Abstract
Based on the content of feces, we studied the food habits of the endangered rodent Chinchitta lanigera. On a seasonal basis, during two years of contrasting rain levels (1992 = 242 mm; 1993 = 123 mm), we collected chinchilla feces from El Cuyano ravine, adjacent to the Chinchilla National Reserve in north central Chile (31° 29′10.8t” S, 71°03′43.9t” W). The main plant species eaten was the perennial graminoid Nassetta chilensis. Chinchillas showed a broader trophic niche during the rainy year, than during the dry year, consuming 55.5 and 40.7% of the 38 and 27 plants available, respectively. Within the wet year the diet differed less between winter and summer (Horn similarity index R0 = 0.58) than within the dry year (R0 = 0.83). Between years, the diet differed more during winters (R0 = 0.20) than during summers (R0 = 0.52). Chinchillas are folivorous, using a feeding pattern of a generalist species. The opportunistic feeding behavior of chinchillas may be an adaptation to the harsh conditions and high variability in food availability triggered by fluctuations in rainfall among years in the arid north central Chile.
Zusammenfassung
Anhand der Zusammensetzung von Kotproben studierten wir die Ernährungsgewohnheiten des gefährdeten Nagers Chinchilla lanigera. In zwei Jahren unterschiedlicher Niederschlagshäufigkeit (1992: 242 mm; 1993: 123 mm) sammelten wir in verschiedenen Jahreszeiten Chinchilla-Kotproben in der El Cuyano-Schlucht, die an das Chinchilla-National-Reservat im nördlichen Zentral-Chile (31° 29′10.8″ S, 71° 03′43,9″ W) angrenzt. Die wesentliche Futterpflanze ist die mehrjährige Gramineen-Art Nassella chilensis. Chinchillas zeigten während des niederschlagsreicheren Jahres eine weitere trophische Nische als während des Trockenjahres. Beobachtet wurden die Nutzung von 55,5% bzw. 40,7% von jeweils 38 bzw. 27 verfügbaren Pflanzen. Während des niederschlagsreicheren Jahres variierte die Nahrungszusammensetzung zwischen Winter und Sommer weniger (Horn-Index R0 = 0,58) als während des Trockenjahres (R0 = 0,83). Im mehrjährigen Vergleich sind größere Unterschiede im Winter (R0 = 0,20) als im Sommer (R0 = 0,52) zu beobachten. Chinchillas sind herbivore Generalisten, deren opportunistische Ernährungsgewohnheiten als Anpassung an die Aridität und die niederschlagsbedingten Änderungen im Nahrungsangebot im nördlichen Zentral-Chile zu deuten sind.
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Cortés, A., Miranda, E. & Jiménez, J.E. Seasonal food habits of the endangered long-tailed chinchilla (Chinchilla lanigera): the effect of precipitation. Mamm Biol 67, 167–175 (2002). https://doi.org/10.1078/1616-5047-00024
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DOI: https://doi.org/10.1078/1616-5047-00024