Browsing by Author "PAVEZ, EF"

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    DIET SHIFTS OF BLACK-CHESTED EAGLES (GERANOAETUS-MELANOLEUCUS) FROM NATIVE PREY TO EUROPEAN RABBITS IN CHILE
    (1992) PAVEZ, EF; GONZALEZ, CA; JIMENEZ, JE
    For two years we studied the feeding ecology of Black-chested Eagles (Geranoaetus melanoleucus) in San Carlos de Apoquindo, central Chile. We estimated the diet of eagles using three different methods and evaluated the abundance of introduced European Rabbits (Oryctolagus cuniculus) throughout one year. Eagles preyed in decreasing order of frequency on mammals, reptiles, insects and birds. The biomass component of insects in the diet was negligible. At the species level, the European Rabbit was the most frequently consumed prey (43.9% by number and 81.7% by biomass). The diet composition changed only slightly throughout the year. During non-breeding seasons birds and insects were not consumed. Depending on the technique used, we found differences in the estimated diet. Birds were underestimated and insects were overestimated by direct observations of prey captures and transportations. In contrast, insects were underestimated by the analysis of prey remains. At the class level, the analysis of regurgitated pellets seems to represent the diet of eagles better. European Rabbits were present throughout the year in the study site, peaking during the eagles' breeding season, when kittens were abundant. Eagles preyed preferentially on small rabbits and apparently avoided large individuals. Eagles have increased their consumption of European Rabbits over time as did foxes in the study area.