Marjorie Matocq

University of Nevada, Reno | UNR · Department of Natural Resources and Environmental Science

Hybridization is a common process that has broadly impacted the evolution of multicellular eukaryotes; however, how ecological factors influence this process remains poorly understood. Here, we report the findings of a 3-year recapture study of the Bryant’s woodrat (Neotoma bryanti) and desert woodrat (N. lepida), two species that hybridize within...

The microbiome is critical to an organism's phenotype, and its composition is shaped by, and a driver of, eco‐evolutionary interactions. We investigated how host ancestry, habitat and diet shape gut microbial composition in a mammalian hybrid zone between Neotoma lepida and N. bryanti that occurs across an ecotone between distinct vegetation commun...

Little is known about the tolerances of mammalian herbivores to plant specialized metabolites across landscapes. We investigated the tolerances of two species of herbivorous woodrats, Neotoma lepida (desert woodrat) and Neotoma bryanti (Bryant’s woodrat) to creosote bush (Larrea tridentata), a widely distributed shrub with a highly toxic resin. Woo...

The genomic architecture underlying the origins and maintenance of biodiversity is an increasingly accessible feature of species, due in large part to third‐generation sequencing and novel analytical toolsets. Applying these techniques to woodrats (Neotoma spp.) provides a unique opportunity to study how herbivores respond to environmental change....

The woodrats or packrats of the genus Neotoma have been the subject of a wide array of research including paleoecology, physiology, morphological evolution, systematics, speciation, and hybridization. In recent years, much work has been done to elucidate evolutionary relationships within and between closely related species of the genus; in particul...

ContextEnvironmental changes produce discontinuities in suitable habitat. However, drawing inference into the effects of these changes on contemporary genetic patterns is often difficult. Recent approaches for evaluating landscape resistance facilitate increased understanding of landscape effects on gene flow.Objectives We investigated the effects...

Over the past 50 years conservation genetics has developed a substantive toolbox to inform species management. One of the most long-standing tools available to manage genetics - the pedigree - has been widely used to characterize diversity and maximize evolutionary potential in threatened populations. Now, with the ability to use high throughput se...

Over the past 50 years conservation genetics has developed a substantive toolbox to inform species management. One of the most long‐standing tools available to manage genetics ‐ the pedigree ‐ has been widely used to characterize diversity and maximize evolutionary potential in threatened populations. Now, with the ability to use high throughput se...

Over the past 50 years conservation genetics has developed a substantive toolbox to inform species management. One of the most long-standing tools available to manage genetics-the pedigree-has been widely used to characterize diversity and maximize evolutionary potential in threatened populations. Now, with the ability to use high throughput sequen...

When organisms experience secondary contact after allopatric divergence, genomic regions can introgress differentially depending on their relationships with adaptation, reproductive isolation, recombination, and drift. Analyses of genome‐wide patterns of divergence and introgression could provide insight into the outcomes of hybridization and the p...

Local adaptation can occur when spatially separated populations are subjected to contrasting environmental conditions. Historically, understanding the genetic basis of adaptation has been difficult, but increased availability of genome‐wide markers facilitates studies of local adaptation in non‐model organisms of conservation concern. The pygmy rab...

As the world population grows, so does the demand for food, putting unprecedented pressure on agricultural lands. At the same time, climate change, soil degradation, and water scarcity mean that productivity of many of these lands is deteriorating. In many desert dryland regions, drinking wells are drying up and the land above them is sinking, soil...

The genomic architecture underlying the origins and maintenance of biodiversity is an increasingly accessible feature of species, due in large part to third-generation sequencing and novel analytical toolsets. Woodrats of the genus Neotoma provide a unique opportunity to study how vertebrate herbivores respond to climate change, as two sister speci...

• Ecotones, characterized by adjacent yet distinct biotic communities, provide natural laboratories in which to investigate how environmental selection influences the ecology and evolution of organisms. For wild herbivores, differential plant availability across sharp ecotones may be an important source of dietary‐based selection. • We studied smal...

