Publications

Most of the 27 species and subspecies of surviving crocodilians have declining populations and 22 of them are considered to be severely endangered (IUCN 1971). The United States population of the American Crocodile is no exception; it probably numbers between I00 and 300 individuals (OGDEN 1976). Nests of the species have been regularly surveyed by the staff of Everglades National Park...

Various studies (Mulla et al. 1963; Ferguson and Gilbert 1967; Cooke 1973) have examined the effects of pesticides on anuran amphibians, but the routes of contaminant uptake by transformed amphibians have not been evaluated. The need of frogs and toads to imbibe water from natural surface water would seem to make them vulnerable to uptake from this source. Fish are known to accumulate...

Over a period of years interested individuals have submitted many dead or moribund herons of various species to our laboratory to learn whether the birds had been affected by diseases or organochlorine poisoning. Residue concentrations in carcasses of birds and mammals are considered the best measure of sublethal exposure, whereas residues in brains are best to use for diagnosing death...

The population ecology of the royal tern Sterna maxima and sandwich tern Sterna sandvicensis was investigated in South Carolina from 1970 through 1977. Royal and sandwich terns nested together in all of the colonies that we located. The peak in egg laying usually occurred in early May; peak hatching occurred from late May to mid-June. Clutch size for both species was one egg. Tidal...

Modern man serves as both a direct and an indirect cause of the death of birds. In the early 1970's, human activity was responsible for the death of approximately 196 million birds per year, or about 1.9% of the wild birds of the continental United States that died each year. Hunting was the largest direct mortality factor and accounted for about 61% of human related bird deaths. Control...

No abstract available.

Geese are assumed to accumulate fat on the winter range (Bent 1962, Williams 1967) to sustain them through the long northward migration and early part of the nesting season. However, there are no weights given in the literature of lesser snow geese (Anser c. caerulescens) on their winter ranges to compare with weights on the breeding grounds. For many years biologists relied on Kortright...

No abstract available.

Examination of 8,141 adult mourning doves (Zenaida macroura) in North and South Carolina revealed that substantial numbers complete primary feather molt in September. Adult mourning doves shed primaries at the rate of 1 per 14 days. No difference was found in this rate between sexes or among years, 1969-74. The initiation of molt differed from year to year, and female molt always...

In 1972 and 1974, 112 dead or moribund snow geese (Chen c. caerulescens), mostly immature white-phase males, were found in a study area on the Garwood Prairie, Texas. Dying geese were observed within 2 days after rice fields planted with aldrin-treated seed were flooded by heavy tains6n 21 March 1972 and 25 March 1974. Brains from 8 snow geese that were moribund when found contained an...

Aerial censusing has been used to determine densities of many large mammals, including deer (Odocoileus virginianus) in agricultural areas or deciduous forests (Saugstad 1942, Morse 1946, Petrides 1953, Sanderson 1953, Berner pers. comm.). However, observability of deer from the air remains a problem in northern coniferous forests. LeResche and Rausch (1974) determined that even with the...

No abstract available.