A Noteworthy Record of the Swift Fox in McPherson County, Nebraska

An adult female swift fox (Vulpes velox) was killed by an automobile 1 mile E Ringgold, McPherson Co., Nebraska, on 25 March 1966. Standard external measurements (mm) of this specimen are: 723, 275, 132, 59, and weight, 2000 g. This record is approximately 80 miles south of the nearest occurrence listed by Jones (Univ. Kansas Publ., Mus. Nat. Hist., 16: 1-356, 1964) and appears to be the first verification of the occurrence of this fox in the Nebraska Sandhills, although specimens have been taken on all sides of this area. Jones (1964) indicated that this species may have been extirpated in Nebraska in the early 1900\u27s as there was only one record of specimens being taken in the State (a female and two kits in 1953 or 1954) since 1900. Although this record of the swift fox raises more questions concerning possible changes in its range and numbers than are answered, it merits attention particularly since Jones (1964) indicated that this species is making an apparent comeback in the southern portion of its range

Retrospective: Adjusting Contaminant Concentrations in Bird Eggs to Account for Moisture and Lipid Loss During Their Incubation

By the 1960s, research and monitoring efforts on chlorinated pesticide residues in tissues of wildlife were well underway in North America and Europe. Conservationists and natural resource managers were attempting to resolve whether pesticide exposure and accumulated residues were related to population declines in several species of predatory and scavenging birds (e.g., bald eagle Haliaeetus leucocephalus, peregrine falcon Falco peregrinus, brown pelican Pelecanus occidentalis and osprey Pandion haliaetus). The avian egg was a favored sampling matrix even before the realization that eggshell thinning was linked to population declines (Ratcliffe 1967; Hickey and Anderson 1968) and that the concentration of p,p’-DDE in an egg was associated with the shell thinning phenomenon (e.g., Blus et al. 1972; Wiemeyer et al. 1988). The necessity for making wet-weight concentration adjustments to account for natural moisture loss during incubation of viable eggs was realized. Correction for the more dramatic moisture loss in non-viable decaying eggs was recognized as being paramount. For example, the ∑DDT residues in osprey eggs were reported to vary by as much as eightfold without accounting for moisture loss adjustments (Stickel et al. 1965). In the absence of adjusting concentrations to the fresh wet-weight that was present at the time of egg laying, the uncorrected values exaggerated contaminant concentrations, yielding artifactual results and ultimately incorrect conclusions. The adjustment to fresh wet-weight concentration is equally important for many other persistent contaminants including PCBs, dioxins, furans, and brominated diphenyl ethers

Lead and Cadmium Concentrations in Mink from Northern Idaho

Northwest Science, Vol. 64. No. 4, 199

Retrospective: Adjusting Contaminant Concentrations in Bird Eggs to Account for Moisture and Lipid Loss During Their Incubation

By the 1960s, research and monitoring efforts on chlorinated pesticide residues in tissues of wildlife were well underway in North America and Europe. Conservationists and natural resource managers were attempting to resolve whether pesticide exposure and accumulated residues were related to population declines in several species of predatory and scavenging birds (e.g., bald eagle Haliaeetus leucocephalus, peregrine falcon Falco peregrinus, brown pelican Pelecanus occidentalis and osprey Pandion haliaetus). The avian egg was a favored sampling matrix even before the realization that eggshell thinning was linked to population declines (Ratcliffe 1967; Hickey and Anderson 1968) and that the concentration of p,p’-DDE in an egg was associated with the shell thinning phenomenon (e.g., Blus et al. 1972; Wiemeyer et al. 1988). The necessity for making wet-weight concentration adjustments to account for natural moisture loss during incubation of viable eggs was realized. Correction for the more dramatic moisture loss in non-viable decaying eggs was recognized as being paramount. For example, the ∑DDT residues in osprey eggs were reported to vary by as much as eightfold without accounting for moisture loss adjustments (Stickel et al. 1965). In the absence of adjusting concentrations to the fresh wet-weight that was present at the time of egg laying, the uncorrected values exaggerated contaminant concentrations, yielding artifactual results and ultimately incorrect conclusions. The adjustment to fresh wet-weight concentration is equally important for many other persistent contaminants including PCBs, dioxins, furans, and brominated diphenyl ethers

Organochlorine Pollutants and Population Status of Least Terns in South Carolina

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