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Full-Text Articles in Life Sciences

Thermal Constraints On Foraging Activity Of Adult Starlings, Larry Clark Jan 1987

Thermal Constraints On Foraging Activity Of Adult Starlings, Larry Clark

Larry Clark

The operative temperature of the environment was estimated for starlings using hollow, unheated taxidermic mounts. On average, adults foraging in full sun were characterized by shorter foraging bouts than those adults foraging in full shade. Simultaneous observations of air temperature, operative temperature, and the foraging duration of adults indicated that air temperature was a poor predictor of the maximum length of a foraging bout. The operative temperature of the environment was not correlated to the maximum and mean length of foraging bouts for temperatures below 31.5 ~ C, but was negatively related to maximum and mean foraging duration for values …


Olfactory Discrimination Of Plant Volatiles By The European Starling, Larry Clark, J Russell Mason Jan 1987

Olfactory Discrimination Of Plant Volatiles By The European Starling, Larry Clark, J Russell Mason

Larry Clark

Passerine species that re-use nest sites often incorporate fresh green vegetation into their nests, a behaviour consistent with the possibility that some birds may use chemical properties of plants to counteract the selective potential of parasites and pathogens. We tested adult starlings (Sturnus vulgaris) for their physiological capacity and behavioural ability to detect and discriminate between volatiles emitted from plant material. Multi-unit electrophysiological recordings from olfactory nerves of adults indicated that strong responses were reliably elicited by volatiles from six plant species. After pairings of plant volatiles with gastro-intestinal malaise, birds exhibited conditioned avoidance in behavioural experiments, and made all …


Genetic Compatibility Of Aedes (Protomacleaya) Triseriatus With A. (P.) Brelandi And A. (P.) Hendersoni (Diptera: Culicidae)., David B. Taylor Jan 1987

Genetic Compatibility Of Aedes (Protomacleaya) Triseriatus With A. (P.) Brelandi And A. (P.) Hendersoni (Diptera: Culicidae)., David B. Taylor

David B Taylor

Interspecific hybridization was used to examine reproductive compatibility of Aedes (Protomacleaya) triseriatus (Say) with Aedes (P .) brelandi Zavortink and Aedes (P.) hendersoni Cockerell. Most male progeny were sterile intersexes when A. brelandi or A. hendersoni males were crossed with A. triseriatus females. Female hybrids, and males from the reciprocal crosses, were morphologically normal and fertile. Varying percentages of intersex males were observed among progeny when normal F1 hybrids were crossed to either parental species or with other hybrids. Egg and female sterility resulting from a partial incompatibility between A. triseriatus cytoplasm and A. brelandi male-determining chromosome was observed. No …


Degree Of Behavioral Neoteny Differentiates Canid Polymorphs, R Coppinger, J. Glendinning, E. Torop, C. Matthay, M. Sutherland, C. Smith Dec 1986

Degree Of Behavioral Neoteny Differentiates Canid Polymorphs, R Coppinger, J. Glendinning, E. Torop, C. Matthay, M. Sutherland, C. Smith

Charles Kay Smith

As with juvenile wolves or coyotes, adult livestock conducting dogs displayed the first-half segment of a functional predatory system of motor patterns and did not express play or social bonding toward sheep; whereas, like wolf or coyote pups, adult livestock protecting dogs displayed sequences of mixed social, submissive, play and investigatory motor patterns and rarely expressed during ontogeny (even when fully adult) predatory behaviors. The most parsimonious explanation of our findings is that behavioral differences in the two types of livestock dogs are a case of selected differential retardation (neoteny) of ancestral motor pattern development.