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Abstract
The Tucson shovel-nosed snake (Chionactis annulata klauberi) is a small specialized colubrid associated with sandy loams of the elevated portions of the Lower Colorado River Valley Sonoran Desert in central Arizona. This taxon is a recently redefined subspecies based on genetic data, and may be extirpated in the Tucson region, including the type locality. A recent (USFWS 2014) decision against protecting it was based in part on an expansive definition of its geographic range and a habitat model. Here, we redefine the subspecies distribution by uniting published results of mitochondrial and nuclear DNA. We then present a new ecologically based model of its original and current habitat using the machine learning algorithm Random Forests. The new model accurately matches known and estimated presenceabsence data for this taxon, and is consistent with morphometrics and, largely, with color pattern variation. It estimates 60% less available habitat than the USFWS model. We estimate that 39% of the 1,255,946 ha (3,103,505 ac) of original habitat has been converted to urban developments, roads, agriculture, or otherwise altered non-habitat. Of the remaining 770,971 ha (1,905,108 ac), 60% is susceptible to habitat conversion in the region, with only 10.9% of habitat having current legal protection. Ongoing and projected urbanization and energy development in its flatland desert habitat present a bleak future for this subspecies.
Parent Publication
Keywords
forest restoration,
history,
climate,
soils,
vegetation,
geomorphology,
watersheds,
water quality,
water quantity,
fluvial ecosystems,
fish and invertebrate fauna,
riparian ecosystems
Citation
Bradley, Curtis M.; Rosen, Philip C. 2022. Defining suitable habitat and conservation status for the Tucson shovel-nosed snake (Chionactis annulata klauberi) in the Sonoran Desert. In: Neary, D. G.; Gottfried, G. J., eds. Collaboration Now for the Future: IV Conference on the Biodiversity and Management of the Madrean Archipelago. Proceedings RMRS-P-79. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 249-262.
