Brown-headed cowbirds (Molothrus ater) are obligate brood-parasites, that is, female cowbirds lay their eggs in nests of other species. If the cowbird eggs are accepted, the host pair may raise the young cowbird, often at a reduction of the hosts’ reproductive success. Cowbird females are also known to remove host eggs and nestlings from nests, which may also affect the reproductive success of ...

Brood parasitism by Brown-headed Cowbirds (Molothrus ater (Boddaert, 1783)) often reduces the reproductive success of their hosts. We examined whether the ability of females to avoid or mitigate the costs of brood parasitism improved with age in a population of YellowWarblers (Setophaga petechia (L., 1766)) breeding near Revelstoke, British Columbia, between 2004 and 2011. Cowbirds parasitized ...

Obligate brood parasites must find host nests in which to lay their eggs. The search for a suitable host nest is predicted to be more difficult if the host nest is well-concealed by vegetation (nest-concealment hypothesis) and brood parasitism of better concealed nests should be less common than parasitism of less well-concealed nests. We experimentally tested this hypothesis by placing nest-bo...

Parasitoids are mostly insects that develop at the expense of other arthropods, which will die as a result of the interaction. Their reproductive success thus totally depends on their ability to successfully infest their host whose reproductive success relies on its own ability to avoid or overcome parasitism. Such intense selective pressures have resulted in extremely diverse adaptations in pa...

1. C. landanifer is a selfincompatible shrub which forms a major component of many Mediterranean habitats. It typically occurs in large, dense mono-species stands, though in some areas individuals may be more sparsely distributed. The plant produces prominent flowers which attract a wide diversity of pollinators. A proportion of these flowers subsequently develop into fruits which are subject t...

the ovipositiomil behaviour and success of anagyrus pseudococci (girault), an encyrtid endoparasitoid of mealybugs, planococcus citri (risso) and pseudococcus affinis (mask.) were studied in the laboratory. behavioural sequences during oviposition starting from the searching for the host to the post-oviposition activities were described. once encountered, the mealybug host was examined and ...

Identifying the factors used by an avian brood parasite to select host nests is important in understanding the determinates of individual reproductive success, yet such factors are poorly known for most parasitic species. Insights into these factors may come from understanding the conditions under which female parasites lay more than one egg per host nest (multiple parasitism). Using genetic te...

—Bot fl ies (Diptera: Muscidae: Philornis spp.) are a group of fl ies comprising mostly species with a Neotropical distribution. Their larvae parasitize several species of birds, living subcutaneously on altricial chicks. We investigated the eff ect of parasitism by bot fl ies (P. seguyi) on the reproductive success of Chalk-browed Mockingbirds (Mimus saturninus) in temperate grasslands near th...

Diaprepes abbreviatus L. is a highly polyphagous root weevil that causes damage to several fruit crops, ornamental plants, and other naturally occurring plants in Florida. Haeckeliania sperata Pinto is a gregarious endoparasitoid that attacks D. abbreviatus eggs. We hypothesized that the reproductive success of H. sperata is affected by the host plant of D. abbreviatus. Six host plants with var...