Heteromys anomalus

7. Trinidad Spiny Pocket Mouse Heteromys anomalus French: Souris-a-ajaboues de Trinidad / German: Trinidad-Stacheltaschenmaus / Spanish: Raton espinoso de Trinidad Other common names: Caribbean Spiny Pocket Mouse, Northern South American Spiny Pocket Mouse Taxonomy. Mus anomalus Thompson, 1815, “Trinidad... [near] St. Anne’s barracks,” Trinidad and Tobago. With the exception of H. desmarestianus in the north-western corner of Colombia, the South American spiny pocket mice all belong to the anomalus species group: H. anomalus, H. catopterius, H. oasicus, H. australis, and H. teleus. Only H. australis exists outside of South America in eastern Panama. Four subspecies recognized. Subspecies and Distribution. H.a.anomalusThompson,1815—N&EVenezuela(mainlandandMargaritaI)andTrinidadandTobago(TrinidadI). H.a.brachialisOsgood,1912—NWVenezuela(EofLakeMaracaibo);specimensfromtheSerraniadePerijaalongtheColombian-VenezuelanborderWofLakeMaracaibomaybeassignabletothissubspecies. H.a.hershkovitziHernandez-Camacho,1956—WCColombia(MagdalenaRiverValleyofAndeanregion,forestedslopesoftheEAndes). H. a. jesupiJ. A. Allen, 1899 — N Colombia (Sierra Nevada de Santa Marta, sea level to 610 m). Descriptive notes. Head-body mean 134 mm (males) and 129 mm (females), tail mean 156 mm (males) and 150 mm (females), ear mean 19 mm, hindfoot mean 34 mm. No specific data are available for body weight. Male Trinidad Spiny Pocket Mice are somewhat larger than females. It is a scansorial rodent, medium-sized for the genus, with coarse adult pelage having abundantstiff, flattened spine-like hairs on dorsal and lateral surfaces of body. Upper parts are dark gray to grayish brown or pale brown, interspersed with dark spines and ocherous hairs. There is no buffy lateral line, and belly is white. Ears are large and rounded. Posterior parts of soles of hindfeet are naked. Tail is moderately haired, strongly bicolored (darker on upper part), and relatively long. Cheekteeth have high crowns, and lower premolar has 3-4 lophids. Auditory bullae are only moderately inflated. Chromosomal complement has 2n = 60 and FN = 68. In addition to their distinctively large ears, most individuals in populations of the Trinidad Spiny Pocket Mouse are pale, with strongly grizzled dorsal pelage, in contrast to dark-brown or dark-gray pelage of Nelson’s Spiny Pocket Mouse (H. nelsoni), the Mountain Spiny Pocket Mouse (H. oresterus), the Southern Spiny Pocket Mouse (H. australis), the Ecuadorean Spiny Pocket Mouse (H. teleus), and Desmarest’s Spiny Pocket Mouse (H. desmarestianus). Although Desmarest’s Spiny Pocket Mouse has a grizzled appearance due to an infusion of ocherous hairs, those species are not nearly as strongly grizzled as the typical pale, strongly grizzled populations of the Trinidad Spiny Pocket Mouse. Gaumer’s Spiny Pocket Mouse (H. gaumeri) has haired plantar surfaces of hindfeet. The Paraguana Spiny Pocket Mouse (H. oasicus) is markedly smaller, with no overlap in size of adults, has relatively shorter and more strongly tapering nasals, relatively wider braincase, and paler dorsal pelage color andlittle or no dark color on forearms. The Trinidad Spiny Pocket Mouse has distinct patch ofdark color on its forelimbs, as do many spiny pocket mice. Habitat. Deciduous and evergreen tropical forests along the Caribbean coast of Colombia, Venezuela, and Trinidad and Tobago and from parts of the dry Magdalena Valley in Colombia, from sea level to elevations of ¢.1600 m. One confirmed locality at a higher elevation (2430 m) is from Macizco de Bocon¢ in the Cordillera de Mérida, where several other mammals show atypical elevational distributions. The Trinidad Spiny Pocket Mouse is most commonly collected from the Andean piedmont and western tropical savannas and has been found in remnant forests, disturbed forests, and secondary scrub habitats in agricultural areas, but it does not appear to enter agricultural fields. All records from savannas with habitat data indicate its presence only in gallery forests and not in open savanna. The Trinidad Spiny Pocket Mouse digs extensive burrow systems in which it constructs its nest. Food and Feeding. The Trinidad Spiny Pocket Mouse feeds on seeds, somefruit, grains, succulent vegetation, and insects, transported in external, fur-lined cheek pouches. Breeding. Breeding season in the Trinidad Spiny Pocket Mouse begins early in the rainy season. Young mature to independence within ¢.50 days of birth and may be caught near the maternal burrow. They subsequently disperse to establish a new burrow system. Activity patterns. The Trinidad Spiny Pocket Mouse is nocturnal and terrestrial, but it can climb small shrubs. Movements, Home range and Social organization. The Trinidad Spiny Pocket Mouse is tolerant of conspecifics in the laboratory and may have evolved toward a “loose” type of social organization. Estimated densities are as high as 2-2 ind/ha. Status and Conservation. Classified as Least Concern on The IUCN Red List. Bibliography. Anderson (2003), Anderson & Gémez-Laverde (2008), Anderson et al. (2006), Best (1993a), Eisenberg (1963, 1989), Rogers & Gonzalez (2010), Williams et al. (1993).Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Heteromyidae, pp. 170-233 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on pages 197-198, DOI: 10.5281/zenodo.661116