Habitat Selection

Habitat Selection

When an animal chooses a place to live

Habitat Preference

When organisms may select specific area(s) within their overall habitat, even in apparent homogenous environments

Natal Philopatry

When the offspring remain in their natal area, sharing home range/territory with their parents

Natal Dispersal

When offspring move from their birthplace and never return

Advantages of Philopatry

Predator avoidance, known food resources, reduced aggression w/ neighbors, lower overall stress

Disadvantages of Philopatry

Increased risk of inbreeding, can lead to overcrowding, greater competition for food and mates

Males

In mammals, which sex is more likely to disperse?

Females

In birds, which sex is more likely to disperse

Reduce Inbreeding

Hypothesis about dispersal

one sex must leave natal area

Resource Defense Mating System

Males compete for territory as opposed to mates.

Seen in birds

Mate Defense Mating System

Males directly compete for females

No

If the father is not around during sexual maturity of their daughters, females will have first choice of breeding sites, do the females disperse?

Yes

If the father is around (i.e., in chimps, most birds, etc…), do the females disperse?

Polygynous

In what type of sexual social group do the males compete and disperse?

Monogamous

In what type of sexual social group do both the females males compete and they both disperse?

Reduce Competition with Parents

What is the purpose of parents throwing their young out of the home?

Males

In lions, do males, females, or both disperse?

Both

In praire/pine voles, do males, females, or both disperse?

Physiological Mechanisms

Reason for Belding’s Ground Squirrel Dispersal

dispersal is caused by effects of testosterone, increasing curiosity and activity as opposed to females.

4 Weeks

How long do Belding’s Ground Squirrels spend in their mother’s underground burrow?

1-2 Weeks

How long do Belding’s Ground Squirrels live in their mother’s home range after emerging from burrow

Developmental Processes

Reason for Belding’s Ground Squirrel Dispersal

Dispersal is triggered by reaching a certain body size. Starts a cascade of curious and high-movement behaviors among males.

Effects on Fitness

Reason for Belding’s Ground Squirrel Dispersal

Juvenile males benefit because it reduces the chance of inbreeding. Male-Male conflict is not a causal factor.

Evolutionary Origins

Reason for Belding’s Ground Squirrel Dispersal

Widespread male preference for dispersal is inherent, squirrels are not specifically benefited.

Heredity and Learning

What two factors determine habitat preference?

Wild Caught Mice

In the Habitat Imprinting in Deer Mice Experiment, which group selected their compatible habitat?

Lab Reared 1GEN

In the Habitat Imprinting in Deer Mice Experiment, which group had 10-20% select their incompatible environment?

Cross Fostered

In the Habitat Imprinting in Deer Mice Experiment, which group selected the habitat of their surrogate parent?

Lab Reared 20GEN

In the Habitat Imprinting in Deer Mice Experiment, which group had a random habitat selection?

Social Facilitation

Animals join others of the same species if they see them in a particular habitat/area.

Reduces interspecific competition.

Tradition

Behavior is passed down from one generation to the next through learning 

Migration

Movement of animals away from an area, and the eventual return to that area

What animal has the longest known migration (50,000 miles)?

Arctic Tern

Timing of Migration

Cue is set by internal clock mechanisms characterized by the Stage of Preparation

Stage of Preparation

The build up for the eventual migration of an animal. Involves Fat deposition and Zugunruhe

Zugunruhe

migratory restlessness; increased activity.

Costs of Migration

Energy cost, predator risk, inhospitable terrain, territory relinquishing, unstable weather

Benefits of Migration

Energy/reproductive profit, days in the north are longer, protected environment, reduced competition