| the ecology of tularaemia. | tularaemia, a zoonotic disease caused by the bacterium francisella tularensis mccoy, 1912, is reported from north america, europe and northern parts of asia, but not from the southern hemisphere. two subspecies of f. tularensis are recognised: the highly virulent type a and the milder type b, with additional subdivisions reported. tularaemia has been reported in more than 250 animal species including man, other mammals, birds, fish, amphibians, arthropods and protozoa. type a is reported to have ... | 1992 | 1305858 |
| thyroid follicular carcinoma with pulmonary metastases in a beaver (castor canadensis). | an 11-yr-old female beaver (castor canadensis) died after a 3 1/2 mo course of intermittent diarrhea, lethargy and anorexia. a postmortem examination revealed both a necrotizing ulcerative colitis and bilaterally enlarged thyroid glands. histologically, the necrotizing colitis was similar to that caused by canine or feline parvovirus. thyroid glands were multilobulated. lobules were composed of irregularly arranged, variably sized follicles, some of which contained colloid. follicles were lined ... | 1989 | 2810561 |
| reservoirs of giardia spp. in southwestern alberta. | a survey of potential hosts of giardia spp. was carried out during 1982 and 1983 in the kananaskis valley and banff national park, alberta, canada. diagnosis was based mainly on fecal analysis but a few animals were examined at necropsy and scrapings from the small intestine analyzed. a total of 304 specimens was examined from humans (homo sapiens l.) and a variety of animal species. cysts and/or trophozoites of giardia were found in 10.5% of the specimens examined. positive samples were found f ... | 1984 | 6397598 |
| municipal waterborne giardiasis: an epidemilogic investigation. beavers implicated as a possible reservoir. | in march 1976, 128 persons in camas, washington, had laboratory-confirmed giardiasis. a questionnaire survey of 498 camas residents revealed that 3.8% had clinical giardiasis, while none of 318 residents in a control town were ill. no associations between illness and sex, pet ownership, travel, time spent in wilderness areas, public gatherings, or food preference were found. giardia cysts were recovered from raw water entering the city water treatment system via two streams and also from two st ... | 1980 | 7188724 |
| dipetalonema from the eye of a man in oregon, u.s.a. a case report. | a 21-mm filarial worm appeared suddenly in the anterior chamber of the right eye of a 32-year-old man in western oregon. by a simultaneous irrigation-aspiration procedure, it was removed alive and only slightly damaged and was identified as a female dipetalonema in the fourth stage of development. it was the third such case to be reported from western oregon. in this and one other case the worms were morphologically similar to adult worms identified as dipetalonema arbuta highby 1943 from the bo ... | 1980 | 7189968 |
| prevalence of antibodies to toxoplasma gondii in wild mammals of missouri and east central kansas: biologic and ecologic considerations of transmission. | sera from 273 wild mammals from missouri and kansas (usa), collected between december 1974 and december 1987, were tested for the presence of antibodies to toxoplasma gondii using the sabin-feldman dye test. sixty-five (24%) had antibodies at titers of > or = 1:8, including 38 (66%) of 58 carnivores, 14 (15%) of 94 omnivores, 13 (11%) of 117 herbivores, and none of four insectivores. the prevalence of antibodies in mice (mus musculus and peromyscus spp.) and rats (rattus norvegicus and sigmodon ... | 1995 | 7563419 |
| fatty acids in extremity tissues of finnish beavers (castor canadensis and castor fiber) and muskrats (ondatra zibethicus). | site-specific differences in fatty acid composition of adipose tissues from finnish beavers (castor canadensis and castor fiber) and muskrats (ondatra zibethicus) were studied by gas liquid chromatography. in the total lipids of heterothermic extremities the proportions of potentially endogenous (delta 9-desaturated) monoenoic fatty acids were 1.5-fold and those of the saturated fatty acids 0.5-fold the proportions of subcutaneous or inner depots. thus the role of delta 9-desaturation in the bio ... | 1996 | 8936044 |
| differentiation of castor fiber and castor canadensis by noninvasive molecular methods. | the aim of the study was to develop a simple and reliable method for differentiation of the two phenotypic, very similar eurasian and north american beavers. hair bulbs were plucked as tissue samples from the fur of living animals. the mitochondrial cytochrome b locus was amplified by polymerase chain reaction and sequenced. the fragments of the two species differed at 44/41 nucleotide sites. rsai recognised two mutations, resulting in a restriction fragment length polymorphism that seems to be ... | 2000 | 11180412 |
| attempted isolation of blastomyces dermatitidis from rectal cultures of beaver (castor canadensis) from north central wisconsin. | | 1996 | 11990111 |
