Black-Tailed and White-Tailed Jackrabbits in the American West: History, Ecology, Ecological Significance, and Survey Methods

Abstract

Across the western United States, Leporidae are the most important prey item in the diet of Golden Eagles (Aquila chrysaetos). Leporids inhabiting the western United States include black-tailed (Lepus californicus) and white-tailed jackrabbits (Lepus townsendii) and various species of cottontail rabbit (Sylvilagus spp.). Jackrabbits (Lepus spp.) are particularly important components of the ecological and economic landscape of western North America because their abundance influences the reproductive success and population trends of predators such as coyotes (Canis latrans), bobcats (Lynx rufus), and a number of raptor species. Here, we review literature pertaining to black-tailed and white-tailed jackrabbits comprising over 170 published journal articles, notes, technical reports, conference proceedings, academic theses and dissertations, and other sources dating from the late 19th century to the present. Our goal is to present information to assist those in research and management, particularly with regard to protected raptor species (e.g., Golden Eagles), mammalian predators, and ecological monitoring. We classified literature sources as (1) general information on jackrabbit species, (2) black-tailed or (3) white-tailed jackrabbit ecology and natural history, or (4) survey methods. These categories, especially 2, 3, and 4, were further subdivided as appropriate. The review also produced several tables on population trends, food habits, densities within various habitats, and jackrabbit growth and development. Black-tailed and white-tailed jackrabbits are ecologically similar in general behaviors, use of forms, parasites, and food habits, and they are prey to similar predators; but they differ in their preferred habitats. While the black-tailed jackrabbit inhabits agricultural land, deserts, and shrublands, the white-tailed jackrabbit is associated with prairies, alpine tundra, and sagebrush-steppe. Frequently considered abundant, jackrabbit numbers in western North America fluctuate temporally and spatially. We also reviewed methods used to investigate jackrabbit populations, including spotlight line transects, flushing transects, drive counts, pellet plot counts, collections, roadside counts, mark-recapture studies, and radio-telemetry studies. Our review of jackrabbit literature illustrates a number of deficiencies in our understanding of jackrabbits in general. As an example, a detailed quantitative description of habitat preferences is lacking, as is a thorough understanding of sympatric jackrabbit species interactions. Even the existence of the oft-cited jackrabbit "cycle" is a matter of debate. Survey methods generally do not address efficacy or accuracy in measuring jackrabbit density or abundance. In addition, there is a paucity of information about jackrabbits in the Mojave Desert, with no real understanding of home ranges, habitat preferences, and population dynamics or demographics in this region.

Spatial and Temporal Patterns in Golden Eagle Diets in the Western United States, with Implications for Conservation Planning

“…Before-after-control-impact (BACI) design could be used to assess the potential effects of prey enhancement protocols, such as prairie dog relocation and plague mitigation, on Golden Eagle prey selection and productivity. Incorporating prey management into conservation planning and considering actions that support a diverse prey community could buffer against periodic fluctuations in leporid population density (Simes et al 2015).…”

A Review of the Ongoing Decline of the White-Tailed Jackrabbit

“…Some have presumed these range shifts were due to competition, but other factors can produce the same patterns. Compared to the whitetailed jackrabbit, the black-tailed jackrabbit has a smaller average home range (Smith 1990), greater recruitment potential, and lower mortality rate, and Simes et al (2015) suggest it is more adaptable to disturbed habitats and reduced forage quality. Readers should note, however, that populations of most western leporid populations, including black-tailed jackrabbits, declined after the early 1970s (Brown et al 2018).…”

“…We compiled, read, and evaluated~210 articles in the popular and peer-reviewed literature on white-tailed jackrabbit status, abundance, population trends, survey results, and responses to environmental stimuli. We obtained additional content and references from the white-tailed jackrabbit IUCN Red List account (Brown and Smith 2019) and overarching species accounts (Lim 1987;Simes et al 2015;Beever et al 2018). To determine white-tailed jackrabbit population trends, we also sought agency reports, wildlife surveys, and harvest information collected by state natural resource agencies within the species' present and former range.…”

“…The dominant Lepus in North America's intermountain region prior to the Holocene, the grassland-adapted white-tailed jackrabbit Lepus townsendii (Figure 1), began giving way to the black-tailed jackrabbit Lepus californi-cus with the onset of warming temperatures and changing vegetation between 2,000 and 8,000 y ago (Grayson 1977;Schimitt et al 2002;Fisher 2012). Reduction in the numbers and distribution of this Nearctic crossover from Eurasia, while subject to periodic fluctuations, continues today (Anthony 1928;Simes et al 2015;Gilcrease et al 2016;Brown et al 2018). Cold tolerant, with large furry feet and thick winter pelage that turns white in winter in its northern range (Hanson and Bear 1971), the white-tailed jackrabbit exhibits higher body temperatures and metabolic rates in winter than in summer (Rogowitz 1990).…”

Raptor nest–site use in relation to the proximity of coalbed–methane development

“…If the temporal patterns in nest-site use in our study reflected actual population trends (Sergio and Newton, 2003;Kennedy et al, 2014), there were likely key factors affecting local raptor populations independent of potential energy-development effects. Raptor occupancy, site fidelity, and population trends are known to be associated with local prey availability (Smith et al, 1981;MacLaren, et al 1988;Woffinden and Murphy, 1989;Kostrzewa, 1996;Kochert and Steenhof, 2002;Sergio et al, 2006;Millsap et al, 2015) which varies temporally and spatially (Fedy and Doherty, 2011;Simes et al, 2015). Raptor prey deficits can be exacerbated by exogenous factors such as Fig.…”