Accession Number : ADA322847

Title :   Characterization of Habitat Used by Whooping Cranes During Migration.

Descriptive Note : Biological rept.,

Corporate Author : NATIONAL ECOLOGY RESEARCH CENTER FORT COLLINS CO

Personal Author(s) : Armbruster, Michael J.

PDF Url : ADA322847

Report Date : MAY 1990

Pagination or Media Count : 24

Abstract : Information is drawn from the literature and the professional opinions of behaviorists and habitat use experts, and used to describe requirements of whooping cranes (Grus americana) during migration. Migration strategies of North American cranes are compared and inferences drawn. The requirements for usable food and cover are examined and described quantitatively for evaluations that focus on roosting habitat. When possible, information is presented in terms of both traditional and nontraditional stopover areas. Perceived problems with the data and their interpretation, are discussed, and issues requiring further study are identified. Relations presented do not represent selection, as defined by use and availability studies, but rather should be interpreted as a formalized synthesis of information directed by the opinions of recognized authorities in crane biology. Site-specific evaluation criteria address issues of visibility, water depth, wetland size, and disturbance; suitability relations are presented for each habitat component. Horizontal visibility is defined as a straight-line distance to the nearest obstruction greater than 1 m in height, and that distance must be greater than 20 m before a site can be considered as potential habitat. Optimum water depth is considered to be less than or equal to 30 cm. The minimum wetland size considered usable for roosting is 0.04 ha. Disturbances are treated as zones of influence around selected features with no zone having a minimum width of less than 100 m. Broad-scale evaluations can employ information readily available from inventories or surveys such as wetland system, class, water regime, and size, to rapidly screen potential habitat suitability over large geographic areas. Suggestions for application of evaluation criteria are presented.

Descriptors :   *MIGRATION, *CRANES, *HABITATS, *ENDANGERED SPECIES, *WILDLIFE, TEST AND EVALUATION, OPTIMIZATION, STRATEGY, SIZES(DIMENSIONS), BIOLOGY, SYNTHESIS, WATER, AVAILABILITY, VISIBILITY, HORIZONTAL ORIENTATION, RANGE(DISTANCE), WETLANDS, GEOGRAPHIC AREAS, FOOD, NORTH AMERICA.

Subject Categories : Biology
      Ecology

Distribution Statement : APPROVED FOR PUBLIC RELEASE