Here, we report that on six widely separated Scandinavian islands, the coal tit Parus ater has evolved morphologically in the direction of two absent competitors, the crested tit P. cristatus and the willow tit P. montanus, to the effect that it is up to 10% larger in linear dimensions than conspecifics on the adjacent Swedish mainland, where all three species coexist. The large size is genetic...

Ab stract : This paper presents a technique for embedding w ater mar k into video f ra mes. The proposed sche me is an i mpercept ible and a robust hy b r id video w ater mar king scheme. PCA i s appl i ed to each block of the tw o bands (LL – HH) w hich resul t fro m Discrete Wavele t t rans for m of every video f ra me. The w ater mark is e mbedded into the principal components of the LL bloc...

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...

Resumen.—La cuantificación del uso de hospederos a nivel comunitario por parte de parásitos de nido generalistas es importante porque representa una medida de los recursos que los parásitos necesitan para la reproducción. Durante los periodos reproductivos de los años 2002 a 2007, cuantificamos el uso de hospederos por parte de individuos de Molothrus ater en la Estación Biológica Konza Prairie...

Brown-headed cowbirds (Molothrus ater) might reduce populations of the songbird species they parasitize, including endangered species. Data are therefore needed on the frequency with which cowbirds use different species of foster parents. Hahn et al. propose a clever new approach by which the identity of foster parents can be inferred from host-specific lice the cowbirds acquire as nestlings. W...

Oceanic archipelagos are vulnerable to natural introduction of parasites via migratory birds. Our aim was to characterize the geographic origins of two Plasmodium parasite lineages detected in the Galapagos Islands and in North American breeding bobolinks (Dolichonyx oryzivorus) that regularly stop in Galapagos during migration to their South American overwintering sites. We used samples from a...

—Field studies of amphibians and reptiles rarely span more than two or three years necessitating that inferences concerning population biology of many forms are derived from brief snap-shots of their life history. In 2011 we resurveyed one small population of the Common Chuckwalla (Sauromalus ater) in the Lookout Mountain Preserve in the Phoenix Metropolitan region studied intensively during th...

Here we review the systematics of the threadsnakes of the Epictia goudotii Species complex in Middle and northern South America using external morphology and molecular data. Two species, Epictia goudotii and E. magnamaculata, are currently recognized from that region, but we provide evidence for recognizing, as species, three other nominal forms usually treated as subspecies of E. goudotii: E. ...