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Robert G. Heath

Publications and source records attributed to Robert G. Heath.

4 recordsLinked to original sources
USGS1969

Nationwide residues of organochlorine pesticides in wings of mallards and black ducks

Nationwide monitoring of organochlorine pesticides in wings of more than 24,000 mallards and black ducks bagged during the1965 and 1966 hunting seasons showed DDE to be the predominant residue, followed in order by DDT, DDD, dieldrin, and heptachlor epoxide. Residues were generally highest in wings from the Atlantic and Pacific Flyways, and lowest in the Central Flyway. DDE was reported for every State and was notably high in wings from New Jersey, Massachusetts, Connecticut, Rhode Island, New York, Pennsylvania, Alabama, California, and Utah. Dieldrin residues were prevalent in wings from Arkansas, Texas, Utah, California, and several Stales in the Atlantic Flyway.

Pesticides Monitoring Journal↗
USGS1965

A method for estimating fall adult sex ratios from production and survival data

This paper presents a method of utilizing data relating to the production and survival of a bird population to estimate a basic fall adult sex ratio. This basic adult sex ratio is an average value derived from average production and survival rates. It is an estimate of the average sex ratio about which the fall adult ratios will fluctuate according to annual variations in production and survival. The basic fall adult sex ratio has been calculated as an asymptotic value which is the limit of an infinite series wherein average population characteristics are used as constants. Graphs are provided that allow the determination of basic sex ratios from production and survival data of a population. Where the respective asymptote has been determined, it may be possible to estimate various production and survival rates by use of variations of the formula for estimating the asymptote.

Journal of Wildlife Management↗