Lecture 16: Pop Dynamics continued

Question 1

Special problem of small populations

Answer 1

Allee effects may be occurring
Positive density dependence
You need enough individuals before population can exist
Threshold when population drops and will not recover on its own

Question 2

Small populations more susceptible to

Answer 2

stochastic (random) variation- more susceptible to random events
Great chance of complete of population extinction
Greater chance of no reproduction
Stronger genetic drift: great probability of increase of bad alleles and loss of good alleles

Question 3

All populations are finite and dependent on stochastic variation in…

Answer 3

everything!
(rainfall, predator populations, fecundity, surivvial, etc)

Question 4

Demographic parameters can be strongly influenced by

Answer 4

weather

Question 5

Population dynamics driven by

Answer 5

immigration

Question 6

Metapopulation

Answer 6

a set of spatially isolated populations linked to one another by dispersal
Consists of source/sink populations and years

Question 7

Source population

Answer 7

λ > 1, r > 0 (population increasing, constant rate of per capita pop growth)

population is thriving and support individuals to disperse to other areas

Question 8

Sink population

Answer 8

λ < 1, r < 0 (population decreasing, constant rate of per capita pop growth)

population is decreasing, less likely to migrate

Question 9

Population viability analysis (PVA)

Answer 9

Estimate the probability of extinction within
a given time period, given allee effects and
effects of stochastic fluctuations

Question 10

What is recommended for population viability for maintaining to keep extinction risk ?

Answer 10

Population size to maintain to keep extinction risk below 5%

Question 11

Why is habitat fragmentation bad for population viability?

Answer 11

turns big populations into many smaller ones, vulnerable to stochasticity

Question 12

Habitat fragmentation amelioration (help)

Answer 12

Add corridors for species specific effectiveness
One large reserve better than many small reserves
Ex. Fish ladder

Question 13

Not all individuals contribute in the same way to

Answer 13

population dynamics

Question 14

Type 1 Survivorship Curve

Answer 14

Mortality increases with old age

Question 15

Type II Survivorship curve

Answer 15

Constant mortality

Question 16

Type III

Answer 16

High initial mortality for young age

Question 17

Survivorship curves scale are

Answer 17

log/linear scale

Question 18

Stage structure: Dependence of ____ on individual stage

Answer 18

vital rates

Question 19

Stages include

Answer 19

Sex
Age
Size
Developmental stage

Question 20

Common life history tradeoffs

Answer 20

Allocate to current population OR growing bigger first (risking death) and reproducing more

Few large offspring OR many small offspring

Question 21

fast r-selected

Answer 21

species that do well under high resource conditions, immediately after disturbance

Question 22

slow k-selected

Answer 22

species that are competitive and do well when resources are limiting

Question 23

Community

Answer 23

Populations that live together in a defined area

Question 24

Competition

Answer 24

(-/-)
interaction hurts both species

Question 25

Predation

Answer 25

(+/-) Benefits one and hurts other

Question 26

Herbivory

Answer 26

(+/-) Benefits one and hurts other

Question 27

Parasitism

Answer 27

(+/-) Benefits one and hurts other

Question 28

Disease

Answer 28

(+/-) Benefits one and hurts other

Question 29

Mutualism

Answer 29

(+/+) each species benefits the other

Question 30

Commensalism

Answer 30

(+/0) One species benefits while the other is unaffected

Question 31

Types of carnivores and their food sources

Answer 31

1. Predator, prey 2. Parasite, host 3. Parasitoid, host 4. Pathogen, host

Question 32

Carnivore: Predator, prey

Answer 32

Predator kill and eat all of an individual of a resource species Predators usually larger than their prey Ex. Lion, antelope

Question 33

Carnivore: Parasite, host

Answer 33

Parasite live off resources of a host, but rarely kill the host Often lie inside host, usually smaller Ex. Tick, cow

Question 34

Carnivore: Parasitoid, host

Answer 34

Parasitoids are combination parasite/predators Certain fly or wasp species larvae-live in a host insect, eat it kill it when or just before emerging as adults Ex. baconoid wasp, tabacco hornworm

Question 35

Carnivore: Pathogen, host

Answer 35

A pathogen is a parasite that is a bacterium, virus, or other microorganism that causes disease Much smaller than their hosts Live in or on the body, may or may not kill the host Ex. malaria, human vector: mosquito

Question 36

Types of herbivores

Answer 36

1. Grazers 2. Browser

Question 36

Herbivore: Grazers

Answer 36

Eat mostly grass Ex. cow

Question 37

Herbivore: Browser

Answer 37

twigs and buds also major part of their diet Ex. deer

Question 38

Other vertebrates herbivores eat grass and also..

Answer 38

seeds, nectar, or other plant parts Ex, hummingbird eating nectar and squirrel eating acorn of trees

Question 39

Herbivore: leaf miners

Answer 39

insect larvae that live and feed within the leaf tissue of plants.

Question 40

Most herbivorous insects are

Answer 40

specialists on only one or few plant species

Question 41

Plant pathogens

Answer 41

plant disease causing microorganisms Ex. fungi, bacteria, or viruses

Question 42

Why is adaptation for jaws and teeth benefit for herbivores?

Answer 42

Grinding surfaces (ex. molars) good for eating plants with lots of cellulose, and lignin like grasses and twigs

Question 43

Why is adaptation for jaws and teeth benefit for carnivores?

Answer 43

Shearing surfaces, like canines, have for cutting meat and holding prey Ex. mountain lion Long rows of pointed teeth for catching, holding, and eating aquatic prey Ex. killer whale

Question 44

Adaptations from hiding

Answer 44

Hide when predators are present, less time for foraging food Ex. Bullfrog tadpoles are hunted by fish and dragonfly larvae

Question 45

Crypsis

Answer 45

Adaptation of blending with environment to hide from predators

Question 46

Adaptations: mobile escape

Answer 46

Ability to sprint at fast speeds to run from predators Ex. pronghorn antelope

Question 47

Adaptations: physical protection

Answer 47

Physical protection helps escape from predators Ex. shell of turtle to hide, or thorns on plants