Toromys grandis (Wagner, 1845)Echimys chrysurus, Zimmermann, 1780Echimys saturnus, Thomas, 1928

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Echimyidae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 552-604 : 593-594

80.

Black Toro

Toromys grandis

French: Toromys géant / German: Schwarze Tororatte / Spanish: Rata arboricola grande

Other common names: Giant Armored Tree-rat, Giant Tree-rat

Taxonomy. Loncheres grandis Wagner, 1845 , “vom Amazonenstrom.” Restricted by J. Moojen in 1952 to “Manaquiri, lower Rio Solimoes, Amazonas, Brazil.”

Toromys grandis was formerly classified in the genera Loncheres , Echimys , and Makala- ta. Monotypic.

Distribution. Lower Brazilian Amazon at both sides of the Amazon River, from its confluence with the Rio Negro to its mouth at Caviana I.

Descriptive notes. Head—body 303 mm, tail 285 mm. No specific data are available for body weight. The Black Toro is a large arboreal species. Dorsum and flanks have uniform mix of black and golden guard hairs, with darker mid-dorsum. Venteris yellowish gold, sometimes with median yellowish gold midline; hairs are bicolored, light brown at bases, and golden or yellow at tips. Dorsal pelt has coarse, harsh, flexible, and stiff bristles (aristiforms and setiforms). Head is black, sprinkled with golden tint. Furry tail is 80-90% of head-body length and covered with short black hairs, hiding tail scales. Tail hairs decrease in density from proximal to distal end. Hindfeet are broad and have stout claws. Dorsal surfaces of forefeet and hindfeet are dark brown or black, sprinkled with gold bicolored hairs. There are two pairs of lateral mammae. Plantar and palmar surfaces between pads are covered with tubercular rugosities. Ears are black, rounded, and hairy externally. Skull of the Black Toro is short, robust, and broad. Rostrum is distinguished by typical medial constriction of nasal bones when viewed dorsally. Squamosotympanic fenestra is narrow horizontal slit. It has extended and well-developed supraorbital region, with shelf-like supraorbital edge that curves upon frontal bone. Lateral process of supraoccipital is short and situated at mid-part of auditory meatus opening and does not extend beyond lower edge of meatus. Maxillary vein passage is located within foramen. Tympanic bulla is not inflated, with auditory meatus situated high near squamosal bone and with short auditory tubes having outward orientation. Basioccipital is narrow and short. Wide mesopterygoid fossa reach M* and M’ contact zone and make 60° angle with posterior edge of M* lamina. Incisive foramina are short and slit-like. Tooth rows are parallel, with uneven loph size occlusal patterns. Upper cheekteeth are square to rectangular and longer than wide. Tooth row is somewhat longer than in species of Pattonomys . Lower dP, is tetralophodont. On tooth rows, anteroloph, protoloph, and metaloph are connected by slender mure, as in species of Pattonomys . Lowerincisors are not strongly curved, and upperincisors are opisthodont. Angular process of jaw is slender, with well-developped massteric ridge and wide condyle.

. theWorld of Mammals the of Handbook

82.

White-faced Tree-rat

Echimys chrysurus

French: Rat-épineux a face blanche / German: \WeiRnasen-Stachelratte / Spanish: Rata arboricola de cara blanca

Other common names: \White-faced Spiny Tree-rat

Taxonomy. Myoxus chrysurus Zimmermann, 1780 , “Surinam [= Suriname],” based on Allamand’s (1778) “lérot a queue dorée.”

Generic assignment of E. chrysurus varied extensively in the 18" and 19™ centuries; it was initially assigned to Hystrix and subsequently to Myoxus, Glis, the South American Loncheres , Nelomys and appropriately to Echimys . Monotypic.

Distribution. The Guianas and Guianan region of NE Brazil and E Amazon Basin E of the Rio Negro and N of the Amazon River, but extending S of the Amazon to the E of the Rio Xingu in E Brazil.

632

FAMILY ECHIMYIDAE

Hutias, South American Spiny-rats and Coypu

Plate 38

Species Accounts

Descriptive notes. Head-body 242-333 mm, tail 250-395 mm; weight up to 760 g. The White-faced Tree-rat is large, with dark gray-brown dorsum densely covered with large

Habitat. Floodplain and riverine rainforests near sea level.

Food and Feeding. There is no specific information available for this species, but the Black Toro is reportedly folivorous.

Breeding. There is no information available for this species.

Activity patterns. There is no specific information available for this species, but the Black Toro is reported to be nocturnal.

