Lecture 8 - Migration

Question 1

define migration

Answer 1

movement away from and then subsequent return to the same location on a regular basis

Question 2

define dispersal
is this migration?
why/when disperse?

Answer 2

movement away from a particular area.
no, do not return.
natal or breeding dispersal

Question 3

during winter, approx how many birds in Mexica are migrants?

Answer 3

50%

Question 4

what are duck/goose migration routes called?

describe them

Answer 4

flyways
-narrow and well defined
hunter band returns

Question 5

songbird routes?

Answer 5

less known

appear to use weather fronts

Question 6

how are stable isotopes used to track migration?

Answer 6

deuterium in feathers reflect rainfall in areas where feathers were grown
measure deuterium to hydrogen ratio of feathers

Question 7

how do patterns differ between birds that soar and birds that flap?

Answer 7

soar
-use updrafts and thermals
-only fly in daytime
--->obtain heat and updrafts
-stay over land
flap
- fly over the ocean
--> fewer updrafts/less turbulence
- fly at night
-->less heat!!

Question 8

benefits to night flying?

Answer 8

avoid predators
feed during day
less turbulence caused by thermals and updrifts
cooler - avoid overheating
–>flight muscles generate lots of heat
- convective & evaporative cooling (no sweat glands but secrete water through skin)
-more humid = less moisture loss

Question 9

what animal undergoes the longest migration?

how long?

Answer 9

arctic tern!

19,000km each way

Question 10

how of advancements in geolocators increased our understanding of migrations?

Answer 10

record ambient light intensity, reveal info on sunrise/sunset!
combine light data with time recordings

Question 11

satellite locators?

Answer 11

smaller = can go on small birds!
cheaper
but can’t transmit data (need to be retrieved)
accuracy within 185km

Question 12

How did Nbound vs Sbound trip compare time wise for terns?

Answer 12

Nbound was almost twice as fast. corresponded with wind patterns. Need to be back for breeding - more direct
Sbound less direct, some areas where birds stopped for a bit

Question 13

What are the 3 stages of migration evolution?

Answer 13

partial migration
migratory & resident pop’s
only migrant pop remains

Question 14

What is the ancestral state?

Answer 14

not to migrate

Question 15

example of a split btwn migrant and non migrant?

Answer 15

fox sparrow

Question 16

hypotheses for how migration behaviour started?

Answer 16

lived in warm place

climate change

Question 17

discuss hyp 1-lived in warm places

Answer 17

competition for resources –> range expansion
during warm moths, members began living in more northern warm areas
winter came - food grew scarce so temp relocated to warmer latitudes

Question 18

discuss hyp 1-climate change

Answer 18

species lived in N all year during periods when climate was warm
as climate changed, winters eventually get too cold facing species to head south

Question 19

phylogenetically most migrating species are of _____ origin

what hyp does this support?

Answer 19

tropic

supports H1

Question 20

what are ultimate questions vs proximate questions

Answer 20

ult=functional or evolutionary history questions

prox= causal mechanisms or developmental questions

Question 21

why does a bird migrate?

proximate and ultimate answer

Answer 21

P=perception of day length, hormonal triggers

U=what is the purpose and why now?

Question 22

define adaptation

Answer 22

inheritable characteristic that gives the individual an advantage (reproductively) over others with different inherited abilities

Question 23

costs of migrating?

Answer 23

energy
predation
getting lost

Question 24

how to mitigate the costs of migrating?

Answer 24

energetics = V formation reduces drag
starvation = get really fat the long flight OR not so fat, short flights, stopover and feed

Question 25

how has the Eleonora’s Falcon adapted to its feeding approach?

Answer 25

preys on migrants so it delays breeding season to late summer, early fall

Question 26

reproductive rate, adult and juvenile survival of temperate residents?

Answer 26

high
low
low

Question 27

reproductive rate, adult and juvenile survival of tropical residents?

Answer 27

low
high
moderate-high

Question 28

Benefits of breeding in the north

Answer 28

greater habitat availabiltiy
long periods of daylight for foraging
high abundance of food in spring
fewer competitors
fewer predators

Question 29

list examples of mammals that migration

Answer 29

caribou
bowhead whale
gray whale
humpback whale
bats

Question 30

How do zooplankton migrate?

Answer 30

vertical migration!
Day = 40m
night = surface

Question 31

list the cues to direction for migration

Answer 31

visual landmarks
solar compass
stellar compass
geomagnetism
olfaction

Question 32

describe use of solar compass with an example

Answer 32

homing pigeons use the direction of the sun to navigate

Question 33

describe stellar compass

Answer 33

use of stars in navigation

Question 34

what happened when Austrian and southwest germany blackcaps were hybridized?

Answer 34

direction was somewhere in the middle