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J.G. Rogers

Publications and source records attributed to J.G. Rogers.

4 recordsLinked to original sources
USGS2013

Effect of salt on the response of birds to sucrose

The preference of male red-winged blackbirds for solutions of sucrose and sucrose with 0.03 M sodium chloride was tested, using a two-bottle choice test. Preliminary experiments demonstrated that the birds were indifferent to 0.03 M NaCl in water. Both control and experimental animals exhibited indifference to the solutions at the lowest concentration and aversion at the highest. The data suggest that the added sodium chloride makes the sucrose stimulus more discriminable.

Physiological Psychology↗
USGS1976

Influence of stimuli from populations of Peromyscus leucopus on maturation of young

The effects of stimuli associated with conspecific laboratory populations on parameters of sexual maturation in Peromyscus leucopus were examined. Beginning at birth, experimental litters were exposed to the constant infusion of urine, feces, and other material from the populations through a metabolism funnel into their cages. As evidenced by age at first vaginal estrus, experimental females matured later than controls. They also had lighter weight reproductive organs. Testis weights were much greater in control than experimental males. These data suggest that stimuli from populations of P. leucopus can inhibit reproductive maturation of conspecifics. In view of the well-documented effects of chemical stimuli on reproductive maturation and function in other rodents, it is suggested that chemical stimuli in the feces, urine, or from other sources mediated the reproductive inhibition observed in this study.

Journal of Mammalogy↗
USGS1974

Percutaneous absorption of several chemicals, some pesticides included, in the red-winged blackbird

Percutaneous absorption in vivo through the skin of the feet of the red-winged blackbird (Agelaius phoeniceus) has been investigated. Absorption after 18-24 hours exposure to 0.01 M solutions of salicylic acid, caffeine, urea, 2,4-D, dieldrin, diethylstilbesterol, and DDT was measured. Of these, only DDT and diethylstilbesterol were not absorbed to a measurable degree. The solvents ethanol, dimethylsulfoxide (DMSO), and vegetable oil were compared with water in their effects on the absorption ofcaffeine, urea, and salicylic acid. Ethanol, DMSO,and oil each decreased percutaneous absorption of salicylic acid. DMSO increased absorption of caffeine, and ethanol had no effect on it. Neither DMSO nor ethanol affected penetration of urea. Partition coefficients (K) (epidermis/water) were determined for all seven penetrants. Compounds with higher values of K showed lower percutaneous absorption. These findings suggest that K may be useful to predict percutaneous absorption in vivo. It appears unlikely that percutaneous absorption contributes greatly to the body burden of 2,4-D and dieldrin in A. phoeniceus.

Environmental Physiology and Biochemistry↗