Intra- and interspecific variation in home-range size in sympatric tuco-tucos, Ctenomys australis and C. talarum

CUTRERA AP; MORA MS; ANTINUCHI, CD; VASSALLO AI

JOURNAL OF MAMMALOGY

ALLIANCE COMMUNICATIONS GROUP DIVISION ALLEN PRESS

Lugar: Lawrence; Año: 2010 vol. 91 p. 1425 - 1434

0022-2372

Despite the fundamental nature of the home range to the biology of a species, aspects of its size, shape, andstructure are not well defined in certain groups, such as subterranean rodents. These rodents, characterized bylimited individual mobility and a patchy distribution of local populations, generally defend multipurposeterritories in which breeding and foraging take place, increasing the chances for trade-offs among factors ofhabitat quality. The present study assessed the home-range size and shape of 2 species of tuco-tucos, Ctenomysaustralis (300–600 g) and C. talarum (100–180 g), using radiotelemetry in an area where they occur insympatry, and explored the factors that could influence space use in these subterranean rodents. Home-rangesize (95% adaptive kernel) of C. australis (1,282.22 6 1,014.83 m2) was ,19-fold larger than that of C.talarum (66.69 6 22.34 m2). The area covered daily by C. australis represented only about 9% of the totalhome-range size estimated by radiotelemetry in this study and was almost twice as large as that of C. talarum,but the area covered by the latter species represented an average of 35% of its total home-range size. Totalaerial and subterranean plant biomass, plant cover, and soil hardness were significantly higher in the habitatoccupied by C. talarum. Contrary to expectation, body size was not the predominant factor explaining intra- andinterspecific variation in home-range size. We discuss how variation in food availability in space and time anddifferences in the intensity of polygyny could be more important factors shaping home-range size in this genusof subterranean rodents. DOI: 10.1644/10-MAMM-A-057.1.