WFC 110 Final Flashcards

Home Range

A general area where an animal lives, characterized by repeated use

— Occasional sallies not considered

Why would an animal have a home range

foraging patches, safe resting places, nesting, conspecifics, high predator densities or predation risks all known of

Side fidelity

areas within a home range frequently used for one purpose maybe every year

Can a home range have no site fidelity

yes, on small spatial scales. some animals may not always visit the same area of a range over and over again for the same purpose, or have several denning sites throughout a year within the home range for example

Non-static home range

Example in mountain lions or coyotes, can shift seasonally, a winter range, summer range, etc.

three factors that determine home range size

body size

• animals that are larger tend to have larger home ranges

environment

• marine mammals often have larger home ranges

diet

• carnivores> omnivores > herbivores, mostly due in part to trophic scaling

Anthropogenic impacts on home range and endangerment of animals

Studies found that home range size is a better way to determine how impacted mammals may be by anthropogenic causes.
This was determined through transects from remote areas and villages, and the assignment of a sensitivity score

Territory

This defines a home range that is defended actively for it’s resources, restricting them from other populationW

What are some ways a territory may be defended

through conflict, or communication:

• scent marking

• visual display

• auditory signaling

Sizes of home ranges and their pros and cons

large home ranges —> lots of resources, but costly to defend

smaller home ranges —> not enough resources to make worth defending

Who might defend a territory

An individual, a mating pair, or a family

How might human impact affect territorial animals

For animals that avoid territorial overlap, humans may impact the amount of overlap, leading to more deaths, like in mountain lions.

Mountain lions example of territoriality

Individual males defending

through scent marking and direct conflict

often defending and conflicting for breeding opportunities

North American Beaver example of territoriality

Mated pairs of beavers defending

scent marking and direct conflict

defending limited lodging space and food

Chimpanzee example of territoriality

Defense by troops

boundary patrols

defending territories from other groups

Home range connection to wildlife ecology

Selection for Resources

• depending on animal preferences for what resources

Area Requirements

• carrying capacities, since area and habitat is important for designated spaces for conservation

Energetics and Behavior

• understanding how much animals move, caloric needs for behaviors

Resilience to environmental change

• resilience to change, moving up elevation, faring well in several kinds of habitats

Dispersal

Animals leaving natal home range for breeding opportunities

avoiding inbreeding and local competition within a range

What are the two kinds of dispersal

Natal

• when animals disperse from their home range only (once) to breed somewhere else, where they stay, likely for the rest of their lives

Breeding

• when a species will disperse after each reproduction event this can occur several times.

Why might dispersal be tricky to study

A large focus on the individual, following them doing their own things, which is different from migration, with regular and repeated movements

Sex and dispersal

Typically, males disperse farther, and more typically, only males disperse

What are the 3 stages of dispersal

Emigration

leaving of current range can be condition dependent or genetically hardwired

• sex ratio(too many males), habitat condition (lack of resources), or body condition (better will disperse)

Transfer

Movement through unfamiliar territory, difficult to measure failed attempts at dispersal

Immigration

Animals found the right habitat, access to resources, water, etc.

• often lower quality because other competing species are there

Migration

The movement back and forth between two areas for resources,
— two distinct non-overlapping ranges

habitats are not suitable year-round, or static, so extreme movement strategies may be necessary

The disappearance of many great mammal migrations

a result of human impact and the blocking of migration corridors

What allows these mammals/animals to move farther distances

mobility, aerial/marine environments

Importance of migration

allows migrants to reach high densities and to persist

increase growth rates and reproductive success

Range residency

Animal doesn’t migration, stays in one place (home range)

Dispersal

animal disperses to a new home range, and stays there

Nomadism

Animal is constantly on the move, potentially for distributed resources

Migration

animal migrates from same 2 places

Partial migration

some members of the group stay back and feed on scarce resources while rest of group migrates

Facultative migration

migration only occurs when conditions are right, not a regular annual occurance

Mixed migration

Migration occurs year to year with different seasonal ranges (summer A, Summer B, winter A, B,) etc. different sites

Latitudinal migration

Migration occurs closer and farther away from the equator

whales, wildebeest, saiga

Altitudinal

Moving up slopes in summer, down slopes in winter

for resources that change availability with seasons up and down elevations

other kinds of migration

elephant seals migrate longitudinally to breed and to the pacific to forage.

Scales of migration

Temporal— Seasonal (per season), dial (one day migrations, think zebras and waterholes)

Spatial— Regional (far), local (short distances, think grizzlies in yellowstone)

Drivers of migration

Alimental movement — for food or water

Climatic — avoid predation, disease, parasitism, weather

Gametic — recruitment of mates

**all three possible

What do ruminant digestors migrate for versus hindgut ?

