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Flashcards in Ecology Deck (485):
1

ecology come from the word

Oikos- house, place to live
Ernst Haeckel 1869

2

Ecology interval/range

Organsims-Earth (biosphere)
Behavioural ecology-- population ecology-- community ecology-- deep ecology

3

Subsection of ecological genetics

genetic variability
natural selection
evolution

4

ecological genetics

study of genetic/phenotypic variability in natural populations, relationship to ecological processes

5

If all individuals in a population are homozygous

monomorphic

6

If any individual in a population has a heterozygous locus

polymorphic

7

Average percent of loci in a population that are polymorphic

5-15%

8

genes/individual

~20,000

9

Genetic variability

percentage of heterozygous loci : population size
increased genetic variability with increased population size

10

Natural selection in moth species

evolved to mostly black because lichens were less common on trees after industrial revolution

11

Natural selection of sea snails living on kelp

Yellow snails have advantage over predator below kelp
brown has advantage over predator above kelp
due to light source

12

evolution of spirit bears

white bears have advantage over darker coloured bears when fishing

13

zygosity in populations <100

nearly monomorphic

14

monomorphic populations

increases susceptibility to disease
decrease adaptability to environmental change

15

Initial genetic variation vs. generations

N = 20, genetic variation = 0 after 200 generations
N=100, variation down to 0.2 ~300 generations
N=1000 small decrease in variation over 500 generations

16

reduced number of individuals in population

increased inbreeding-- increased homozygosity-- increased juvenile mortality

17

MVP

minimum viable population

18

minimum viable population

smallest possible size at which a biological population can exist without facing extinction
90% of genetic variability after 200 years

19

MVA

minimum viable area

20

minimum viable area

minimum land area required to maintain genetic variability after 200 years

21

MVP then and now

used to think ~500 was viable
now know it must be ~2500-4000

22

most common park size

~20-50km^2

23

immigration in regards to genetic variability

even a small amount of migration per generation allows persistence of genetic variability

24

no immigrants per generation

<60% genetic variability left after 100 generations

25

1 immigrant per generation

~90% genetic variability left after 100 generations

26

natural selection 2.0

non-random and differential reproduction of genotypes resulting in preservation of favourable variants

27

adaptation

physiological, morphological, or behavioural modification that enhances survival and reproductive success of an organism

28

evolution

serial change over time
descent with modification

29

Anagenesis

gradual change over time
changing adaptations over time
does not lead to species diversity

30

Cladogenesis

branching of lineages and formation of new species
usually occurs with geographical or genetic isolation

31

anagenesis graph geological time vs. trait condition

relatively straight line

32

cladogenesis graph of geological time vs. trait condition

branching tree

33

when life began on earth

first life developed on earth ~3billion years ago

34

total number of species on earth

8-100 million

35

Subsections of behavioural ecology

optimal foraging
territoriality
sex and mating systems
group living
life histories

36

first hard shelled organisms

542mya explosion of diversity

37

mass extinction

250mya
~94% of life extinct

38

diversification of mammals and birds

65mya

39

Foraging decisions

large/small, soft/hard, plant/animal, sweet/sour, uncommon/common, closer/more quality, opportunistic?

40

OFT

optimal foraging theory

41

optimal foraging theory

rules in optimizing choice of food/prey

42

3 subsets of OFT

preference for food with greatest net energy gain
feed more selectively when food is abundant
low quality food only when profitable food is scarce

43

optimal foraging, net energy gain

catching difficulty, amount of prey that can be consumed

44

Pied-wagtail (bird) foraging strategies

beetle size most eaten- not biggest or most common
biggest beetles take longer to eat
7mm beetle provides most calories/handling time

45

intrinsic quality of food

amino acids, fatty acids, salts, vitamins, trace elements

46

importance of sodium

primary extracellular ion, major role in body fluid volume, acid-base balance, tissue pH, muscle function, nerve synapse

47

sodium defficiencies

on average animals are sodium deficient
plants do not contain sodium
why animals are given salt licks
aquatic plants are rich in sodium

48

primary reason for animals to move to coastal regions

compensation for sodium deficiency

49

aquatic plant properties

low calories
high Na levels
high moisture (bulk)

50

Terrestrial plant properties

High calories
Low Na levels
low moisture

51

Aquatic vs. terrestrial plants in moose diet

low terrestrial would require high aquatic intake for energy
stomach not large enough for high aquatic intake
high terrestrial not enough energy or sodium
small range for optimal diet

52

bison foraging strategy

migrate to salt lakes

53

Patch foraging time

food occurs in a patchy distribution and in patches of different size

54

optimizing foraging time among patches

concentrate foraging activity in most productive patches
ignore patches of low productivity
stay with patch until profitability falls to level equal to average for all foraging patches combined

55

as time spent in foraging patch increases

energy obtained 'flattens out'

56

leave foraging patch when

probability is that the next patch will be more dense

57

time to spend in foraging patch graph

cumulative net food gain vs. time spent in patch

58

if it takes a long time to obtain food

animals spend more time on that food
birds that open containers easily didn't stay long

59

foraging time vs. predation risk graph

state of hunger dictates willingness to risk predation
starving- straight line, foraging activity is independent of predation risk
very hungry- sloped line, foraging activity decreases linearly with increased predation
slightly hungry- no foraging activity with high predation

60

Home range

area over which an animal travels in search of food/mates/resources and which is not defended
present in majority of animal species

61

territoriality

defines of an area and active exclusion of resource use by others through display, advertisement or defense

62

Territoriality is common in

predators (african lion, cheetah, hyaena, bear, eagle, hawk, owl)
birds during nesting
fish during reproduction
social insects (ants, bees, wasp, dragonfly)

63

Influences on size of territory

body size, aggressive behaviour, habitat quality, population density, competition with others, ability to share resources

64

black-capped chickadee territoriality

male sings to mark territory
same species avoid each others territory, other species do not (intraspecific competition)

65

Great Tit territoriality experiment

Remove individual 3 to see if there would be a change in territories, boundaries expanded, new arrivals came
was 3 dominant to the others? defended territory more..

