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Flashcards in Ecology Deck (485)
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151

yellow-eyed junco group living

flock size 1 = lots of predator scanning, decent amount of feeding, no fighting
flock 3-4 = little predator scan, little fights, lots of feeding
flock 6-7 = slightly more predator scan, more fighting, a little less feeding

152

results of yellow-eyed junco study

if groups become too large fighting will take up valuable feeding time

153

reproductive effort

amount of total allocations that an individual makes for reproduction

154

categories of reproductive effort

r-selected
k-seleceted

155

r-selected

high # offspring
high population growth potential
boom/bust cycles
usually short lived

156

k-selected

low # offspring
low population growth potential
stable populations
usually long lived

157

categories of reproductive effort are

relational categories (rather than absolute)
species A is k-selected compared with species B

158

subcategories of Life History

categories of reproductive effort
frequency of reproduction
occurrence of parental care
clutch size and litter size in k-selected species
age of first reproduction

159

frequency or reproduction

semelparous
iteroparous

160

semelparous

single reproduction, breed once and then die

161

iteroparous

repeated reproduction (usually yearly)

162

semelparous examples

most insects, octopus, salmon

163

iteroparous examples

plants, snails, most fish, amphibians, reptiles, birds and mammals

164

occurrence of parental care

absence/presence
amount

165

parental care absent in

most invertebrate taxa
most fish
most amphibians
most reptiles

166

parental care common in

social insects
small fish
dinosaurs
birds
all mammals

167

another name for semalparous

'big bang reproduction'

168

precoccial

offspring are born without needing care

169

example of precoccial organisms

caribou babies can run as fast as adults within hours of life
semipalmated plover born with adult size legs

170

occurrence of parental care - amount needed

absent
precoccial
altricial

171

altricial

offspring are born helpless and require extensive postnatal care

172

example of altricial young

social insects, some fish, amphibians, most birds, most mammals

173

clutch size and litter size in k-selected bird species

birds can only lay one egg a day
all bird species lay fewer eggs in the nest than they are capable of doing

174

David Lack (1948) proposed that

clutch size represents the maximum number of young parents can successfully raise

175

clutch size tends to increase with

geographical latitude

176

why more eggs with latitude

more food, less competition, easier to care for young

177

test of Lacks hypothesis, collared flycatcher

can lay 8, normal clutch 4
chicks- reduced survival first year, reduced egg production as adults
parents- reduced winter survival, reduced egg production next year

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test of Lacks hypothesis, Canada goose

can lay 12, normal clutch 4, added 1
chick- survival similar
parents- delayed molt, delayed migration, reduced weight next year, female bred later next year

179

results of Lacks hypothesis

clutch size corresponds to maximum number of offspring parents can raise without a net reduction in future reproductive effort

180

difference in collared flycatcher, canada goose study

collared flycatcher feed young 50 times a day
canada goose does not feed young