Tag: American Kestrel

Antibody-mediated immunotoxicity in American Kestrels (Falco sparverius) exposed to polychlorinated biphenyls.

American Kestrel (Falco sparverius) Science Article 23 abstract Antibody-mediated immune function in adult and recently fledged (30 to 33 d old) American kestrels (Falco sparverius) was examined in birds exposed directly, or only in ovo, to polychlorinated biphenyls (PCBs). In 1998, 9 mature male and 9 female kestrels were fed PCBs, whereas 9 females and […]

Misdirected incubation in American Kestrels: a case of competition for nest sites?

American Kestrel (Falco sparverius) Science Article 20 abstract Reports of birds exhibiting unusual incubation behaviors are perhaps not surprising, giventhe wide variety of physical properties that can elicit incubation responses in birds (seeBaerends and Drent 1982). Birds that normally are solitary nesters occasionally have beendocumented sharing the same nest site (Terres 1982, Fournier and Hines […]

Nest Success of Southeastern American KestrelsAssociated with Red-Cockaded Woodpeckers inOld-Growth Longleaf Pine Habitat in Northwest Florida

American Kestrel (Falco sparverius) Science Article 8 abstract The Southeastern American Kestrel (Falco sparverius paulus), anon-migratory subspecies of the widespread American Kestrel, has declined tothe point that it is listed as threatened in Florida, the state in which it is mostcommon. We studied the nesting biology of Southeastern American Kestrels in1999 and 2000 at Eglin […]


American Kestrel (Falco sparverius) Science Article 19 abstract During 1983 and 1984 one adult member of 20 pairs of breeding kestrels was removedfrom the wild during the third week of incubation. We measured several variables, e.g., relative prey abundance, female body condition, territory size, amount of adjacent habitat, and time of removal at each experimental […]

Size dimorphism in mated pairs of American Kestrels

American Kestrel (Falco sparverius) Science Article 3 abstract The degree of dimorphism between males and females has been examined in a number of raptors (Storer 1966, Reynolds 1972, Balgooyen 1976, Snyder and Wiley 1976), but few studies have reported the amount of dimorphism between mated pairs of birds. If the maintenance of a size difference […]


American Kestrel (Falco sparverius) Science Article 16 abstract An Eastern Screech-Owl (Otus asio) was found incubating her own egg and that of a Southeastern American Kestrel (Falco sparverius paulus) in late March 1995. Three owlets and the kestrels uccessfully hatched in early May; all appeared normal. The kestrel was not present in the nest box […]

Plasma corticosterone in American kestrel siblings: effects of age,hatching order, and hatching asynchrony

American Kestrel (Falco sparverius) Science Article 18 abstract Although it is well documented that hatching asynchrony in birds can lead to competitive and developmental hierarchies, potentiallygreatly affecting growth and survival of nestlings, hatching asynchrony may also precipitate modulations in neuroendocrine developmentor function. Here we examine sibling variation in adrenocortical function in postnatally developing, asynchronously hatching […]

Haemoproteus tinnunculus in the American Kestrel (Falco sparverius)

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 […]

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 […]