Aim Climate change poses significant challenges for tree species, which are slow to adapt and migrate. Insight into genetic and phenotypic variation under current landscape conditions can be used to gauge persistence potential to future conditions and determine conservation priorities, but landscape effects have been minimally tested in trees. Here...

The montane sky islands of the Great Basin are characterized by unique, isolated habitats and communities that likely are vulnerable to extirpation with environmental change. A subspecies of yellow pine chipmunk, the Humboldt yellow pine chipmunk (Tamias amoenus celeris), is associated with the whitebark and limber pine forests of the Pine Forest R...

Understanding how species have responded to past climate change may help refine projections of how species and biotic communities will respond to future change. Here, we integrate estimates of genome-wide genetic variation with demographic and niche modeling to investigate the historical biogeography of an important ecological engineer: the dusky-f...

Sagebrush-steppe ecosystems are one of the most imperiled ecosystems in North America and many of the species that rely on these habitats are of great conservation concern. Pygmy rabbits (Brachylagus idahoensis) are one of these species. They rely on sagebrush year-round for food and cover, and are understudied across their range in the intermounta...

Sharp ecological boundaries often present animals with abrupt transitions in various resources, including the availability of food, potentially creating strong selective gradients. Yet little is known concerning how animals respond to abrupt shifts in resources, especially when gene flow may limit local adaptation. Here, we used DNA metabarcoding a...

Habitat loss and fragmentation in the Mojave desert have been increasing, which can create barriers to movement and gene flow in populations of native species. Disturbance and degradation of Mojave desert tortoise habitat includes linear features (e.g. highways, railways, a network of dirt roads), urbanized areas, mining activities, and most recent...

We assessed body condition, diet quality (indexed by fecal nitrogen), and stress levels (using fecal glucocorticoid metabolites) in mule deer Odocoileus hemionus in southeastern Idaho, USA, during a mild (2007) and a harsh winter (2008) to evaluate spatial overlap and potential competition with North American elk Cervus elaphus. We used data from G...

Genomic technologies have advanced rapidly in recent decades and have ushered in an exciting new era for the study of mammals. Mammalogists working with non-model species are now able to explore many new research areas that were unimaginable only a short time ago. For example, it is currently possible for individual researchers to sequence and asse...

To understand how foraging decisions impact individual fitness of herbivores, nutritional ecologists must consider the complex in vivo dynamics of nutrient–nutrient interactions and nutrient–toxin interactions associated with foraging. Mathematical modeling has long been used to make foraging predictions (e.g. optimal foraging theory) but has large...

Conservation biologists have increasingly used translocations to mitigate population declines and restore locally extirpated populations. Genetic data can guide the selection of source populations for translocations and help evaluate restoration success. Bighorn sheep (Ovis canadensis) are a managed big game species that suffered widespread populat...

We examined patterns of genetic variation and diversity of extant pygmy rabbit (Brachylagus idahoensis) populations across the species' current range in Nevada and California. Our aims were to determine population genetic structure and levels of diversity across the southern portion of the species' range. We genotyped 13 microsatellite loci from 19...

We examined patterns of genetic variation and diversity of extant pygmy rabbit (Brachylagus idahoensis) populations across the species’ current range in Nevada and California. Our aims were to determine population genetic structure and levels of diversity across the southern portion of the species’ range. We genotyped 13 microsatellite loci from 19...

Climate change has been implicated as driving shifts of hybridizing species’ range limits [1, 2]. Whether and how much hybrid zones move depends on the relative fitness of hybridzing species under changing conditions [3, 4]. However, fitness is rarely linked to both climatic conditions and movement of hybrid zones, such that the relationship betwee...

In the mid-20th century, many populations of large-bodied mammals experienced declines throughout North America. Fortunately, within the last several decades, some have begun to rebound and even recolonize extirpated portions of their native range, including black bears (Ursus americanus) in the montane areas of the western Great Basin. In this stu...

