Habitat Selection: Behavioral Ecology and Settlement Decisions

Vocabulary practice flashcards covering concepts, definitions, models, and mechanisms of animal habitat selection from BIO 3240.

Habitat

The specific set of environmental resources and physical conditions in an area that permit an animal to survive and reproduce.

Habitat Selection

The behavioral process and decision-making by which an individual animal chooses among alternative spatial patches or environments to occupy.

Distribution

The spatial population pattern across an environment that emerges as an aggregate result of many individual settlement decisions.

Use

What an animal actually occupies or visits, measured directly by observations such as the spatial locations of a collared elk.

Availability

The total set or proportion of habitats and environmental resources accessible to an animal within a defined area.

Selection

Use of a habitat type that is disproportionate to its availability, such as an animal occupying a habitat for $30\%$ of its locations when that habitat makes up only $10\%$ of the total area.

Preference

How likely a habitat is chosen by an animal when all habitat alternatives are offered on strictly equal terms, as tested in controlled experiments.

Habitat Quality

The per-capita demographic contribution of a habitat patch to an organism's Darwinian fitness, quantified directly by survival and reproductive success.

First-Order Selection

The broadest scale of habitat selection, defining where on a continent or region a species occurs as its overall geographic range (Johnson 1980).

Second-Order Selection

The spatial scale of habitat selection that determines where an individual animal establishes its home range within the broader landscape (Johnson 1980).

Third-Order Selection

The scale of habitat selection that dictates which specific habitat types or patches within an established home range are used most frequently (Johnson 1980).

Fourth-Order Selection

The finest scale of selection, involving the procurement of specific food items or micro-sites from those available at a feeding location (Johnson 1980).

Conspecific Attraction

A settlement behavior where searching animals use the physical presence of other members of their own species as an informative cue to choose a habitat.

Public Information

Social cues derived from assessing the reproductive or foraging performance of conspecifics (such as fledgling numbers in collared flycatchers) to evaluate patch quality.

Foliage Height Diversity (FHD)

A quantitative measure of how plant foliage is vertically distributed across structural forest layers, demonstrated by MacArthur & MacArthur (1961) to predict bird species diversity better than plant species diversity.

Food vs. Safety Trade-Off

An ecological conflict where foraging patches with the highest energetic returns also present the greatest predation danger, forcing animals to balance nutritional gain against mortality risk.

Selection Ratio ($w$)

A quantitative index defined as $w = \frac{\%\text{ used}}{\%\text{ available}}$, where $w > 1$ denotes positive selection, $w = 1$ denotes proportional use, and $w < 1$ denotes avoidance.

Ideal Free Distribution (IFD)

A theoretical model (Fretwell & Lucas 1970) where individuals with complete environmental knowledge freely enter any habitat without cost or interference, causing density to rise until per-capita fitness equalizes across all occupied patches.

Ideal Despotic Distribution (IDD)

A model (Fretwell & Lucas 1970) where dominant territorial individuals monopolize high-quality patches and exclude competitors, forcing subordinates into poorer habitats and resulting in higher fitness in the crowded, superior patches.

Source Habitat

A high-quality habitat where local reproductive output exceeds local mortality ($\text{births} > \text{deaths}$), producing a demographic surplus of emigrating individuals (Pulliam 1988).

Sink Habitat

A low-quality habitat where local mortality exceeds reproduction ($\text{deaths} > \text{births}$), maintaining a population only through continuous immigration from external source populations (Pulliam 1988).

Ecological Trap

A scenario where rapid environmental changes decouple proximate settlement cues from true patch quality, leading organisms to preferentially settle in poor habitats where fitness is severely reduced.

Resource Selection Function (RSF)

A statistical modeling method that evaluates multiple environmental and spatial variables simultaneously to predict the probability of an animal using a resource unit relative to its availability.