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Personality definition
Consistent individual behavioural variation
Categories of behaviours relevant to animal personality
Boldness
Exploration
Activity
Aggression
Sociability
Among-individual variation
How different individuals are from each other in their average behaviour.
Within-individual variation
How consistent individuals generally are in repeated expressions of behaviour.
How do you now which behaviour (in regards to animal personality) fits where?
Use operational definitions:
Define the behaviours by what is measured, for example, latency to leave a refuge or distance travelled in an open field, and leave the interpretation of the behavioural response for the analyses and discussion.
Behavioural syndrome
A suite of correlated behaviours reflecting between individual consistency in behaviour across two or more contexts.
On a species/population level, not individual
Within a behavioural syndrome, individuals have a behavioural type (personality)
e.g. in a behavioural syndrome, where aggression and exploration are correlated, an animal can also be identified as having a more/less aggressive behavioural type
Among-individual correlations
When animals’ averages of each behaviour correlates
(often animals repeatedly engage in several behaviours simultaneously
Within-individual correlations
When an animal’s expression of one behaviour correlates with another behaviour.
Near-unlimited behavioural plasticity
An individual should be able to show the optimal behaviour in every context
(something that classic behavioural ecology assumes)
Evolutionary constraint
A trait that may have evolved as a spill over effect of selection for high and non-discriminate aggression during previous ontogenetic stages
Common pitfalls when it comes to studying animal personality
What is being measured?
Tests can be used to measure other behaviours than what you intend on measuring
e.g. is latency to emerge from a refuge measuring exploration or boldness? Or mobility?
is response to a novel object boldness, activity, or exploration?
A variety of tests are used to measure the same behaviour
e.g. boldness can be measured via
latency to emerge from a refuge
latency to resume activity post-disturbance
response to a novel environment
response to a novel object
Terminology lacks consensus
behavioural type vs personality vs behavioural correlation? Are they all interchangeable or do they mean different things?
What is the difference between personality traits (e.g. boldness) and the behaviours being measured (latency to approach object)
Ways behaviour can be used as a conservation tool
Behavioural biology has many applications to conservations. Key areas include:
Habitat selection
Reproductive behaviour
Foraging
Anti-predator behaviour
Species interactions
Foraging behaviour
How Tinbergen’s Four Questions Matter for Conservation
Causation
Allows targeted intervention by removing the trigger or using it to attract/deter animals.
Proximate knowledge is the entry point for practical management.
e.g. understanding what triggers dispersal allows better corridor placement.
Development
Is the behaviour innate, learned, or experience-dependent?
Critical for reintroduction as captive-bred animals often lack key learned behaviours.
Diagnosing behavioural deficits requires developmental knowledge.
e.g. animals must learn predator recognition.
Function
Predicts outcomes based on the adaptive value of a behaviour.
Can be used to predict consequences when behaviour is disrupted.
Functional understanding allows prediction, not just description.
E.g. if mate-choice behaviour is disrupted, reproductive failure follows.
Evolution
Which species can adapt to rapid environmental change?
Behaviourally flexible species survive — inflexible specialists are at a higher risk
Evaluating outcomes requires evolutionary context.
e.g. evolutionary history of habitat selection predicts response to fragmentation
Discuss the gap between conservation research and application
Awareness does not translate into applicable management tools
Solution-focused papers only represented 33% of all behaviour-conservation intersections
Potential reasons for the gap
Behavioural research is often species-specific
Is the behaviour applicable to conservation problem-solving?
Behavioural studies rarely include management recommendations
Poor communication between researchers and conservation managers
Priority conservation research questions
Habitat Loss & Fragmentation & Sensory Pollution
How does the landscape impede or facilitate animal movement?
Behavioural traits determine whether animals can colonize habitat patches or tolerate edge effects
Sensory pollution disrupts critical behaviours including signal transmission, predation risk assessment, habitat quality assessment, migration
e.g. turtle babies that follow moonlight to the ocean — light pollution could make them go the wrong way and DIE (not ideal)
Human-Wildlife Conflict
Species must adapt to urbanization and human disturbance
How can we use learning theory to improve aversive conditioning in the wild to train animals to avoid people, livestock, or infrastructure.
