| pseudopterygium in a pygmy rabbit. | | 1979 | 257965 |
| phylogenetic relationships of cottontails (sylvilagus, lagomorpha): congruence of 12s rdna and cytogenetic data. | the genus sylvilagus, which comprises the new world cottontail rabbits, contains several commercially important as well as endangered (or threatened) species. understanding the evolution of this group is pertinent to their management and conservation. the purpose of this study was to examine the evolutionary history of the cottontails using sequence data from the mitochondrial 12s rrna gene. the 12s data provide a robust phylogeny which was supported under a variety of phylogenetic approaches an ... | 1997 | 9187089 |
| a pathogenic new species of eimeria from the pygmy rabbit, brachylagus idahoensis, in washington and oregon, with description of the sporulated oocyst and intestinal endogenous stages. | in january 2003, fecal samples from 13 live pygmy rabbits, brachylagus idahoensis (merriam, 1891), were collected at the oregon zoo in portland, oregon, and sent to the university of new mexico (unm), albuquerque, new mexico, to be examined for coccidia. in july 2004, 14 more fecal samples were collected and sent to unm, 6 from some of the same rabbits and 8 from 16 other rabbits (4 were pooled samples from siblings). in addition, tissue sections from 3 dead rabbits (2 from the oregon zoo, 1 fro ... | 2005 | 16108556 |
| nutritional requirements and diet choices of the pygmy rabbit (brachylagus idahoensis): a sagebrush specialist. | sagebrush (artemisia tridentata) comprises up to 99% of the winter and 50% of the summer diets of pygmy rabbits (brachylagus idahoensis). few animals specialize on such plants as sagebrush, which contain high levels of plant chemicals that can be toxic. we investigated the nutritional requirements of pygmy rabbits and their ability and propensity to consume sagebrush alone and as part of a mixed diet. we compared diet choices of pygmy rabbits with that of a generalist forager, the eastern cotton ... | 2006 | 17082988 |
| mycobacterium avium in pygmy rabbits (brachylagus idahoensis): 28 cases. | the columbia basin subpopulation of pygmy rabbit brachylagus idahoensis was listed as endangered by the united states fish and wildlife service in november 2001, and no pygmy rabbits have been seen in the wild since spring 2002. captive propagation efforts have attempted to increase population size in preparation for reintroduction of animals into central washington. disseminated mycobacteriosis due to mycobacterium avium has been the most common cause of death of adult captive pygmy rabbits. be ... | 2006 | 17315435 |
| effects of enhanced uv-b radiation on plant chemistry: nutritional consequences for a specialist and generalist lagomorph. | ultraviolet-b (uv-b) radiation has been increasing in temperate latitudes in recent decades and is expected to continue rising for some time. enhanced uv-b radiation can change plant chemistry, yet the effects of these changes on mammalian herbivores are unknown. to examine the influence of enhanced uv-b radiation on nutrition of a specialist and generalist hindgut fermenter, we measured nutritional and chemical constituents of three common north american range plants, big sagebrush (artemisia t ... | 2007 | 17406969 |
| haemodipsus brachylagi n. sp. (phthiraptera: anoplura: polyplacidae), a new sucking louse from the pygmy rabbit in nevada. | the male and female of haemodipsis brachylagi n. sp. (phthiraptera: anoplura) are described from specimens collected from a pygmy rabbit, brachylagus idahoensis (merriam) (lagomorpha: leporidae), from nevada. morphological features that differentiate the new species from other known species of haemodipsus are elucidated, and an identification key to both sexes of the 3 species now known from this genus in north america is included. geographical distributions of the other 4 species of haemodipsus ... | 2007 | 17539405 |
| characterizing gonadal and adrenal activity by fecal steroid analyses in pygmy rabbits (brachylagus idahoensis). | in 2001, the sudden collapse of the columbia basin population of pygmy rabbits prompted the initiation of a captive breeding program to facilitate reintroduction, but reproductive success in captivity has not met expectations. therefore, the objective of this study was to characterize the reproductive and adrenal endocrinology of this endangered rabbit species so that appropriate management strategies could be developed to monitor animal welfare and increase reproduction. fecal samples were coll ... | 2011 | 21377469 |
| 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. to aid in detection and population monitoring, we developed a species identification test that uses mitochondrial dna species-specific primers to distinguish among six symp ... | 2011 | 21518302 |
| 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 0.26 to 0.89 and from 0.63 to 0.88, respectively. these loci will be useful in determining population genetic structure and assessing patterns of gene flow in the pygmy rabbit. | 2008 | 21585792 |
| mycobacteriosis in the rabbit and rodent. | spontaneous mycobacteriosis is rare in rabbits and rodents with the exception of the pygmy rabbit, and there are only a handful of reported cases involving other rodents. mycobacterium avium complex was the most commonly identified organism in reports of spontaneous mycobacteriosis involving rabbits and rodents. the resistance of rabbits and rodents to mycobacterial disease has been useful in understanding the disease in humans and other animals. preventing or controlling mycobacterium sp transm ... | 2011 | 22244115 |
| evolutionary insights into il17a in lagomorphs. | in leporids, il17a had been implicated in the host defense against extracellular pathogens, such as francisella tularensis that infects hares and rabbits and causes the zoonotic disease tularemia. here, we studied il17a from five lagomorphs, european rabbit, pygmy rabbit, brush rabbit, european brown hare, and american pika. we observed that this protein is highly conserved between these species, with a similarity of 97-99% in leporids and ~88% between leporids and american pika. the exon/intron ... | 2015 | 26788019 |
