Effect of microwave irradiation (2.45 GHz, CW) on egg weight loss, egg hatchability, and hatchling growth of the Coturnix quail

Fertile eggs of the Coturnix quail were exposed twice a day for 30 min to 2.45-GHz continuous wave radiation at power densities of 25 or 50 mW cm-2 throughout the 17-day incubation period. Other eggs were exposed to 20 degrees C or 24 degrees C temperatures twice daily. Repeated exposures to 20 degrees C, 24 degrees C, or 25 mW cm-2 did not reduce hatchability. Irradiation at 50 mW cm-2 lowered hatchability, probably as a result of high egg temperatures. Hatchlings that had been irradiated by microwaves as embryos had normal growth rates and no obvious developmental abnormalities.

Aversion/attraction of blue jays to microwave irradiation

Aversion/attraction experiments were conducted to determine whether birds can perceive the presence of 2.45 GHz continuous wave microwave irradiation by observing whether Blue Jays (Cyanocitta cristata) exhibit an attraction or an aversion to the field when exposed to 25 and 50 mW/cm2. At power densities of 25 and 50 mW/cm2 Blue Jays exhibit an aversion to microwave irradiation.

The effects of microwave radiation on avian dominance behavior

Seventeen birds from 12 flocks were exposed to microwave radiation under various combinations of power density and duration; three birds from two additional flocks served as sham-exposed controls. Experiments were conducted outdoors at Manomet, Massachusetts (41 degrees 56'N, 70 degrees 35'W) under normal winter ambient temperatures. Although irradiated birds maintained their positions within a flock hierarchy with one exception, some appeared to have a change in their level of aggression after exposure.

JO. An evaluation of fecal analysis for determining food habits of insectivorous bats

To evaluate the reliability of fecal analysis in determining food habits of insectivorous bats, individual insects were identified to major taxa by the first author, weighed, enumerated, and fed to 14 female little brown bats (Myotis lucifugus). Fecal pellets were collected from these bats and sent to the second author without informing him of the insects which had been fed to the bats. The second author identified the insect fragments from the feces and determined the percent volume and percent frequency for each taxon. The four most common insect taxa recovered in the feces were the same as those in the diet and occurred in the same order of importance when expressed as percent volume and percent frequency. This blind test is the first to demonstrate that fecal analysis can yield reasonable estimates of food eaten by insectivorous bats, but it also indicates the amount of "error" that one can expect in these kinds of analysis.

Identification of androgen metabolic pathways in the brain of little brown bats (Myotis lucifugus): sex and seasonal differences

During the reproductive cycle of the little brown bat (Myotis lucifugus), the display of sexual behavior is out of synchrony with maximal gonadal development, suggesting that changes in plasma hormone levels per se are not the primary determinants of neural responsiveness. In the present study, we investigated pathways of androgen metabolism in the brain of the bat and compared brain aromatase activity in spring and in autumn. Tissue homogenates were incubated with [3H] androstenedione in the presence of an NADH/NADPH-generating system, and radiolabeled products isolated and their authenticity verified by recrystallization to constant specific activity. Aromatase was identified in preoptic/hypothalamic and adjacent limbic areas, and 5 alpha-reductase was detected in all major brain divisions. No gender-based differences in brain aromatase were seen in spring just prior to emergence from hibernation; however, activity was greater in males than in females when measured during maximal breeding activity in autumn. In addition, seasonal changes were evident in the preoptic/hypothalamic regions of both sexes (spring greater than autumn), although estrone yields from limbic tissues remained constant. Thus, in seasonally breeding species, the rate at which circulating androgen is converted to estrogen or other biologically active metabolites in the brain itself may be an important determinant of behavioral or feedback responsiveness.

A comparison of milk composition in Myotis lucifugus and Eptesicus fuscus (chiroptera: vespertilionidae)

Milk composition in two species of insectivorous bats (Myotis lucifugus and Eptesicus fuscus) was determined. No significant differences in fat, lactose, protein, or energy content were evident during the lactation period for M. lucifugus. The percentage of fat, lactose, and protein averaged 13.5, 3.3, 7.4, respectively, for M. lucifugus, and 16.4, 2.5, 6.2, respectively, for E. fuscus. Energy content of milk averaged 7.32 kJ/g for M. lucifugus and 8.37 kJ/g for E. fuscus. The percentage of lactose in milk from M. lucifugus was significantly greater than in E. fuscus, but there were no significant interspecific differences in percentages of fat or protein. The two species also differed significantly in content of five out of nine fatty acids.

Osteological and ocular anomalies in juvenile big brown bats (Eptesicus fuscus)

Osteological and ocular anomalies are reported from four wild-taken, juvenile (16–32 days old) big brown bats (Eptesicus fuscus) from eastern Massachusetts. Anomalies include polydactyly, deformed sacral and caudal vertebrae, underdeveloped radius and ulna, closed eyelids, unpigmented choroid layer, undifferentiated retina, and an underdeveloped lens. Bats with osteological anomalies showed no apparent ocular deformities and those with ocular deformities showed no evidence of bone anomalies. The combined incidence of anomalies represents 3.3% of the young bats born in this maternity colony in 1978.

Structure and dynamics of arthropod communities in bat guano deposits in buildings

This study characterizes the composition, structure, and dynamics of arthropod communities associated with bat guano deposits in buildings. Guano beneath three summer roosts of the little brown bat (Myotis lucifugus) in southern New Hampshire was sampled over a 1-year period.Twelve arthropod species are reported of which most are cosmopolitan associates of dried organic matter and stored products. Included are psocopterans, beetles, mites, hemipterans, a flea, and a pseudoscorpion. These taxa function as fungivores, sarcophages, predators, and ectoparasites.These simple arthropod communities exploit a seasonally rich resource produced by roosting bats. Nycteriglyphine mites were the first free-living colonizers of fresh guano deposits and were the most numerous arthropods throughout the year. Older guano deposits and those with the most diverse resource base generally supported the greatest number of species.Seasonal changes in communities included the presence of fleas only when bats were present, a greater number but lower diversity of other arthropod species when bats were present, and a more equitable distribution and abundance of species when bats were absent. Fresh, wet guano supported higher densities of fungivorous mites and flea larvae than did older, drier guano.

Night roosting and the nocturnal time budget of the little brown bat, Myotis lucifugus: Effects of reproductive status, prey density, and environmental conditions

The insectivorous bat Myotis lucifugus typically apportions the night into two foraging periods separated by an interval of night roosting. During this interval, many bats occupy roosts that are used exclusively at night and are spatially separate from maternity roosts. The proportion of the night which bats spend roosting, and thus the proportion spent foraging, vary both daily and seasonally in relation to the reproductive condition of the bats, prey density, and ambient temperature. A single, continuous night roosting period is observed during pregnancy. During lactation, females return to maternity roosts between foraging bouts, and night roosts are used only briefly and sporadically. Maximum use of night roosts occurs in late summer after young become volant. Superimposed upon these seasonal trends is day-to-day variation in the bats' nightly time budget. Long night roosting periods and short foraging periods are associated with cool nights and low prey density. This behavioral response may minimize energetic losses during periods of food scarcity.