Differential regional response of the bushy‐tailed woodrat (Neotoma cinerea) to late Quaternary climate change

Abstract

Aim To reconstruct the regional biogeographical history of the bushy-tailed woodrat, Neotoma cinerea (Rodentia: Cricetidae), across its distribution using multiple sources of information, including genetic data, ecological niche models and the palaeorecord.Location Western North America.Methods We analysed complete cytochrome b gene (1143 bp) sequences from 182 specimens of N. cinerea using Bayesian and coalescent methods to infer phylogenetic relationships, time of major divergences, and recent demographic trends. For comparison, we developed clade-specific ecological niche models for groups of interest and analysed spatial trends of N. cinerea in the palaeorecord as well as temporal frequency trends across strata of individual palaeomiddens.Results We found two largely allopatric clades within N. cinerea, with several regionally distinct subclades showing contrasting recent population dynamics. Niche models showed consistent habitat at the Last Glacial Maximum (LGM) and modern times in the Rocky Mountains and northern United States, while the Great Basin may have been markedly less suitable at the LGM than today. The palaeorecord showed great spatio-temporal variability in the presence of N. cinerea, but documents broad-scale patterns of occupancy and regional population trends. Main conclusionsThe Quaternary dynamics and evolutionary history of N. cinerea appear to have been shaped by both vicariant events associated with geographical barriers and the availability of suitable habitat through time. Divergence of the two major clades dates to the Pliocene-Pleistocene transition, with clades separated by the Green and Colorado rivers and northern Rocky Mountain Pleistocene glaciations. We found largely concordant genetic, niche model and palaeorecord patterns suggesting long-term population stability in the Rocky Mountains, while extant clades in the Great Basin and far north appear to have expanded or re-expanded into these regions relatively recently. Furthermore, disjunct haplotype distributions, regional demographic history, and historical distribution of suitable habitat suggest that the Great Basin has been a particularly dynamic region.

From Desert to Rainforest: Phenotypic Variation in Functionally Important Traits of Bushy-Tailed Woodrats (Neotoma cinerea) Across Two Climatic Extremes

“…Associations between moisture and auditory bulla morphology have been described in other rodent species (Monteiro et al 2003), including N. cinerea (Hornsby 2009). Consistent with our findings, Great Basin Desert subspecies of N. cinerea have the largest auditory bullae relative to skull size and that variation was explained by precipitation (Hornsby 2009). Although increased middle ear size via inflation of the auditory bulla is a common adaptation of desert rodents to arid environments (Mares 1993), other factors need to be considered to comprehensively address whether such pattern is adaptive in N. cinerea.…”

“…Because xeric environments feature little vegetative cover and strong winds, increased sensitivity to low frequency sound could improve the use of auditory cues to detect predators (Webster and Webster 1980). Associations between moisture and auditory bulla morphology have been described in other rodent species (Monteiro et al 2003), including N. cinerea (Hornsby 2009). Consistent with our findings, Great Basin Desert subspecies of N. cinerea have the largest auditory bullae relative to skull size and that variation was explained by precipitation (Hornsby 2009).…”

Ecological niche models in phylogeographic studies: applications, advances and precautions

“…; Banta et al . ; Hornsby & Matocq ). For example, to evaluate the role of environment differentiation in the divergence of three distinct genetic lineages of the Spanish lizard ( Psammodromus hispanicus ), Fitze et al .…”

Phylogeography of the western jumping mouse (Zapus princeps) detects deep and persistent allopatry with expansion

“…Evidence for the persistent allopatry scenario would include geographically structured lineages. Signatures of genetic divergence and geographically structured variation in montane organisms have been recorded for alpine stonecrops (DeChaine and Martin 2005b), foxtail pine (Eckert et al 2008), kittentails (Marlowe and Hufford 2008), alpine butterflies (DeChaine and Martin 2005a), birds , and various mammals (Sullivan et al 2000;Demboski and Cook 2001;Hornsby and Matocq 2011).…”

“…Because these habitats are limited in extent and isolated within predominantly xeric environments, populations of montane mesic-associated mammals are hypothesized to exhibit a deeper divergence than their northern counterparts. For example, genetic breaks across arid barriers such as the Columbia and Wyoming basins (Nielson et al 2001;Carstens et al 2005;DeChaine and Martin 2005b;Carstens and Richards 2007) suggest that isolation during warm interglacial periods may contribute to allopatric divergence in mammals (Demboski and Cook 2001;Demboski and Sullivan 2003;Good et al 2008;Galbreath et al 2010;Hornsby and Matocq 2011). Persistent allopatric divergence is expected to result in deeper genetic distance and lineage cohesion, suggesting limited or no mixing through multiple glacial cycles (Nielson et al 2001(Nielson et al , 2006DeChaine and Martin 2006).…”