This Black-tailed Woodrat from northwest Mexico is named for its dark, almost black tail, which contrasts with its much paler body. It lives in the desert scrub of Sonora and northern Sinaloa, where it builds its shelters taking advantage of the protection offered by columnar cacti and thorny shrubs. For a long time, it was treated as a mere local variant of the White-throated Woodrat (Neotoma albigula). Even today, some authors consider it a subspecies of the latter rather than a full species. This complicates any separate assessment of its conservation status.
Greyish-brown fur above, white belly and feet, and a distinctly bicoloured tail, dark above and pale below, more contrasted than in most of its relatives. It is easily confused with Neotoma albigula, from which it is barely distinguishable by sight; only genetic or cranial analysis allows them to be reliably separated. It shares habitat with other smaller field rats, from which it is distinguished by its more robust body and proportionally large ears.
It builds mounds of thorny branches, cholla segments, and other cactus remains, piled at the base of a shrub or columnar cactus. The accumulated spines protect the entrance. Tracks, 1.5-2 cm long, show four toes on the fore feet and five on the hind feet, without the deep claw mark left by a similarly sized canid. Droppings, cylindrical and less than 1 cm long, are concentrated in small latrines inside the mound instead of being dispersed. This pattern helps differentiate them from the droppings of rodents without a fixed refuge.
Desert and semi-desert scrubland of northwest Mexico, particularly Sonora and the extreme north of Sinaloa, where columnar cacti and thorny shrubs abound, offering protection to the mound.
It primarily feeds on cacti (prickly pear pads and fruits, cholla), seeds and leaves of desert shrubs.
Solitary and nocturnal, the Black-tailed Woodrat defends its mound from other individuals, sharing it only during breeding. Reproduction probably follows the general pattern for the genus, with a gestation of 30-38 days, although no specific studies have been published on this population.
The Black-tailed Woodrat is not independently evaluated on the IUCN Red List. Much of the literature treats it as a subspecies of Neotoma albigula, whose population is considered stable in northwest Mexico. This taxonomic ambiguity is, in practice, the biggest obstacle to assessing its true status separately.
Conversion of desert scrub to irrigated farmland and grazing land in northwest Mexico, and loss of columnar cacti due to collection or changes in land use.
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