avian ecology and conservation

Question 1

MacArthur’s warblers

Answer 1

demonstrated niche partitioning by showing that many warblers seemingly occupy the same niche but actually have minor foraging differences in which parts of the tree they use and slightly different nesting times; differentiation depends on the number of different species

Question 2

equilibrium theory of island biogeography

Answer 2

experiments in which islands were entirely wiped out and new growth and migrants were observed; found that the number of species on an island is where extinction and immigration intersect; larger and closer islands have more species than smaller further islands; also applies to forest fragmentation

Question 3

Darwin’s finches and the Grants

Answer 3

finches are descended from a common ancestor that radiated to fill new niches; even when a bottleneck effect occurs leaving primarily a single bill type, bill type will eventually spread back out to refill those niches

Question 4

ecological trap

Answer 4

environment organisms are attracted to that does not actually fill their needs

Question 5

stopover sights

Answer 5

vast expanses of inhospitable land with small patches of suitable habitat in which birds can stop to fuel, rest, rebuild muscle, and rebuild the digestive system while migrating

Question 6

lacey act

Answer 6

limits market hunting by making it illegal to hunt birds in one state and sell them in another

Question 7

migratory bird treaty act

Answer 7

made it illegal to take or sell migratory bird nests, eggs, or feathers

Question 8

ways humans have harmed birds

Answer 8

habitat destruction, exploitations, hunting, the pet trade, reduction in food supple, disturbance

Question 9

leading causes of avian mortality in the US

Answer 9

window kills: > 1 billion
car collisions: > 50 million
tower/power line collisions: 134-225 million
cats: > 532 million

Question 10

habitat alteration

Answer 10

conversion of rainforest to non shade coffee plantations removes high vegetation that neotropical migrants live and feed in

Question 11

DDT

Answer 11

pesticides that built up via bioaccumulation in fish and other food sources for large birds causing it to get into egg shells and weaken them resulting in hatchling mortalities; quickly banned resulting in success stories for species like bald eagles

Question 12

peregrine fund

Answer 12

raised money to build nesting sites for peregrine falcons to save them from extinction; also helped fund captive breeding and habitat construction for the California condor

Question 13

other conservation successes

Answer 13

whooping cranes now have 2 overwintering populations; piping plovers and least terns