.265
p = .060
N = 5126 females25 males
No correlated suites of behavior across test situations.
Discussion
• Behavior in one situation did not correlate or predict behavior in a different situation
• Behavioral responses are distinct and stand alone
• Animals interpret context differently• Null hypothesis in hierarchy
Behavioral Syndromes Hypotheses Hierarchy
• H0: no correlations of behavior responses across situations or contexts = no syndrome = STATE RESPONSE
• H1: correlations of behavior response across situations or contexts = syndrome = TRAIT RESPONSE
• H1a: correlations of behavior responses within one context = DOMAIN SPECIFIC
• H1b: correlations of behavioral responses across two or more contexts = BROAD
• Fox et al. (2009). Mountain chickadees, Poecile gambeli, – Exploration in a novel room and with novel objects
• Nelson et al. (2008). Roosters, Gallus gallus domesticus– calling behavior in three different contexts: anti-
predator, territoriality, and foraging in both a real and a virtual environment
• Dingemanse (2008). Sticklebacks, Gasterosteus aculeatus • Adriaenssens & Johnsson (2008). Brown trout, Salmo trutta • Milderman (2008) Starlings, Sturnus vulgaris• Snekser et al. (2008). Damselfish, Stegastes leucostictus
Historical accounts
• Context – Learning ability and congition
• Selected lines of “bright” and “dull” rats
• Various labyrinth mazes
• No two trials of the exact same test correlated with any degree of reliability. Tolman (1924)
• Learning ability is specific to the apparatus. Tryon (1940), Searle (1949)
Take home messages
• No single test can serve as a proxy for an entire domain
• Test domain-specific syndromes first, then broad
• Do not assume evidence of broad behavioral syndromes means domain-specific behavioral syndromes also exist
ACKNOWLEDGEMENTS• Fritz Trillmich & Robyn Hudson• The Tang Gang
Gena Sbeglia, Laura Kent, Elizabeth Congdon, Javier Hernandez
• Blog readers and SM supporters• Jasmine Clayton, Robert Clayton,
Allison Clayton• Stan Braude, Karen Norberg, Lon
Wilkens, George Taylor• David Chisholm• Lab Assistants
– Meital Laks, Dominique Craven, Evynn Craven, AnnaLynn Harris, Dianne Voorhis
• American Society of Mammalogists GIAR
• TWA Scholarship for Environmental Science
• Dr. John P. Rier Biology Student Travel Award
• Animal Behavior Society Young Scientist International Travel Award (ABS-NSF)