Development of Sarcocystis falcatula in its intermediate host, the Brown-headed Cowbird (Molothrus ater)

Development of Sarcocystis falcatula in its intermediate host, the Brown-headed Cowbird (Molothrus ater).

Sporocysts of Sarcocystis falcatula obtained from experimentally infected Virginia opossums (Didelphis virginiana) were inoculated orally to 60 wild-caught Brown-headed Cowbirds (Molothrus ater). Another 30 Brown-headed Cowbirds were not challenged and served as uninfected controls. Two inoculated and one control cowbird were necropsied every 2 weeks and the pectoral and thigh muscles were exam...

FEMALE INFLUENCE IN THE BROWN-HEADED COWBIRD (Molothrus ater): AN INVESTIGATION OF EMERGING SOCIAL ECOLOGIES

Mite-filled cyst on a Brown-headed Cowbird (Molothrus ater) in Florida, USA.

A large, partly pedunculated mass on the scapular area of a wild-caught captive Brown-headed Cowbird (Molothrus ater) consisted of a multiloculated keratin cyst inhabited by a new species of harpirhynchid mite (Harpirhynchus quasimodo). The mass did not interfere with flight or behavior. This is the first record of such an infestation of cowbirds in Florida.

Brown-headed Cowbird (molothrus Ater) Parasitism on Warbling Vireos (vireo Gilvus) in Southwest Colorado Catherine

A8s~~nc~.-From May through July, 1993-1998 and 2001, effects of Brown-headed Cowbird (Molothrus ater) parasitism on 36 Warbling Vireo (Vireo gilvus) nests were documented in southwest Colorado. Overall parasitism was 75.0% and was the major source of nest failure. Among vireo nests that were not depredated, a significantly lower proportion of parasitized nests (10.2%) than nonparasitized nests ...

Brown-Headed Cowbird (Molothrus ater) Response to Pyrotechnics andLethal Removal in a Controlled Setting

Pyrotechnics have long been used to frighten birds from specific areas but birds might habituate to them. Anecdotal and limited published reports suggest that killing a flock member can reduce habituation. However, little behavioral work has been conducted in this area. We exposed brown-headed cowbirds (Molothrus ater) to noise from either 0.22 caliber blanks or 15-mm pyrotechnics in a series o...