Habitat and Habitat Management

Clouded Salamanders

  • Have no lungs; breathe through their skin, which must be kept moist for respiration to occur.

  • Occur in wet coastal forests of Douglas fir, cedar, alder, and redwood.

  • Prefers wetter, less dense stands of forest to dry dense stands.

  • Clouded Salamanders of redwood canopies are found most frequently in epiphytical fern mats that store water like a sponge.

What is Habitat?

  • "Habitat" is SCALE dependent.

  • A place where an organism or a population of organisms normally lives.

  • A place where something is commonly found.

  • A place where a plant or animal can get the food, water, cover, and space it needs to survive and successfully reproduce.

Components of Habitat

  • Food

  • Cover

  • Water

  • Space

Habitat Considerations

  • Plant community and habitat are not synonyms.

  • Habitat is species-specific.

Food and Cover

  • Vegetation is a central component to habitat.

Water

  • Many times the limiting factor.

  • Most wildlife species require surface water.

  • Many desert species can survive on metabolic or preformed water in food items. E.g., Kangaroo rats

Space

  • “Usable space” (Guthery 1997)

  • Commonly, not all of the landscape is usable as habitat for a given organism. May not be accessible, environmental conditions,

Example

  • Northern bobwhites

    • Center of buffelgrass fields are not usable space

Habitat and Usable Space

  • “Usable space” is an important concept when making decisions regarding carrying capacity and account for other elements of habitat: food, water, cover.

  • The portion of the landscape that is not usable should not be considered in calculating carrying capacity of an area.

Managing Habitat: Desires

  • What drives our desire to manage habitat?

    • Wildlife

    • Abundance

    • Fitness

    • Conservation

  • What is the objective for managing habitat?

    • Maintain? – probably best

    • Improve?

    • Restore? – a reasonable objective?

Influence of Human Perceptions

  • Determining habitat quality is a scientific process.

  • Landscape perception is a social process.

Managing Habitat Components

  • Food

    • Nutrition

  • Cover

    • Thermal, predators

  • Water

    • Metabolic processes, lactation

  • Space

    • Carrying capacity, breeding

  • Depends… what is the limiting factor to the population of interest?

Habitat Loss

  • Loss of habitat is the most significant threat to wildlife conservation in the United States and the major cause of declines in wildlife populations.

Causes of Habitat Loss

  • Urbanization

  • Agricultural

  • Changing climate

  • Deforestation

Habitat Degradation

  • The quality of the remaining habitat is being degraded by a variety of factors fragmentation as larger ranches are broken up.

  • Ranchettes

  • Oil and gas

  • Wind farms

  • Excessive livestock grazing

Habitat Management

  • Aldo Leopold – axe, fire, plow, cow, gun

Plant Succession

  • Plant Succession Stages: Lichens and Mosses → Exposed rocks and weeds → Grasses and herbaceous plants → Mixed Shrubs → Young forest (tulip poplar) → Mature forest (white oak and hickory) → Climax forest (beech and sugar maple)

Secondary Succession

  • Fire → Annual plants (1-2 years) → Grasses and perennials (3-4 years) → Aspen, cherry, broadleaf forest (5-150 years) → Beech and maple (150+ years)

Compensatory Plant Growth

  • Compensatory growth- phase of rapid growth that allows individuals that have had growth depression to achieve the same size as continuously fed contemporaries

Grazing Intensity and Plant Species Richness

  • Low Grazing: Low Plant Species Richness

  • Moderate Grazing: Intermediate Plant Species Richness

  • High Grazing: Low Plant Species Richness

Brush Management Methods

  • Chemical

  • Mechanical

    • Plant removal

    • Top growth removal

  • Prescribed or natural burns

Brush Management Effects

  • Mechanical treatments may temporarily increase forbs.

Browse Rejuvenation

  • Regrowth of browse following top removal is temporarily greater in nutritional quality.

  • Browse regrowth is temporarily more palatable.

Managing Habitat

  • Human Activities

    • Alter environment or behavior

Mule Deer Migration

  • Example of managing habitat by considering migration routes, land ownership, and potential impediments.

Pronghorn Migration

  • Another example of managing habitat by understanding migration corridors and working across different land ownerships.

Science and Habitat

  • Thinking back on the mule deer video, what made it possible to manage/protect habitat?

Connecting the Dots

  • How do we assess habitat quality? Food, water, cover, space

Tracking Technologies

  • The accelerated growth and development of tracking technologies allows us to tie animals to their habitat preference.

Habitat Selection Study Design

  • Scale: Spatial and temporal

  • Geographical Distribution / Where is Home-range?

Sampling and Inference

  • Sampling Unit: Individual animal

Overlaying Points

  • Overlay used and available points on covariate layers (resources) of interest. Extract