Bassaricyon alleni Thomas, 1880:397.

Helgen, Kristofer M., Pinto, C. Miguel, Kays, Roland, Helgen, Lauren E., Tsuchiya, Mirian T. N., Quinn, Aleta, Wilson, Don E. & Maldonado, Jesus E., 2013, Taxonomic revision of the olingos (Bassaricyon), with description of a new species, the Olinguito, ZooKeys 324, pp. 1-83 : 30-34

Bassaricyon alleni Thomas, 1880:397.

Bassaricyon beddardi Pocock, 1921a: 231.

Bassaricyon medius siccatus Thomas, 1927:80.

Type specimens and localities.

The holotype of alleni is BMNH 80.5.6.37, an adult female (skin and skull), from "Sarayacu, on the Bobonasa River, Upper Pastasa River … this must not be confused with the far larger and better known Sarayacu on the Ucayali in Peru", in Amazonian Ecuador ( Thomas 1880). An image of the holotype as a living animal was figured by Thomas (1880: plate XXXVIII), and the anatomy of this specimen was further discussed by Mivart (1885, 1886).

The holotype of beddardi was an adult female, from "Bastrica Woods, Essequibo River", Guyana ( Flower 1895; Pocock 1921a), and was an animal that lived in the London Zoological Gardens from 1894 to 1900 (Beddard 1900; Allen 1908). Aspects of the internal anatomy of this specimen were described in detail by Beddard (1900), and the skull of this specimen was figured and discussed by Pocock (1921a), who also mentioned the specimen was prepared as a skeleton ( Pocock 1921b), but apparently this specimen was not retained as a museum specimen in the collections of the BMNH, and now cannot be found (D. Hills, BMNH, in litt., 2004).

The holotype of siccatus is BMNH 27.5.3.2, an adult female (skin and skull), from "Guaicaramo, on the Llanos of Villavicencio, east of Bogata, about 1800 feet", Colombia ( Thomas 1927).

Diagnosis.

Bassaricyon alleni is a medium-sized olingo, smaller than Bassaricyon gabbii of Mesoamerica, and larger than Bassaricyon neblina of the Andes. It requires closest comparison with the closely-related and allopatrically-distributed taxon Bassaricyon medius , from which it differs especially in having (externally) more strikingly black-tipped dorsal pelage (giving the pelage a slightly darker appearance in Bassaricyon alleni ), (cranially) in its proportionally wider and (on average) shorter rostrum, and in having more inflated auditory bullae (Table 3), and (dentally) in its generally larger p4 (Table 4). Bassaricyon alleni is considerably larger than Bassaricyon medius medius (of South America west of the Andes), such that there is a clear body size contrast between the two lowland olingo taxa of South America ( Bassaricyon alleni east of Andes vs. B. medius medius west of Andes), but is very similar in size to Bassaricyon medius orinomus (of eastern Panama). Bassaricyon medius orinomus often has a reddish tail that contrasts somewhat with the less rufous head and body; Bassaricyon alleni tends to be more uniformly colored head to tail. In life, Bassaricyon alleni usually has a darkly pigmented nose, whereas in Bassaricyon medius the nose is often pink (Ivo Poglayen-Neuwall to C.O. Handley Jr., in litt., 9 February 1973; Figures 21-22). Sequence divergence in cytochrome b in these sister species ( Bassaricyon alleni , Bassaricyon medius ), separated by the Andes, is 6-7% (Table 2).

Distribution.

