Lecture 12- Navigation and migration

Question 1

what is migration

Answer 1

regular, long-distance movements- generally to alter resources and habitats

Question 2

4 types of long-distance movement (these arent necessarily migration)

Answer 2

multi-generation migration
nomadism
dispersal
philopatry

Question 3

multi-generation migration- what is it, why is it useful

Answer 3

common in insect migration- a population moving, but not the same individuals
good for escaping conditions incompatible with specific developmental stages, escaping high density, reproductive bet-hedging

Question 4

nomadism- what is it, why is it useful

Answer 4

individuals moving around, usually in search of more abundant resources

Question 5

dispersal- what is it, why is it useful

Answer 5

distribution of individuals- helps escape competition and reduce inbreeding risk

Question 6

philopatry- what is it, why is it useful

Answer 6

returning to a known place despite migratory activity
good if resources are predictable, but requires quite good navigational ability

Question 7

3 migration patterns

Answer 7

leapfrog, chain, telescopic

Question 8

factors which can influence migratory pattern

Answer 8

cost of migration, competition, Bergmann’s principle and temperature, variations in seasonal reliability

Question 9

how migratory patterns can be maintained

Answer 9

asymmetric competition with larger animals (Bergmann’s rule), which pushes animals south

Question 10

what is partial migration/example

Answer 10

differences in migratory habits within populations- e.g. species of kingbird where the adult males seem to migrate more if their weight is higher

Question 11

examples of some ecological consequences of migration

Answer 11

spread of zoonoses, escaping from diseased individuals, trophic consequences (e.g. issues with decomposing birds)

Question 12

example of a bird where tracking migration has been useful in understanding ecological problems

Answer 12

wilson’s warbler- could identify an issue with the breeding site, rather than wintering sites etc

Question 13

how can birds time migration

Answer 13

often sensory cues such as temperature

Question 14

how can birds adapt to long-distance migration

Answer 14

energy conservation, e.g. through reducing organ mass, and regrowth at stop sites for feeding
increased wing length

Question 15

example of migratory behaviour possibly being socially transmitted

Answer 15

bighorn sheep- translocated individuals not generally being migratory, can see ‘knowledge’ increase as generations become integrated

Question 16

examples of techniques which can be used to follow migration

Answer 16

-radar
-ringing
-genetic analysis
-geolocation
lab experiments, e.g. capturing individuals and putting them in specific environments