How can knowledge about social relationships and information transmission be used to reduce the acquisition and spread of “problem” behaviours?
Behavioural research can be used as a management tool to halt the spread of invasive species and mitigate human-wildlife conflict.
Disease & Invasive Species
Habitat Degradation
Conservation Breeding & Translocation
Most breeding decisions are made through genetic management
Understanding mate choice can have major effects on the productivity of breeding programmes
Are certain behavioural types more likely to survive translocation?
Cross-cutting themes
Translocation
Relocating animals from one site to another to create, re-establish, or supplement wild populations for the purposes of conservation.
Reintroduction is a restorative translocation where a species is released back into the wild in a habitat it used to be native in but has since gone extinct
Many translocation efforts do not succeed
Mortality is highest in the first day to a couple of weeks as animals decide where to settle and travel through unfamiliar areas in search of resources
Solitary animals? Alone?
Solitary territorial species may benefit from stable social relationships with established neighbours during translocation.
Species considered 'asocial' still invest in neighbour relationships — disrupting these distracts from fitness-enhancing behaviour.
Bycatch
Unintentional entanglement in fishing gear.
significant threat to marine mammals. nets used by commercial fishing is a pronounced threat
Landscape of fear
Behavioural change driven by perceived predation risk.
(e.g. prey avoid predator territories, kill-sites, travel corridors etc)
cannot be replicated by human hunters due to not being present in the area in the same way as predators are
e.g. when wolves are present, deer may retreat from fields to wooded areas which limits crop damage to farmers.
Research animal
Animals that are used or intended to be used in animal experiments
Kept at a facility or another housing area for experimental animals
“Animals shall be treated well and protected from unnecessary suffering and disease.”
Animals are allowed to suffer in research if it is considered necessary.
Ethical permits are needed for
Certain species
mammals, birds, reptiles, amphibians, fishes, cyclostomata, octopus
Certain experiments
Not needed if
you have the owner’s permission
for e.g. enrichment or observational studies at zoos etc
3R
Replace
Reduce
Refine
(Respect)
(Responsibility)
Humane end point
Predefined criteria on when to end (interrupt) the experiment
“upper limit of suffering”
Not equal to experimental endpoint
Sentience
Ability to obtain and interpret stimuli + has a basic ability for memory, judgment, and emotion
Not equal to intelligence
Nocireception
Not equal to experience of pain/suffering
E.g. insects still react to pain/stress but we don’t know how it actually affects them
Taming vs domestication
Taming
On an individual level
Non-inheritable process
Happens within a singular individual’s lifetime through habituation or conditioning
Purely behavioural, no genetic change to the species or population
Not passed down to offspring: a tame animal’s offspring is not tame from birth
Can apply to any species
Domestication
On a population level
Evolutionary process across many generations
Heritable — genetic change is passed onto offspring whether or not they are personally ever handled by a human
Driven by selection
natural, artificial, or both
Only a few number of species have ever been domesticated
Taming vs tameness
Taming is a human action
Tameness is a behavioural trait
can be selected upon
Domestication requires
Selection on tameness
Reproductive isolation
A founder population breeds under human conditions not in the wild
Multi-generational selection
includes unconscious selection
The three pathways to domestication
Commensal
A species voluntarily enters the human niche
drawn by food or shelter
e.g. cats, dogs
Prey
Managed hunting gradually becomes controlled breeding
e.g. cows, turkey
Directed
Deliberate capture of a wild species for a specific purpose
e.g. horses, bees
Are some species pre-disposed for domestication?
