Cattle tyrant

Abstract: We present the first documented record of the Cattle Tyrant Machetornis rixosa (Vieillot, 1819) to the midwest of Goias State. One specimen was photographed in an urban area in the municipality of Ipora. This record extends the geographical distribution of M. rixosa for about 248.75 km northeast over the nearest boundary. Its expansion is probably related to the increase of grasslands and other modified areas, or may result from a lack of ornithological studies in the Cerrado.

Abstract: Several birds associate with grazing mammals to use them as perches, beaters or to feed on ectoparasites. Here, foraging strategies of the cattle-tyrant associated and non-associated to capybaras were compared. The study was developed in urban areas of Campinas, Brazil. Seventeen feeding bouts of cattle tyrants associated with capybaras and 16 of cattle tyrants in the absence of capybaras were timed. Feeding bouts of birds associated with capybaras were significantly longer than those of birds not associated with the mammals. This may be associated with the fact that association with capybaras enhance the birds efficiency in catching arthropods.

Abstract: Some bird species feed on external parasites, such as ticks and flies, on the body of mammals (hosts or clients). So called cleaner birds that occur in Brazil were reviewed recently, but gathering of significant new data indicates the need for an update and a brief reappraisal of such association. New records raise the number of known clients for some cleaning birds. The Southern Caracara (Caracara plancus) picks ticks on cattle, and the Black Caracara (Daptrius ater) picks ticks on capybaras. The Wattled Jacana (Jacana jacana) picks ticks, horseflies, arthropods and organic debris on capybaras, and tick-picking on capybaras by the Shiny Cowbird (Molothrus bonariensis) is substantiated by photographs. The Cattle Tyrant (Machetornis rixosa) deftly catches horseflies on capybaras, and these latter clients are recorded posing for the Giant Cowbird (Molothrus oryzivorus), which also pick parasites from the marsh deer. The Cattle Egret (Bubulcus ibis) definitely picks ticks directly on cattle. With the new records, some poorly documented or controversial issues in the literature are here confirmed, a hypothesis is validated, and a suggestion is invalidated.