Food quality, security, and thermal refuge influence the use of microsites and patches by pygmy rabbits () across landscapes and seasons.

How intensely animals use habitat features depends on their functional properties (i.e., how the feature influences fitness) and the spatial and temporal scale considered.

Habitat selection by Dall's sheep is influenced by multiple factors including direct and indirect climate effects.

Arctic and boreal environments are changing rapidly, which could decouple behavioral and demographic traits of animals from the resource pulses that have shaped their evolution. Dall's sheep (Ovis dalli dalli) in northwestern regions of the USA and Canada, survive long, severe winters and reproduce during summers with short growing seasons. We sought to understand the vulnerability of Dall's sheep to a changing climate in Lake Clark National Park and Preserve, Alaska, USA.

Evolution of ungulate mating systems: Integrating social and environmental factors.

Ungulates exhibit diverse mating systems that range from monogamous pair territories to highly polygynous leks. We review mating systems and behaviors across ungulates and offer a new approach synthesizing how interacting factors may shape those mating systems. Variability exists in mating systems among and within species of ungulates and likely is affected by predation risk, availability of resources (food and mates), habitat structure, and sociality.

Linking forest management to moose population trends: The role of the nutritional landscape.

Forested lands in the western USA have undergone changes in management and condition that are resulting in a shift towards climax vegetation. These changes can influence the quality and quantity of forage for herbivores that rely on early-seral plants. To evaluate how management of forested landscapes might affect nutrition for Shiras moose (A.

Preferences of Specialist and Generalist Mammalian Herbivores for Mixtures Versus Individual Plant Secondary Metabolites.

Herbivores that forage on chemically defended plants consume complex mixtures of plant secondary metabolites (PSMs). However, the mechanisms by which herbivores tolerate mixtures of PSMs are relatively poorly understood. As such, it remains difficult to predict how PSMs, singly or as complex mixtures, influence diet selection by herbivores.

Seasonal temperature acclimatization in a semi-fossorial mammal and the role of burrows as thermal refuges.

Small mammals in habitats with strong seasonal variation in the thermal environment often exhibit physiological and behavioral adaptations for coping with thermal extremes and reducing thermoregulatory costs. Burrows are especially important for providing thermal refuge when above-ground temperatures require high regulatory costs (e.g.

Interacting effects of ambient temperature and food quality on the foraging ecology of small mammalian herbivores.

Both temperature and diet quality play an important role in the time and energy budgets of small mammalian herbivores. However, little is known about how temperature and diet quality interact to influence diet selection, nutrient extraction, and energetics, and how these effects might differ among species. Therefore, we examined the effects of diet quality and temperature on aspects of the foraging ecology of two species of lagomorphs, pygmy rabbits (Brachylagus idahoensis), which are small dietary specialists, and mountain cottontail rabbits (Sylvilagus nuttallii), which are larger dietary and habitat generalists.

Evaluation of micro-GPS receivers for tracking small-bodied mammals.

GPS telemetry markedly enhances the temporal and spatial resolution of animal location data, and recent advances in micro-GPS receivers permit their deployment on small mammals. One such technological advance, snapshot technology, allows for improved battery life by reducing the time to first fix via postponing recovery of satellite ephemeris (satellite location) data and processing of locations. However, no previous work has employed snapshot technology for small, terrestrial mammals.

Consequences for conservation: population density and genetic effects on reproduction of an endangered lagomorph.

Understanding reproduction and mating systems is important for managers tasked with conserving vulnerable species. Genetic tools allow biologists to investigate reproduction and mating systems with high resolution and are particularly useful for species that are otherwise difficult to study in their natural environments. We conducted parentage analyses using 19 nuclear DNA microsatellite loci to assess the influence of population density, genetic diversity, and ancestry on reproduction, and to examine the mating system of pygmy rabbits (Brachylagus idahoensis) bred in large naturalized enclosures for the reintroduction and recovery of the endangered distinct population in central Washington, USA.

Selection of food patches by sympatric herbivores in response to concealment and distance from a refuge.