66

larger territory =

more food, shelter, reproduction
harder to defend
want largest area with lowest cost

67

determining optimal territory size from benefit/cost vs. territory size graph

optimal size is where there is the largest slope on benefit curve

68

maximum territory size from benefit/cost vs. territory size graph

where benefit curve flattens out

69

changes in optimal territory size

ex. predator moves into area

70

Asexual reproduction

offspring genetically identical to parent
common in bacteria, unicellular eukaryotes, plants
occasional in vertebrates
harder for species to persist

71

predictor of asexual reproduction

small, short lifespan animals
consistent environment

72

asexual species using sexual reproduction at particular stages of life

times of stress

73

Sexual reproduction

majority of species
genotype different from mother and father

74

in changing environment/niche, new genotypes may have

higher reproductive output than either parental genotype

75

categories of sexual reproduction

dioecious
monoecious

76

dioecious

'two houses' 'two sexes'
male/female organs on separate individuals
~equal sex ratio
majority of species

77

monoecious

'one house'
m/f organs on same individual
bisexual or hermaphrodite

78

types of hermaphrodites

simultaneous hermaphrodite
sequential hermaphrodite

79

simultaneous hermaphrodite

both sets of reproductive organs at same time
common in plants/invertebrates
can't mate with self

80

sequential hermaphrodites

m/f reproductive parts at different times
common in coral reef fish

81

ontogeny

origination and development of an organism, usually from the time of fertilization of the egg to the organism's mature form

82

example of simultaneous hermaphrodites

slugs, worms

83

example of sequential hermaphrodite

Wrasse
small ones- genderless
medium- female (beta position)
large- male (alpha position)

84

simultaneous/sequential hermaphrodites don't have

sex determining chromosomes

85

Mating structures

Panmixis
Polygamy
Monogamy

86

Panmixis

unrestricted random mating
all individuals equally potential partners
sexes look alike (monomorphic)
eggs and sperm dropped all over the place

87

panmixis examples

some marine invertebrates
marine schooling fish

88

Polygamy

many marriages, multiple partners
widespread
sexes look different (dimorphic)
males often larger/more elaborate

89

types of polygamy

Polygyny
Polyandry

90

polygyny

female defense polygyny- individual males defend groups of females
resource defense polygyny- individual males defend resources which female seek out

91

polygyny examples

fish, amphibians, reptiles, songbirds, mammals

92

female defense polygyny examples

deer, primates

93

resource defense polygyny examples

fish, songbirds

94

polyandry

many males, single/few females
males take on 'mother' roles- incubate eggs, sexually inactive
sexual genes are down regulated
females compete for males and defend resources

95

polyandry example

shorebirds

96

monogamy

serial or lifetime
one marriage, high fidelity to single partner
care for young for a long time, often predators
bi-parental care required to raise young (or they die)
sexes usually look similar (monomorphic)

97

monogamy examples

carrion beetle, most seabirds, swans, hawks, beavers, weasels, wolves

98

new data on genetic fingerprinting indicate offspring of monogamous couples

are often sired by more than one father
socially monogamous (cheating)

99

extra pair copulations (EPC)

copulation with a male other than the bonded male, gives birth to offspring whose father is not the bonded male

100

fitness of offspring is a function of

who female mates with (genetic makeup)

101

females choosier than males in mate choice

fitness cost is greater than in males (limited eggs 400 vs. unlimited sperm 200 million per ejaculate)

102

sexual selection

mate choice- tendency for individual to be selective in whom they choose to mate with

103

male fitness increased by

maximizing number of fertilized eggs (increased number of females)

104

female fitness is increased by

maximizing genetic quality and genetic variability of their offspring

105

female mate choice criteria

nuptial gift
dominant/strong male preference
handicapped male hypothesis
parasite free male hypothesis
symmetric male hypothesis
display evaluation
inbreeding avoidance

106

nuptial gift

males provide gift to female to solicit matings
females use resource characteristics to determine quality of male

107

examples of nuptial gift

hanging fly
thynnine wasp
song birds

108

hanging fly

larger prey (gift) = more sperm transferred (longer copulation)
sperm is stored in female, she chooses which to use later

109

Thynnine wasp

female doesn't fly, releases scent to winged males
males ability to carry female to multiple flowers increases probability of male mating

110

songbirds (nuptial gift)

gift to female is safe territory for foraging/breeding
male evaluated based on length and complexity of song- correlated with territory size (physically demanding)

111

examples of Dominant/strong male in sexual selection

ram
elephant seal
damselfly/dragonfly

112

damselflys dominant sexual selection acts

males engage in aerial combat over pond
winners do the mating
female increases genetic quality of offspring by mating with winner

