Lecture 6: Behavioural Ecology

behavioural ecology

the study of the behaviour of organisms, with reference to adaptive significance.

what does behavioural ecology investigate?

why animals in the wild behave the way they do.

- relates to evolutionary adaptiveness of behaviour.

where are behavioural ecology investigations done?

in the field, because you want to understand how they behave in their own environment.

behaviour

Decisive processes whereby organisms adjust their state in response to environmental changes

true or false: proper behaviour enables the organism to improve its situation

true. animals are behaving for survival, if they behave wrong they may not survive.

ex. things move after death due to parasites trying to attract predators to spread themselves

range of behaviour from normal to obscene can be understood with

behavioural ecology

list behavioural interactions among organisms

•Food

•Enemies (predators, parasites, pathogens)

•Social behaviour with conspecifics (competition, collaboration)

•Sexual selection

•Viability selection

what is a key attribute of an organism

feeding.

true or false: food choices and intake do not influence fitness.

false. food choices and intake influence fitness.

foraging and processing of food costs energy, there for animals must be

efficient by selecting and utilizing good patches only.

weigh cost vs benefit.

ex. bees passing low nectar flowers on their way to get nectar rich flowers.

foraging -

animal grazes. how animals make their food choices and the act of feeding.

true or false: animals are always selective of food.

false, under food deprivation, animals are less selective.

feeding can transition into being _____ or the function of feeding might require ______

prey, predation.

foraging activity increases an organism's risk of

getting preyed upon or infected.

organisms are less likely to be active and will only move around as much as necessary which may

limit food intake and slow down maturation.

moving around can cost a prey their life, they have lower consumption habits because of this. example is syrphid fly

true or false: parasites influence behaviour

true. parasites change their hosts behaviour in their own interest.

- intermediate hosts behaviour changed to increase the change of encounter with the final host.

- nematode has two hosts: ants and birds.

- abdomen of parasitized ants becomes berry like to attract birds.

reproducitve success is key to

fitness.

two types of sexual selection

intrasexual selection and intersexual selection

intrasexual selection

competition between members of the same sex.

- ex. male vs. male same competing for mating. aggression between rivals which can result in the evolution of aggressive behaviour, risk-taking, and weaponry (antlers)

intersexual selection

females discriminate among advertising males.

- the act of choosing

aggression is common in this type of sexual selection

intrasexual selection - males competing for female attention.

reproduction has very close linkage with

the survival of the species.

- may be more important for species' success than individual survival

sexual competition greater in

males

females invest more into

offspring.

ornamentation is associated with

intersexual selection

ornamentation

•Visual displays and acoustical and pheromonal signals in males to increase desirability by females.

ornamentation is costly and shows the

wealth of the male

females choose to acquire a _________ mate

genetically superior.

or one that provides better resources.

ornamentation for sexual selection may increase

risk of predation.

mating may increase

risk of predation and venereal disease.

eusocial organisms

focus on the benefit of all vs their own desire.

- sacrifice their own reproduction to aid others.

- have specialized phenotypes: work, defense, reproduction.

- have high levels of social development.

- ex. ants

kin selection

Natural selection that favours genetic contributions to future generations through altruism to close relatives

for altruism to evolve, its costs

to the actor, such as any loss of direct fitness, must be outweighed by its indirect benefit, weighed by the relatedness of the actor and recipient.

workers of social insects

do not have progeny, all related to the queen, and work for the success of the colony (which does provide wider distribution for their own genes)

- kin selection

true or false, plants do not behave.

false, while behaviour is usually associated with animals, but plants behave (respond to environmental conditions).

- carrots in search of light grow long necks

- phenotypically change in search of resources

plants under attack by herbivores can

send signals to attract predators

- trying to survive.

•Tree branch broken, sap comes out. Trying to heal, may be poisonous to fight, may attract predators.

plant may respond to signals from attacked plants by

increasing production of defense substances.

proper understanding of mating habits important for

conservation efforts.

- ex. kakapo mothers in good conditions produce more sons because they spread genes farther.

- intervention by conservationists to yield more females because the number of females was limiting and population was endangered.

- more females means population can increase, more males means more aggressive competition.