Publications

One egg was removed from five Wood Stork (Mycteria americana) nests at each of eight colonies in central and northern Florida in 1982. DDE and mercury were present in all eggs with concentrations ranging up to 9.4 and 0.73 ppm wet weight, respectively. PCBs were detected in 25 eggs (63%) with a high value of 3.5 ppm. Other organochlorine compounds occurred in less than 30% of the eggs...

Exposure of songbirds to organophosphate and carbamate pesticides is often determined by comparing the brain cholinesterase (ChE) activity of individuals that have been exposed with that of unexposed birds of the same species (e.g., see Busby et al. 1981, 1982; Hamilton et al. 1981). Knowledge of the normal pattern of ChE development in the brains of nestling and fledgling passerines is...

A general approach for obtaining solutions to a class of biological optimization problems is provided. The general problem is one of determining the appropriate time to take some action, when the action can be taken only once during some finite time frame. The approach can also be extended to cover a number of other problems involving animal choice (e.g., mate selection, habitat...

A method for evaluating the classification table from a discriminant analysis is described. The statistic, kappa, is useful to ecologists in that it removes the effects of chance. It is useful even with equal group sample sizes although the need for a chance-corrected measure of prediction becomes greater with more dissimilar group sample sizes. Examples are presented.

Grasshoppers (Orthoptera) were collected in pastures that had been sprayed with malathion and acephate to estimate the secondary exposure of insectivorous birds to those pesticides. Residues of malathion were below 3 ppm at 30 and 54 hours after spraying and no malaoxon was detected. In contrast, acephate was found at 8 and 9 ppm 4 hours after spray; 3–5 ppm of the toxic metabolite...

American kestrels (Falco sparverius) were randomly paired and fed 0, 10, or 50 ppm metallic lead in their diet from November 1979–May 1980. Lead levels were elevated in bones and livers of birds receiving the treated diets, particularly the 50 ppm treatment group. Differential deposition of lead was noted between males and females, with the highest levels in the females. No adverse...

Ninety-eight samples of 16 species of animals were collected at Lake Providence, 88 samples of 15 species at Lake Bruin, and 21 samples of 5 species at Lake St. John, Louisiana, between 15 July and 25 September 1980. Residues of 13 organochlorine compounds were identified in these samples. Substantial concentrations of many of these compounds throughout the food webs of all three lakes...

Results are reported for the embryotoxicity of 42 environmental contaminants applied externally to mallard (Anas platyrhynchos) eggs including crude and refined petroleum, and commercial formulations of herbicides and insecticides. Many of the petroleum pollutants were embryotoxic and moderately teratogenic and had LD50s of 0.3 to 5 μl per egg (∼6–90 μg/g egg). The most toxic was a...

The giant tortoises in the Galapagos Archipelago diverge considerably in size, and in shape and other carapace characteristics. The saddleback morphotype is known only from insular faunas lacking large terrestrial predators (i.e. Galapagos and Mauritius) and in Galapagos is associated with xeric habitats where vertical feeding range and vertical reach in agonistic encounters are adaptive...

No abstract available.

No abstract available.

No abstract available.