Behavioural ecology

What is the definition of Behavioural Ecology?

How ecological factors drive behavioural adaptations

The roots of behavioural ecology can be traced back to ______, which emphasised the adaptive significance of behaviour

Darwin’s theory of natural selection

Behavioural ecology emerged as a distinct field in ___

1960-70s

Definition of comparative approach

Observational studies in natural habitats to understand evolutionary and ecological contexts

Definition of the experimental approach

Controlled experiments to establish cause and effect relationships by isolating specific factors and measuring their impact

The comparative approach examines behaviour across species, population or individuals to infer evolutionary and ecological adaptations. By identifying ____ under varying ecological pressures, researchers attempt to explain why certain behaviours prevail

Behavioural differences and similarities

comparative case studies

Forest and Savanna weaver birds, Gibbons and Gorillas

__ study of weaver birds

Crook

When was Crooks study of weaver birds

1964

In the forest, items are cryptic, easily disturbed and widely distributed insects, which leads to ___ foraging

Solitary

Forest dwelling weaver birds have ___ coloured plumage and nests to reduce predation

Cryptically

Dispersed food and spaced out breeding territories leads to ___ pair bonds in Forest Weaver Birds

Monogamous

Dispersed food and spaced out breeding territories in forest dwelling weaver birds = ____ sexual selection

Weak

Key facts about forest dwelling weaver birds

Monogamous, cryptic nests, solitary foraging

Savannah dwelling weaver birds eat seeds, which are

Patchy and abundant

____ can help locating food patches for savannah dwelling weaver birds

foraging in groups

Savannah dwelling weaver birds live in ___ nests because camoflauge does not work in open and less complex environment, instead elaborate nests can serve as signals to assert dominance

Conspicuous colonial

What is a colonial nest? (Where savannah weaver birds live)

Large communal structures that house multiple nests within a single complex

How does limited safe nesting leas to polyamary in savannah dwelling weaver birds?

Males competing for nesting sites

How does locally abundant food lead to polyamary?

Females can feed entire brood alone, males seek additional mating opportunities

Why do savannah dwelling weaver species have sexual plumage dimorphism

More energy and male competition

Crooks research demonstrated that the ecology of weaver birds is closely linked to their social organisation. He found that during nonbreeding and breeding seasons, the _____ influenced whether weaver birds formed flocks or foraging solitarily and whether they bred colonially or solitarily.

Spatial distribution of food resources and breeding habitats

Crook proposed that changes in one aspect of a species ecology such as habitat or food availability could lead to simultaneous changes in dispersal patterns and breeding systems. This idea of _______ suggests these factors are interconnected and evolve together

Non independent transitions

Limitations of crooks: cant rule our alternative hypothesis - for example while flocking behaviour in savannah dwelling birds might be bc of food distribution, it could also arise from ___

Predation avoidance

Crooks study did not use ____ methods to test hypothesis, species were categories by ecological and social traits

Statistical

Crook did not consider ___ species may have similar behavioural traits bc of shared ancestry, species that share phylogenetic history are not independent data points

Congeneric

Who did phylogenetically controlled analysis of 107 weaver species? (2022)

Zitan Song

When did Zitan Song research weaver species?

2022

Zitan Songs reaearch on weaver birds confirm that both diet and habitat type are significantly associated with the ____ of weaver birds, which predicts their mating system

Spatial distribution

____ in savannah weaver birds could be bc of food, but also bc of reduced predation threats due to predator confusion, group defense and enganced vigilance (ZITAN SONG)

Flocking

Alan F Dixson: species like ___ which are monogamous live in env. where resources are evenly distributed

Gibbons

ALAN F DIXSON: gibbons live in env. where resources are evenly distributed, how does this lead to monogamy

reduced competition for mates and favouring pair bonding

ALAN F DIXSON: in contrast to gibbons, gorillas exhibit _____ systems where dominant males control harems of females

Polygynous

ALAN F DIXSON: gorillas polygynous systems correlates with ___ resource distribution, where males compete to secure areas rich in reasources

Patchy

How could predation pressure also play a role in primate mating systems

Large multi-male groups more common in areas of high predation

How could group size and composition (social structure) influence mating systems in primates

Larger groups may have more complex social interactions

_____ might impact primate mating systems eg some gorilla populations may exhibit different mating behaviours based on local environment conditions

Behavioural plasticity

How might human influence primate mating systems

Habitat destruction and climate change altering resource distribution

__ (1962) studied black- headed gulls

Niko Tinbergen

When did Niko Tinbergen study black headed gulls

1962

By painting artificial eggs and placing them near nests, Tinbergen demonstrated that

Nests with conspicuous eggshells experience higher predation

Tinbergen’s findings that black-headed gulls experience higher predation supports the hypothesis that

Eggshell removal had adaptive significance

Criticisms of Tinbergens black headed gull research: _____ to isolate specific variables, useful for controlled experiments but may overlook multifaceted nature of animal behaviour

simplification of behaviour

Criticisms of Tinbergens: ____ may not fully replicate natural environment

Controlled conditions

Criticisms of Tinbergens: ___ altering nesting environment and directly interacting with birds is considered invasive

Ethical considerations

__ (1986) researched optimum foraging in crows

Richardson and Verbeek

richardson and verbeek (__) researched optimum foraging in crows

1986

Richardson and Verbeek observed that crows selectively consumed clams…

Above a certain size threshold

To test the hypothesis that crows selectively consumed clams above a certain size threshold, researchers manipulated __

Clam availability

To test the hypothesis that crows selectively consumed clams above a certain size threshold, researchers manipulated clam availability and measured ___

Crows decision-making

In Richardson and Verbeek (1986), the crows were observed to selectively feed on larger clams, which provided a ____ despite the increased effort required to handle them

Higher net energy gain

Experiments on crows on clams revealed an ___ , crows only consumed clams above a specific size threshold to maximise energy efficiency

Optimal decision rule

criticism of Richardson and Verbeek: simplification of natural behaviour

Focused on single prey type and specific conditions

criticism of Richardson and Verbeek: Although conducted in a natural setting, specific conditions and prey availability might not represent all environments

Ecological validity

criticism of Richardson and Verbeek: model assumptions

Animals may face uncertainties and constraints

criticism of Richardson and Verbeek: presence of researchers could influence behaviour of crows

Observer effects