This is the only species of Bassaricyon found east of the Andes. Bassaricyon alleni has a wide distribution in forests on the eastern slopes of the Andes and in lowland forests east of the Andes, with records from forested areas of Venezuela ( Thomas 1920, Handley 1976, Bisbal 1989, 1993, Ochoa et al. 1993, Linares 1998, BMNH, USNM), Guyana ( Pocock 1921a, Lim and Engstrom 2005, ROM), eastern Colombia ( Thomas 1927, Donegan and Salaman 1999, AMNH, BMNH, USNM), eastern Ecuador ( Thomas 1880, 1920, Schulenberg and Aubrey 1997, Pitman et al. 2002, Tirira 2007, Borman et al. 2007, Alverson et al. 2008, Pinto and Tirira 2011b, BMNH, EPN, FMNH, MCZ, QCAZ), eastern Peru ( Thomas 1920, Grimwood 1969, Patton et al. 1982, Terborgh et al. 1984, Aquino and Encarnación 1986, Janson and Emmons 1990, Woodman et al. 1991, Pacheco et al. 1993, Pitman et al. 2003, 2004, Emmons et al. 1994a, 1994b, Emmons and Romo 1994, Boddicker 1997, Emmons 2001, Rodríguez and Amanzo 2001, Emmons et al. 2001, Vriesendorp et al. 2004, Alverson et al. 2008, Gilmore et al. 2010, BMNH, FMNH, MVZ, UMMZ, USNM, ZMB), northwestern Bolivia ( Crespo 1959, Emmons 1991, Redford and Stearman 1993, Anderson 1997, Alverson et al. 2000, 2003, Alverson 2003, Ríos-Uzeda and Arispe 2010), and western Brazil ( Calouro 1999, Kays and Russell 2001, Vaz 2004, Oliveira 2009, Magalhães-Pinto et al. 2009, Sampaio et al. 2010).

In Guyana, Bassaricyon alleni is recorded only from two specimens, the type of beddardi ( Pocock 1921a, see above) and a specimen from Iwokrama Forest ( Lim and Engstrom 2005, at ROM); there are no records to date from either Suriname or French Guiana, where it might be expected to occur ( Tate 1939, Husson 1978, Voss et al. 2001, Lim et al. 2005).

In Brazil, the only firm records are from southwestern Amazonia (the states of Amazonas and Acre) ( Calouro 1999, Kays and Russell 2001, Vaz 2004, Oliveira 2009, Magalhães-Pinto et al. 2009, Sampaio et al. 2010), though it is likely to occur also in Roraima and Pará (Figures 11-12). Brazilian Amazonian records of olingos from the state of Roraima, as " Bassaricyon beddardi " ( Mendes Pontes and Chivers 2002, Mendes Pontes et al. 2002, Mendes Pontes 2004, 2009, Cheida et al. 2006), are thus far apparently based on misidentifications of kinkajous, Potos ( Sampaio et al. 2011).

The elevational range of Bassaricyon alleni as documented by museum specimens extends from sea level to 2000 m. The great majority of records originate from lowland forests below 1000 m, but specimens from Ecuador and Peru (especially from Chanchamayo) have been collected from 1100 to 2000 m (specimens at BMNH, FMNH, USNM). It seems likely that the distribution of Bassaricyon alleni extends higher on the eastern slopes of the Andes than that of Bassaricyon medius does on the western slopes because of the apparent absence of Bassaricyon neblina on the eastern versant of the Andes.

Karyotype.

The karyotype of a male Bassaricyon alleni (2n = 38, NF = 68; then identified as " Bassaricyon gabbii ") was reported and described by Wurster and Benirschke (1967, 1968) based on an animal at the National Zoo (Washington, D.C.)-most likely USNM 395837, an adult male received from Leticia, Amazonas District, Colombia (the only male olingo at the zoo at the time).

Geographic variation.

Some geographic variation is apparent in Bassaricyon alleni , and several taxonomic names have been applied to different regional representatives of this species, including in the western Amazon (typical alleni Thomas 1880), Guyana (beddardi Pocock 1921a), and the Eastern Andes of Colombia (siccatus Thomas 1927).

The most notable morphological distinction that we have observed within Bassaricyon alleni is between lowland specimens (from forests below 1000 m) and specimens collected in montane forests above 1000 m in the Eastern Andes (e.g., Chanchamayo and Pozuzo in Peru). Specimens from these higher elevations have somewhat shorter tails and are more brownish (less orange tones in pelage), with notably longer fur, and greater development of black tipping to the fur, though the pelage is not as long and luxurious as in Bassaricyon neblina . Press reports of a possibly new species of Bassaricyon discovered in the Tabaconas - Namballe National Sanctuary in the Eastern Andes of Peru (e.g., Hance 2012), where Bassaricyon alleni is predicted to occur (Figure 11-12), may refer to such a highland population of Bassaricyon alleni .

