Year of Award


Document Type


Degree Type

Master of Arts (MA)

Department or School/College

Department of Zoology

Committee Chair

Philip L. Wright


University of Montana


Hostile behaviors and reproductive territories of Blue-winged and Cinnamon Teal were investigated in the spring of 1974 and 1975. Nine Blue-winged and 14 Cinnamon Teal territories were mapped on the study area near Ninepipe Reservoir. Territories were mutually exclusive and territorial requirements were the same for both species. Five hostile behaviors were described and flow charts of those behaviors were drawn. Three behaviors were previously described, but not in the natural state for Cinnamon Teal. On the study area, 938 observations were recorded, and an equal or larger number of observations were made off the study area and during 1973. Hostile behaviors were described based on 100 interactions recorded on the study area and observations off the area. The hostile behaviors of these two species were the same with the exception of vocalization. The similarity in hostile behaviors, interspecific interaction, and mutually exclusive territories pointed to direct competition between these two species on the breeding grounds. Two alternatives were suggested: (1) that competitive advantage would allow one species to supplant the other, or (2) that these two species are affected little if any by competition in this area of range overlap. The first alternative was rejected due to the long history of both species in the area of overlap, and it was suggested that these two species are partial competitors, holding each other in check in the area of overlap, with each having a competitive advantage at some other level of niche organization.



© Copyright 1976 Gerald L. Dwyer