| an early manuscript in the history of american comparative psychology: lewis henry morgan's "animal psychology" (1857). | lewis henry morgan (1818-1881) is best known as the 1st ethnographer of native american culture, but he also wrote on animal psychology, beginning in 1843, some 50 years before the founding of comparative psychology as a scientific discipline. although not an evolutionist, morgan argued that animals possess many human mental abilities, such as reason and moral judgment, and he rejected the scientific utility of the concept of instinct, a view that did not gain much currency in psychology until t ... | 2002 | 12465615 |
| [on the brain of castor fiber and comparative anatomical considerations on the brain of castor canadensis (rodentia)]. | | 1963 | 14054394 |
| normal ocular features, conjunctival microflora and intraocular pressure in the canadian beaver (castor canadensis). | the aim of the study was to assess the ocular features, normal conjunctival bacterial and fungal flora, and intraocular pressure (iop) in the canadian beaver (castor canadensis). | 2003 | 14641823 |
| systemic toxoplasmosis in a five-month-old beaver, (castor canadensis). | a 5-mo-old orphan beaver, castor canadensis, died of severe systemic toxoplasmosis during rehabilitation. histologic lesions included lymphohistiocytic encephalitis, myocarditis, and interstitial pneumonia with multinucleated cells. intracytoplasmic cysts containing tachyzoites and bradyzoites identified as toxoplasma gondii by immunohisto-chemistry were present in macrophages, type-ii pneumocytes, and endothelial cells. immunohistochemistry using a polyclonal morbillivirus antibody and transmis ... | 2004 | 15193086 |
| intrapopulation variation in gray wolf isotope (delta(15)n and delta(13)c) profiles: implications for the ecology of individuals. | trophic relationships among organisms in terrestrial boreal ecosystems define ecological communities and are important in determining dynamics of energy flow and ecosystem function. we examined trophic relationships between the gray wolf (canis lupus) and 18 mammalian species from the boreal forest of central saskatchewan, canada, using delta(13)c and delta(15)n stable isotope values measured in guard hair samples. variance in isotope values for wolves and other carnivores was investigated as a ... | 2005 | 15883848 |
| prevalence of agglutinating antibodies to toxoplasma gondii and sarcocystis neurona in beavers (castor canadensis) from massachusetts. | the present study examined the seroprevalence of toxoplasma gondii and sarcocystis neurona in a population of beavers (castor canadensis) from massachusetts. sixty-two blood samples were collected during the field seasons over 3 consecutive years from different animals. blood was collected onto filter paper and shipped to the department of biomedical sciences, virginia tech, blacksburg, virginia, for parasite testing. the samples were tested at dilutions of 1:25, 1:50, and 1:100 against each par ... | 2005 | 16419776 |
| identifying potential receptors and routes of contaminant exposure in the traditional territory of the ouje-bougoumou cree: land use and a geographical information system. | great concern has been raised with respect to the 13 traplines that constitute the traditional territory of the ouje-bougoumou cree located in the james bay region of northern quebec, canada, with respect to mine wastes originating from three local mines. as a result, an "integrative risk assessment" was initiated consisting of three interrelated components: a comprehensive human health study, an assessment of the existing ecological/environmental database, and a land use/potential sites of conc ... | 2007 | 16897501 |
| prevalence of microsporidia, cryptosporidium spp., and giardia spp. in beavers (castor canadensis) in massachusetts. | feces from 62 beavers (castor canadensis) in massachusetts were examined by fluorescence microscopy (ifa) and polymerase chain reaction (pcr) for microsporidia species, cryptosporidium spp., and giardia spp. between january 2002 and december 2004. pcr-positive specimens were further examined by gene sequencing. protist parasites were detected in 6.4% of the beavers. all were subadults and kits. microsporidia species were not detected. giardia spp. was detected by ifa from four beavers; cryptospo ... | 2006 | 17315434 |
| management by assertion: beavers and songbirds at lake skinner (riverside county, california). | management of ecological reserve lands should rely on the best available science to achieve the goal of biodiversity conservation. "adaptive resource management" is the current template to ensure that management decisions are reasoned and that decisions increase understanding of the system being managed. in systems with little human disturbance, certain management decisions are clear; steps to protect native species usually include the removal of invasive species. in highly modified systems, how ... | 2007 | 17318698 |