113

handicapped male hypothesis

expression of costly elaborate display by males provide female the greatest information on genetic quality of male
"honest signal" of fitness, low possibility of cheating
male survives despite handicap

114

example of handicapped male hypothesis

peacock
widowbird

115

widowbird handicap

male tail is longer than body, reduces flight, feeding ability, predator evasion

116

elephant seal dominant sexual selection act

fight for female attraction
only the winner mates with females for the year

117

results of widowbird study (handicapped male hypothesis)

lengthened tail of bird- was much more successful reproductively

118

parasite free male hypothesis

differing susceptibility to disease can lead to mortality in young, males without parasite = better immunological genes- improved physiological ability, immunocompetence heritable

119

bright displays- parasite free male hypothesis

bright displays are physiologically costly to produce
parasitized birds can't produce as bright of colours
if females choose these males- provide offspring with genes more resistant to disease

120

proof parasitized birds can't produce as bright of colours?

removal of lice-- birds moult--- new coat is brighter

121

symmetric male hypothesis

bilateral species
an excellent genotype can correct asymmetries during development

122

developmental instability

asymmetries in structure
minor errors in embryological development and growth

123

can lead to asymmetry

stress, pollutants, parasitism, homozygosity, poor genotype

124

symmetric male hypothesis bird study

symmetry was altered in male birds tail feathers
female switches her favourite to most symmetric male

125

symmetric male hypothesis is commonly observed in

insects, fish, birds, mammals

126

symmetry can be evaluated by

sight and sound

127

example of symmetry evaluation by sound

crickets having symmetric (monotone) frequency wing harps- indictor of body symmetry

128

fluctuating asymmetry

random deviation from perfect bilateral symmetry in otherwise symmetrical morphological traits, originates from developmental errors during ontogeny

129

fluctuating asymmetry reflects

inability of a genotype to buffer itself effectively against environmental perturbations

130

symmetric male hypothesis fish study

females have significant preferences for fish with symmetric vertical bars

131

facial asymmetry in rhesus macaques

honest indicator of health
used in mate choice situations

132

display evaluation

females evaluate quality, complexity, coordination of display (dances, songs)

133

inbreeding avoidance

all animal/plant species in the wild have mechanisms to avoid inbreeding

134

animal species can detect genetic kinship based on

pheromones

135

MHC

major histocompatibility complex

136

what is MHC

~30 genes coding for proteins in cell membranes essential for immune system, 2 different proteins at each gene, each gene multiple alleles, each individual unique, MHC molecules bind to specific receptors and have distinct odours

137

females prefer what in regards to MHC

males with the most dissimilar odour (genotype) to themselves

138

how birth control affects females and MHC

females are attracted to male similar to self-- birth control mimics pregnancy-- want family close

139

MHC based mating preference may be affected by

genetic background, sex, early life experience

140

inbreeding is potentially problematic in all animal species. the major ecological cost of inbreeding is

reduced capacity to cope with environmental changes

141

increased homozygosity is not an ecological cost

it is a genetic cost

142

advantages of group living

increased food search efficiency
increased capture efficiency of large prey
increased detection of predators
increased defense against predators
selfish herd theory

143

examples of increased food search efficiency in group living

seed detection by songbirds
fish detection in gulls- repeatedly catching fish signals a good feeding area

144

examples of increased capture efficiency in group living

wolves, lions
african hunting dogs- pack 20 catch ~80,000 kJ/dog/day, threshold number before a large difference is seen

145

increased detection of predators in group living

'many eyes' theory- Hawks have significantly lower attack successes with large number of pigeons present.
1-10 pigeons = 60-80% success
>50 pigeons = ~10% success

146

increased defense against predators

mobbing- ex. small birds can mob owls

147

selfish herd theory

dilution effect- schooling/herding/flocking- if there is an attack on a group it is less likely the attacker will get you

148

examples of species that exploit selfish herd theory

wildebeest, pronghorn, herring, flamingos

149

evolution of selfish herd theory

belted kingfisher in a tree above a lake.. if fish are individual and he has one is his sights the probability that he is looking at that one is 1, if that fish joins a group the probability that he the one being spotted is decreased..

150

Disadvantages of group living

increased transmission of parasites
shared resources and resource depletion
conflicts/stress

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

178

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

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

211

Warbler migration

south in winter for food (no insects in north in winter)
north in spring- easier to raise children in north (less competition)

212

monarch butterfly migration

migration is multi generational (4 generations for round trip)
adults mate and leave mt.s in mexico in feb, lay eggs on milkweed, die, eggs hatch feed on milkweed, adults migrate north

213

monarch butterfly eggs hatch in

4 days

214

monarch pupation to chrysalis

10 days

215

monarch generations 1-3

adult 2-6 week migration

216

monarch generation 4

south migration, adult 6-8 months

217

why milkweed

cardiac glycoside, caterpillar puts toxin in its skin

218

density

individuals per unit area/volume

219

estimating absolute density

total counts (photographic)
quadrat sampling
mark, release, recapture estimates

220

Peterson/Lincoln index for mark, release, recapture

N = Mn / m

221

variable in Peterson/Lincoln index

N- population size
M- number of marked individuals
n- number of individuals in sample
m- number of marked individuals in sample

222

confidence intervals in mark recapture

sampling must be repeated to obtain decent confidence interval

223

problems with mark recapture

50% of released steelheads die of stress
birds target butterflies marked on wings
polar bears marked with paint couldn't capture prey

