Animal Behavior Final Flashcards
Optimal Diet Model Assumptions
1) foragers must maximize fitness by maximizing energy intake
2) Food items are encountered one at a time and in proportion to their abundance
3) all food items in the environment can be ranked according to their profitability
Why are the ODM assumptions better predictors for the diets of animals with immobile prey?
there is more variation among prey encounter rates and capture success with mobile prey compared to immobile
What assumption is shared by the ODM and patch-use model?
foragers want to maximize their energy intake rate
what is the zero-one rule?
the prediction that each food type should either always be eaten or always rejected when found
A researcher examines the hunting success of a visual predator as it searches for cryptic prey. She finds that a foragers hunting success increases over time. What can explain this observation?
the forager formed a search image (knows exactly what the cryptic prey will look like)
how is the profitability of a food item calculated?
E/h
E = energy gained from item
h = handling time
the size of a group often increases after a predator is spotted. What anti predator benefit best explains this observation?
safety in numbers - as group size increases, each individual is safer due to the dilution effect
What are the findings of Shora et al (2018) regarding diet and welfare in zoo-housed species such as coatis?
Being provided whole food resulted in significantly less infraspecific aggression compared to when the animals received chopped food
whole food = good!
Explain why the fitness of the scrounger strategy declines declines as their frequency increases in a group
more scroungers means less producers and less food available for each individual
What is involved in the foraging trade-off between the probability of being killed by a predator and risk of starvation?
Food carrying: as distance between food patch and safety increases -> less likely to carry food items to safety
The selfish herd hypothesis predicts that individuals should do what?
Continuously adjust their position in the group and place others between themselves and predators
In some species, individuals behave in ways that make them more apparent to a predator. Why would this be beneficial? What theories explain this?
it could annoy the predator enough that it leaves or deter it from attacking since its been spotted
Pursuit deterrence hypothesis:
making oneself more noticeable to a predator = alert predator that you see them -> informs them they have been detected and that their pursuit will not be successful
Alarm signal hypothesis:
warn nearby conspecifics of danger
ex: tail flagging in deer
explain how the dilution effect differs from selfish herd hypothesis
dilution effect means individuals need to scan less due to more individuals present whereas the selfish herd hypothesis means moving oneself around in the group and placing others between you and a predator to avoid being the first one caught
identify the unique predictions of the pursuit deterrence hypothesis and alarm signal hypothesis
pursuit deterrence:
- inform predator they are detected
- should occur more often as the distance between the predator and prey increases
alarm signal:
- inform conspecifics of danger
- signaling should be more common when kin are nearby
why does migration occur?
migrate during specific seasons in search of food/water or mating reasons
internal factors: annual rhythms and associated physiological changes
external factors: changes in photoperiod and local environmental conditions
describe the differences between orientation and navigation. formulate an experiment that would allow you to determine these capabilities in a species.
orientation: maintaining the proper directions of travel
navigation: determining how to reach a particular location
describe the difference between ornaments and weapons. in which sex do these traits most often appear?
weapons: used in fights within the same gender to win a sexual partner
ornaments: morphological, acoustic, chemical, or behavioral features to attract sexual partners
males
define a sex role reversed species and provide one example. what conditions are required for the evolution of such a species?
females exhibit high level of territorial defense and aggression while males provide high levels of parental care
ex: seahorses
favored in resource poor environments or where predation on offspring is high
under what conditions would you expect sexual selection to be more intense on females than males?
selection will favor mating systems that provide the greatest resources:
monogamy: if sexual partner provides high levels of resources for young
polyandry: multiple males provide care for her offspring
describe the predictions of Bateman’s hypothesis with respect to males and females
1) males have higher variation in reproductive success (male-male competition)
2) males reproductive success is limited by the number of completed mating obtained
3) female reproductive success is limited by the number of eggs the female produces
Polygyny
males have sole access to several females, females share one male
ex: feral horses
Polyandry
males share one female, females have stolen access yo several males
ex: European badgers
monogamy
males have sole access to one female, females have sole access to one male
ex: california mouse
promiscuity
males have access to many females, females have access to many females (no bonds)
in polygynous vs. monogamous mating systems, which would you expect to have the highest intensity sexual selection amongst males and why?
Monogamy because males stay with their single mate and offspring for life and need to make sure they are the fittest
in the study in warblers, what is mate guarding and did the results of the study support or not support its effectiveness.
mate guarding: males maintain close proximity to their mate during the fertile period in attempt to deter other males
it was effective in reducing the risk of extra pair fertilization
how did Rodd and colleagues (2002) evaluate the sensory bias hypothesis in guppies?
by examaning the color preference of both males and females
what differentiates intersexual competition from intrasexual competition? provide an example of each.
intersexual competition: when one sex chooses which members of the opposite sex to mate with (ex: males form a lek to display to females)
intrasexual competition: when members of the same sex compete for mates (ex: males compete with eachother for mating with a female)
what does beluga sexual play look like? do they have preferences with whom they play?
genital rubbing, thrusting, s posturing, ventral present, riding, erection
1st year: prefer to play with their mother and other male calves
2nd year: begin to diversify who they play with
3rd year: prefer to play with other calves and adult males
in elephant seals, a male competes with other males while defending several families with whom he mates. What term best describes this social mating system?
polygyny
hotspot hypothesis
all males can benefit from aggregating in a location where they are likely to encounter many females (ex: peafowl)
hotshot hypothesis
low-ranking males can benefit by aggregating around high-ranking males because females are more likely to visit attractive males (ex: little bustard)
how can you tests if a given species follows the hotspot or hotshot hypothesis?
remove the hotshot from a lek:
- if attractiveness falls to other males and females = species follows hotshot
- if other males begin to settle on lek still = species follows hotspot
You discover a new species of bird and observe that males defend similar-sized territories early in the breeding season and that females then settle in these territories. on some male territories, only one female settles to breed, while on others, multiple females settle and breed. how would you best classify this mating system?
polygyny
direct material benefits
material resources received by a female from mating with a male
ex: nuptial gifts, territory, parental care
indirect benefits
increase genetic fitness of offspring
ex: new genes
social monogamy is rare in mammals but common in birds. What difference is hypothesized to explain this observation?
birds need for biparental care
Hamilton-zuck hypothesis and predictions
parasites and pathogens play an important role in sexual selection while secondary sexual traits are costly and condition dependent
predictions:
1) females should prefer males with the greatest expression of secondary sexual traits
2) high parasite loads will reduce that expression in males
peackock Hamilton-zuck hypothesis example
elaborate trains with more eyespots = more mates
- females can learn information from high spot counts such as if the male has good genes, parasite load, and disease resistance
- more ornaments = pathogen/disease resistance
in what situation can cryptic female choice enhance the fitness of a female?
when mating with males that differ in quality
5 proposed adaptive categories for sociosexual behavior
1) can act as social glue
2) regulates conflict
3) act as practice for younger animals
4) kin selection
5) indirect insemination
what does research on mating systems in various reed warbler species tell us about the development of different mating systems?
- resource abundance affects mating systems (scarce = monogamy, abundant = polygyny)
- females invest in care regardless while males vary
what features distinguish promiscuity from polygynandry
promiscuity has no social bonds while polygynandry does
polygynandry example
chimps/bonobos