Planet of Birds

Shiny Cowbird (Molothrus bonariensis) Science Article 1 abstract I studied the interaction between a brood parasite, the Shiny Cowbird (Molothrusbonariensis), and a large host, the Rufous-bellied Thrush (Turdus rujventris), in the Pampas Region of Argentina. Shiny Cowbird eggs were observed in 34 out of 70 (48.6%) thrush nests throughout the host’s breeding season. The main […]

Shiny Cowbird (Molothrus bonariensis) Science Article 7 abstract Feeding associations between capybaras Hydrochoerus hydrochaeris (Linnaeus, 1766) and some bird species were registered in the Lami Biological Reserve, southern Brazil, through observations in a set of transects established in the five major vegetation types of the study area: shrubby and herbaceous swamps, wet grasslands, sandy grasslands […]

Shiny Cowbird (Molothrus bonariensis) Science Article 3 abstract Hellmayr (Field Mus. Nat. Hist. Publ. 347, Zoo1. Set. vol 13, 1935, p. 319) includes Surinam in the range of Conirostrum bicolor on evidence of the Penard brothers (Vogels van Guyana, 2, 1910, p. 475), though he mentions no specimens nor localities. In Surinam, as elsewhere in […]

Shiny Cowbird (Molothrus bonariensis) Science Article 9 abstract Host selection by brood parasitic Shiny Cowbirds (Molothrus bonariensis) was studied at two sites in Buenos Aires Province, Argentina. The eggs of the parasite are either spotted or immaculate, so host selection was studied with respect to egg type as well as to site. Immaculate eggs were […]

Shiny Cowbird (Molothrus bonariensis) Science Article 2 abstract Parasitic cowbirds lay eggs in the nests of other species and dupe them into caring for their young. Unlike other brood parasites,cowbirds have not developed egg mimicry or bizarre chick morphology. However, most of them parasitize a large number ofhosts. Several features of cowbirds have been proposed […]

Shiny Cowbird (Molothrus bonariensis) Science Article 5 abstract The Rufous-collared Sparrow or Chingolo (Zonotrichia cupensis) is one of the main hosts of the Shiny Cowbird (Molothrus bonariensis) through most of their overlapping range in South America. The most recent study on the interaction between these species was carried out by King (1973) in Horco Molle, […]

Shiny Cowbird (Molothrus bonariensis) Science Article 4 abstract I analyzed the origin, distribution, and hosts of the Shiny Cowbird (Molothrus bonairensis) in Chile, using specimen records and the literature. It is more likely that the species was introduced to Chile before natural dispersal could take place from Argentina. The earliest specimens are from mid-1865 and […]

Shiny Cowbird (Molothrus bonariensis) Science Article 8 abstract The Shiny Cowbird (Molothrus bonariensis) of South America, Panama, and the West Indies is an obligate brood parasite known to have used 176 species of birds as hosts. This study documents wide variability in the quality of real and potential hosts in terms of response to eggs, […]

Shiny Cowbird (Molothrus bonariensis) Science Article 6 abstract Recent human settlement in Brasilia, Central Brazil, has greatly reduced the extent of native cerrado vegetation. This has favored the Shiny Cowbird, Molothrus bonariensis,which is common in farmland and certain urban sites. Between September and December of 1982 to 1984, we observed cowbird nestlings(n) or fledglings(f) attended […]