Northern Prairie Wildlife Research Center
Effects of Weather on Breeding Ducks in North Dakota
The dependence of waterfowl on aspects of spring weather for the timing of arrival
and the onset of breeding activities has long been part of biological folklore.
Despite an awareness of these associations, relations between weather and waterfowl
biology have rarely been quantified, partly because studies were too short to
elucidate clear dependencies. We examined the effects of temperature and precipitation
on waterfowl arrival, nesting, and production on two breeding areas in North Dakota.
Dates of arrival, initiation of first nests, and peak hatching, as well as length
of period of most active nesting, productivity, and brood size, were studied in
the mallard (Anas platyrhynchos), gadwall (A. strepera), blue-winged
teal (A. discors), and redhead (Aythya americana).
The areas we studied were on the J. Clark Salyer National Wildlife Refuge (Salyer)
in Bottineau and McHenry counties, and at the Woodworth Station, a field station
of the Northern Prairie Wildlife Research Center in Stutsman County, about 200
km southeast of Salyer. Basic climatological information is provided in Table
1; further details were presented by Jensen (1972).
Wetlands at Salyer are mainly impounded marshes managed with water control
structures on the Souris River. At Woodworth, however, the wetlands are natural
and include most of the classes described by Stewart and Kantrud (1971), although
only a few are semipermanent or permanent.
Table 1. Climatological information for the Salyer and Woodworth study areas.
|Mean Temperature (°C)
bWoodworth elevation=582 m.
cInterpolated from graphs in Jensen (1972).
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