16. Chapter 51: Behavioural Ecology Flashcards
Behaviour
an animal does and it does itWhat
Behaviour
an animal does and it does itWhat
What does behaviour directly impact?
fitness of individuals, molded by natural selection, influence lifetime reproductive success
Innate behaviours
due to genetic programming (environmental diff. does not alter this)
Learning
the modification of behaviour resulting from specific experiences (predator-specific alarm calls of primates)
Habituation
A loss of responsiveness to unimportant stimuli (“cry-wolf” effect)
Maturation
behavioural improvement because of ongoing neuromuscular development
(ez to mistake for innate - hockey player example)
Imprinting
A type of learned behaviour with a significant innate component, acquired during a limited critical period (geese firs hrs with Konrad Lorenz)
Play
As a behaviour has no apparent external goal, but may facilitate social development and neuromuscular development
Spatial Learning
the modification of behaviour based on the spatial structure of the environment
Optimal foraging theory
states that natural selection will benefit animals that maximize their energy intake-to-expenditure ratio (i.e. crows dropping shellfish at 5m)
Altruistic behaviour
decrease individual fitness (altruist), but increase the fitness of others (recipient)
How is altruistic behaviour maintained by evolution?
- recipient related to altruist
2. altruist keep own genes in the population
Inclusive fitness
the effect on fitness of reproduction and helping relative raise offspring
Reciprocal altruism
current altruist benefits in the future when recipient reciprocates (e.g. primate grooming)
Eusociality: Sertile castes
- are extreme case of altruism
- difficult to reconcile with evolutionary theory
- In bees, wasp and ants: worker females give up reproduction and raise sisters
How has eusocial animals evolved such a system?
Haplo-diploid genetics: therefore more relatedness of sister to sister than daughter to mother. Females have greater chance on passing on alleles by raising sisters rather than offspring)
What is an example of a eusocial mammal?
naked mole rates even though they don’t have haply-diploid system but are highly inbred
What causes sexual selection?
competition over the limiting sex (important component of natural selection)
Why are females the limiting resource?
Produce larger, more energetically costly gametes where as males produce smaller, less genetically costly gametes
How do the sexes increase reproductive success?
- Females look for better genes, limit mate access
2. males fertilize anything, always sperm donor
Differential reproductive success
drives evolution of certain traits and can lead to amplification of those traits
Secondary sexual characteristics
not directly associated with reproduction
Sexual size dimorphism
increases as harem size increases - strong combat results
Why are testicles so large in the chimp:
sperm competition (promiscuous species)
Intrasexual selection
direct competition b/w individuals of same sex for mates (e.g. physical battles - fighting, vocalizations, ritualized displays - often significant risk)
Intersexual selection (mate choice)
occurs when females are choosy in selecting a mate (certain features attractive to females like bright colours, exposes male to extra risk)
What is the underlying basis of female choice?
Not purely aesthetics, often advertises health of a male
Parental investment
- refers to the time and resources expended for raising of offspring
- generally lower in males
- may have higher mating costs (up from)
Certainty of paternity
- can influence male parental care
2. unsure of offspring = lower investment
Infanticide
intentionally causing the death of an infant by a member of the same species
Under what conditions could infanticide be selected for?
Advantage: female want to reproduce again (come into heat - ovulate right away instead of spend all energy on current offspring that is not his)
example: lions when new male takes over pride
When is certainty of paternity higher?
External fertilization: 60% show investment but on 7% investment when internal (in fish)
What is the worst outcome for males?
investing heavily in offspring that are not yours (monogamy is very rare - only 3% of mammals)