Week 1 Flashcards
What is behavioural ecology?
the study of the ecological and evolutionary basis for animal behaviour and the roles of behaviour in enabling an animal to adapt to its environment
Darwins theory of evolution:
there is inherited _____ among organisms.
there is _____ between organisms for survival
______ leads to the accumulation of favoured variants, which over a long period produce new life forms, the ______ __ _____
variation
competition
selection
origin of new species
What is natural selection?
the process whereby certain genetically inherited characteristics increase the chances of their carriers surviving and reproducing in a particular environment. These individuals will pass on their beneficial charactersitics to the next generation. The process of natural selection determines which charactersics of the animal confer greater fitness
what is fitness?
a measure of the ability of genetic material to perpetuate itself in the course of evolution. It is dependent on the individuals ability to survive, the rate of reproduction and the viability of offspring
Individuals that produce higher numbers of ____ _____ are said to have greater individual fitness
viable offspring
the fitness of an individual depends on what 4 factors?
ability to survive to reproductive age
its success in mating
the fecundity of the mated pair
probability of survival to reproductive age of the resulting offspring
what are the 5 types of selection that are considered in behavioural ecology?
natural selection kin selection sexual selection runaway selection group selection
what is natural selection?
(direct selection)
the process that produces evolutionary change when individuals differ inheritable traits that are correlated with differences in their individual reproductive success
what is kin selection?
a form of natural selection that occurs when individuals differ in ways that affect their parental care or helping behaviour, and thus the survival of thier own offspring or of non-descendant kin
what is sexual selection?
a form of natural selection that occurs when individuals differ in their ability to compete with others for mates or to attract members of the opposite sex
what is runaway selection?
a form of sexual selection that occurs when female mating preferences for certain male attributes create a positive feedback loop favouring both males with these attributes and females that prefer them
what is group selection?
selection that occurs when groups differ in their collective attributes and those differences affect the survival chances of those groups
what is imprinting?
it is a form of associative early learning, involved in social development
What can fixed action patterns lead to?
the evolution of ritualised displays, and formed part of the comparitive approach to the study of behaviour by ethologists
example of fixed action pattern
courtship in great-crested grebes, males and females face each other, dive and return to the surface several times with water plants in their bills
what are supernormal stimuli?
refer to artificial stimuli that are more effective than the real thing in eliciting a behavioural response
example of a supernormal stimulus
herring gull chicks peck at a red spot on their parents bull to induce their parents to regurgitate food. Chicks will also peck at a model consisting of a red spot against a yellow background. However, it is possible to construct a model that is even more effective than a real head by using a red pencil with three white bars at the end.
what is a functional approach to asking questions in behavioural ecology?
how do features (mechanisms, behaviours) contribute to an organisms survival and fitness (reproductive success)
what are Tinbergens 4 questions?
Proximate factors:
causation (physiological mechanisms)
development (ontogeny)
Ultimate factors:
function (adaptive value)
history (evolution)Example of tinbergens 4 questions to address a question?
Why do male nightingales sing in spring? Function (adaptation) - ultimate Mechanism (Causation) - proximate development (ontogeny) - proximate evolution (history) - ultimate
why do male nightingales sing in spring? To: function (adaptation) ultimate (6)
attract a mate defend a territory advertise return from migration demonstrate health maintain social bonds get rid of excess energy
Why do male nightingales sing in spring? As a: mechanism (causation) proximate (4)
response to increase in hormone levels
response to increased day length
because theyre “happy”
because they have enough energy in spring
Why do male nightingales sing in spring? because: development (ontogeny) proximate (4)
because they heard their fathers sing in spring
they’re copying what other birds around them are doing
because their vocal apparatus has developed fully
its encoded in their genes
Why do male nightingales sing in spring? because: evolution (history) ultimate (3)
because their ancestors that sang in spring attracted more females
they inherited the behaviour from their fathers
its just an evolutionary carryover
individuals are always in _____ with others for limited resources, including food, territories, and mates
competition
_____ will occur between predators and prey, between rivals for mates, between siblings, mates, and even between parents and their offspring. ____ happens as well.
conflict
co-operation
Much of behavioural ecology is concerned with the effects of natural selection on ??? and the consequent ???
conflict
cooperation
competition
behavioural responses and decision making processes
Example of function - an adaptation for survival
vigilance in socially foraging animals such as elk may serve to
monitor the behaviour of conspecifics (reduce conspecific risk and/or increase reprodcutive benefits)
detect predators (reduce predation risk)
these potential benefits and costs of vigilance may not be equal among different genders and age classes foraging together
Study evidence for function - an adaptation for survival
Lung and Childress 2007
Ontogeny of behaviour can be ___ and exhibit ___
complex
plasticity
Evolution - phylogeny of behaviour, comparatieve methods need to take into account phylogeny why?
these test for correlated evolutionary changes in 2 or more traits
determine whether a trait contains a phylogenetic signal (the tendency for related species to resemble each other)
Example of a study with phylogeny of behaviour
Sexual swelling in primates. When females are coming into oestrous they develop a bright colouration around the genitals. Common around some primates but not in all of them. So what is the function of it? And why did it evolve?
The evolutionary history shows you the phylogeny of old world monkeys. Map on whether or not there is the exaggerated swellings, and what the social system is in the particular species. Filled in purple = bright swellings. Filled in purple row 2 = multi male social system – where there are lots of males competing to mate with a female.
By advertising when they are fertile, the female is signalling to the dominant male, I am ready to conceive, but there are also other subordinate males around that can potentially kill the offspring if they are not their own. In order to confuse parentage and paternity, the female chimps make themselves attractive around a period of time, and so the dominant male gets to mate as do the other subordinate males, and so there is confusion with the paternity and so the males are less likely to kill the offspring.
It is believed that this is the main reason for exaggerated swellings – confusing parentage.
Evolved 3 times separately – convergent evolution.
Also note that the trait has been lost in some areas of the phylogeny. Lost in macaques as it is no longer an adaptive trait.
Nearly always where you have exaggerated swellings there is the multi male mating system.
There is growing evidence that the neuropeptides ___ and ____ modulate complex social behaviour and social cognition
oxytocin
vasopressin
Both oxytocin and vasopressin show a conserved role in modulating social behaviour in general, the specific behaviours they influence show extensive variation among _____
different species
Vassopressin administration stimulates behaviours associated with ____
monogamy
Lim et al 2004 gave evidence that vassopressin modulates social behaviour how?
Prarie voles - monogamous
Meadow voles - polygamous
when V1A receptor levels are artificially increased within the VP of meadow voles using adeno associated viral rector gene transfer they display social beaviour that is reminiscent of monogamous prarie voles.
this is supported with brain scans showing similar display patterns between meadow voles and injected prarie voles.
Goodson and bass 2001 provided evidence that vasopressin show extensive variation in the behaviours they affect in different species how?
In birds vasopressin homolog, vasotocin increases vocalisation and aggressive behaviours in territorial male field sparrows but has only weak effects on aggression in zebra finches.
These species specific behavioural effects are thought to be mediated in part by variation in brain receptor patterns rather than differences within the peptides
