Sciurus igniventris Wagner, 1842

PATTON, JAMES L., DA SILVA, MARIA NAZARETH F. & MALCOLM, JAY R., 2000, Mammals Of The Rio Juruá And The Evolutionary And Ecological Diversification Of Amazonia, Bulletin of the American Museum of Natural History 2000 (244), pp. 1-306 : 85-87

Sciurus igniventris Wagner, 1842

Northern Amazonian red squirrel

TYPE LOCALITY: Marabitanos, north of Rio Negro, Estado do Amazonas, Brazil.

DESCRIPTION: This is a large rufous squirrel with a long and bushy tail (Patton, 1984; see also summary in Lawrence, 1988: tables 1

and 2). The species is readily distinguished from the closely similar S. spadiceus by its conspicuous bright orange postauricular patches and uniformly rusty orange limbs and upper surfaces of both fore and hind feet that lack a mixture of black hairs. The single specimen collected from the Rio Juruá has a sparsely haired, pale orange, as opposed to white, venter, and its tail hairs have six alternating bands of black and orange color, with black at the base terminating in a deeporange tip. The overall dorsal color is similar to that of S. spadiceus , but is darker orange or rust, with fewer black hairs, resulting in a more uniform color. The skull is shorter, with larger orbits, shorter rostrum, and broader palate (fig. 60). In all respects, comparisons of measurements given in table 19 are of the same general magnitude, and direction of difference, as those recorded for samples of the

two species from throughout Ecuador and Perú (Patton, 1984).

DISTRIBUTION AND HABITAT: As mapped by Emmons and Feer (1997), this species extends across northern Amazonia, west of the Rio Branco and lower Rio Negro in northcentral Brazil to the Andean foothills in southeastern Colombia, eastern Ecuador, and eastern and central Perú, extending as far south as the upper Río Ucayali drainage (Patton, 1984). It is apparently not known from central Amazonia south of the Solimões­ Amazonas axis and east of the Rio Jurua´. Our single specimen was taken on the left bank of the Rio Juruá near the river mouth (locality 14). Large squirrels were observed, but not taken, in the central regions of the river on both banks, but all of these were identified in the field as S. spadiceus . Wheth­ er S. igniventris has a more extensive distribution within the Rio Juruá basin is un­ known. Individuals of this species were observed only in undisturbed or second growth terra firme; none were seen or collected in várzea.

REPRODUCTION: Our single specimen is an adult female that lacked evidence of prior reproductive activity; it was collected in May 1992.

SPECIMENS EXAMINED (n = 1): (14) 1f— JUR 547.