Short-distance migrants


Summary of Geographic Patterns

Species Richness

Short-distance migrants are migratory species that breed and winter within the U.S. and Canada. Species richness for this group is highest in the northern U.S. and southern Canada. Relatively few short-distance migrants breed in the southern U.S.

Population Trends

For this group, negative trends prevail where the species richness is greatest, from New England across the northern Great Lakes and into the Prairie Provinces of Canada. Similar trends also predominate from California and Nevada northward through Washington and Idaho, and from Florida and southern Georgia across Alabama, Mississippi, and Arkansas to the eastern Great Plains from Oklahoma to Iowa and southern Minnesota. Positive trends are most evident along the Rocky Mountains and western Great Plains, as well as along the southern Great Lakes west of the Appalachian Mountains and locally along the Atlantic coast from Pennsylvania to the Carolinas.


Discussion

For short-distance migrants, 46% of the species have positive trend estimates. These migrants include species from all habitat groups, although many grassland and scrub/successional birds fall into this category. The geographic patterns to their trends defy an easy explanation. This group has been shown to be susceptible to dramatic declines following winters with severe weather, especially in eastern North America (Robbins et al. 1986), which may partially explain the prevalence of negative trends in that portion of the continent.

Literature Cited


Robbins, C.S., D. Bystrak, and P.H. Geissler.  1986.  The Breeding
     Bird Survey: its first fifteen years 1965-1979.  U.S. Fish and
     Wildl. Serv. Res. Publ. No. 157.  196 pp.