migration and navigation

Question 1

24 hour cycle

Answer 1

controlled by the pineal gland

Question 2

circadian rythem

Answer 2

cycle influenced by zietgebers which are natural cues that aid in regulation of body cycles such as light cues

Question 3

circannual cycle

Answer 3

tracks roughly one year without external cues

Question 4

hypothalmus

Answer 4

region of the brain that can sense low light which penetrates the brain which induces signal to the pituitary gland

Question 5

pituitary gland

Answer 5

releases neurohormone leading to luteinizing hormones and follicle based hormone production to control daily cycles and breeding onset

Question 6

dispersal

Answer 6

having multiple nests in a single year and sending grown offspring out of the nest dispersing the population
ex: robins

Question 7

nomadic

Answer 7

wander throughout their lives following food and nesting resources
ex: snowy owl

Question 8

irruptive

Answer 8

large groups of a species show up in atypical locations all at once
ex: waxwings

Question 9

migration

Answer 9

movement of long distances over a map in a regular cycle often following seasonal availability of food resources

Question 10

routes of migration

Answer 10

north to south: north temperate zones
south to north: south temperate zones
inland to coast: waterbirds and Eurasia
high to low: tropics, white crowned
to and from wet spots: tropics

Question 11

costs of migration

Answer 11

energetic costs, navigational errors and unknown territories, weather, predators, time away from breeding; most migrants have an increased mortality rate their first year

Question 12

benefits of leaving the tropics for breeding

Answer 12

migration allows for use of seasonal high protein food sources; tropics are high in predators

Question 13

benefits of leaving temperate zones for winter

Answer 13

many temperate regions have harsh winters with low temperatures and food availability

Question 14

lifetime reproductive success

Answer 14

roughly equal in migrants and nonmigrants because residents live short lives and have large clutches while migrants live long lives and have more clutches

Question 15

leap frog migration

Answer 15

some members of the species stay in place or make a small movement wile other populations move from north of them to south of them or vice versa

Question 16

disjunct migration

Answer 16

not all members of a species follow the same migratory pattern; can lead to different evolutionary pressures and eventually speciation

Question 17

migratory patterns

Answer 17

can be determined by sex, season, time or age; many species travel faster in the spring to compete for breeding grounds but take their time in the fall

Question 18

loop migrations

Answer 18

making northern movement overland and returning over the coast

Question 19

nocturnal migration

Answer 19

a common pattern because at night it is cooler, more humid, and the air is more stable

Question 20

fat stores

Answer 20

4% of the body in resident birds, 19% in short distant migrants, and up to 50% in long distance migrants

Question 21

staging grounds

Answer 21

locations where large numbers of birds congregate to prepare for a migratory bout typically over a body of water

Question 22

homing

Answer 22

most birds are good at finding their way back home even if they are in an unknown area, utilizing a built in map and compass

Question 23

directional heading

Answer 23

a genetic compass

Question 24

navigation

Answer 24

the mental map, must be learned from experience

Question 25

star compass

Answer 25

birds can learn the movement of the night sky while sitting in their nests for incubation, learn the central star (polaris or betelgeuse) which the rest of the stars move around and can apply what they know when moved from one hemisphere to another

Question 26

sun compass

Answer 26

the sun moves at a steady rate and has a consistent location based on season and time of day allowing birds to use it to determine direction

Question 27

magnetic compass

Answer 27

magnet in the forefront of their brain that pulls to magnetic north

Question 28

other forms of navigation

Answer 28

olfactory cues and learned landmarks are both used in local and known areas

Question 29

Emlen funnel

Answer 29

an inkpad surrounded by a funnel covered by a screen allowing vision up but not out of the funnel; used to track the direction of migration via migratory restlessness

Question 30

zugunhru

Answer 30

migratory restlessness; trapped birds try to walk in the direction in which they would take off, longer distance migrants are more restless

Question 31

learning orientation

Answer 31

indigo buntings must see the sky within their first month to be able to orient properly