Lecture 11

Question 1

Factors such as —— and ——- influence the evolution of acitvity timing

Answer 1

food/climate

Question 2

The major activities- reproduction, molt and migration- are guided by ———- ——– so that they coincide with approprate seasons

Answer 2

internal clocks

Question 3

In general, seasonal changes in day length (photoperiod) control what?

Answer 3

gondadal development and reproductive activites

Question 4

Each year, birds are faced with the following tasks:

Answer 4

1. Breed 2. Molt 3. Survive until next year

Question 5

Transferring between stages may depend on ——- or ——— condtions

Answer 5

internal or external

Question 6

when do pigeons breed and molt?

Answer 6

If food is good and mate present then they remain breeding, however, if there is no mate then they will stay molting. Their stages are not controlled by seasons

Question 7

However, unlike the pigeon, what do many birds do?

Answer 7

adults molt after young feldge ad continue to molt until food becomes scarce in winter. The gonadal hormones appear to inhibit molt.

Question 8

How do birds cope with physiological cost of migration?

Answer 8

Many species exhibit periods of (hyperphagia) before and during migration to build lipid reserves.

Question 9

where is most lipid stored?

Answer 9

under the skin in peritoneal cavity and in muscle tissue

Question 10

Lipids are labile meaning….

Answer 10

added to body quickly and burned efficiently

Question 11

Regular refueling is —– on both spring and fall migrations

Answer 11

common

Question 12

For most species that breed away from the equator, ———— is the most dependable proximate factor for migtration

Answer 12

photoperiod

Question 13

Ultimately selection is selected if what?

Answer 13

it increases the birds fitness: - warm climate helps with egg development and reducing thermoregulatory costs. - Growing vegetation provides food, cover and nest sites - Extended photoperiod increasing daily activity time

Question 14

what were the 2 experiments done on varying photoperiod?

Answer 14

1. Juncos, chnaged photoperiod and in sub-zero temp and go the male to get mature testes 2. Was able to orient crows to the north by akltering photoperiod

Question 15

Like many animals, birds have internal biological clocks associated with what gland?

Answer 15

the pineal gland

Question 16

If environmental light is perceived by the pineal gland in the photosensitive periods, ————– changes are triggered

Answer 16

phsyiological

Question 17

Internal cicardian cycle:

Answer 17

allows birds to measure daylength

Question 18

Once the pineal gland is triggered it triggers what gland?

Answer 18

pituitary gland

Question 19

what 2 master hormones does the pituitary gland releasE?

Answer 19

Lutenizing Hormone (LH) and Follicle Stimulating Hormone (FSH)

Question 20

Leutenizing hormone= Follicle stimulating hormone =

Answer 20

growth gamete production

Question 21

In case of the crossbills what is their proximate factor?

Answer 21

the appearance of abundant food and stimulates the annueal cycle of breeding. Not photoperiod.

Question 22

what is the corssbills ultimate factor?

Answer 22

The seasonal unpredictability of their food supply (conifer cones) is the ultimate factor that caused the nomadic behaviour and nonperiodic breeding to evolve in this spcies

Question 23

Soot Tern on Ascension Island are what kind of residents?

Answer 23

permeenant since conditions are benign and stable

Question 24

what is the similarity between the albatross, frigatebirds and griffon vilture?

Answer 24

all have long costly periods of reproduction so won’t breed every year

Question 25

what is the example of the variability between 2 different sub-species of white crowned sparrows?

Answer 25

Northern populations are long distance migrants whereas california breeders are year-round residents. Therefore Northern poplations breed later than southern. Therefore what triggers breeding is different

Question 26

In North America how many birds migrate to and from central and souther america annually?

Answer 26

~5 billion

Question 27

Migration:

Answer 27

the predictable, seasonal movement of individuals in response to variation in climate and/or resource availabilty.

Question 28

How does migration differ from nomadism?

Answer 28

predictabilty

Question 29

Nomadism:

Answer 29

movement related to unpredictable changes in climate and resources like the cross bills

Question 30

Irruptions:

Answer 30

irregulsr movement between consistent or incosistent locations. Like owls who are always found North are all of a sudden found south

Question 31

Historically what was migration viewed as and what does it look like recently?

Answer 31

historically, migration seen as an escape from hostile climates, limited food, predation etc. More recently, migration is viewed positively as a means to exploit temporarily favourable opportunities

Question 32

what are the benefits to migrating?

Answer 32

1. Avoid lack of food during winter especially for frugivores and insectivores 2. avoid lack of cover during winter

Question 33

temperatre resident species often have ——- reproductive rates and ——- annual survival rates than migrants

Answer 33

higher/lower

Question 34

Tropical resident spcies have —– productivity and —– srvival

Answer 34

low/high

Question 35

on average, –% of individual do not return from migration

Answer 35

50%, due to exhaustion, depletion of fat, harsh dangerous weather, predation, buildings

Question 36

Proximate factors:

Answer 36

(rainfall, photoperiod, temperature) provide the annual information that can preict the timing of the ultimate factor. can be internal or external changes

Question 37

Migration stimulus?

Answer 37

the stimulus for changing hormone levels brought about by a change in day length.

Question 38

what is the evidence that photoperiod and circannual cycles are important for bird migration?

Answer 38

captive birds under constant temp and food, migratory birds exhibit Zegunruhe

Question 39

Phenology=

Answer 39

the seasonal timing of biological processes

Question 40

Draw a graph that illustrates that timing is everything in terms of nest initiation, prey availability and young hatch

Answer 40

Question 41

Draw a similar diagram when timing is off for similar parameters like nest, prey and hatching

Answer 41

Question 42

what are some responses to mismatching?

Answer 42

1. arrive earlier like the House Martion
2. Breed earlier. Tree swallows reacting to difference in insectivore levels
3. Migrate earlier, shorter stopovers, faster flight
4. Migrate faster like fewer stops,

Question 43

why might migrating earlier not be a solution for mismatching prey?

Answer 43

Endogenous ryhtyms and photoperiodic cues initiate migration and not temperature. Wintering grounds may not indiciate what is occuring on breeding grounds so it is unlikely that long distance migrants will be able to adjust departure time for migration

Question 44

what the problem with suggesting migrating faster?

Answer 44

may be travelling at max speed already and they are limited by the amount of recovery and re-fueling required

Question 45

carry over effects:

Answer 45

snap shot of breeding grounds or winter grounds. What is happening through the annual cycle of the bird and its performance carry over to the other breeding stages. Cab be seen in american redstarts. the timing of migration relates to the environemntal they go to. Has a carry over effect for how soon they cana rrive in north and how productive it will be.