Foraging & Predation Flashcards
consuming food is based on (3)
- searching time
- handling time
- energy values
describe the howler monkeys
at first seemed to not be optimally foraging but feeding on young, smaller, harder to find leaves
BUT these young leaves/ petiole are more nutritious and so worth the energy to find them
~ low levels of toxins
ways in which animals select food optimally, and can change these strategies in response to…..
- maximize energy input/ nutrients in response to predation risk
describe Marginal Value Theorem
looks at access to resources and travelling time (to and from and how long should stay in a patch)
~ says you should stay in a patch of food until the rate of food gain drops below the average rate of gain it could get elsewhere
describe game theory
used to determine which strategies are likely to evolve for a population or in a specific context
what are Evolutionary Stable Strategies (ESS) and an example
unbeatable strategy, that once adopted by most of population, cannot be replaced
ex. sex ratio/ hawks within doves
describe cryspsis
~ ability of an animal to avoid detection from a predator, via behavioural/ morphological adaptations
describe counter adaptations
used by predators to detect prey
describe the Co-evolutionary arms race
~ constant arms race between adaptation and counter adaptations of prey and predator
predation affects …(3)
- abundance
- distributions
- diversity
what is camouflage
shape or color that helps animal hide from visual predators
what is mimicry
one species evolve to look, sound, smell or act like another species
types of crypsis
- countershading
- background matching / camouflage
- disruptive camouflage (disruptive coloration hides an animals outline)
~ giraffe in front of tree - changing colors or pattern (response to enviro / weather)
~ bunnies in winter/ summer
aposematic coloration
= warning coloration, indicates toxicity
2 types of mimicry and describe
Batesian = a palatable mimic resembles an unpalatable model to gain protection
(harmless species pretends to be dangerous)
~henry bates
Mullerian = two or more unpalatable species resemble eachother, reinforcing the warning signal
(harmful species all look similar to each other)
~fritz muller
emslyan mimicry
a deadly species mimics a less deadly/ harmful species
describe Masquerade mimicry
organisms mimic inanimate objects like bird droppings, twigs or leaves to avoid detection
what is scent mimicry
when an organism produces a smell that imitates another species or substance
costs and benefits of mimicry
benefits:
- protection
- increases survival/ reproductive success
costs:
- if mimicry fails = predator
- energetic costs
- environment dependent (a mimic in an area without the model serves no advantage)
what is feign injury or death
playing dead/ injured
what is startle behaviour & examples
sudden movement or sound to detract a predator
ex. snake rattling tail/hissing
~eyespots on moths and butterflies
~gazelles stotting (seems to work against cheetahs)
anti predator defence (evasion) examples (3)
physical deterrence:
- horns/ spikes/ teeth
chemical deterrence:
- venoms/ stings
pathogen avoidance:
- grooming
- self medication
color of crypsis has several functions (3)
- concealment
- intraspecific communication
- interspecific warning
describe vigilance and social behaviour against predators (5)
- confusion effect (so many don’t know who to go after)
- dilution effect (so many low chance YOU get eaten)
- selfish herd
- more eyes to watch for predators & can take turns
- communal defence
