Douglas Johnson (Former Employee)

Abstract has not been submitted

The Apparent estimator of nest success may be severely biased because unsuccessful nests are less likely to be found than are successful nests. The Mayfield estimator is a preferred alternative. The situation is somewhat different for nests in colonies or on islands because of greater visibility of nests, higher synchrony of nesting, and often higher hatch rates than dispersed mainland...

Review of: Ornithology. Frank B. Gill. New York : W.H. Freeman, 1990. ISBN: 0716720655.

Body mass of adult female and male sandhill cranes (Grus canadensis) increased an average of 17 and 20%, respectively, from early September to late October on staging areas in central North Dakota and varied by year. Increases in body mass averaged 550 and 681 g among female and male G. c. canadensis, respectively, and 616 and 836 g among female and male G. c. rowani. Adult and juvenile...

During 1976-81 we weighed several thousands of wild Mallard, Gadwall, and Blue-winged Teal in central North Dakota to examine duckling growth patterns, adult weights, and the factors influencing them. One-day-old Mallard and Gadwall averaged 32.4 and 30.4 g, respectively, a reduction of 34% and 29% from fresh egg weights. In all three species, the logistic growth curve provided a good...

A straightforward least squares method of estimating the rate at which birds molt feathers is presented, suitable for birds captured more than once during the period of molt. The date of molt onset can also be estimated. The method is applied to male and female mourning doves.