American Kestrel (Falco sparverius) Science Article 2 abstract Unspecified species of Haemoproteus have been recorded from American Kestrels in Texas, Colorado and Panama; and Haemoproteus elani de Mello, 1935 has been recorded from kestrels in Oklahoma. However, there are no published identifications of Haemoproteus tinnunculus in this avian host in North America. This investigation reports […]
Tag: Falco sparverius
Sex-related differences in habitat selection in wintering American kestrels,Falco sparverius
American Kestrel (Falco sparverius) Science Article 1 abstract The American kestrel, Falco sparverius, has sex-related differences in habitat use during thenon-breeding season, with females occupying more open habitats than males. Two competinghypotheses have been proposed to explain this phenomenon: (1) males and females prefer differenthabitats, and (2) males and females prefer similar habitats, but larger […]
VOCAL DEVELOPMENT IN AMERICAN KESTREL (FALCO SPAR VERIUS) NESTLINGS
American Kestrel (Falco sparverius) Science Article 7 abstract We studied the acoustical characteristics of calls made by nestling American Kestrels (Falco sparverius). A total of 563 vocal samples was obtained from 88 chicks (49 males and 39 females) from 20 broods. Thirteen frequency, three numerical, and two temporal characteristics were measured using audio spectrography. Discriminant […]
The effects of temperature and artificial rain on the metabolism ofAmerican kestrels (Falco sparverius)
American Kestrel (Falco sparverius) Science Article 5 abstract The effect of rainfall on the metabolism of birds is poorly understood. We measured the metabolism as rate of oxygen consumption (V? O2)of four male and four female American kestrels (Falco sparverius) using open-circuit respirometry. We measured V? O2 during the spring atambient temperatures (Ta) of 5, […]
Possible relationships between morphology, territoryquality, and skin color of American Kestrels
American Kestrel (Falco sparverius) Science Article 10 abstract Carotenoid-based coloration of skin and plumage has been found to be correlated with individualquality in many species of birds during the breeding season. However, less is known about the possible role of thesesignals during the nonbreeding season, particularly among nonpasserines that defend winter territories. AmericanKestrels (Falco sparverius) […]
ISOLATION OF A HERPESVIRUS FROM AN AMERICANKESTREL WITH INCLUSION BODY DISEASE
American Kestrel (Falco sparverius) Science Article 13 abstract A herpesvirus was isolated from the liver of a captive-bred American kestrel(Falco sparverius) which had died of inclusion body disease. Initial isolation wasachieved in chicken embryo fibroblasts after three blind passages. Cell-adapted virusproduced a distinct rounding of CEF cells within 24 to 48 h. Biologic and serologictests […]
Regulation of Yolk-Androgen Concentrations byPlasma Prolactin in the American Kestrel
American Kestrel (Falco sparverius) Science Article 12 abstract The concentrations of maternally derived androgens in the yolks of avian eggs vary within and among clutches, but a mechanistic basis for this variation has not been elucidated. We investigated in the American kestrel, Falco sparverius, whether changes in plasma-prolactinconcentrations induced by changes in photoperiod and food […]
Copulatory behaviour and paternity in the American kestrel:the adaptive significance of frequent copulations
American Kestrel (Falco sparverius) Science Article 11 abstract The adaptive significance of repeated withinpair copulations is not well understood. We analysed thecopulatory behaviour of 16 pairs of solitary-nesting American kestrels, Falco sparverius, in southernQuebec (Canada), and the achieved reproductive success (paternity) of 21 kestrel families determined byDNA fingerprinting, in terms of four hypotheses. (1) The […]
Capture Rate of American Kestrel During NonbreedingSeason Influenced by Sex of Bird inUpstate South Carolina
American Kestrel (Falco sparverius) Science Article 9 abstract Assuming equal distribution of male and female American Kestrels (Falcosparverius) according to genetic frequency, a near equal capture rate might beanticipated (Cooke et al. 1987). Conversely, it is known that during the nestingseason males tend to provide most of the female’s energetic needs, so maleswould be more […]
Reverse mounting in the American Kestrel.
American Kestrel (Falco sparverius) Science Article 17 abstract Reverse mounting during mating has been reported in a number of avian orders (see James 1983 for review). Several authors imply that the behavior is aberrant (Ficken 1963, Nolan 1978, Thompson and Lanyon 1979), while others suggest that reverse mounting is a normal behavioral trait during courtship […]