The Mohave ground squirrel (Xerospermophilus mohavensis) is endemic to the western Mojave Desert of California and is state-listed as Threatened. This species is of conservation concern because of the potential for large-scale renewable energy development within its range. Recent evidence suggests that this threatened species may at least occasiona...

Topographically complex regions on land and in the oceans feature hotspots of biodiversity that reflect geological influences on ecological and evolutionary processes. Over geologic time, topographic diversity gradients wax and wane over millions of years, tracking tectonic or climatic history. Topographic diversity gradients from the present day a...

Chipmunks (Tamias spp.) in western North America are important for their numerical abundance, their role in pathogen transmission, and the composition and structure of food webs. As such, land management agencies (e.g., U.S. Forest Service) often conduct field surveys to monitor the diversity and abundance of chipmunk species as a measure of forest...

Conservation planning and biodiversity management require information on landscape connectivity across a range of spatial scales from individual home ranges to large regions. Reduction in landscape connectivity due changes in land use or development is expected to act synergistically with alterations to habitat mosaic configuration arising from cli...

Predicting changes in species distributions under a changing climate is becoming widespread with the use of species distribution models (SDMs). The resulting predictions of future potential habitat can be cast in light of planned land use changes, such as urban expansion and energy development to identify areas with potential conflict. However, SDM...

Biodiversity can be driven and limited by a changing landscape. This is evident in the California Floristic Province, where millennia of geologic change molded one of the world’s most biodiverse regions. Over the last century, the Great Central Valley of this region has experienced extensive habitat loss and fragmentation due to land use change. Ov...

Groups of organisms—whether multiple species or populations of a single species—can differ in several non-exclusive ways. For example, groups may have diverged phenotypically, genetically, or in the evolutionary responses available to them. We tested for the latter of these—response divergence—between two species of woodrats: Neotoma fuscipes and N...

California's San Joaquin Valley has faced dramatic changes in land composition over the last century, offering an example of a highly altered system with few isolated native remnants. Over time, changes in habitat size and connectivity can impede gene flow between populations of species and augment genetic drift resulting in long-term evolutionary...

Conservation planning and biodiversity management require information on landscape connectivity across a range of spatial scales from individual home ranges to large regions. Reduction in landscape connectivity due changes in land use or development is expected to act synergistically with alterations to habitat mosaic configuration arising from cli...

Dusky-footed woodrats are territorial cricetid rodents that individually occupy large stick houses from which they foray to gather food, find mates, and engage in other activities. These rodents are often bitten by Ixodes spp. ticks and are reservoirs of some strains of tick-borne bacterial pathogens such as Anaplasma phagocytophilum and Borrelia b...

Conservation biologists use various approaches to augment imperilled populations in order to supplement genetic variation and restore ecological function. However, understanding genotypic, phenotypic and ecotypic variation is critical in determining the most suitable sources to conserve historical and functional variation. Bighorn sheep (Ovis canad...

When lineages diverge in allopatry and come into secondary contact, we have a unique opportunity to examine the degree to which they have become reproductively isolated from one another and the mechanisms that contribute to rates of interspecific gene flow. If hybridization and introgression have occurred in the past or are ongoing, examining patte...

Abstract Patterns of host-parasite association may vary across the landscape in part because of host and parasite diversity, divergence, local ecology, or interactions among these factors. In central coastal California, we quantified parasite prevalence, infection intensity, and diversity in two sister species of wood rats (Neotoma fuscipes and Neo...

Reconstructing the assembly of local ecological communities requires insight from a wide range of disciplines including biogeography, paleontology, ecology, and evolutionary biology. Community assembly depends on the availability of species in a regional species pool (a ‘‘biota’’), which itself is assembled through a history of diversification, geo...

The Great Basin is a vast area of interior drainage including much of the expanse between the Sierra Nevada and Rocky Mountains. The unique geomorphology of this region has resulted in high local and regional biodiversity. Today, the Great Basin is considered one of the most threatened bioregions in North America. In this Special Feature, we bring...