Pros
Large gregarious group
Non-territorial
Promiscuous mating system
Precocial young (born “functional”)
Generalist feeders
Short flight distance from humans
Low reactivity to novelty
Cons
Family groups
Territorial
Monogamous mating system
Altricial young (“useless” when born)
Specialist feeders
Wariness and long flight distances
High sensitivity to novelty
Reasons why the wolf was an unlikely candidate for domestication
First domesticated species of any animal or plant
The only domesticated large carnivore
Not instigated by human action
less fearful wolves were pre-adapted to exploit this new niche
Exaptation
An old trait being used in a new context
Domestication syndrome
The general alteration of morphological, physiological, and behavioural traits occurs simultaneously in domesticated animals
e.g. floppy ears, curly tails, white pigmentation, playfulness
Domestication traits vs Improvement traits
Domestication traits
Essential at the early stages of domestication
Generally shared across all domesticates of a species
Under selection during the initial stages of domestication. In animals, these traits will primarily be behavioural, e.g.
tameness
low reactivity
tolerance of restricted space/movement
Often (partly) a relaxation of natural selection, not only positive selection
Improvement traits
Arose after the initial stages of domestication
Present in only a portion of domesticates, often fixed within particular breeds or regional populations
Product of later, increasingly deliberate (artificial) selection, e.g.
Milk yield
Egg number
Body size
Specific coat colours
Specific behaviours (e.g. herding)
Methods to quantify behavioural evolution
Common garden
Raise both populations in the same environment. A difference that persists indicates genetic differentiation
Cross-fostering
Allows the separation of genotype, environment, and parental effects
Selection experiment
A response to selection across generations is evolved change by definition
Note that most (if not all) domesticates have been so heavily improved that we can no longer separate domestication traits from improvement traits.
Motivation vs Decision making
Motivation
Readiness to act (internal state)
What drives the behaviour?
e.g. low blood glucose —> hunger motivation
Decision making
Selection process
Should current energy level be used for something else?
E.g. is it safe to forage right now? Is it a better opportunity to mate right now?
Motivation may depend on
Hormone level
Time of day
Season
Age
Sex
Climate
Homeostasis
Maintenance of a stable state of internal physical and chemical conditions within narrow optimal ranges by living organisms.
Maintains stability through negative feedback
Involves:
Blood pH
Core temperature
Blood glucose and oxygen levels
Potassium, calcium, and sodium concentrations
Fluid balance
Energy balance
Allostasis
Process by which animals actively adjust their internal state to meet predictable and unpredictable demands.
allows for dynamic shifts in parameters to match needs to eventually return to homeostasis.
e.g. increase in heart rate and blood pressure during physical activity, elevation in glucocorticoids before a breeding season (to be more aroused)
Why does allostasis matter in the context of motivation?
not every rise in a hormone or a drive reflects a deficit being corrected. Some reflect anticipation of a demand.
Homeostasis vs allostasis
Homeostasis
Fixed set points within a narrow range
Allostasis
Dynamic set points that can adapt to changing demands
Can be predictive (changes before deviation from set point occurs), e.g. while watching a horror movie you anticipate a scary scene and your pulse goes up
Allostatic load
The cumulative cost of the body of allostasis
When stressors become too often and lead to chronic stress

How to measure an animal’s motivation
Testing its willingness to pay to gain access to a resource
e.g. how many obstacles it is willing to overcome in order to get to a resource, e.g. food or a new environment.
Wallowing
A behaviour where an animal rolls or lies in mud, water, or wet soil.
Displacement activity
A normal behaviour that appears out of its usual context.
Redirected behaviour
The correct behaviour that is directed at the wrong object.
Intention movements
Suboptimal or fractions of the correct behaviour.
Ambivalence
Combination of intention movements from both conflicting motivational systems (e.g. approach and retreat)
Stereotypic behaviour
A repetitive, functionless, and often damaging behavioural pattern.
Often response to chronic stress, frustration, or inability to perform natural behaviours.
Not necessarily a displacement activity, but prolonged state of motivational conflict can lead to development of stereotypic behaviours as a coping mechanism
Persists even if the animal is taken out of the situation that triggered it.
Judgment vs Decision
Judgment
Acquiring and processing information to make an inference
Relies on ability to discriminate, categorize, assess, and recognize.
Can be difficult to assess, but time spent can indicate judgment.
Decision
Evaluating and selecting options based on information
Expressed through preference and choice
Often more clear cut and quantifiable in behavioural tests
Things to keep in mind during preference tests:
If the individual does not make a choice, we cannot say whether this is due to lack of judgment (no discrimination) or a choice not to act (lack of preference)
To solve this, you can add additional measures:
Physiology
Neurology
More behaviours
Aposematism
Advertising defence strategy where an animal uses bright colours, bold patterns, distinctive sounds, or strong smells to warn predators that it is toxic, venomous, or tastes bad.