Ruminant digestors migrate for higher quality foods that may not be available

Hindgut travel for water, food is not necessarily a limit for them

Large versus Small body sizes in migration

Smaller and larger animals may not migrate for food because it can be hard for them
Smaller will likely pick out food from habitats more closely

Larger bodied animals tend to be hindgut fermenters, so they can afford to stay in place, if surface level water is there

medium-sized ungulates typically move the farthest

High vs Low productivity environments

Typically, for high productivity environments, there is less migration because food is stable year-round

ungulates are smaller in high productivity environments

What are the four stages of migration

Preparation

— fueling up, metabolism changes and feeding to prepare for movement

Movement

—occurs over land or water for mammals, sometimes air

Stopovers

—breaks in migration to rest and renourish

Arrival

— often reproduction, feeding, to survive season in new environment

How may humans affect migration

blockages in corridors through infrastructure
For instance, ranchers putting up barb wire fences that prevent pronghorn migration

Path of the Pronghorn

large scale migratory pronghorn corridor, because they cannot jump over fences,

Habitat fragmentation

Taking a large habitat and breaking up

despite low human influence, habitat frag rates are huge

Connectivity

The measure of an animal’s ability to move from patch to patch of suitable habitat

Matrix

The space between suitable habitat patches (nonsuitable)

Metapopulation theory

source and sink, migration between, relationship

Island biogeography theory

Distance between islands to a mainland

Corridor

Any space that facilitates the movement of animals or plants between patches of habitat that are separated

Considerations of corridors (5)

• focal species

• scale of interest

• generalist vs. Specialist

• habitat requirements

• human tolerance

  • this determines how the corridor will be like and the dimensions

Small Scale of corridor

highway crossing, over water conveyance i

intermediate scale of corridors

Requiring a land purchase and easment, preventing land conversion in cities

// associated with urban development

Large scale of corridors

Collaborative landscape, Y2Y example

Why might we pick corridors (3)

Individual animals
Animal populations
Human well-being

Examples of corridors benefits for individual animals (3)

• increase survival — fences, cars, etc.

• movement and dispersal ability — reprod. success, variability in genetics

• access to resources

Example of corridors benefits for animal populations (3)

• genetic variability (mountain lions)

• metapopulation dynamics

• increase population growth rates through connectivity for stable populations

Examples of corridors for human well-being (2)

• ecosystem services

  • more mountain lions to get rid of deer and elk roadkill

  • reduced risk from vehicle collisions

What defines a population

A collection of individuals of a species occupying a defined area, can be referred to for birth and death rates, and more

BIDE

Birth, immigration, death, emigration

rates determine abundance and density

What are the two key descriptors of population growth

lambda

r

Lambda

— geometric population growth rate, describes the proportional change in abundance between time periods (n(t+1) and nt)

r

exponential growth rate, instantaneous at one point.
r= ln(lambda)

Range of lambda versus R

greater than 1 or less than, can’t be negative
R, can be negative or positive

Type I survivorship curve

Live until old age, then most mortalities begin showing up

Examples include most larger mammals, like zebras, impala, red deer, etc

Type II survivorship curve

Mortality is constant throughout all ages
warthogs and gray squirrels

Type III survivorship curve

Most mortalities at younger ages

not common in mammals because of the maternal care put into gestation and lactation

Intraspecific Competition

Competition within a species through direct conflict, dominance hierarchies, social living, etc.

Examples of intraspecific competition

Red deer populations going into the winter, because of lack of resources population numbers go down

Voles and the fence effect, crashes in population as a result of limited space

Fence Effect in voles

Study using fencing of voles and unfences voles to test the intraspecific competition within voles
- Study found that populations that were unfenced can grow larger before crashing due to emigration when space became a limiting resource

Other example of intraspecific competition (sexes)

Estimated monthly energetic consumption of resources can be sex biased, depending on home range overlap of specific sexes for minks in the UK

For Gerbils, time spent resting affected the availability of dunes for these gerbils

males are active earlier in the night, which gives them an advantage

What are the two general ways that animals can respond to food availability changes

Numerically - RIDE

Functionally — behavior changes (3 types)

Example of numerical change response to food availability

snowshoe hare population growth leading to the population growth of other predators like great horned owls, lynx, and coyotes

Kit foxes, no change in functional behavior when main food source (rodents) went down as a result of a drought so populations also went down

Three types of functional responses to changes in food availability

Type I — linear relationship, as food availability goes up, activity in food consumption also goes up
Type II — specialist — immediate increase up to a saturation point
Type III — generalist — gradual increase up to a saturation point

