3: feeding behaviour Flashcards
what are predators and prey often locked into?
co-evolutionary struggle
what did Tinbergen observe about caterpillars and song birds?
if a new type of caterpillar in the woodland songbirds would barely bring them to the nest
- once some were brought back would collect them at a greater rate
- recognised the caterpillars and formed a search image
what did pietrewicz and Kamil do to test the search image hypotheses? (4)
- operant conditioning used in captive blue jays
- show them 16 slides of cryptic moths of either the same or 2 different species
- birds improved when given one species but not 2
- hard to build up a simultaneous search image
what is the skunk smell search image example?(4)
- striped skunk is a nocturnal forager locating food by odor
- let young skunks forage in enclosure
- found food at greater distances as they gained experience
- increased max distance that detect food
what is the lizard foraging evolutionary history? (3)
- ancestral was ambush predator
- 3 evolutionary events give rise to olfactory foraging
- 1 event where olfactory reverted to ambush predation
what are the 2 animal groups as information centres?
social insects
other group living
what are features of the non social other group living groups? (4)
- normally composed of mostly unrelated individuals
- cooperation not favoured by kin selection
- incidental communication with conspecifics
- observing location of successful foragers
give some examples of how individuals benefit in foraging in groups as they can catch larger prey
- wolves take moose
- army ants take arthropods/other insect colonies
- lions take wildebeests
what are features of social insect groups? (7)
- composed of related individuals
- cooperation favoured by kin
- deliberate communication with nest mates
- waggle dancing, direct leading, pheromone trails in ants
- workers help by capturing prey such as in army ants
- or by defending a food patch such as ants and some stingless bees
- communicate location of food to nestmates
- who discovered the waggle dance in bees?
- what are the 2 main types and the distances from food they are exhibited at?
- Karl von Frisch
- round dance (<50m)
- figure of eight dance (>50m)
where are figure of eight waggle dances performed?
in the nest on vertical combs in the darkness of the hive/colony
what are the 2 things need for the waggles dance and explain each
- direction- angle from the vertical, matches the angle between the food source and the sun
- distance to food - indicated by how long the dance takes, duration correlated with distance
how did von Frisch test for bees communicating direction in their dances? (6)
- in a fan test trained scout bees to fly to feeder F
- returned to hive to perform dance
- feeders of equal attractiveness places at 7 stations same distance from the hive but at different angles
- counted recruits
- more arrived at F location, directly straight from hive
- bees are gaining information from the dance
how did von Frisch test for bees communicating distance in their dances? (4)
- feeders placed in same direction but different distances from the hive
- scout bees trained to feeder 750m from hive
- more bees arrived at feeders close to advertised distance of 750m
- after the dance recruits went most often to these feeders
how will honey bees oreintate on horizontal combs?
orientate to directional light source rather than gravity
how did the bees respond when directional information was removed?
if no directional light source from horizontal combs then they will dance in random directions
when combs are vertical or horizontal do a larger proportion of recruits come to the advertised site?
vertical- more accurate determination of direction and easier location of site
when may honeybees not be able to achieve fitness by dancing?
in summer
in some coastal areas what do ospreys form and what is their usual prey?
loose gregarious nesting colonies
- shoaling fish in large groups
how do informed ospreys compare to naive ospreys in their behaviour when searching for prey?
- informed birds watch others and will follow the direction of those that return with fish
- informed birds find fish faster
how do barn swallows not gain help from companions?
- unsuccessful foragers don’t follow successful ones
- their prey of insects are constantly moving so likely to have moved by the time they follow a previous nestmate
how do army ants benefit from being in groups? what are 2 other examples?
small ants can capture larger prey by working together
- female african lions
- spotted hyenas
why may in some cases solitary female lions do better alone than being in a group?
can eat the same as those in a group and do well when prey is scarce
what was Creel and Creels study on why species may continue to hunt in groups even if they may gain less prey? (4)
- measured weight of meat caught and cost from distance run when hunting in African wild dogs
- benefits from meat gain but costs from energy expended chasing prey
- when in a group is less total energy expended by the group capturing prey and a greater net intake of calories
- larger packs had an increased net energy gain
