8095

• UCREFRP Catalog Number: 8095
• Author: National Research Council.
• Title: Impacts of Emerging Agricultural Trends on Fish and Wildlife Habitat.
• USFW Year: 1982.
• USFW - Doc Type: Washington, D.C.
• Copyright Material: NO

Chapter 1

INTRODUCTION

Habitat is the environmental setting in which an animal or plant
normally lives, grows, and reproduces. Agricultural land use,
including grazing, crop production, and forestry, affects the quality
and quantity of the water and land available for food, cover, space,
and living and reproducing sites for fish and wildlife. This report
examines agricultural trends and their likely impacts on fish and
wildlife habitats.

HABITAT FEATURES OF IMPORTANCE TO WILDLIFE

TO understand how agricultural and forestry activities affect habitat,
it is necessary first to understand how wildlife are attracted to and
use various natural habitats. The complexity and infinite diversity
of wildlife habitats make the categorization of the habitat
characteristics of numerous species an imposing and impractical task.
Patterns of use in this study will be illustrated by examples, instead
of by attempting to address the multiplicity of types observable in
various species or groups of animals.
Some comprehensive, broad habitat characteristics have been
identified by scientists. Key habitat characteristics were presented
as early as 1938 (King 1974). These include the availability and
adequate interspersion of cover, food, and water. The special
requirements associated with reproduction include special foods (often
protein rich), den or nest sites, and the territorial spacing often
associated with breeding. Such spacing depends on the social system
of the animal; some colonial species like herons cluster in limited
habitat during breeding periods and disperse at other times, whereas
other birds flock during the winter and become highly territorial
during breeding.
The habitat needs of resident species may differ from those of
migratory ones. Where changes from season to season due to climate or
rainfall are severe, mobile species find the resources they need by
moving to different habitats. Muskrats may do this locally, but birds
annually migrate long distances to exploit resources. Anadromous fish
swim from the ocean or a lake to streams to breed.
Recent studies of animal communities have identified certain

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