Example of functional responses in changes to food availability

Canadian Lynx and coyotes in response in increase in snowshoe hare populations

Canadian Lynx — specialist, type II

Coyotes — generalist, type III

Herbivores

North American Beaver and saplings — specialist type II

Larger predators versus smaller predators, population ecology

Larger predator eat a larger variety of species, but are more selective

Smaller predators eat a smaller variety, but tend to be more opportunistic

ex. wolves will be selective of age in moose, whereas weasels will eat any vole they find

In the presence of unlimited resources, popoulations will grow exponentially but end up in one of two places

1. crash after exponential growth

2. Leveling out to a carrying capacity

Example of crash due to unlimited resources

Crash in introduction reindeer population in the Islands in the bering sea

exponential growth and then crash due to scarcity of resources later on

likely due to the inability to emigrate, and limiting resources on islands can be constraining for species

Moose population carrying capacities differing in Quebec in comparison to the Isle Royale national park.

despite the same area, Royale Isle had more moose, why?
Presence of wolves in Isle Royale, likely stopped moose from overconsuming the unlimited resources, leading no crashes as a result of unlimited resources, hence, a larger carrying capacity.

Example of carrying capacity plateau

River otters in Finland, exponential growth until plateau

likely due to the lack of spatial constraint

dispersal into other areas

How can K change with prey abundance?

Grizzly bears also forage for pine seeds.
with lots of pine there is a positive growth rate, without, it is a negative growth rate. Lambda not negative, but alternating between <1<

this changes carrying capacity.

Density Independent factors

As population size increases

• births and deaths increase

• birth and mortality rate remain constant

abiotic, like weather flooding, etc.

Density dependent factors

as population size increases

• rate of birth decreases

• rate of death increases

note that these are nonconstant rates, leading to nonlinear lines

often biotic, like disease transmission

Cycling in animals

OFten found in density dependent animals, due to biotic factors, populations tend to cycle through demographic phases

ex. Snowshoe hares and lynx cycling or Voles and cycling

What was studied in the gray sided vole

4 stages of vole cycling with marked changes in population numbers

1. increase

2. peak

3. decline

4. low

   These changes in population also had marked characteristics, like differences in

• survival, mortality, reproductive periods, sexual maturity, dispersal, densities, and duration.

Dispersal in voles: pre-saturation

At the saturation point, this is when all the available space for voles would’ve been taken up

• pre saturation dispersal likely involves competitive individuals who had a good chance of surviving, if they left first before things got tougher down the line

Dispersal in voles at Saturation

a competitive environment, old, young, and weaker voles has a lower chance of survival due to the lack of resources

In decision tables, what does C and E represent

C represents the cause and E, the effect.

In these cases, the hypothesis is not supported.

Is C-E+ = unnecessary

C+E-= insufficient

In order for our hypothesis to be demonstrated, the study has to be both necessary and sufficient.

Causes are typically segregated into two groups:

Intrinsic or Extrinsic

Four Proposed Causes for Vole Cycling

1. Food

2. Predation

3. Qualitative changes in Individuals

   • Stress, Behavioral-genetic Senescence

4. Multiple Interacting Effects

Pitelka’s Food supply Hypthesis

It was suspected that food may be the cause of cycling
Food was given to voles when pop. were low and high

Cycles occurred without food,
And cycles would not occur with food
You couldn’t cause cycling with food, nor could you prevent cycles by taking away food

insufficient and unnecessary

Predation Hypothesis

Looking at voles and predators, imitation of predation and removal of primary predators of voles.
Removal of predators did not prevent cycles and removal of voles did not impede the decline
insufficient.

Northern Fennoscandia

More specialist, fewer generalist, more natural forest

Southern Fennoscandia

fewer specialists, more generalist, a lot more extensive agriculture

Small mammal populations exhibit higher amplitude cycles in northern or southern Fennoscandia

northern,

Predation is a density __ regulating factor

More predators = more impact on prey —> density dependent!

Direct density depdendence

quick impact on prey populations by predators

Delayed density dependent

delayed impact on prey by predators

What do generalists exhibit/what kind of influence on prey populations? (Direct or delayed density dependent)

Direct, quick prey switching, and responding both numerically and functionally to changes in oscillation.

What do specialists exhibit/what kind of influence on prey populations? (direct or delayed density dependence?)

delayed, due to a lack of prey switching, only do so when focal species are uncommon, but at that point, predators will be uncommon,

numerical will be delayed

A study on vole populations in Canada found that

the direct density impact of generalists on vole populations is what lead to decline after peak phases
and that the delayed density impact of specialists is what drove cyclic vole populations

What were the flaws with the generalist specialist vole study on predation

1. cycles defined mathematically and not biologically

2. non universal

3. founded by various land use, what applied to Fennoscandia north is not in the same conditions as South Fennoscandia