224

assumptions for reliable population estimates in mark recapture

population is largely constant over duration of studies
marked individuals have same chance of getting caught
marked individuals do not incur greater mortality
marks are not lost

225

population is largely constant over duration of mark recapture studies

no immigration, emigration, births, deaths
only possible in short time frame

226

marked individuals have same chance of getting caught

assumption of equal catchability

227

marked individuals do not incur greater mortality

stress-related mortality
mark-associated mortality

228

problems with flipper bands on penguins

banded birds had 16% lower survival, 39% fewer chicks

229

non-invasive methods of evaluating density

genotyping / genetic fingerprinting
hair, feathers, faeces, scales, identify individual genotypes

230

Estimating future population

N_t+1 = N_t + B + I - D - E

231

variables of future population equation

N_t+1 - individuals in pop. at t+1 year or generation
N_t - individuals in pop at time t
B- births
D- deaths
I- immigration
E- emmigration

232

B - births

natality, number of individuals produced
fecundity / fertility

233

fecundity

ecological concept, number of offspring produced

234

fertility

physiological concept, females ability to produce offspring per unit period of time

235

PPP

primary population parameters
B D I E

236

demography

statistical study of human populations

237

life tables useful for

estimating mortality rate, survival rates, survivorship curves, average life expectance

238

types of life tables

age specific
time specific

239

cohort analysis

age-specific- group of individuals of same age class
follow specific cohort from birth to death
most useful on short lived species

240

cohort

group of animals of same species, identified by common characteristic, studied over time as part of scientific/medical investigation

241

nestling

eggs that hatch

242

fledglings

birds that can fly from nest

243

in order to construct age specific life table

follow cohort from eggs to adults for 1 generation

244

blue tit cohort

50 eggs followed, x eggs lost, y nestlings, x nestlings die, y fledglings, x fledglings die, y new adults, x new adults die, y adults left

245

survivorship calculated

relative to original cohort
3 new adults left, out of 50 eggs = 6% survivorship

246

mortality calculated

relative to each stage
3 new adults, 30 fledglings = 1 - (3/30) = 90%

247

time-specific life table

age structure at single point in time
long lived, large animals
snapshot in time
'static life table'
requires age distribution of a population

248

determining age for time specific life table

growth rings- mussels/clams/trees/fish scales
cross section of tooth- large animals
horn growth- mt sheep

249

survivorship in time specific life table

I_x = N_tx / N_t
number entering age class / total count

250

mortality

1000q_x = ( N_tx - N_tx+1 ) / N_tx
number entering age class x, minus number in age class x+1 divided by number entering age class x

251

life expectancy

e_x - expected number of additional years of life remaining at any specific age

252

lowest mortality rates

intermediate age- healthiest, predators attack old and young

253

more information in

mortality rate curve than survivorship curve

254

Idealized survivorship curves

Type I
Type II
Type III

255

survivorship curve type I

k-strategists, many mammals, number of survivors relatively constant till later age

256

survivorship curve type II

many birds, small mammals, lizards, turtles, linear with negative slope, probability of survivorship is same each successive year

257

survivorship curve type III

many invertebrates, fish, amphibians, plants, r-stratigists, why they lay so many eggs, largely decreasing survivorship at early age

258

dominant cause of survivorship curve shape

predation

259

atual survivorship curves

are ~same shape, lower (in survivors) than idealized curves

260

population growth

occurs when births (natality) and immigration exceed mortality and emigration

261

ASFR

age specific fecundity rate

262

ASFR =

average number of male and female offspring produced per female for each class

263

TFR

total fertility rate
average number of male and female offspring produced per female over her lifetime

264

TFR =

ASFR x number of years in age class (range)

265

critical information for population growth

sex ratio- life tables often calculated only for females

266

importance of sex ratio

A=10 reproductive adults, B=100
A produces 9X more offspring than B?
A= 1 male, 9 females
B= 99males, 1 female

267

NRR

net reproductive rate

268

NRR =

Ro = ∑ Ixmx

269

Ixmx

survivorship of reproductive females in any age group * number of daughters produced for each age class of female

270

Ro

number of breeding daughters that will be produced by each breeding female in the population per generation

271

Ro < 1

population is decreasing
each female produces ~<1 breeding daughter by end of reproductive period

272

Ro = 1

population is stationary

273

Ro > 1

population is increasing
each female produces ~>1 breeding daughter by end of reproductive period

274

if Ro = 1.33

population of 100 females will grow to 133 females per generation

275

population growth without restraint

geometric growth

276

if Ro is unknown

use lambda- geometric rate of increase, finite multiplication rate, finite rate of increase

277

lambda =

N_t+1 / N_t

278

estimate geometric growth of population in to future

N_t = N_o * lambda^t
useful for non overlapping (discrete) generations
semelparous species

279

population growth of iteroparous species

dN/dt = rN
dN = rate of change in numbers
dt = rate of change in time
dN/dt = rate of population increase
r = per capita rate of population growth (intrinsic rate of natural increase)
N = population size

280

r ??

b - d
number of births/thousand yrs
number of deaths/thousand yrs

281

alternative estimation of r

r ~ ln Ro / Tc
Tc = generation time, mean time elapsing between birth and first reproduction

282

If r < 0

population declines

283

If r = 0

population is stable

284

if r > 0

population increases

285

to determine N at some point in future, for population with overlapping generations