Small herbivores face risks of predation while foraging and are often forced to trade off food quality for safety. Life history, behaviour, and habitat of predator and prey can influence these trade-offs. We compared how two sympatric rabbits (pygmy rabbit, Brachylagus idahoensis; mountain cottontail, Sylvilagus nuttallii) that differ in size, use of burrows, and habitat specialization in the sagebrush-steppe of western North America respond to amount and orientation of concealment cover and proximity to burrow refuges when selecting food patches.

Modeling trade-offs between plant fiber and toxins: a framework for quantifying risks perceived by foraging herbivores.

When selecting habitats, herbivores must weigh multiple risks, such as predation, starvation, toxicity, and thermal stress, forcing them to make fitness trade-offs. Here, we applied the method of paired comparisons (PC) to investigate how herbivores make trade-offs between habitat features that influence selection of food patches. The method of PC measures utility and the inverse of utility, relative risk, and makes trade-offs and indifferences explicit by forcing animals to make choices between two patches with different types of risks.

ANTIOXIDANT CAPACITY OF WYOMING BIG SAGEBRUSH ( SSP. ) VARIES SPATIALLY AND IS NOT RELATED TO THE PRESENCE OF A SAGEBRUSH DIETARY SPECIALIST.

Sagebrush ( spp.) in North America is an abundant native plant species that is ecologically and evolutionarily adapted to have a diverse array of biologically active chemicals. Several of these chemicals, specifically polyphenols, have antioxidant activity that may act as biomarkers of biotic or abiotic stress.

Spatial interactions between sympatric carnivores: asymmetric avoidance of an intraguild predator.

Interactions between intraguild species that act as both competitors and predator-prey can be especially complex. We studied patterns of space use by the black-footed ferret (Mustela nigripes), a prairie dog (Cynomys spp.) specialist, and the American badger (Taxidea taxus), a larger generalist carnivore that competes for prairie dogs and is known to kill ferrets.

Plant protein and secondary metabolites influence diet selection in a mammalian specialist herbivore.

For herbivores, nutrient intake is limited by the relatively low nutritional quality of plants and high concentrations of potentially toxic defensive compounds (plant secondary metabolites, PSMs) produced by many plants. In response to phytochemical challenges, some herbivores selectively forage on plants with higher nutrient and lower PSM concentrations relative to other plants. Pygmy rabbits () are dietary specialists that feed on sagebrush () and forage on specific plants more than others within a foraging patch.

Evaluating DNA degradation rates in faecal pellets of the endangered pygmy rabbit.

Noninvasive genetic sampling of faecal pellets can be a valuable method for monitoring rare and cryptic wildlife populations, like the pygmy rabbit (Brachylagus idahoensis). To investigate this method's efficiency for pygmy rabbit monitoring, we evaluated the effect of sample age on DNA degradation in faecal pellets under summer field conditions. We placed 275 samples from known individuals in natural field conditions for 1-60 days and assessed DNA quality by amplifying a 294-base-pair (bp) mitochondrial DNA (mtDNA) locus and five nuclear DNA (nDNA) microsatellite loci (111-221 bp).

Uncertainty in Population Estimates for Endangered Animals and Improving the Recovery Process.

United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery. The objective of our study was to evaluate whether recovery plans provide uncertainty (e.g.

Rapid species identification of pygmy rabbits (Brachylagus idahoensis) from faecal pellet DNA.

The pygmy rabbit (Brachylagus idahoensis) is a small lagomorph of the western United States that specializes in sagebrush (Artemisia spp.) habitat. Intensive habitat loss and modification have increased the vulnerability of pygmy rabbit populations, but the current geographic distribution and population status remain unclear.

PERMANENT GENETIC RESOURCES: Ten polymorphic microsatellite markers for the pygmy rabbit (Brachylagus idahoensis).

We developed 10 polymorphic microsatellite loci for the pygmy rabbit (Brachylagus idahoensis). Nine of the 10 loci amplified reliably and had a low frequency of null alleles. Number of alleles per locus ranged from four to 12, and observed and expected heterozygosities ranged from 0.