Bassaricyon beddardi of Guyana has often been recognized as a species distinct from Bassaricyon alleni in checklists and inventories (e.g., Lim and Engstrom 2005, Reid and Helgen 2008c, Sampaio et al. 2011, Wozencraft 1993, 2005), but supporting justification has been lacking. The holotype of beddardi, originally a zoo animal, appears to be lost (see above). However, both the holotype (as described by Beddard [1900] and Pocock [1921a]) and a second (and the only additional) specimen from Guyana (ROM 107380, from Iwokrama Forest) closely correspond in their morphological characteristics to Amazonian and Andean specimens of Bassaricyon alleni , and our molecular comparisons demonstrate little molecular divergence between the ROM specimen and a specimen of Bassaricyon alleni from the Peruvian Amazon (Table 1; 1.3% sequence divergence in cytochrome b), such that we suggest that Bassaricyon beddardi can be regarded as a synonym of Bassaricyon alleni . We allocate the name siccatus to the synonymy of Bassaricyon alleni based on geography and craniodental morphology of the type specimen, but further, more detailed study of geographic variation across the range of Bassaricyon alleni would be welcome, perhaps focused in particular on variation across different regions of the Eastern Andes (cf. Thomas 1920, 1927). At present, we recognize no subspecies within Bassaricyon alleni .

Notes.

Though this is the most widely distributed member of the genus (Figure 12), relatively little is known of this species in the wild. Brief notes about the ecology and behavior of wild Bassaricyon alleni are included in the publications of Aquino and Encarnación (1986), Emmons (1990, 1991), Janson and Emmons (1990), and Patton et al. (1982). However, captive olingos described and discussed in detail by Poglayen-Neuwall and Poglayen-Neuwall (1965) (also Poglayen-Neuwall 1966, 1989) were all (or almost all) Bassaricyon alleni , originally from the vicinity of Iquitos (Amazonian Peru), such that for behavior under captive conditions, Bassaricyon alleni is the best studied member of the genus. Most olingos discussed by Poglayen-Neuwall (1976) were probably also Bassaricyon alleni , though one animal, an adult female named “Ringerl” (Figure 15), was an Olinguito, Bassaricyon neblina osborni (see account of Bassaricyon neblina , above). Poglayen-Neuwall’s (1973) delightful popular article, "The Odorous Olingo," remains one of the most concentrated sources of firsthand information for this species (and olingos in general), discussing how Bassaricyon alleni is highly arboreal but will cross open spaces on the ground, is active from sunset to dawn, is predominantly frugivorous but also eats some animal matter (small rodents and lizards, nestling birds, insects, and eggs), has little social organization beyond mother-offspring pairs, displays a high intensity of scent marking in both sexes, flees and releases a foul-smelling odor when threatened, has one young following a 72-74 day gestation period, and that males are aggressive with one another and cannot be housed together. Relevant (and limited) field notes associated with Bassaricyon alleni include: "stomach contents fruits and a green vegetable pulp" (USNM 194315); “lactating” on 7 April 1967 (USNM 443717).

Specimens examined.

Colombia: AMNH 70532, 142223, BMNH 27.5.3.2 (type of siccatus), USNM 281482, 281483, 281484, 281485, 395837, 544415. Ecuador: AMNH 67706, BMNH 14.4.25.38, 80.5.6.37 (holotype of alleni), EPN “4”, RM0151, FMNH 41501, 41502, MCZ 37920, 37921, 37922, 37923, QCAZ 3371, YPM 1458, 1459. Guyana: ROM 107380. Peru: AMNH 98653, 98654, 98662, 98709, BMNH 5.11.2.6, 27.1.1.70, 1912.1.15.3, 1922.1.1.17, FMNH 34717, 65787, 65789, 65805, 86908, 86909, 98709, MVZ 153646, 155219, 155220, UMMZ 107907, USNM 194315, 194316, 255121, 255122, ZMB 63197. Venezuela: BMNH 99.9.11.25, USNM 443279, 443717, 443718.