Birds of Indian Subcontinent

An Ecological Study of the Waterfowl of the Potholes Area, Grant County, Washington

Publication Type:Journal Article
Year of Publication:1954
Authors:Harris, SW
Journal:American Midland Naturalist
Date Published:1954
ISBN Number:00030031
Keywords:Anas, Anas carolinensis, Anas crecca, Anas platyrhynchos, Anatidae, Branta, Branta canadensis, Fulica, Fulica atra, Oxyura, Oxyura jamaicensis, Rallidae
Abstract:The vegetation of the Potholes area was arranged in zones along a moisture gradient. These zones from dry to wet were: 1) no vegetation on high, dry, shifting sand dunes; 2) Psoralea on the windward faces of lower shifting dunes with sand dock and willows on the leeward faces; 3) saltgrass-Nevada clubrush meadows; 4) Baltic rush-sedge meadows; 5) bulrush-cattail; and 6) submerged aquatic plants. The potholes area as a waterfowl winter range was acceptable to those species which are adapted to its winter climate, the mallard being the most abundant winter resident. Permanent and temporary potholes (800-1000), flooded flats, and creeks were used as territorial sites. Territories included a water area, one or more loafing sites, a nearby resting cover, and in some instances, a feeding area. Defense of territory varied with the species and individuals. Nesting extended from April until late August. Nesting sites depended upon available cover, wild rye grass, Juncus, and bulrushes, being primarily used. Nearly two thirds of all nests were within 30 feet of water. Predation was the major factor of nest failure. The brood season extended from April to September. Six major cover types used by broods m order of their importance were Scirpus acutus, Juncus balticus, open water, Typha latifolia, Scirpus americanus, and Salix. Potholes with heavy infestations of carp were little used by broods. Reduction in brood size occurred in the first two weeks after hatching. Nest predation by coyote, destruction of cover by cattle, and high breeding populations of coots were some apparent factors serving to limit duck populations by making nesting and brooding areas less desirable. Activities of beaver and muskrat were beneficial to waterfowl by providing ponds and loafing areas. The mallard, Canada goose, green-winged teal, ruddy duck, baldpate, and coot were important species in both spring and fall migrations. Flooding of the Potholes area will result in the destruction of one of central Washington's major waterfowl breeding areas.
Short Title:American Midland Naturalist
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith