EX 2 TECH: RESOURCE SELECTION

What is resource selection?

A non-random hierarchical process where animals choose resources such as food and habitat.

What decisions are involved in food selection?

Animals choose among prey species and also among sizes, colors, and shapes within the same species.

What are examples of discrete habitat variables?

Open field, forest, rock outcropping.

What are examples of continuous habitat variables?

Shrub density, percent cover, canopy height, distance to water.

What types of variables are used in resource selection studies?

Discrete variables, continuous variables, or a combination.

What are the four hierarchical levels of resource selection?

Geographic range, individual home range, habitat components within home range, specific resource use such as food.

Why can selection criteria differ across hierarchical levels?

Different ecological pressures and constraints operate at different spatial scales.

Define resource usage.

The quantity of a resource utilized by an animal during a fixed period.

Define resource availability.

The quantity of a resource accessible to an animal during the same period.

What is selective use?

When resources are used disproportionately relative to their availability.

What is preference in resource selection?

Disproportionate resource use suggesting behavioral choice.

Why must preference be interpreted cautiously?

Apparent preference may result from prey catchability, handling time, satiation, or experimental limitations.

What is the best method to test food preference hypotheses?

Controlled choice experiments.

What factors can influence apparent habitat preference?

Presence of competitors, predators, or environmental cues.

Why is association not always causation in selection studies?

Resource use may reflect constraints or random use rather than true preference.

What lesson comes from the Lord Howe Island Woodhen example?

Apparent habitat preference may result from external pressures such as predators.

What is a functional response in resource selection?

Animals change selection behavior depending on resource availability.

How does social status affect habitat selection?

Subordinate individuals may be forced into suboptimal habitats.

How does anthropogenic disturbance affect selection?

Animals may prioritize risk avoidance over maximizing resources.

Why are diet studies important in ecology?

They help understand behavior, ecological niche, competition, predator-prey dynamics, and health.

How can diet studies help conservation and pest management?

They predict impacts on prey populations and guide sustainable management.

How can food availability be sampled?

Vegetation surveys, trapping, fishing nets, and biocenometers.

Why is estimating food availability difficult?

Not all prey present are accessible due to cover or predator limitations.

How can diet composition be quantified?

By proportions of food items, number or mass consumed, or size estimates.

Why does digestion stage affect diet analysis?

Differential digestion can cause bias and under-representation of soft prey.

What are advantages of direct observation in diet studies?

Provides accurate pre-digestion information on food items consumed.

What are disadvantages of direct observation?

Difficult prey identification and observer presence may influence behavior.

What are cafeteria trials?

Controlled feeding experiments used to test food choice.

Why are scat and pellet analyses commonly used?

They are easy to collect and non-lethal.

What is morphological diet analysis?

Identifying prey remains visually or microscopically.

Why may large mammal scats lack hard prey parts?

Large mammals often consume prey tissue rather than whole individuals.

What is DNA metabarcoding?

Identifying prey species from DNA in feces or pellets.

What are advantages of molecular diet analysis?

High resolution identification, species detection, and sex determination.

What is the principle behind stable isotope analysis?

Tissue isotope ratios reflect an animal’s diet.

What ecological information can stable isotope analysis provide?

Food web structure, energy flow, nutrient sources, and trophic relationships.

What diet analysis methods are common for carnivores?

Scat analysis, morphological identification of hair and bones, and molecular sequencing.

What diet methods are used for rodents and small mammals?

Scat analysis, stomach contents, and cafeteria trials.

What diet analysis methods are used for ungulates?

Fecal analysis, direct observation, bite-count studies, and DNA from browse.

What are non-invasive bird diet techniques?

Pellet analysis, fecal analysis, direct observation, and cameras.

What are invasive bird diet techniques?

Induced regurgitation, neck ligatures, and stomach flushing.

What diet analysis methods are used for reptiles and amphibians?

Stomach lavage, fecal analysis, direct observation, and dissections.

Define habitat.

The resources and conditions that allow survival and reproduction.

Define habitat selection.

A hierarchical behavioral decision process determining habitat use.

Why must managers avoid judging habitat adequacy by human standards?

Management must match the natural behavioral patterns of the species.

What spatial scales are used in habitat studies?

Microhabitat scale, patch scale, and landscape scale.

What methods are used to observe animals in habitats?

Transects, point counts, camera traps, radio telemetry, and GPS tracking.

How are stable isotopes used in migration studies?

Isoscapes link tissue isotope ratios to geographic origins.