Timing of hibernation and reproduction in the endangered New Mexico meadow jumping mouse (Zapus hudsonius luteus)

Abstract

Hibernation is a key life history feature that can impact many other crucial aspects of a species’ biology, such as its survival and reproduction. I examined the timing of hibernation and reproduction in the federally endangered New Mexico meadow jumping mouse (Zapus hudsonius luteus), which occurs across a broad range of latitudes and elevations in the American Southwest. Data from museum specimens and field studies supported predictions for later emergence and shorter active intervals in montane populations relative to low-elevation populations. A low-elevation population located at Bosque del Apache National Wildlife Refuge (BANWR) in the Rio Grande valley was most similar to other populations of Z. hudsonius: the first emergence date was in mid-May and there was an active interval of 162 days. In montane populations of Z. h. luteus, the date of first emergence was delayed until mid-June and the active interval was reduced to ca 130 days, similar to some populations of the western jumping mouse (Z. princeps). Last date of immergence into hibernation occurred at about the same time in all populations (mid to late October). Evidence suggests that females may have a single litter per year in montane populations. At BANWR two peaks in reproduction were expected based on similarity of active season to Z. h. preblei, but the population exhibited little detectable above-ground activity in August, which could stem from a failure of the population to produce early litters. Recommendations are made with respect to appropriate timing of surveys for Z. h. luteus.