| genetic characterization of interleukins (il-1α, il-1β, il-2, il-4, il-8, il-10, il-12a, il-12b, il-15 and il-18) with relevant biological roles in lagomorphs. | ils, as essential innate immune modulators, are involved in an array of biological processes. in the european rabbit (oryctolagus cuniculus) il-1α, il-1β, il-2, il-4, il-8, il-10, il-12a, il-12b, il-15 and il-18 have been implicated in inflammatory processes and in the immune response against rabbit hemorrhagic disease virus and myxoma virus infections. in this study we characterized these ils in six lagomorpha species (european rabbit, pygmy rabbit, two cottontail rabbit species, european brown ... | 2015 | 26395994 |
| 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 pro ... | 2016 | 27069587 |
| antioxidant capacity of wyoming big sagebrush (artemisia tridentata ssp. wyomingensis) varies spatially and is not related to the presence of a sagebrush dietary specialist. | sagebrush (artemisia 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. this study investigated the spatial variation of antioxidant capacity, as well as the relationship between a mammalian herbivore and antioxidant capacity in wyoming big sagebrush ... | 2015 | 26582971 |
| 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 (brachylagus idahoensis) are dietary specialists that feed on sagebrush (artemisia spp.) and forage on ... | 2017 | 26366011 |
| mechanisms for eliminating monoterpenes of sagebrush by specialist and generalist rabbits. | pygmy rabbits (brachylagus idahoensis) are one of only three vertebrates that subsist virtually exclusively on sagebrush (artemisia spp.), which contains high levels of monoterpenes that can be toxic. we examined the mechanisms used by specialist pygmy rabbits to eliminate 1,8-cineole, a monoterpene of sagebrush, and compared them with those of cottontail rabbits (sylvilagus nuttalli), a generalist herbivore. rabbits were offered food pellets with increasing concentrations of cineole, and we mea ... | 2012 | 23053918 |
| 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. we evalua ... | 2017 | 28301495 |
| evolutionary morphology of the rabbit skull. | the skull of leporids (rabbits and hares) is highly transformed, typified by pronounced arching of the dorsal skull and ventral flexion of the facial region (i.e., facial tilt). previous studies show that locomotor behavior influences aspects of cranial shape in leporids, and here we use an extensive 3d geometric morphometrics dataset to further explore what influences leporid cranial diversity. facial tilt angle, a trait that strongly correlates with locomotor mode, significantly predicts the c ... | 2016 | 27688967 |
| 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 e ... | 2016 | 27411250 |
| 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 ... | 2015 | 26909434 |
| 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) mito ... | 2013 | 23590236 |
| role of familiarity and preference in reproductive success in ex situ breeding programs. | success of captive-breeding programs centers on consistent reproduction among captive animals. however, many individuals do not reproduce even when they are apparently healthy and presented with mates. mate choice can affect multiple parameters of reproductive success, including mating success, offspring production, offspring survival, and offspring fecundity. we investigated the role of familiarity and preference on reproductive success of female columbia basin pygmy rabbits (brachylagus idahoe ... | 2012 | 22809353 |
| 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 diet ... | 2018 | 29301704 |
| the balancing act of foraging: mammalian herbivores trade-off multiple risks when selecting food patches. | animals face multiple risks while foraging such as the risk of acquiring inadequate energy from food and the risk of predation. we evaluated how two sympatric rabbits (pygmy rabbits, brachylagus idahoensis, and mountain cottontail rabbits, sylvilagus nuttallii) that differ in size, use of burrows, and habitat specialization in the sagebrush-steppe of western north america respond to different types and levels of perceived risks (i.e., fitness cost × probability of occurrence), including fiber an ... | 2017 | 28963624 |
| evolution of ccl11: genetic characterization in lagomorphs and evidence of positive and purifying selection in mammals. | the interactions between chemokines and their receptors are crucial for differentiation and activation of inflammatory cells. cc chemokine ligand 11 (ccl11) binds to ccr3 and to ccr5 that in leporids underwent gene conversion with ccr2. here, we genetically characterized ccl11 in lagomorphs (leporids and pikas). all lagomorphs have a potentially functional ccl11, and the pygmy rabbit has a mutation in the stop codon that leads to a longer protein. other mammals also have mutations at the stop co ... | 2016 | 27189425 |
| 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. although relative rates of detoxification of psms have been used to explain tolerance of psms by dietary specialist herbivores, few studies have used the rat ... | 2019 | 30397901 |
| 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., water or energy) or exceed the physiological tolerances of an organism. our objective was to explore the role of burrows as thermal refuges for a small endotherm ... | 2018 | 29576977 |
| effects of genetic management on reproduction, growth, and survival in captive endangered pygmy rabbits (brachylagus idahoensis). | a quarter of all lagomorph species worldwide are threatened with extinction. captive breeding programs, such as that developed for the columbia basin (cb) pygmy rabbit (brachylagus idahoensis), sometimes are implemented as emergency conservation measures to restore small, genetically distinct populations. however, small source populations also may have low genetic diversity, which may influence attributes related to fitness, including growth, survival, and reproduction. we used mixed-effects reg ... | 2013 | 32287380 |