N_t = No * e ^ rt

286

overlapping generations vs. discrete generations

over. Nt = Noe^rt
discret. Nt = No*lambda^t

287

projected population in 100 years if r=0.01 and No = 7 billion

19.6billion
Nt = No e^rt

288

why can populations not grow indefinitely

finite resources run out
renewable resources are limited

289

K

carrying capacity

290

carrying capacity

total numbers of individuals of a species that be sustained in a habitat in the long term

291

determining carrying capacity

often estimated indirectly as the average population numbers of the species observed across multiple years
many factors are involved, usually determined in hindsight

292

logistic growth

population 'flattens out' as it approaches K

293

types of / variations in logistic growth

ideal logistic growth (smooth response)
damped oscillations (up and down before settling at k)
stable limit cycle (up and down around k without settling)
chaotic (extreme up and down, rise and crash)

294

logistic growth equation

dN/dt = rN [ ( K - N ) / K ]

295

carrying capacity of habitat is influenced by

most limiting resource

296

if populations exceed K

resources decline-- morality increases-- birth rate decreases-- population decreases

297

factors limiting population growth

density-dependent population regulation
density-independent population regulation

298

density-dependent population growth

due to intrinsic (natural) factors
due to individuals (birth rate, mortality)

299

mechanisms for density-dependent effects when population exceeds K

intraspecific competition
delayed breeding/reduced offspring production
territoriality
dispersal
parasites/disease
predators

300

intraspecific competition (populations exceeding K)

occurs when required resources are in limited supply (food, space, mates)

301

types of intraspecific competition

interference competition
differential ability to secure resources

302

Inference competition

individuals interfere with others for limited resources
leads to one individual having less

303

examples of inference competition

gulls stealing from others
lions excluding others from a kill

304

differential ability to secure resources

law of constant final yield- only a certain amount can be sustained in certain area, ex. start with 1000 or 100 plants, end with ~same amount

305

delayed breeding or reduced offspring production (populations exceeding K)

applicable to almost every bird and mammal
increased population = agonistic encounters = stress-- females reabsorb embryo

306

agonistic

combative, conflicting, aggressive/submissive interaction

307

how stress can be birth control

stress triggers hyperactivation of hypothalamus, pituitary and adrenocortex- alters secretion of growth and sex hormones-- suppression of body growth, reproduction, immune system-- pregnant females enlarged adrenal glands, kidney inflammation, uterine mortality, reduced lactation

308

young born to stressed mothers

low body weight, poor survival, delayed puberty, low reproductive rate

309

delays puberty in juveniles born during periods of high population density

odour of female urine

310

increased territoriality (populations exceeding K)

territorial defense by dominant individuals leads to reduced access to resources by sub-dominant individuals
leads to reduction in # of non-territorial individuals (reduced reproduction)

311

dispersal (populations exceeding K)

migration
w/o migration population exceeds K and crashes
with migration population can 'flatten' at K

312

example of parasite/disease controlling population

Myxomatosis introduced in European rabbits in Australia, 99% mortality

313

example 2 of parasite/disease controlling population

gastrointestinal nematodes-- reindeer-- negative impact on female reindeer becoming pregnant-- parasites have potential to regulate population dynamics-- in presence of parasite populations = stable dynamics

314

average number of parasite species per host

fish ~2
birds ~8
mammals ~15
bugs, beetles, flies 4-6
butterflies, moths ~10
trees 95

315

Predators (populations exceeding K)

major source of mortality in survivorship curve
increased density of prey = predator expansion = proportionately greater predation on prey

316

parasitic wasp

~1mm, lays one parasitic eggs in each aphid, rapidly controls population

317

analysis of density dependent population regulation

parasites and disease - ~50% insects
predators - ~40% insects
mortality from limited food- ~40% small mammals/birds, ~50% insects, ~90% large mammals
mortality from limited space- 100% small mammals/birds

318

density-independent population regulation

reduction in carrying capacity of habitat
mainly due to extrinsic factors
mortality due to severe external conditions
mostly independent of NK

319

examples of density-independent population regulation

winter, severe draught, fire

320

lynx abundance

correlated to snowshoe hare abundance- increased food source

321

snowshoe hare abundance

correlated with 11yr cycles sunspots-- higher solar output, more plant life, more food for winter

322

why don't hare, lynx, sunspot curves match all the time

many factors are working together- plants produce anti-grazing chemicals, lynx produces stress changes in hares, hares reproduce less

323

a population of 50 female deer with stable age distribution has a Net Reproductive Rate of 1.1, if generation time is 2yrs, population is increasing by how many female individuals per generation

2

324

if population = 50, NRR = 1.1, generation time = 2yrs, population increases by 2 individuals per generation, how many will there be in 20 years?

