Sciurus ignitus (Gray, 1867)

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 : 88-89

Sciurus ignitus (Gray, 1867)

Bolivian squirrel

TYPE LOCALITY: ‘‘ Bolivia,’’ near Yungas upper Río Beni, Departamento de Beni.

DESCRIPTION: This species is intermediate in size between the large red squirrels of the S. igniventris ­ spadiceus complex and the diminutive squirrels of the genus Microsciurus The upper parts are a uniform olivaceous brown, finely grizzled by individual black hairs. There is a small buffy postauricular patch and an indistinct pale eye­ring. The tail is long and slender, of the same ground color as the dorsum, but the hairs are tipped with orange or deep yellow in contrast to that of Microsciurus flaviventer . All specimens from the Rio Juruá had buffy venters. The skull is small, with a distinctly short rostrum, proodont incisors, and rather domed cranium There are four cheekteeth above and below Table 20 presents external and cranial measurements for specimens from the Rio Jurua´

DISTRIBUTION: As mapped by Emmons and Feer (1997), this species ranges south of the Marañón­Solimões axis from northeastern Perú and adjacent Brazil south through eastern Perú throughout Amazonian Bolivia and western Brazil. They indicated a questionable distributional hiatus in the Rio Juruá basin. However, we collected specimens in the headwaters of the Rio Juruá on the right bank and Vieira (1948) recorded a specimen from João Pessoa (= Eirunepe´), which is on the left bank in the central region of the river Additional specimens from this locality and from Igarapé do Gordão (which is near Eirunepé on the left bank) are in the collection of the Royal Natural History Museum in

Sweden (Patterson, 1992). We took all specimens only in either undisturbed or second growth terra firme forest.

REPRODUCTION: All specimens were taken in February during the rainy season. The three females were either pregnant (one, with 2 embryos) or lactating (two, each with 2 placental scars), and all males had scrotal and enlarged testes.

COMMENTS: The intermediate­sized tree squirrels of Amazonia are often placed in the genus (or subgenus) Guerlinguetus Gray (e.g., Hoffmann et al., 1993). Species boundaries, no matter how conceptually defined, are poorly understood, as the distinction between the western Amazonian S. ignitus and eastern S. aestuans remains to be investigat­ ed. Patterson (1992) treats the single specimen he examined from João Pessoa as representative of S. aestuans , and allocates it to the subspecies gilvigularis Wagner, which is considered a distinct species by Emmons and Feer (1997) and Hoffmann et al. (1993).

SPECIMENS EXAMINED (n = 18): (1) 1f — MNFS 1362; (3) 1f — JUR 223; (b) 6m, 2f — MNFS 1009­1010, 1017­1018, 1021­ 1023, 1043. Specimens from Royal Natural History Museum, Stockholm (see Patterson 1992): Igarapé do Gordão, 1f — RNHM 2314; João Pessoa [= Eirunepe´], 6m, 1f — RNHM 2103–2106, 2248, 2250, 2382.

MICROSCIURUS J. A. ALLEN, 1895