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Flashcards in Ecology Deck (485)
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181

age of first reproduction

generation time- major variation

182

examples of variation in generation time

fish: guppies 3wks, sharks 30yrs
birds: songbirds 6mnths, albatross 6-10 yrs
mammals: mice 3wks, elephant, whale, human 13yrs

183

fecundity

number of eggs

184

in most plants and ectothermic animals fecundity is

positively related to size
lay eggs at older/larger stage = more eggs

185

lay 2 eggs and die at 12 months of age, or lay 10 eggs at 48mnths and die, which is a better strategy?

work out by adding up population size over months
eventually 2 eggs at 12 months has a greater impact

186

how many species breed within first year of life

98%

187

useful to produce early in life?

if higher mortality rate in getting to the older production age (does probability of survival decrease)

188

mule deer in BC

adult size- 3yrs
can reproduce at 2yrs- body growth reduced, increased winter mortality from predators
without predators most reproduce at 2 yrs

189

r-selection life history attributes

development- rapid
reproductive rate/age/type- high, early, semelparous
body size- small
life length - short
competitive ability- weak
survivorship- high mortality of young
population size- usually well below carrying capacity

190

k-selection life history attributes

development- slow
reproductive rate/age/type- low, late, otero parous
body size- large
life length - long
competitive ability- strong
survivorship- low mortality of young
population size- usually at or near carrying capacity

191

essential features of scientific explanation

testability
falsifiability

192

scientific experiments

evaluate hypotheses (do not prove)

193

population ecology

dispersion, movement, estimating population size, life tables, mortality and survivorship curves, population growth and population regulation

194

dispersion types

regular/hyperdispersion
random
aggregated/clumped

195

regular dispersion

equidistant
fish school, seabirds

196

random dispersion

individuals distributed without respect to others
grazing wildebeest, beach clams, forest spiders

197

aggregated dispersion

most common
2 types

198

types of aggregated dispersion

coarse grained
fine grained
plants (due to trace minerals left by glacial till)

199

coarse grained aggregated dispersion

clumps separated by large areas

200

fine grained aggregated dispersion

clumps separated by short distances

201

dispersion

how individuals are distributed in habitat
structured by where resources are

202

dispersion allows

spread/mixing of genetic information

203

reasons for clumped distribution - plants

local difference in microhabitat- soil moisture, nutrients, sunlight

204

reasons for clumped distribution- animals

resources are clumped
behaviour which facilitates grouping

205

animal behaviours that facilitate grouping (clumped distribution)

social context, family groups, predator defense, shelter

206

types of individual movement

dispersal
migration

207

dispersal

movement of individual away from place of birth
leads to geneflow

208

migration

mass directional movement of large number of individuals from one location to next

209

migration examples

salmon, whales, wildebeest, seabirds, songbirds, monarch butterfly

210

grey whales migrate south in the fall

calves have high thermoregulation needs, born in Baja where water is warmer so they can store energy