130

325

anti grazing chemicals

phenols, bitter, less delicious, less nutritious

326

subcategories of interactions

competition, niche concepts, predation, defenses

327

Interspecific competition

any use or defense of a resource by one species that reduces the availability of that resource to other species

328

resource

any substance that leads to individual/population growth if substance is increased

329

resources

food, water, trace elements, space, elements (O2, CO2)

330

is air a resource

not generally (unless it was limited)

331

Liebigs law of the minimum

we often don't know what the limiting resource is

332

what did Justus von Liebig do

discovered that nitrogen is the major nutrient for plants

333

competitive exclusion principle

Gause's Law of competitive exclusion
2 species with same niche cannot coexist

334

Gause's discovery

paramecium grown separately had logistic growth curves, grown together one species crashed, one species always outcompeted the other

335

evidence of interspecific competition

habitat shifts in allopatry and sympatry
character displacement and resource partitioning
habitat differences and resource partitioning
allelopathy

336

character displacement

feeding structures, breeding times, changing bill size, displacement of characters reduces competition

337

alpha

competition coefficient
per capita competitive effect of species 2 on species 1
measure of inhibitory effect "

338

alpha = 1

one individual of species 2 equals one individual of species 1

339

alpha = 0.1

then 10 individuals of species 2 equals one individual of species 1

340

total competitive effect of species 2 on species 1 =

alpha * N2
N2 - population size of species 2

341

competition model

dN1/dt = r1N1 [ (K1 - N1) - alphaN2] / K1

342

to coexist 2 species must have

alpha ~ 1.3 difference (ratio) in feeding parts

343

paradox of the plankton

limited range of resources supports wide range of planktonic organisms, paradox results from competitive exclusion principle, which suggests when 2 species compete for the same resource, only one will persist

344

grain beetle competitive exclusion

just a 3.2ºC difference in habitat switches competitive ability of two beetle species

345

allopatric speciation

populations of same species become isolated from each other, prevents genetic interchange

346

sympatric speciation

new species evolve from single ancestral species while inhabiting same geographic region

347

habitat shifts in allopatry and sympatry

allopatric populations habitat whole area, sympatric populations stick to one area, ex. when fish species are mixed one species lives in middle of lake, other around edges and bottom

348

character displacement (interspecific competition)

two allopatric species have same size feeding structures
species in sympatry have different size feeding structures

349

hutchinsons ratio

character displacement, size differences between similar species when living together compared to when isolated

350

average hutchinsons ratio for sympatric species

1.28

351

sympatric monkeyflowers (reproductive character displacement)

mean divergence of reproductive structures was greater in sympatric than allopatric, P values of reproductive structures <0.05

352

types of habitat differences and resource partitioning

the ghost of competition past
competition in the present

353

the ghost of competition past

at some point in the past, several species inhabited an area, all of these species had overlapping niches, through competitive exclusion, the less competitive species were eliminated, leaving only the species able to coexist

354

example of ghost of competition past

desert plants- developed different root systems to coexist

355

competition in the present

exotic species- artificially introduced, displacement of native species

356

examples of competition in the present

European starlings introduced to New York, most common nesting bird in US and south Canada, Scotch Broom from Europe threatening Vancouver island

357

allelopathy

chemical competition in plants and animals
release of chemicals by one species in order to reduce growth/survivorship of another

358

examples of allelopathy

antibiotics, poisons
penicillin by mild
jug lone by black walnut tree
terpines by salvia
corrals produce defenses to stop overgrowth from others

359

juglone

highly toxic, kills/injures other plants species within 20m, toxic to herbivore insects, reduces growth of weeds

360

species resistant to juglone

corn, maple, birch

361

salvia study

salvia produces terpines when predation is a problem
doesn't when it is not (when caged)

362

habitat

physical place where an organism lives

363

niche

how an organism makes its living (carnivore, herbivore)

364

Elton's niche

the role of a species in a community

365

Hutchinson's niche

all biophysical conditions that characterize the life of a species

366

fundamental niche

entire multidimensional space that represents the total range of conditions within which an organism can function without limiting factors (prospective ecospace)

367

realized niche

actual multidimensional space that a species can occupy taking into account biotic factors such as predators, competitors and parasites (actual ecospace)

368

variable in quantifying niche space

d = distance between two species in average resource use (peak to peak, between species)
w = measure of resource spectrum breadth of a species (peak to one side of curve, each species)
K = resource availability

369

d/w < 1 (quantifying niche space)

no co-existance

370

d/w > 1 (quantifying niche space)

full co-existance

371

resource spectrums

most species have narrow resource spectrum
specialists have VERY narrow resource spectrum
ex. pandas only eat bamboo

372

Hutchinson's concept of niche space

viewing overlap between species in multi dimensions
ex. foraging height, size of prey, time of day
n-dimensional hypervolume
increases organisms ability to coexist

373

biophagy

predation

374

types of predation

carnivory
herbivory (grazing, browsing)
parasitism (pathogens, parasitoids)
detritivores (dead plant/animal)

375

FRC

functional response curves

376

Functional response curves

rate of food consumption and density of prey
FRC#I, FRC#II, FRC#III

377

FRC#II

positively sloped, flattens out
single prey species
consumer is limited by its capacity to process food
only needs so much , satiated, caloric requirements met

378

FRC#III

standard logistic curve
multiple prey species
increases slower than II

379

threshold of security

occurs when there are multiple prey species
minimum density under which no further predation occurs- asymptote at lower end of curve

380

why threshold of security

when there are a rare amount of prey, go to new location or find other prey species to consume

381

FRC#1

increasing linearly
single prey species
assumes time needed by consumer to process food is negligible, consuming food does not interfere with searching for food
mostly theoretical, can apply to species with very high metabolism

382

low prey densities

reduced search efficiency
prey switching
search image
aggregated responses of predators

383

search image

predator develops 'image' of what to search for based on first prey it sees (likely most common)

384

proportion of prey population taken by predator predicts that

predators are rarely able to overexploit the prey

385

age class of prey taken by predators

virtually all predators target juveniles and post-reproductive adults
lowest cost of injury