The degree of concordance between patterns of divergence in genetic and morphological characters provides insight into the process of evolutionary diversification. We analyzed species-wide morphological variation in a broadly distributed species of small mammal, the bushy-tailed woodrat (Neotoma cinerea), for comparison against a recently developed...

Neotoma cinerea specimens examined for morphological and genetic analyses

Tukey-Kramer contrasts of size-corrected and standardized craniodental measurements between all N. cinerea subspecies of n ≥ 3

Townsend's big-eared bat (Corynorhinus townsendii) is a widespread species of special concern that hibernates in large numbers in the lava-tube caves of southeastern Idaho. We measured 24 habitat variables describing landscape-level, physical, and microclimate characteristics of 13 caves and identified at least three that were useful for predicting...

Female mate preferences may be under strong selection in zones of contact between closely related species because of greater variation in available mates and the potential costs of hybridization. We studied female mate preferences experimentally in a zone of secondary contact between Desert and Bryant's Woodrat (Neotoma lepida and N. bryanti) in th...

It is time to weigh up the pros and cons of using genetic engineering to rescue species from extinction, say Michael A. Thomas and colleagues.

Mohave ground squirrels Xerospermophilus mohavensis Merriam are small grounddwelling rodents that have a highly restricted range in the northwest Mojave Desert, California, USA. Their small natural range is further reduced by habitat loss from agriculture, urban development, military training and recreational activities. Development of wind and sol...

Identifying historic patterns of population genetic diversity and connectivity is a primary challenge in efforts to re-establish the processes that have generated and maintained genetic variation across natural landscapes. The challenge of reconstructing pattern and process is even greater in highly altered landscapes where population extinctions a...

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) seq...

The Mojave Desert is characterized by a unique biodiversity and is an area of particular interest for the development of renewable energy facilities, which could impact habitat quality and population connectivity. To begin understanding current habitat connectivity in a Mojave Desert endemic, we examine population genetic characteristics of the Moh...

Many montane species respond to climate change by shifting their range upslope as temperatures at lower elevations increase. An elevation range shift causes a range contraction that may result in a population bottleneck. Joseph Grinnell surveyed the fauna along the Yosemite transect from 1914 to 1920. In 2003 Craig Moritz and his colleagues began t...

We characterized 12 polymorphic microsatellite markers for Xerospermophilus mohavensis, the Mohave ground squirrel, in order to contribute to the conservation management of this species. We tested polymorphism in the Cactus Peak population (N=84) and found that allele number ranged from 4 to 9 with observed and expected heterozygosity ranging from...

Our understanding of the development and maintenance of phylogeographical structure is aided by integrating information from genetics, subfossil assemblages, and models of ecological niche distributions through the late Quaternary. The bushy-tailed woodrat, Neotoma cinerea, offers an interesting study case for several reasons: • Molecular work in N...

Aim The Mohave ground squirrel (Xerospermophilus mohavensis) is one of a few endemic species of the Mojave Desert of south-western North America. We describe phylogeographic patterns within this species and its sister taxon (Xerospermophilus tereticaudus) and test hypotheses concerning their biogeographical history using genetic signatures of stabl...

The role of hybridization in generating diversity in animals is an active area of discovery and debate. We assess hybridization across a contact zone of northern (Myodes rutilus) and southern (M. gapperi) red-backed voles using variation in skeletal features and both mitochondrial and nuclear loci. This transect extends approximately 550 km along t...

Specimens examined in this study. List of specimens and their voucher numbers used in this research.

Identifying the genetic architecture of adaptive traits is fundamental to understanding how organisms respond to their environment, over both ecological and evolutionary timeframes. Microarray technology that allows us to capture the simultaneous expression of thousands of genes provides unparalleled insight into how organisms cope with their envir...

Two of the five subspecies of the western big-eared bat, Corynorhinus townsendii, are listed as federally endangered with the remaining three being of conservation concern. Knowing the degree of connectivity among populations would aid in the establishment of sound conservation and management plans for this taxon. For this purpose, we have develope...

