Vertebrate of BC Part 2 Flashcards Preview

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Flashcards in Vertebrate of BC Part 2 Deck (484)
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1

Pacific loon nesting

northern tip of BC

2

Pacific loon migration

huge groups (10's of thousands - >150,000 witnessed passing HG)
large groups susceptible to anthropogenic issues (ex.oil spill)

3

Red-throated loon winter distribution

inshore marine
Alaska - California
solitary - small group (

4

Red-throated loon breeding distribution

small ponds/lakes within 20km of ocean, close to coast
rarely more than 1 pair per pond/lake

5

how can red-throated loons use small ponds

shortest take off distance of loons
some distribution overlap w/ Pacific loon (which is more competitive)

6

drizzle lake site characteristics

4 nesting territories
minimal wave exposure
abundant fish in lake

7

Red-throated loon nesting

choose perfect spot on lake based on fetch, choose site and practice nesting year before (even practice mating)
incubation 28 days

8

why RTLO nests on lake

less predators than ocean

9

RTLO defence

nesting- only protect ~2-3m
after hatching protection area enlarged

10

why RTLO only protects small area when nesting

protecting eggs from ooivores- raccoon, raven, squirrel

11

RTLO defence after chicks hatch

larger area to protect, defend against other birds

12

RTLO defending against other RTLO

same same defence in both sexes

13

RTLO defending against common loon

female takes chick to shore
male defends with very good success

14

why does RTLO have to defend against COLO

COLO eats other loon chicks!

15

RTLO male/female differences

male a little larger
slight difference in necks marks

16

brood patch

bald patch for direct heat transfer to eggs (while incubating)

17

Number of fish eaten vs. age of chick (days), RTLO

declines from ~20 - 10 @ 42 days - 0 @ 48 days

18

why does the number of fish eaten decrease (RTLO)

able to eat bigger fish
change diet at ~12 days from small fish (sand lace, gunnel) to intermediate (herring, smelt, cod..)

19

RTLO ocean trips

up to 18/day
hatchlings need ~20g/day
male carries larger fish

20

relative parental contribution, RTLO

males take longer trips to ocean
males bring back less fish (but more weight)
females 4X as much rearing
males defend 100% successful
total energetic investment equal

21

% of feeding failure vs. age of chick

100% of large fish (brought back by males) are lost up to 6days of age

22

loon abundance in Alaska, BC coast

Alaska- 50% decline in RTLO
Here- ~50% decline in COLO
opposite pattern.. displacing each other?

23

why do RTLO go to ocean to catch fish

anti-parasite mechanism
tape worms in freshwater fish
COLO chicks die

24

where are raptors in the phylogeny

neoaves
all in the top group, landbirds
sister group to shorebirds
not monophyletic
falcons s.g. to owls s.g. to hawks&eagles

25

BC raptors

30 species

26

BC raptor wing span

~50cm - 300cm
characterize niche space

27

Northern Spotted Owl BC range

only SW tip, restricted to old growth coastal forest, declining

28

BC nesting pairs, spotted owl

30-100

29

Spotted Owl characteristics

territorial, nocturnal, solitary in winter, pair in spring/summer, home range 3-50km^2

30

spotted owl diet

small mammals, birds