lecture 20

Question 1

Facultative brood parasites

Answer 1

lay eggs in own nest and nests of conspecifics (same species); common trait, particularly in colonial and cavity-nesting species

Question 2

Obligate parasites

Answer 2

lay eggs only in the nests of other species- can’t lay eggs in own species because their own species doesn’t even build nests; 1% of all bird species

Question 3

Intraspecific brood parasitism- experiment bar headed goose

Answer 3

within-species brood parasitism; looked at percent survival of host and donor offspring before and after a parasitic act; survival of recipient offspring decreased after parasitic act and survival of donor offspring increased

Question 4

Jawfish

Answer 4

example of interspecific brood parasitism; when danger, suck young into its mouth

Question 5

Brown headed cowbird

Answer 5

ultimate host generalist brood parasite; lays eggs in over 200 different species’ nests, most (90%) successfully raise the cowbird offspring; continue to grow more generalist over time- able to parasitize more species

Question 6

Cowbird study: effect of cowbird offspring size relative to host nestlings and probability that cowbird will get fed

Answer 6

when cowbird is a greater height than host nestlings, has a much greater chance of getting fed than when a lower height than the host nestlings

Question 7

why tolerate parasite’s eggs?

Answer 7

Rejection has costs- some birds do not recognize parasitic eggs and even if the host does recognize it, still a chance of rejecting one of its own eggs in error

Question 8

Cowbird study- fitness costs to host for rejecting eggs

Answer 8

when cowbird eggs were rejected by host, cowbirds showed high predation- used mafia strategy and destroyed host nest as revenge; cowbirds also used farming strategy where they destroyed the host nest if the host eggs were too developed for the cowbird egg to blend in

Question 9

Adoption: Goldeneye duck example

Answer 9

in ducks, little to no cost of adoption because chicks forage for themselves; they also benefit from increased number of offspring due to the dilution effect

Question 10

Costs of group living

Answer 10

competition for mates, nest sites and food; increased visibility for both predators and prey; spread of disease and parasites

Question 11

Swallow bug study of nest infection

Answer 11

as number of nests (group size) increased, percent of nests infected with swallow bugs increased; supports the increase in parasite transmission due to group living

Question 12

Study of group size effect on male relatedness to offspring

Answer 12

as increase group size (nest density), percentage of offspring related to male decreases; increases probability that you will help raise offspring that are not your own

Question 13

Reproductive interference

Answer 13

includes egg-dumping (wood ducks) and egg-tossing (acorn woodpeckers); decreases reproductive fitness

Question 14

Costs of being subordinate- cichlid fish

Answer 14

spend mass majority of time doing behaviors unrelated to reproduction

Question 15

Energetic cost of behavior study-paper wasps

Answer 15

the more aggressive the behavior, the lower median energy expended per act

Question 16

Long-tailed manakins- Cooperative courtship

Answer 16

pair of males performs a routine to impress the female; there is a younger male apprentice and an older male teacher who gets to mate; over time, younger male will take on an apprentice of his own and he will get to mate

Question 17

Benefits of group living

Answer 17

increased ability to locate mates; increased ability to detect predators; benefits of group defense (dilution effect, selfish herd, etc), increased hunting efficiency; improved foraging

Question 18

African wild dogs study- increased hunting efficiency

Answer 18

as the pack size increases, the net energy consumption per dog increases

Question 19

Ravens- Yelling recruitment signals

Answer 19

when ravens come across dead animals, let out a recruitment calls; only non-territorial ravens let out these calls in order to bring in other non-territorial ravens (the territory owners don’t)

Question 20

Survivorship insurance in paper wasps

Answer 20

when colonies were set up by single foundresses, there was already a decrease in colonies because some foundresses were killed off by predators in the process; when nests were founded by multiple foundresses, there was not a decrease in colonies that survived because if one founder died, there would be another that could take over

Question 21

Social vaccination in termites

Answer 21

when a heat-sensitive infective spore which can destroy larvae was experimentally introduced into the hive, temperature skyrocketed in the brood comb in order to kill off infective spore

Question 22

Heat shielding in honey bees

Answer 22

maintain heat inside hive by contracting flight muscles; use heat in response to pathogens; requires a group to carry out heat shielding