I Flashcards
What is Parental Investement?
Any effort by a parent that increases offspring survival but reduces the parents ability to reproduce again.
What are the direct and indirect parental investements?
- Direct: Feeding/protecting young
- Indirect: Defending territory, feeding mate
What is the size-number trade-off?
Species produce many small offspring with little investment or a few large ones with high investment.
What is the difference between semelparous and iteroparous species?
- Semelparous: breed once in a lifetime (ex: salmon).
- Iteroparous: breed multiple times (ex: rabbits).
What is Residential Reproductive Value (RRV)?
An organism’s potential for future reproduction is higher when young, lower when old.
What is brood parasitism?
A strategy where one individual lays eggs in another’s nest to have them raise their offspring.
What is the difference between intraspecific and interspecific brood parasitism?
- Intraspecific: Same species; facultative
- Interspecific: Different species; usually obligate.
How do Goldeneye Ducks show intraspecific parasitism?
Young females lay eggs in older females’ nests - likely due to nest predation or saving energy for future reproduction
What adaptations do obligate brood parasites like cuckoos have?
Cuckoo chicks eject host eggs/chicks; females mimic host eggs. It’s an evolutionary arms race.
What host defences against brood parasitism?
Egg recognition and removal, egg burial (x: Yellow Warbles), or nest desertion (ex: clay-coloured sparrows).
Why dont more birds reject cowbird eggs?
Two hypotheses: Evolutionary lag (not enough time to evolve defences) and inability to remove the large eggs.
What is an exaptation in the context of Clay-coloured Sparroes?
Nest desertion originally evolved for predator defence but now helps against brood parasitism.