Naïve predators learn to avoid this prey more quickly than cryptid defended prey.
Designing studies around motivations
Avoid anthropomorphism
“worked hard for it” is not the same as motivation
Control and report deprivation/energy state before testing (for tests involving food)
Note that some animals are less food motivated than others
Watch for displacement activities being mistaken for what you are actually measuring.
Social organizations
Solitary
e.g. Maned wolf
Pairs
e.g. Laysan Albratross
Family groups
e.g. wolves
Herds/flocks
e.g. Pronghorn antelope
Complex societies
= eusociality
e.g. naked mole rat
highest level of social organization
division of labour into a caste system
single reproductive female (queen)
sterile workers
drones (male)
soldiers
cooperative in child care etc
Benefits to group-living
Reduced predation risk
“many eyes” effect
confusion by blending in
Information sharing
More reliable access to mates
Increased success in obtaining food
ability to take down larger prey
ability to mob larger predators off kills
Shared rearing of offspring
Energy conservation
huddling together to stay warm
Costs of group-living
Greater conspicuousness
Competition
Food sharing
Dominance disputes
Spreading of diseases
Reduced reproductive fitness
infidelity
inbreeding
infanticide
Pros vs Cons with Group living
Benefits to group-living
Reduced predation risk
“many eyes” effect
confusion by blending in
Information sharing
More reliable access to mates
Increased success in obtaining food
ability to take down larger prey
ability to mob larger predators off kills
Shared rearing of offspring
Energy conservation
huddling together to stay warm
Costs of group-living
Greater conspicuousness
Competition
Food sharing
Dominance disputes
Spreading of diseases
Reduced reproductive fitness
infidelity
inbreeding
infanticide
Techniques in group size when predators are present
Zebra and impala aggregate into larger groups
Wildebeest split into smaller groups
Grant’s gazelle and giraffe show weak responses
Vigilance levels in species
Obligate grazers that form largest herds
Lowest level of vigilance
Mixed feeders with intermediate group sizes
Intermediate level of vigilance
Obligatory browsing (giraffe) forming small groups
Highest level of vigilance
Selfish herd
Predation risk is not evenly distributed across positions within a group
due to edge effect
animals want to be in the middle
social status, health, age, food motivation, reproductive status all affect an animal’s physical position in the group
Edge effect
Higher exposure to predation risk at the edge of a group
Social network analysis
Nodes
represent individuals, groups, classes etc
Edges
represent how two nodes relate to each other
can be used to describe how frequently they associate or interact
Centrality
measure of an individual’s structural importance in a group based on its network position
Degree centrality
based on the number of direct edges an animal has
animals with more edges (degree nodes) will have more influence on the individuals around it (and possibly the entire network)
Direct edges
a focal individual’s immediate connections
Indirect edges
connections with individuals through other individuals
Bridges
individuals that connect two “populations”
What is dominance, really?
A social relationship reducing conflicts.
Determines priority access to contested resources (food, shelter, mates)
NOT a personality trait! Rank can change
Only applicable WITHIN species
Establishing dominance hierarchies:
Signals of dominance
Phenotype linked with dominance rank
Influences rank-related interactions in stable groups
e.g. chemical signals in social insects
Signals of individual identity
unique phenotype that is learned and associated with dominance information
influences rank-related interactions with known individuals
e.g. unique whoops in hyenas
Signals of fighting ability
Phenotype linked with resource holding potential, but not dominance per se
Influences contests with unknown individuals
e.g. call frequency in frogs
Why bother with cooperative breeding?
Kin selection
Habitat saturation/fragmentation
Reliable food supply
Succession for breeding opportunity
may breed another year and then receive help
Super normal behaviour
Preference for exaggerated versions of a normal trait.
E.g. red beak thingy
Tinbergen’s Four Questions
Mechanism/Causation
what mechanism triggers the behaviour?
how does it work?
Development/Ontogeny
how age, environment etc affects the behaviour
how does it develop?