Movements, Home range and Social organization. There is no specific information available for this species, but the Black Toro has been reported to nest in tree hollows in riverine habitats.

Status and Conservation. Classified as Least Concern on The IUCN Red List. As a rainforest species, the Black Toro might be affected by deforestation, but it occurs in flooded forests that are not highly threatened habitats in the Amazonian region. Additional studies on distribution, habitat, ecology, abundance, and conservation threats to Black Toro are needed.

Bibliography. Eisenberg & Redford (1999), Emmons (1990, 1997a, 2005), Emmons, Leite & Patton (2015b, 2015d), lack-Ximenes et al. (2005), Moojen (1952b), Wagner(1845), Woods & Kilpatrick (2005).

G. Cuvier, 1809

81.

Dark Tree-rat

Echimys saturnus

French: Rat-épineux noir / German: Dunkle Stachelratte / Spanish: Rata arboricola oscura

Other common names: Dark Spiny Tree-rat

Taxonomy. Echimys saturnus Thomas, 1928 , “Rio Napo, Oriente of Ecuador. Alt. 3300" [= 1005 m].”

This species is monotypic.

Distribution. E Andean foothills and adjacent Amazonian lowlands in E Ecuador and N Peru.

Descriptive notes. Head-body 272-335 mm, tail 295-383 mm. No specific data are available for body weight. The Dark Tree-rat is medium-sized, with glossy

dorsal fur of brown tones that contains abundant bristles, with flat spines on mid-back but not over rump. Head and mid-back have typical glossy black color. Under parts are white, white-spotted, or whitish with buff tinge; chin is dark. Tail is ¢.140% of headbody length and densely haired from base to tip. Tail is longitudinally bicolored, with its base glossy black and distal white part of varying length. Ears are short and covered by hairs of head. Hindfeet are brown above, with strong claws on each digit. Some melanistic specimens have been reported in museum collections. Habitat. Pre-montane and lowland rainforest at elevations of 230-1005 m. Dark Treerats have been camera-trapped on the ground along stream edges, both partially in water or moving either toward or away from a water channel. Food and Feeding. There is no specific information available for this species, but the Dark Tree-rat is likely folivorous—frugivorous and might also include insects in its diet, as do other species of Echimys . Breeding. Female Dark Tree-rats have been found with two embryos. Activity patterns. There is no specific information available for this species, but the Dark Tree-rat appears to be strictly nocturnal. Movements, Home range and Social organization. Dark Tree-rats were camera-trapped nine times during 297 nights at one locality in Ecuador. Pictures showed eightsolitary individuals and a group ofthree individuals. Potential solitary habits are similar to that of the White-faced Tree-rat ( E. chrysurus ). The group of three individuals might have been a female with two young moving together, apparently in a straight line by following the white-tippedtail of the leading individual. Status and Conservation. Classified as Data Deficient on The IUCN Red List. Additional ecological studies of the rare Dark Tree-rat, an Andean endemic, are needed to assess its conservation status. Bibliography. Blake et al. (2010), Eisenberg & Redford (1999), Emmons (1990, 1997a, 2005), Emmons & Stark (1979), lack-Ximenes et al. (2005), Patton et al. (2015), Thomas (1928a), Woods (1993), Woods & Kilpatrick (2005).

FAMILY ECHIMYIDAE

Hutias, South American Spiny-rats and Coypu

Plate 38

Species Accounts

spines from neck to rump. Remainder of pelage is composed ofstiff and harsh bristles. Throat, chin, and inguinal areas are white, and white stripe occurs on chest; all other ventral parts are gray-brown, not very different from upper parts. Pale yellowish to whitish blaze extends down center of head from crown to nose; it may completely cover face, appear as narrow stripe, or otherwise be present only as small white tuft on crown. Eyes are dark brown, with weak typical red eye shine. Cheeks, sides of crown, and chin are usually dark brown or reddish. Ears are small, slightly haired, and brown. Tail is c.120% of head-body length, fully haired from base to tip, and longitudinally bicolored with dusky basal part and white distal end covering two-thirds of its length. Feet are broad, with powerful claws on all digits, and gray-brown above. Skull of the White-faced Treerat is similar among species of Echimys , but quite distinct compared with other genera by virtue of small to medium bullae, small auditory meatus, short auditory tube thatis oriented laterally, and external meatus short and positioned close to squamosal. Lateral process of supraoccipital is short; squamosotympanic fenestra is small and nearly circular and located anteriorly compared with auditory meatus; premaxillary septum of incisive foramina is incomplete posteriorly; and jugal fossa is broad and deep below post-orbital process. Mandibular foramen is anterior to condyloid ridge, outside fossa of anterior ascending branch ofjaw. Tooth rows are parallel and rectangular, and very high-crowned cheekteeth are longer than wide. Upper teeth have two U-shaped lophs of similar orientations that fuse with wear. Lower dP, is divided into three lophids: anteroconid-anterolophid, metalophid, and enterolophid-posterolophid. Lower molars are similar to other arboreal echimyids that have sigmoid lophid shapes.

