Elevational diversity gradients, biogeography and the structure of montane mammal communities in the intermountain region of North America

Abstract

1 Distribution data were assembled for non‐volant small mammals along elevational gradients on mountain ranges in the western U.S.A. Elevational distributions in the species‐rich Uinta Mountains were compared to those on smaller mountain ranges with varying degrees of historical isolation from the Uintas. 2 For mountain ranges supporting the richest faunas, species richness is highest over a broad low‐ to mid‐elevation zone and declines at both lower and higher elevations. Patterns on other mountain ranges are similar but reflect lower overall species richness. 3 A basic relationship between elevational and geographical distribution is apparent in the occurrence patterns of mammals on regional mountains. Faunas on mountains that have had low levels of historical isolation appear to be influenced by immigration rather than extinction. Species restricted to high elevations in the Uintas are poorly represented on historically isolated mountains and form a portion of local faunas shaped by extinction. Species occurring at lower elevations in the Uintas have better representation on isolated mountains and apparently maintain populations through immigration. 4 Several widespread species show substantial variation in maximum elevation records on different mountain ranges. This involves (1) an upward shift in habitat zones on small, isolated mountain ranges, allowing greater access by low‐elevation species, and (2) expansion of certain low‐ and mid‐elevation species into habitats normally occupied by absent high‐elevation taxa. 5 Results indicate that montane mammal faunas of the intermountain region have been shaped by broad‐scale historical processes, unique regional geography and local ecological dynamics. Parallel examples among mammals of the Philippine Islands suggest that such patterns may characterize many insular faunas.

Elevational gradients of diversity for lizards and snakes in the Hengduan Mountains, China

“…However, area still explained 55% of variation in lizard species richness and 58% variation in snake species richness along the elevational gradient in the mountains. The influence of area in determining regional species richness in altitudinal ranges has also been shown for other taxa, such as plants (Bachman et al 2004), ants (Sanders 2002), fishes (Fu et al 2004), birds (Kattan and Franco 2004) and mammals (Rickart 2001).…”

“…Since Rahbek's review, some studies further confirm a unimodal pattern of richness occurring with altitude in plants (Kessler 2001;Vetaas and Grytnes 2002;Bhattarai et al 2004), invertebrates (Samson et al 1997;Pyrcz and Wojtusiak 2002;Sanders 2002), and mammals (Heaney 2001;Md. Nor 2001;Rickart 2001;Sa´nchez-Cordero 2001;Li et al 2003a, b;McCain 2004), and others support monotonically decreasing patterns of richness occurring with altitude in plants (Tang and Ohsawa 1999;Odland and Birks 1999;Austrheim 2002), invertebrates (Lobo and Halffter 2000), fishes (Fu et al 2004), birds (Patterson et al 1998;Kattan and Franco 2004). For amphibians and reptiles, they generally show a monotonic decline in species richness with increasing altitude (Heatwole 1982;Heatwole and Taylor 1987), although opposite trends have been observed in particular habitats (Heyer 1967;Simbotwe 1985).…”

Mitigating plague risk in utah prairie dogs: Evaluation of a systemic flea‐control product

“…Seven of these 8 flea species have been documented to be competent plague vectors, although the degree of vector competency varies among flea species (Eisen et al 2009). The diversity of flea species we encountered, together with the relatively high reported diversity of small mammals in this area (Rickart 2001), indicate the need to investigate how neighboring rodent communities, along with site-specific habitat factors (such as soil conditions and elevation), collectively contribute to patterns in flea diversity on Utah prairie dogs. This is of particular interest given that small mammals occurring on and near prairie dog colonies have been hypothesized to play a key role in maintaining and transmitting plague in prairie dog colonies (Salkeld et al 2010).…”

Ecological Flexibility of the Top Predator in an Island Ecosystem — The Iriomote Cat Changes Feeding Patterns in Relation to Prey Availability

“…All radio-collared cats preferred using lowland habitats, mainly with elevation of less than 50 m, while they hardly used highlands with elevation more than 200 m. In particular, the effect of elevation was more highly correlated with the habitat use of the cats in rough terrains (NCA, Urauchi and Shirahama). Sometimes, elevation contributed as a factor for determining vegetation type and affected the mammalian fauna [e.g., [61][62][63]. However, this effect was the result of climatic changes that required a vertical interval of several thousand metres.…”