Function/Adaptive value
current function of the behaviour/fitness
what is it for?
Evolution/Phylogeny
how did the behaviour evolve?
which species share its behaviour? did it evolve once or multiple times?
Proximate explanations
1 and 2
“How”
Ultimate explanations
3 and 4
Asks “why?”
How to test each of Tinbergen’s questions?
E.g. measuring hormones, neural activity, or the stimuli that trigger responses.
Compare individuals at different developmental stages or with different early experiences.
Estimation of fitness.
e.g. stotting in gazelles is an honest signal of their fitness
Comparing genetic expression, phylogenetic analyses etc.
Hypothesis vs Prediction
Hypothesis:
A proposed explanation for an observed behaviour
Should always state WHY
Can generate multiple predictions
Predictions:
What you would observe in your data if your hypothesis is true
States WHAT happens
Can be consistent with multiple hypotheses
If prediction fails, the hypothesis is challenged
How to write a good hypothesis
Ask yourself:
Does it state a mechanism?
Does it explain the observation or just redescribe it?
How to write good predictions
State what you will measure and in what direction
Generate at least two predictions from the same hypothesis
If both succeed, confidence increases
If one is wrong, you learn specifically which part of the hypothesis don’t hold up
Identify a prediction that discriminates between competing hypotheses
Kin selection predicts that related individuals call more
Reciprocal altruism predicts social partners call more
State what the data will look like under the null hypothesis
How much of today’s studies can be replicated?
50%
Effect size
A metric that quantifies the size of the difference in the means of two groups or the strength of correlation between two variables. Larger effects are characterised by bigger differences in means or stronger correlations between variables.
Standardised effect sizes (e.g. Cohen’s d) express these latter differences in units of standard deviations, and hence allow estimates from different studies to be compared directly.
α
The criterion for statistical significance, which is p < 0.05
β
The false-negative error rate
1 - β is the power
Power
Affected by the effect size to be detected
Larger sample —> higher power
Calculated through 1 - β
Researcher degree of freedom
The flexibility of choosing which data and statistical tests to use and how to interpret the results.
May be different between researcher due to different approaches.
Problems with doing close replications
Difficult to perform: Despite using the same sample size etc, the conditions can never be truly identical, e.g. time of day, experience etc.
May give unjustified confidence about the generality of findings that in fact rely on one aspect of the methodology.
Small differences (e.g. in a male bird’s song) may actually give large differences in results, which close replications would miss.
Decline effect
When effect sizes systematically decrease in follow-up studies
Over replications, estimates values closer to the smaller (true) value.
The differences between groups are smaller / correlations between variables are lower than those originally reported.
p-hacking
When a non-significant result becomes significant (p < 0.05)
Often driven by the pressure to publish “sexy papers” (positive findings) rather than data/research question
In order to get funding
Ways to p-hack
Ending the data collection as soon p<0.05
Before pre-determined sample size
Conducting multiple experiments but only reporting the one that worked
Only reporting variables that are significant
Despite measuring multiple variables
Removing outliers / transform data to get a significance
= tweaking the data
Performing many tests without correcting for family-wise error rate
How to detect p-hacking
A sudden peak in p-values just around 0.05
Type I errors
due to chance
p significant despite H0 being true
Type II errors
due to lack of power, e.g. small sample size
p insignificant despite H1 being true (H0 false)
HARKing
Hypothesising after results are known
making a coincidental finding look like a prior prediction
Why is HARKing problematic?
Inflates false positive rates
p = 0.05 means that there is a 5% probability that your data appeared due to random chance
If you run 20 independent tests at α= 0.05 and report the best one as a “prediction”, your actual false positive rate is closer to 1 - 0.9520 ≈ 64%, not 5%
Results cannot be replicated
Because the results are post-hoc justified, they are unlikely to replicate in a study with new data
Entire research fields can be based on non-replicable results
Researchers will spend time and money trying to replicate findings that cannot be replicated
Invisible in publications
Readers cannot detect HARKing from the published paper alone
Peer review cannot catch HARKing without access to study logs
Publication bias
Positive findings (p < 0.05) are far more likely to be submitted, reviewed, and published than null/negative results, regardless of scientific value.