386

salmon field study (removal of predators)

removal of predatory birds- twice as many smolts made it to ocean but same number returned, exceeded carrying capacity

387

grouse study (removal of predators)

removal of predators had no effect on grouse population
'law of minimum', prey not controlled by predators

388

mink predation on muskrat populations

most predation occurred on muskrats that had sen excluded from territories due to infraspecific competition, predators took prey where N>K
predators did not control population

389

wolf predation on caribou

without wolves caribou exceed K and population crashes
wolves keep caribou numbers from exceeding K
predator controls prey population in some sense

390

Isle Royal

wolves all homozygous, been studied since 1959, going extinct, moose population greatly increasing

391

parasitic wasp

2 stings to adult cockroach, 1 buckles front legs, 2 into brain, uses sensors along stinger to guid through brain, venom eliminates escape reflex, wasp leads cockroach by antennae, 'zombie' led to wasps burrow, wasp lays egg on underside of cockroach, plugs up burrow, egg hatches, larva chew hole in cockroach and climbs in, grows inside, devouring

392

do predators limit/control prey density

in some circumstances
no if Leibigs law of minimum is acting
yes if carrying capacity has been exceeded
yes but limits tendency of prey population to exceed K
yes when native prey have no defences against non-native predators

393

dingo - kangaroo relationship

no dingos = higher density of kangaroos present

394

dingo - wild pig relationship

with dines absent, biggest increase in population density was in babies

395

the biomass ratio of predator to prey in a community of endothermic predators and prey would be

~ 1:250

396

why is endothermic biomass ratio so high

endotherms have high energy requirements for thermoregulation

397

ectotherm biomass ratio

20:100 (1:5)

398

exploitation rate of prey by predator

average 5% for each predator species (mostly new born and old)

399

exploitation rate is low because

there are multiple predators per prey
why predators can coexist

400

increase in exploitation can be seen

up north (less predators)

401

highest exploitation rate

humans.. by far
only predator that take reproductive adults (target the reproductive capital)

402

escape tactics

camoflouge, disruptive colouration, crypsis, aposematic, mullerian mimicry, batesian mimicry

403

aposematic

be conspicuous
advertising poison/pain
predators learn to minimize contact
warning signal

404

mullerian mimicry

many poisonous species develop same conspicuous colour patterns (mimic each other), similar patterns among poisonous species (7 poisonous butterflies with same colour pattern)

405

batesian mimicry

non-stinging/edible species mimics stinging/poisonous species, very precise
ex. hoverfly mimics yellowjacket wasp

406

post-capture defenses

speed, agility, stamina, protean behaviour, autotomy-limb release, spines/armor/behaviour, reflexive bleeding, venomous

407

protean behaviour

unpredictable escape response (predator can't adapt)
one of most common escape responses of prey

408

autotomy

lizard removing tail, crab releasing claw

409

reflexive bleeding

beetle with 2 separate chemical pouches, can combine them and spray at predator- hot, chemical reaction, blinding

410

effects of herbivory on plants

defoliation
loss of plant vigour, loss of competitive ability
young leaves consumed first (less lignin, most nutrients)
growth rate of plant reduced by up to 25%

411

young leaves consumed first

less lignin
most nutrients
less bitter
taste better

412

plant structural defenses

cactus spikes- protect water supply

413

plant chemical defenses

unpleasant odour
contact irriation
bitter taste
neurotoxins
proteinase inhibitors
growth hormone mimics
psychotropic effects

414

anti-browsing chemicals

alcohols, alkaloids, quinones, glycosides, flavenoids, raphides

415

plant unpleasant odour

mustard

416

plant contact irritation

poison ivy

417

plant bitter taste

very common
Red Ceder- tannins

418

plant neurotoxins

dinoflagellates (marine algae), paralytic shellfish poisoning

419

plant proteinase inhibitors

cotton, chickpea, potato
stops digestion

420

growth hormone mimics

catnip:
nepetalactone (mosquito/tick repellant)
iridodial (attracts aphid eating lacewing)

421

psychotropic effects

peyote (mescaline)
marijuana (THC)
coffee (caffeine)

422

animals utilizing anti-browsing chemicals

monarch butterfly- milkweed
poison dart frog- leaf cutter ant

423

antibrowsing compounds in spider food

mescaline-- irregular web
caffeine-- VERY irregular web

424

selective browsing of plants with anti browsing compounds

leaf veins are under positive pressure with toxins
don't bite veins!

425

animal defense against plant chemical defenses

mixed function oxidaze
concentration of toxins
selective browsing

426

top anti predator mechanisms

1.chemical- reflexive bleeding, toxic chemicals 46%
2.fighting- stinging, biting, kicking, 11%
3.crypsis- camoflouge 9%
4.escape- running/flying, 8%
5.mimicry- batesian/mullerian, 5%

427

interaction categories

competition, niche concepts, predation, defenses

428

ecological succession

continuous unidirectional sequential change in the species composition of the community

429

primary succession

initial establishment of plant and animal communities on substrates lacking living organisms
ex. bare rock, lava, sand dune, glacial melt pond, rainwater

430

alder trees

fix nitrogen, can grow on bedrock
die, make soil, others can grow

431

ecological succession

1º - from original material (rock slide/lava)
2º - change of an established community

