bird reproduction

Question 1

breeding overview

Answer 1

effective breeding: energy and time efficient
number of chicks that are produced and survive
health in an induvial, population and habitat scale

Question 2

birdlife international stats

Answer 2

1/8th bird species globally threatened: conservation importance
128 species have become extinct in last 500 years
but some species disappear before we even know about them
passenger pigeon extinction

Question 3

copulation

Answer 3

allows sperm to fertilise eggs: very quick (1-2 seconds)

Question 4

courtship feeding

Answer 4

nuptial gift from male to female shows foraging ability
shows ability to provide for chicks
feeding often initials mating by brining female into ovulation

Question 5

lekking behaviour

Answer 5

seen in grouse, waders and ruff
many males competing for females
a ritualised dance
female choses based on appearance and dance as a determine of fertility: a secondary sexual signal

Question 6

sperm competition

Answer 6

sperm stored by females in sperm storage tubules
in domestic chicken can be stored for 7-14 days
sperm is then released from these tubules after ovulation
after successive inseminations , no mixing of sperm but sperm functions as last in first out
trying to determine how female “choses sperm”

Question 7

egg formation

Answer 7

sperm fertilises ovum in infundibulum
ovum passes down reproductive tract receiving layers of the album (water and protein) in plumping
plumped egg is calcified in uterus or shell gland
calcification takes 12 hours
normally egg laid every 24 hours in the early morning

Question 8

avian breeding cycle

Answer 8

recruitment (become a member of a breeding population) and foraging
egg laying: clutch of eggs
incubation
chick rearing
fledging

Question 9

reproductive strategies

Answer 9

3 types
social: two birds build and defend a breeding territory and/or provide parental care
sexual: two birds copulate
cooperative: >2 birds care for a single brood of offspring (normally is previous offspring helping)

Question 10

social mating systems

Answer 10

monogamy: 1M and 1F (85%)
social polygyny: 1M many F (10%) female tend offspring and male deserts
social polyandry: 1F many M (only 11 families) male tends offspring and female deserts e.g. penguin

Question 11

David Lack

Answer 11

from 1960s
cool dude in bird world

Answer 12

social bonds are not sexual bonds. of socially monogamous species studied with DNA fingerprinting >85% of them are sexually polygamous.
Extra pair copulations (EPCs) are driving behind extra pair paternity (EPP)

Question 13

sexual mating systems

Answer 13

Variation in sexual mating systems measured with
extra-pair offspring as the unit
EPP can arise from:
EPCs – female mates with >1 male other than
social male.
Intraspecific brood parasitism (IBP) –conspecific female lays egg(s) in another female’s
nest (‘egg dumping’)
Rapid mate switching – pair-female lays eggs
fertilized by previous social male (in polyandrous species)
All of this can lead to male uncertainty of paternity.

Question 14

cooperative mating

Answer 14

3% world species (inc kingfisher, hawk and jay)
large family group (usually related) but one breeding pair, others are helpers
includes polygynandrous dunnock where males are uncertain which chicks are theirs due to multiple potential paternity so males help raise all chicks

Question 15

brood parasites

Answer 15

in 80 species (inc cuckoos and honeyguides)
female brood parasites watches host nest constantly so lays egg when hosts are not there
needs to match her reproductive state to that of the host female if she is to oculate coincidently.
eats hosts egg for nutrient
her eggs spotting pattern must match the host’s closely (birds cant count)

Question 16

chick behaviour in brood parasite

Answer 16

evict host eggs by hatching first
this ensures they receive all food

Question 17

eggshell pigmentation

Answer 17

host will make sure the eggshell pigmentation matches.
pigments are from breakdown of food

Question 18

colony nesting

Answer 18

e.g. black headed gulls
synchronised breeders
lowers predation risk by early detection and safety in numbers
information centre for sharing info by calling and communication

Question 19

communal nesting

Answer 19

all females lay in the same nest
20 eggs can be laid in one nest (e.g. Anis, a cuckoo)
often eggs and chicks are tossed from nest by contributing female so some will wait to lay as late as possible

Question 20

male or female incubating

Answer 20

male only: emporer penguin, kiwi and emu
female only: most passerines, pheasants and ducks
both sexes: pigeon, antbirds, warblers
neither sex Megaphodes (brood paradies)

Question 21

creching behaviour

Answer 21

penguins: keep warm and safe from predator
parents stop chick guarding and disperse o forage

Question 22

brood partitioning

Answer 22

clutch size determined by amount parent can feed (Lack’s hypothesis)
maximises chick survival
in common blackbird each parent looks after half the brood
all chicks may be lost if remain as one and succumbs to a predator