Feeding behaviour of Tympanoctomys barrerae, a rodent specialized in consuming Atriplex leaves

Tympanoctomys barrerae is a monotypic octodontid. This species is endemic t o the desert area of central-western Argentina where it is restricted to sa lt basins and sand dunes. T. barrerae shaves off the epidermis of Atriplex leaves before consuming them. This reduces electrolyte intake. Like two oth er unrelated salt-flat dwelling rodents, Dipodomys microps and Psammomys ob esus, T. barrerae uses the lower incisors to scrape the hypersaline tissue away from Atriplex leaves, only it spends less time in the shaving process. This difference could be accounted for by a peculiar anatomical structure: two bundles of stiff hairs on either side of the mouth that may be functio nally similar to a second set of lower incisors. (C) 2000 Academic Press.