432

secondary succesion

ponds/lakes accumulate sediment
vegetation develops on shoreline
eventually replaced with terrestrial community

433

each sequential community in ecological succession

seral stage

434

climax

last serial stage that has long duration and changes very slowly

435

early stage succession of pond

sedges and reeds, quaking bog

436

seral stage

not discrete stage
not always sequential, cycle back due to environmental factors (flood, fire, heavy storm, volcano, glaciation)

437

identifying succession

yearly pollen influx settles to bottom of pond
take core sample
identify pollen species

438

reconstruct vegetation history

radiocarbon dating
amplify minute quantities of DNA
animal/plant species determination

439

radiocarbon dating

CO2- >99% C12
C14, half life 5730yrs, decays to 14N

440

sedaDNA

securely dated DNA, molecular presence of species that appear absent in macro fossil record

441

allogenic succession

abiotic disturbance

442

autogenic succession

biotic disturbance
beaver dam, virus outbreak, invasive species

443

lodgepole pine

has been replaced by douglas fir
from pond sediment cores

444

species richness vs. seral stage

increases linearly to maximum, flattens out

445

young forest

high plant diversity, low animal diversity, very dense, low sun, few habitats

446

mammal/bird species diversity in forest after clear cutting

summer- immediately after, very high, dips, rises again
winter- immediately low, increases, flattens

447

total biomass in seral stages following clearcutting

large increase, small decrease, levels off

448

why decrease in total biomass following clear cutting

takes time for decomposers to reestablish, break down biomass

449

problem with reestablishing clear cut forest

takes time for soil community to reestablish

450

reestablishing communities in warm/wet climate

~100 yrs
Krakatau near Java
15m hot lava

451

reestablishing communities in cold/dry climate

~20,000 yrs
Yukon
glaciation

452

secondary growth forests have

almost no predatory insects
~1000 yrs to reestablish insect communities

453

ecological mechanisms for succession

stochastic events
facilitation
inhibition
tolerance

454

stochastic events (ecological mechanisms for succession)

unpredictable, who gets there first

455

facilitation (ecological mechanisms for succession)

species creates conditions favourable for a succeeding species but not itself
major process in early stages
leads to assembly rules

456

facilitation example

clover growth without soil-- clovers produce soil for other plants to grow which shade out clover

457

assembly rules

regular and sequential shift in species
species B cannot establish till species A is present

458

examples assembly rules

predators cannot colonize successfully unless prey are present
pollinators can not colonize successfully unless flowering plants are present

459

inhibition (ecological mechanisms for succession)

species inhibits the colonization of subsequent colonists
slows succession and prolongs a seral stage

460

inhibition examples

allelopathy- plants/corals
competitive exclusion- intertidal communities

461

gigartina abundance

red marine algae- high density if Ulva removed, low if Ulva present

462

tolerance (ecological mechanisms for succession)

members of serial stage are those that co-exist due to use of different resources
combines facilitation + inhibition = ghost of competition past

463

early seral stages

seed dispersal - good
plant efficiency low light- low
resource acquisition - fast
biomass- small
stability- low
diversity- low
species life history - r
seed dispersal- wind
seed longevity - long
shoot to root ratio- high

464

late seral stage

seed dispersal - poor
plant efficiency low light- high
resource acquisition - slow
biomass- large
stability- high
diversity- high
species life history - k
seed dispersal- animals
seed longevity - short
shoot to root ratio- low

465

trophic levels

the sequence of steps in a food chain or pyramid

466

what are the trophic levels from lowest

primary producer-- primary consumer-- secondary consumer-- tertiary consumer

467

why trophic levels (food chains) are unrealistic

because real life situations involve food webs

468

what determines food web complexity

number of trophic levels
chain length
connectance
linkage density

469

what is chain length (in food web complexity)

number of links running from a primary producer to a top predator

470

what is conductance (in food web complexity)

actual number of links in a food web divided by the total number of possible links (N)

471

N = (in food web complexity)

[ n (n - 1) ] / 2

472

linkage density (in food web complexity)

number of links per species

473

has the largest effect on a system (food web)

species with high linkage density

474

types of trophic pyramids

by numbers
by biomass
by energy

475

number trophic pyramids

how many individuals per trophic level- tertiary consumer is on top (1 consumer : 250 prey)
how many individuals are supported- top is biggest level, bottom is small (one tree maybe)

476

dominant species

a species with an effect on the community proportional to its biomass

477

umbrella species (indicator species)

species used for conservation decisions, supporting an umbrella species can save the ecosystem

478

examples of umbrella species

grizzly, panda, spotted owl, Garry oak

479

example of dominant species

cod

480

keystone species

a species with an effect on the community that is disproportional to its biomass or abundance

481

example of keystone species

sea otter- without them sea urchins take over-- eat kelp-- nursing grounds collapse-- entire sub tidal community shifts

482

keystone molecule

DMS- dimethyl sulphide- produced when plankton feed on algae-- attract bird/fish-- they poop--nutrients increase algae growth

483

the major advantage to breeding earlier in life rather than later is

is shortens generation time

484

experimental removal of fish eating birds from a salmon river in eastern Canada led to which important ecological observation?

number of adult salmon returning to the river did not change

485

today, there are about 7billion humans on the planet. the yearly mortality rate is ~1% and generation time is about 15years. If each female produced one daughter in her life, the earths total population would be closest to which one of the rolling in 50 years assuming these rates remain similar

4 billion