Zones of secondary contact between closely related species provide a rare opportunity to examine evidence of evolutionary processes that reinforce species boundaries and/or promote diversification. Here, we report on genetic and morphological variation in two sister species of woodrats, Neotoma fuscipes and N. macrotis, across a 30-km transition zo...

Interspecific morphological variation in animal genitalia has long attracted the attention of evolutionary biologists because of the role genital form may play in the generation and/or maintenance of species boundaries. Here we examine the origin and evolution of genital variation in rodents of the muroid genus Neotoma. We test the hypothesis that...

Population declines caused by natural and anthropogenic factors can quickly erode genetic diversity in natural populations. In this study, we examined genetic variation within 10 tiger salamander populations across northern Yellowstone National Park in Wyoming and Montana, USA using eight microsatellite loci. We tested for the genetic signature of...

The field of landscape genetics has great potential to identify habitat features that influence population genetic structure. To identify landscape correlates of genetic differentiation in a quantitative fashion, we developed a novel approach using geographical information systems analysis. We present data on blotched tiger salamanders (Ambystoma t...

Studies of highly kin-structured mammal societies have revealed the importance of natal philopatry in determining the distribution of genetic variation within populations. In comparison, the relationship between philopatry and genetic diversity within populations of moderately kin-structured societies has received relatively little attention. Previ...

Discrepancies between the census size and the genetically effective size of populations (N(e)) can be caused by a number of behavioural and demographic factors operating within populations. Specifically, strong skew in male reproductive success, as would be expected in a polygynous mating system, could cause a substantial decrease in N(e) relative...

Neotoma fuscipes, the dusky-footed wood rat, is a morphologically diverse taxon with recognized intraspecific subdivisions that are based on both quantitative and qualitative morphology. Although there is substantial morphological variation within this taxon, intergradation among the various forms has been observed by previous workers. A recent sur...

The dusky-footed woodrat, Neotoma fuscipes, is a medium-sized rodent that inhabits low elevation woodland habitats along the Pacific coast of North America from Oregon, throughout California and into Baja California. Analyses of mitochondrial sequence variation throughout the distribution reveal substantial phylogeographical structure within N. fus...

Six moderately to highly polymorphic microsatellite loci were developed for dusky-footed woodrats (Neotoma fuscipes) using a modified enrichment protocol. Of the 149 clones sequenced, 33 (22%) contained inserts with greater than 10 repeat units. These loci are currently being used to study various aspects of the ecology and evolution of N. fuscipes...

Examining patterns of genetic diversity has become an integral component of many management plans concerning endangered species, yet interpreting the processes underlying such patterns remains challenging. We demonstrate low genetic diversity in a critically endangered small mammal population. A common interpretation of this pattern would be that i...

Examining patterns of genetic diversity has become an integral component of many management plans concerning endangered species, yet interpreting the processes underlying such patterns remains challenging. We demonstrate low genetic diversity in a critically endangered small mammal population. A common interpretation of this pattern would be that i...

Population history and current demographic and ecological factors determine the amount of genetic variation within and the degree of differentiation among populations. Differences in the life history and ecology of codistributed species may lead to differences in hierarchical population genetic structure. Here, we compare patterns of genetic divers...

Pleistocene vicariance is often invoked to explain the disjunct populations of animals in habitat refugia throughout the southwestern United States. The combined effects of small population size and isolation from the rest of the contiguous range are thought to result in genetic differentiation of relict organisms. Here, we describe a relict popula...

We examined alternative hypotheses for the benefits of footdrumming in the presence of snakes by the banner-tailed kangaroo rat, Dipodomys spectabitis, by testing whether the target of the signal includes conspecifics, the predator or both. Footdrumming recorded in the field revealed that rats altered their footdrumming signatures when drumming at...

The Mexican wolf (Canis lupus baileyi), an endangered subspecies of gray wolf, was native to parts of Mexico and the southwestern United States. Currently, only a few individuals, if any, exist in the wild, so planned reintroduction programs must use captive-raised wolves. In only one captive population, however, designated the certified lineage, a...