File-drawer effect
Null results remain unpublished in researcher’s file drawers. They are not written up or published.
Funnel plot
Scatterplot used in meta-analyses to visually detect publication bias.
Plots individual study effect sizes against a measure of precision (like standard error)
If not biased:
Plot resembles an inverted, symmetrical funnel.
Larger studies at the top, smaller studies spread out equally on its sides
Suggests that both positive and negative results were published equally
If biased:
Plot is asymmetrical
Small studies with negative, non-significant, or unfavourable results were unpublished (file-drawer effect)
Small studies with positive, statistically significant results made it to publication
Types of replication
Close replication
Repeats original study with the same species, sample size, setting, and protocol
Rare
Conceptual replications
Tests the same hypothesis with a different design
also called triangulation or constructive replication
Reasons why replications may give different results from the original study
An unconsidered variable may have caused a difference in the results
These are called moderators.
Individual differences in how animals react and behave.
True-negative or false-positive result (type i and type ii errors)
Larger sample size gives lower false-negative error rate
p-value of 0.05 makes type ii error rate less than one in 20
Random variation
Moderators
Variables that have not been considered, but is actually an important factor that gives different results in replication studies.
Standardisation fallacy
The phenomenon that over-standardisation of laboratory protocols could reduce the replicability of results.
E.g. mice behaviour might change depending on the time of the day
Research team MORNING and research time NIGHT will have different results
If the two teams expanded their study to last the entire day, the mean of their results would be the same, yet more variable.
How to avoid inaccurate reporting in our papers
Pre-register hypothesis, design, sample size, and analysis plan on repositories before collecting data
Eliminates HARKing
Reduces p-hacking
Calculate minimum N needed to reliably detect an effect of the expected magnitude before starting
Prevents underpowered studies
Provide raw data, analysis scripts, and methods in the paper
Actively conduct and publish close replication studies from different labs.
Report null results, failed conditions, and unexpected findings, not just p<0.05 outcomes.
Reduces file-drawer effect
Positive predictive value (PPV)
The probability that a positive research finding is a true-positive result.
Higher power = higher PPV
Why do we like animals?
Biophilia hypothesis
An innate love for nature
Kindchensschema
Konrad Lorenz had a hypothesis that we are more willing to take care of creatures with large eyes, small noses, round faces etc (cuteness, in other words)
Differences between HAI, HAR, HAB?
HAI= Human animal interaction
Simply interactions one may have with the deer crossing the road
Can be positive or negative
HAR= Human-animal relationship
After a couple of interactions once you start to learn their behaviours etc.
May also be general and not specifically to an individual, e.g. HAR between moose and hunters (learn to avoid them), or dogs learning that vets are evil
Can be positive or negative
HAB= Human-animal bond
Once both parts start feeling very good together
Can only be positive
What is needed for a relationship?
Proximity (shared geography)
Cognitive ability to remember/recognize individuals
Understanding social cues (initiating, receiving, responding)
Why eye contact with dogs?
They show us eye contact. Oxytocin is released inside us.
We give them more love. Oxytocin is released within them.
They show us more eye contact. The cycle continues.
Are visitors enrichment or stressors for zoo animals?
Depends on the species
Elephants, grizzly bears, polar bears, cheetahs, servals, black-tailed prairie dogs, and cockatoos respond positively to public feedings.
Show more activity and less repetitive behaviours afterwards
Flightless birds, odd/even-toed ungulates, marsupials, tuatara, and hedgehogs react negatively.
Different kinds of eyes
Pupils
Can be round and expanded
e.g. humans, birds
180 degree visual field with mostly overlap/depth perception
Narrow —> round
e.g. cats, dogs
Better at adjusting their size
Broader visual field with more narrow overlap
Horizontal
e.g. horses, goats, sheep
Very broad visual field (almost 360 degrees)
Horses still have 65-80 degree frontal overlap, just like canids.
Additional “white fingers” that stick out/forwards of the eye to block sunlight (the shade from this can be visible)
“Dots”
Very small dots turning into covering the entire iris (basically)
e.g. gecko, tarsier