Habitat. Mature lowland rainforest, primarily middle and upperstrata, especially vinecovered areas, but also open forest, from sea level to elevations of ¢.200 m.

Food and Feeding. Stomach contents and field observations of White-faced Tree-rats indicate a frugivorous—folivorous diet, but some insects are eaten. Analysis of the 6"°C isotope in White-faced Tree-rats in comparison to more terrestrial rodent species suggested a primary diet of C, plants, with potential consumption ofa significant proportion of arthropods.

Breeding. A female White-faced Tree-rat was found with two embryos.

Activity patterns. White-faced Tree-rats are strictly arboreal and nocturnal.

Movements, Home range and Social organization. White-faced Tree-rats usually move slowly along branches, but speed increases under duress from human disturbance or predators. Mean distance traveled was estimated at 294 m/night based on tracking data and nest locations.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Whitefaced Tree-rat has a wide distribution, and ease of capture and common sightings by zoologists and general extent ofits natural habitat make it presumably less prone to threats from human activity. Additional ecological studies, however, are encouraged in view ofrarity of specimens in museum collections, preference for mature primary forest, and general lack of focused fieldwork.

Bibliography. Allen (1899a), Cuvier (1809), Desmarest (1817), Eisenberg & Redford (1999), Eisenberg & Thor ington (1973), Emmons (1990, 1997a, 2005), Geoffroy Saint-Hilaire (1840), Gloger (1841-1842), lack-Ximenes et al. (2005), llliger (1811), Jourdan (1837), Link (1795), Mares (1982), Mauffrey (1999), Mauffrey & Catzeflis (2003), Mauffrey et al. (2007), Miles et al. (1981), Miranda-Ribeiro (1914), von Olfers (1818), Patton et al. (2015), Richard-Hansen et al. (1999), von Schreiber (1792), Thomas (1916b), Treviranus (1803), Wagner (1840), Woods (1993), Woods & Kilpatrick (2005), Zimmermann (1780).

82.

White-faced Tree-rat

Echimys chrysurus

French: Rat-épineux a face blanche / German: \WeiRnasen-Stachelratte / Spanish: Rata arboricola de cara blanca

Other common names: \White-faced Spiny Tree-rat

Taxonomy. Myoxus chrysurus Zimmermann, 1780 , “Surinam [= Suriname],” based on Allamand’s (1778) “lérot a queue dorée.”

Generic assignment of E. chrysurus varied extensively in the 18" and 19™ centuries; it was initially assigned to Hystrix and subsequently to Myoxus, Glis, the South American Loncheres , Nelomys and appropriately to Echimys . Monotypic.

Distribution. The Guianas and Guianan region of NE Brazil and E Amazon Basin E of the Rio Negro and N of the Amazon River, but extending S of the Amazon to the E of the Rio Xingu in E Brazil.

632

FAMILY ECHIMYIDAE

Hutias, South American Spiny-rats and Coypu

Plate 38

Species Accounts

Descriptive notes. Head-body 242-333 mm, tail 250-395 mm; weight up to 760 g. The White-faced Tree-rat is large, with dark gray-brown dorsum densely covered with large

Habitat. Floodplain and riverine rainforests near sea level.

Food and Feeding. There is no specific information available for this species, but the Black Toro is reportedly folivorous.

Breeding. There is no information available for this species.

Activity patterns. There is no specific information available for this species, but the Black Toro is reported to be nocturnal.

Movements, Home range and Social organization. There is no specific information available for this species, but the Black Toro has been reported to nest in tree hollows in riverine habitats.

Status and Conservation. Classified as Least Concern on The IUCN Red List. As a rainforest species, the Black Toro might be affected by deforestation, but it occurs in flooded forests that are not highly threatened habitats in the Amazonian region. Additional studies on distribution, habitat, ecology, abundance, and conservation threats to Black Toro are needed.

