Diet of the mara (Dolichotis patagonum), food availability and effects of an extended drought in Northern Patagonia (Mendoza, Argentina)

SILVIA PUIG; MONICA I. CONA; FERNANDO VIDELA ; EDUARDO MENDEZ

ZEITSCHRIFT FUR SAUGETIERKUNDE-INTERNATIONAL JOURNAL OF MAMMALIAN BIOLOGY

Elsevier Gmbh

Año: 2010 vol. 75 p. 389 - 398

0044-3468

The mara is a near threatened Cavi omorph, endemic to Argentina. Studies on feeding ecology allow assessment ofthe dietary adaptability of maras to habitat changes. The mara diet and food availability on two sampling sites,belonging to distinct landscapes of Northern Patagonia, were estimated using microhistological analysis and point-quadrat transects, over four seasons, and besides during an extended drought. Significant differences were detected byKruskall-Wallis ANOVA, feeding selection by the w2test, and dietary preferences by Bailey?s confidence interval.Grasses dominated food availability, with Panicum and Poa as major spec ies, followed by shrubs and scarce forbs.Plant cover and forbs increased in spring and summer. The drought caused a strong decrease in plant cover andproportion of grasses. Maras ate all grass species, most forbs and several shrubs. Grasses dominated the diet, with Poaand Panicum be ing the major species, supplemented by the shrubs Lycium and Prosopis. Maras ate more grasses andforbs in spring and summer, and shrubs in autumn and winter. More shrubs and forbs, and less grasses, were eatenduring the drought. Plant categories wer e used selectively only in autumn and winter, and in the drought period, withpreference for shrubs and avoidance of grasses. Bromus, Poa, Plantago and Prosopis were preferred, and Panicumavoided. The mara qualified as a grazer but shifted to a mixed feeder during the drought. Dolichotis patagonum sharedhabitats with several big and medium-sized herbivores and showed the highest dietary similarities with plain vizcachas,brown hares and horses. Protective measures for natural habitats are needed, given that increasing impacts on foodresources and habitat quality could be threats to the survival of maras and other wild vertebrates in NorthernPatagonia.