Revised distribution of an Alaskan endemic, the Alaska Hare (Lepus othus), with implications for taxonomy, biogeography, and climate change

Abstract

The Alaska Hare (Lepus othus Merriam 1900) is the largest lagomorph in North America but remains one of the most poorly studied terrestrial mammals on the continent. Its current distribution is restricted to western Alaska south of the Brooks Range, but historical accounts from north of the Brooks Range (the North Slope) have led to confusion over its past, present, and predicted future distributions. To determine if L. othus occurs or historically occurred on the North Slope, we surveyed museum collections, vetted observational accounts, and produced a spatial distribution model based on the resulting georeferenced records. We located a historic specimen long presumed lost that suggests the occurrence of L. othus on the North Slope as recently as the late 1800s. We also uncovered evidence of L. othus and (or) Mountain Hare (Lepus timidus Linnaeus 1758) on several islands in the Bering Sea, raising the possibility of recurring gene flow between these closely related species across seasonal ice connecting Asia and North America. While our results paint a more complete picture of the current distribution of L. othus, persistent uncertainties surrounding its taxonomic status and potential northward range shift onto lands reserved for oil and gas development call for additional study.

Extralimital Terrestrials: A reassessment of range limits in Alaska’s land mammals

“…These results are consistent with trends of increasing shrub cover in tundra areas that should make these areas more hospitable for Snowshoe Hares [28], although this contradicts future habitat projections that indicated no significant change in available habitat [4]. Recent extralimital records of Alaskan Hares indicated the occurrence of this species along the length of the Alaska Peninsula, and to north of the MCP [27]. In contrast, Hope et al’s [25] models did not predict the Alaska Peninsula to be part of the Alaskan Hare’s range during the 21st century.…”

“…In contrast, Hope et al’s [25] models did not predict the Alaska Peninsula to be part of the Alaskan Hare’s range during the 21st century. New records from the Seward Peninsula are consistent with predictions of an expanding distribution across northern Alaska [27], but there were no recent extralimital records to indicate inland movement of their range as predicted by Hope et al [25]. In contrast, Marcot et al [4] predicted a small but insignificant decline in available habitat for Alaskan Hares.…”

“…Climate change in Alaska is predicted to cause the geographic ranges of species to shift northward, upward in elevation, and towards the coast [4,23,25]), yet the status of such predicted species-specific movements remains largely unknown. Limited research has examined the extent to which terrestrial mammalian range or distribution shifts have actually occurred for select species over historical timescales in Alaska, including the expansion of American Marten ( Martes americana [Turton, 1806]) across the Kenai Peninsula [26], northward shifts in the Alaskan Hare’s ( Lepus othus [Merriam, 1900]) distribution in western Alaska [27], and the expansion of Snowshoe Hares ( L. americanus [Erxleben, 1777]) [28], Moose ( Alces alces [Linnaeus, 1758]) [29,30], and North American Beavers across the Alaskan Arctic [31].…”

Tundra be dammed: Beaver colonization of the Arctic

“…Beavers cut down entire shrubs and favor willow bark, leaves, and new growth for forage, which facilitates dominance by less‐palatable alder shrubs (Aleksiuk, ). More critically, the Alaska Hare ( Lepus othus ), whose global distribution is limited to the western tundra region of Alaska and relies on willow shrubs in winter (Cason, Baltensperger, Booms, Burns, & Olson, ), may be at least temporarily negatively impacted by the reduction of its habitat by encroaching beavers. The decadal and longer effects are unknown, but we believe that ultimately shrubs and shrub herbivores will thrive with the addition of disturbances like changing water levels and thawing permafrost.…”

Nonrandom territory occupancy by nesting Gyrfalcons (Falco rusticolus)

“…Finally, our attempt to describe prey habitat, and by extension prey availability, on the study area and in individual Gyrfalcon territories may have been flawed by a reliance on satellite data. Prior research has supported the validity of using Alaska GAP data for the purposes of this research (Cason et al 2016) as well as the reliability of GAP species-habitat predictions at the landscape level (McClure et al 2012;Steen et al 2012). More research that correlates data from prey surveys (Hawkshaw et al 2017) with occupancy patterns could shed further light on the subject.…”