Bibliography. Eisenberg & Redford (1999), Emmons (1990, 1997a, 2005), Emmons, Leite & Patton (2015b, 2015d), lack-Ximenes et al. (2005), Moojen (1952b), Wagner(1845), Woods & Kilpatrick (2005).

G. Cuvier, 1809

81.

Dark Tree-rat

Echimys saturnus

French: Rat-épineux noir / German: Dunkle Stachelratte / Spanish: Rata arboricola oscura

Other common names: Dark Spiny Tree-rat

Taxonomy. Echimys saturnus Thomas, 1928 , “Rio Napo, Oriente of Ecuador. Alt. 3300" [= 1005 m].”

This species is monotypic.

Distribution. E Andean foothills and adjacent Amazonian lowlands in E Ecuador and N Peru.

Descriptive notes. Head-body 272-335 mm, tail 295-383 mm. No specific data are available for body weight. The Dark Tree-rat is medium-sized, with glossy

dorsal fur of brown tones that contains abundant bristles, with flat spines on mid-back but not over rump. Head and mid-back have typical glossy black color. Under parts are white, white-spotted, or whitish with buff tinge; chin is dark. Tail is ¢.140% of headbody length and densely haired from base to tip. Tail is longitudinally bicolored, with its base glossy black and distal white part of varying length. Ears are short and covered by hairs of head. Hindfeet are brown above, with strong claws on each digit. Some melanistic specimens have been reported in museum collections. Habitat. Pre-montane and lowland rainforest at elevations of 230-1005 m. Dark Treerats have been camera-trapped on the ground along stream edges, both partially in water or moving either toward or away from a water channel. Food and Feeding. There is no specific information available for this species, but the Dark Tree-rat is likely folivorous—frugivorous and might also include insects in its diet, as do other species of Echimys . Breeding. Female Dark Tree-rats have been found with two embryos. Activity patterns. There is no specific information available for this species, but the Dark Tree-rat appears to be strictly nocturnal. Movements, Home range and Social organization. Dark Tree-rats were camera-trapped nine times during 297 nights at one locality in Ecuador. Pictures showed eightsolitary individuals and a group ofthree individuals. Potential solitary habits are similar to that of the White-faced Tree-rat ( E. chrysurus ). The group of three individuals might have been a female with two young moving together, apparently in a straight line by following the white-tippedtail of the leading individual. Status and Conservation. Classified as Data Deficient on The IUCN Red List. Additional ecological studies of the rare Dark Tree-rat, an Andean endemic, are needed to assess its conservation status. Bibliography. Blake et al. (2010), Eisenberg & Redford (1999), Emmons (1990, 1997a, 2005), Emmons & Stark (1979), lack-Ximenes et al. (2005), Patton et al. (2015), Thomas (1928a), Woods (1993), Woods & Kilpatrick (2005).

FAMILY ECHIMYIDAE

Hutias, South American Spiny-rats and Coypu

Plate 38

Species Accounts

spines from neck to rump. Remainder of pelage is composed ofstiff and harsh bristles. Throat, chin, and inguinal areas are white, and white stripe occurs on chest; all other ventral parts are gray-brown, not very different from upper parts. Pale yellowish to whitish blaze extends down center of head from crown to nose; it may completely cover face, appear as narrow stripe, or otherwise be present only as small white tuft on crown. Eyes are dark brown, with weak typical red eye shine. Cheeks, sides of crown, and chin are usually dark brown or reddish. Ears are small, slightly haired, and brown. Tail is c.120% of head-body length, fully haired from base to tip, and longitudinally bicolored with dusky basal part and white distal end covering two-thirds of its length. Feet are broad, with powerful claws on all digits, and gray-brown above. Skull of the White-faced Treerat is similar among species of Echimys , but quite distinct compared with other genera by virtue of small to medium bullae, small auditory meatus, short auditory tube thatis oriented laterally, and external meatus short and positioned close to squamosal. Lateral process of supraoccipital is short; squamosotympanic fenestra is small and nearly circular and located anteriorly compared with auditory meatus; premaxillary septum of incisive foramina is incomplete posteriorly; and jugal fossa is broad and deep below post-orbital process. Mandibular foramen is anterior to condyloid ridge, outside fossa of anterior ascending branch ofjaw. Tooth rows are parallel and rectangular, and very high-crowned cheekteeth are longer than wide. Upper teeth have two U-shaped lophs of similar orientations that fuse with wear. Lower dP, is divided into three lophids: anteroconid-anterolophid, metalophid, and enterolophid-posterolophid. Lower molars are similar to other arboreal echimyids that have sigmoid lophid shapes.

