Lepus callotis

Widely distributed in Mexico, also occurs in extreme southwestern New Mexico; possibly declining in many areas due to loss and degradation of open grassland habitat, but supporting data are minimal, and a 2010 conservation assessment found no major threats; however, better information is needed on current distribution, abundance, and trend throughout most of the range in Mexico.

Range encompasses southern North America, from the southwestern corner of New Mexico (Diamond A Ranch; southern Animas and Playas valleys, southern Hidalgo County; may be extirpated from the Playas Valley; Bednarz and Cook 1984, Frey 2004, Traphagen 2011) discontinuously to northern Oaxaca, Mexico (Hoffman and Smith, in Wilson and Reeder 2005; USFWS 2010). Hoffmeister (1986) mentioned a possible sighting in southeastern Arizona, but no firm evidence exists for the occurrence of this species in that state (USFWS 2010).

Subspecies gaillardi occurs on plains from southwestern New Mexico to northern Durango (Anderson and Gaunt 1962). Subspecies callotis occupies the remainder of the range. Anderson and Guant (1962) reported (but did not map) intergradation between these two subspecies; information in their paper suggests that they felt intergradation occurs in Durango (but see taxonomy comments).

The number of extant, viable occurrences has not been determined using standardized criteria. The species is known from at least several dozen collection sites over a wide area(GBIF database). Anderson and Gaunt (1962) mapped 45 Mexican localities represented by 131 museum specimens. In New Mexico, the total range encompasses about 120 sq km, which might comprise two distinct occurrences (Bednarz and Cook 1984). Anderson (1972) mapped 11 localities in Chihuahua but did not comment on current status in these areas; Baker (1977) and Findley and Caire (1977) regarded the status in Chihuahua as poor. Davis and Lukens (1958) stated that this species was widespread in the central tablelands of southern Mexico, implying a large number of historical occurrences.

Apparent declines in the United States and Mexico have been attributed primarily to (1) conversion of habitat to agricultural uses and (2) overgrazing and deterioration of grassland, with associated invasion of grassland by shrubs and forbs (Baker and Greer 1962, Conway 1976, Baker 1977, Chapman et al. 1983, Bednarz and Cook 1984, Matson and Baker 1986, Best and Henry 1993). Traphagen (2011) reported that suitable white-sided jackrabbit habitat in New Mexico has been reduced from 11,993 hectares as estimated in 1976 to 5,838 hectares in 2010, representing a 51 percent loss of habitat for the species in the United States. The loss of habitat is largely attributable to woody shrub invasion. Traphagen (2011) also reported a conspicuous population decline in an area that previously was relatively dense with L. callotis; he suggested that heavy vehicular traffic may have adversely impacted jackrabbits living in this region. This species is hunted in Mexico, but probably most are taken in conjunction with hunting supported by lagomorph species that are much more numerous (e.g., Lepus californicus).

In a range-wide status assessment, USFWS (2010) concluded that no information exists indicating that habitat degradation from livestock grazing or fire supression leading to shrub encroachment pose significant threats to the species. USFWS (2010) also determined that overutilization for commercial, recreational, scientific, or educational purposes does not pose a threat, nor does disease, predation, or inadequacy of regulatory mechanisms. Additionally, USFWS (2010) concluded that it is not possible at this time to make reliable predictions of climate change effects on the status of the white-sided jackrabbit, due to the current limitations in available data and climate models. Although individual jackrabbits may be subject to impacts as a result of vehicle collisions, there is no evidence that this is occurring at a level that may affect the status of the species as a whole, now or in the foreseeable future. There is no evidence that the short-term impacts of fire management are occurring at a level that may affect the status of the species as a whole now or in the foreseeable future. Further, the long-term impacts of fire management may serve to improve white-sided jackrabbit habitat and thus provide a benefit to the species (USFWS 2010).