Chapter 13 - Breeding Systems Flashcards
In what 2 ways can a bird genetically contribute to future generations?
directly by producing young with one’s own genes and indirectly by helping relatives to raise young that possess some of one’s own genes
The male of what bird species practices deliberate infanticide when his confidence in their paternity is reduced?
Tree swallows
In cooperative breeding, how do breeders and helpers interfere with each other?
Adults may sabotage the initial breeding efforts of young to increase the chance that they’ll stay as helpers.
Helpers may deliberately interfere with parental reproduction to increase turnover. Male helpers sometimes mate with their step-mothers and helper females sometimes slip an egg of their own into the parental clutch.
What hypotheses describe the trade-off between the number of mates that a male has vs. the frequency of extra-pair fertilizations that he can attain?
- Male Tradeoff Hypothesis
2. female choice hypothesis
What is the male tradeoff hypothesis?
Predicts that polygynous males should experience more frequent cuckoldry than do monogamous males b/c polygynous males opt to attract new mates rather than guard their current mates during their fertile period than do monogamous males.
What is the female choice hypothesis?
Predicts less frequent cuckoldry in polygynous species. A female can pair with the best male of her choice. Males with multiple females therefore have less incentive to seek extra-pair copulation. As a result, Extra-pair chicks are more frequent in monogamous species.
What birds practice polyandry?
Not a comprehensive list
Order Gruiformes: buttonquails, roatelos, and some rails.
Order Charadriiformes: jacanas, painted snipes, Eurasian Dotterel, the Plains Wanderer of Australia and a few sandpipers.
What is cooperative polyandry?
several males cooperate to assist 1 or more females
What bird species practice cooperative polyandry?
not a comprehensive list
Acorn Woodpecker, Gallinules (Dusky Moorhen, Tasmanian Nativehen), Hawks (Harris’s Hawk, Galapagos Hawk)
What is brood parasitism?
When a female lays an egg in another female’s nest.
What are obligate brood parasites?
Species that never build their own nest or raise their own young.
What species are obligate brood parasites?
cowbirds (Icteridae), cuckoos (Cuculidae), honeyguides (Indicatoridae), African brood parasitic finches (Viduidae) and one duck (Anatidae)
What is a gentes?
an egg race; e.g. the common cuckoo is made up of several gentes depending on the primary host of their brood parasite behavior to camouflage their egg to look like the other bird’s eggs.
How do baby brood parasites act towards the host’s chicks?
Cuckoo chicks will push the host’s eggs out of the nest.
Honeyguides are born with fanglike hooks on their beaks to kill nestmates.
Cowbirds don’t kill their nestmates to take advantage of increased rates of food delivery.