Habitat. Mature lowland rainforest, primarily middle and upperstrata, especially vinecovered areas, but also open forest, from sea level to elevations of ¢.200 m.

Food and Feeding. Stomach contents and field observations of White-faced Tree-rats indicate a frugivorous—folivorous diet, but some insects are eaten. Analysis of the 6"°C isotope in White-faced Tree-rats in comparison to more terrestrial rodent species suggested a primary diet of C, plants, with potential consumption ofa significant proportion of arthropods.

Breeding. A female White-faced Tree-rat was found with two embryos.

Activity patterns. White-faced Tree-rats are strictly arboreal and nocturnal.

Movements, Home range and Social organization. White-faced Tree-rats usually move slowly along branches, but speed increases under duress from human disturbance or predators. Mean distance traveled was estimated at 294 m/night based on tracking data and nest locations.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Whitefaced Tree-rat has a wide distribution, and ease of capture and common sightings by zoologists and general extent ofits natural habitat make it presumably less prone to threats from human activity. Additional ecological studies, however, are encouraged in view ofrarity of specimens in museum collections, preference for mature primary forest, and general lack of focused fieldwork.

Bibliography. Allen (1899a), Cuvier (1809), Desmarest (1817), Eisenberg & Redford (1999), Eisenberg & Thor ington (1973), Emmons (1990, 1997a, 2005), Geoffroy Saint-Hilaire (1840), Gloger (1841-1842), lack-Ximenes et al. (2005), llliger (1811), Jourdan (1837), Link (1795), Mares (1982), Mauffrey (1999), Mauffrey & Catzeflis (2003), Mauffrey et al. (2007), Miles et al. (1981), Miranda-Ribeiro (1914), von Olfers (1818), Patton et al. (2015), Richard-Hansen et al. (1999), von Schreiber (1792), Thomas (1916b), Treviranus (1803), Wagner (1840), Woods (1993), Woods & Kilpatrick (2005), Zimmermann (1780).

81.

Dark Tree-rat

Echimys saturnus

French: Rat-épineux noir / German: Dunkle Stachelratte / Spanish: Rata arboricola oscura

Other common names: Dark Spiny Tree-rat

Taxonomy. Echimys saturnus Thomas, 1928 , “Rio Napo, Oriente of Ecuador. Alt. 3300" [= 1005 m].”

This species is monotypic.

Distribution. E Andean foothills and adjacent Amazonian lowlands in E Ecuador and N Peru.

Descriptive notes. Head-body 272-335 mm, tail 295-383 mm. No specific data are available for body weight. The Dark Tree-rat is medium-sized, with glossy

dorsal fur of brown tones that contains abundant bristles, with flat spines on mid-back but not over rump. Head and mid-back have typical glossy black color. Under parts are white, white-spotted, or whitish with buff tinge; chin is dark. Tail is ¢.140% of headbody length and densely haired from base to tip. Tail is longitudinally bicolored, with its base glossy black and distal white part of varying length. Ears are short and covered by hairs of head. Hindfeet are brown above, with strong claws on each digit. Some melanistic specimens have been reported in museum collections. Habitat. Pre-montane and lowland rainforest at elevations of 230-1005 m. Dark Treerats have been camera-trapped on the ground along stream edges, both partially in water or moving either toward or away from a water channel. Food and Feeding. There is no specific information available for this species, but the Dark Tree-rat is likely folivorous—frugivorous and might also include insects in its diet, as do other species of Echimys . Breeding. Female Dark Tree-rats have been found with two embryos. Activity patterns. There is no specific information available for this species, but the Dark Tree-rat appears to be strictly nocturnal. Movements, Home range and Social organization. Dark Tree-rats were camera-trapped nine times during 297 nights at one locality in Ecuador. Pictures showed eightsolitary individuals and a group ofthree individuals. Potential solitary habits are similar to that of the White-faced Tree-rat ( E. chrysurus ). The group of three individuals might have been a female with two young moving together, apparently in a straight line by following the white-tippedtail of the leading individual. Status and Conservation. Classified as Data Deficient on The IUCN Red List. Additional ecological studies of the rare Dark Tree-rat, an Andean endemic, are needed to assess its conservation status. Bibliography. Blake et al. (2010), Eisenberg & Redford (1999), Emmons (1990, 1997a, 2005), Emmons & Stark (1979), lack-Ximenes et al. (2005), Patton et al. (2015), Thomas (1928a), Woods (1993), Woods & Kilpatrick (2005).