Predation upon the subterranean rodent Ctenomys talarum (tuco-tucos) by Buteo polyosoma (red-backed hawks) in coastal grasslands of Argentina

AV BALADRÓN; AI MALIZIA; MS BÓ

STUDIES ON NEOTROPICAL FAUNA AND ENVIRONMENT

Taylor & Francis

Año: 2009 vol. 44 p. 61 - 65

0165-0521

Differential predation upon tuco-tucos (Ctenomys talarum) by red-backed hawks (Buteo polyosoma) is reported, considering the characteristics that could lead to prey vulnerability and to predator selectivity. Predation was evaluated through analysis of 100 pellets and 20 prey remains collected in coastal grasslands at Mar de Cobo (Buenos Aires, Argentina) during winter (May to August) 2003-2004. The tuco-tucos represented the main component in the diet of red-backed hawks, registering a high consumption of sub-adult individuals (49.3%). Juvenile individuals (42.0%) were overrepresented and adults (8.7%) were underrepresented in relation to their field frequencies (14.4 and 43.1%, respectively), whereas sub-adults did not show significant differences. This high consumption of smaller tuco-tucos would be based on the higher vulnerability of young individuals to predation rather than raptor´s handling constraints on bigger individuals. Our results indicate that a strong predator-prey relationship between tuco-tucos and red-backed hawks is established at the study area, and that tuco-tucos represent a key component for the survival of wintering hawks.