| elk browsing increases aboveground growth of water-stressed willows by modifying plant architecture. | in the northern elk wintering range of yellowstone national park, usa, wolf (canis lupus) removal allowed elk (cervus elaphus) to overbrowse riparian woody plants, leading to the exclusion of beaver (castor canadensis) and a subsequent water table decline in many small stream valleys. reduced elk browsing following wolf reintroduction may or may not facilitate willow (salix sp.) recovery in these areas. to determine if the effect of elk browsing on willow interacts with that of beaver abandonmen ... | 2007 | 17934763 |
| water tables constrain height recovery of willow on yellowstone's northern range. | excessive levels of herbivory may disturb ecosystems in ways that persist even when herbivory is moderated. these persistent changes may complicate efforts to restore ecosystems affected by herbivores. willow (salix spp.) communities within the northern range in yellowstone national park have been eliminated or degraded in many riparian areas by excessive elk (cervus elaphus l.) browsing. elk browsing of riparian willows appears to have diminished following the reintroduction of wolves (canis lu ... | 2008 | 18372557 |
| design to monitor trend in abundance and presence of american beaver (castor canadensis) at the national forest scale. | wildlife conservationists design monitoring programs to assess population dynamics, project future population states, and evaluate the impacts of management actions on populations. because agency mandates and conservation laws call for monitoring data to elicit management responses, it is imperative to design programs that match the administrative scale for which management decisions are made. we describe a program to monitor population trends in american beaver (castor canadensis) on the us dep ... | 2010 | 19396556 |
| yersinia pseudotuberculosis septicemia in a beaver from washington state. | an emaciated, free-ranging, sub-adult, male beaver (castor canadensis) was found dead and was necropsied. microscopically, the beaver had acute necrotizing hepatitis and splenitis with florid lobulated colonies of extracellular coccobacilli. intravascular septic emboli were identified in lung, small intestine, and kidney, and discrete ulcers with scattered superficial extracellular accumulation of coccobacilli were noted on tail margins and plantar surfaces of the hind feet. yersinia pseudotuber ... | 2009 | 19901394 |
| mitochondrial genomes reveal slow rates of molecular evolution and the timing of speciation in beavers (castor), one of the largest rodent species. | beavers are one of the largest and ecologically most distinct rodent species. little is known about their evolution and even their closest phylogenetic relatives have not yet been identified with certainty. similarly, little is known about the timing of divergence events within the genus castor. | 2011 | 21307956 |
| development of nine new microsatellite loci for the american beaver, castor canadensis (rodentia: castoridae), and cross-species amplification in the european beaver, castor fiber. | we developed nine new nuclear dinucleotide microsatellite loci for castor canadensis. all loci were polymorphic, except for one. the number of alleles ranged from two to four and from five to 12 in populations from arizona and wisconsin, respectively. average heterozygosity ranged from 0.13 to 0.86 per locus. since cross-species amplification in castor fiber was successful only in four loci, we tested also nine recently published c. canadensis loci in the eurasian species. eight of the published ... | 2009 | 21564690 |
| prevalence of giardia sp. in a beaver colony and the resulting environmental contamination. | the prevalence of giardia sp. in a beaver (castor canadensis) colony in colorado was determined by the collection and analysis of fecal samples over a period of 14 mo. environmental contamination was monitored through the use and analysis of water filter samples. beaver shed cysts of giardia sp. in their feces throughout the year with temporal variations in the prevalence, and became infected as kits and remained infected as juveniles and adults. beaver served as amplification hosts for giardia ... | 2013 | 3682082 |
| the chromosomes of the canadian beaver castor canadensis. | a chromosome analysis of 24 canadian beavers, castor canadensis kuhl (12 males and 12 females), captured in laurentides park, qébec, has been performed from preparations of blood lymphocyte and skin cultures. the chromosome number was found to be 2n = 40. measurements were made to determine relative lengths and arm ratios of chromosomes, which are metacentric or submetacentric. results are in agreement with those already published regarding the chromosome number, but differ in the identification ... | 1977 | 476535 |
| baylisascaris procyonis larva migrans in two captive north american beavers (castor canadensis). | baylisascaris procyonis larva migrans was diagnosed in two north american beavers ( castor canadensis ) belonging to a zoological park in clarke county, georgia. both beavers presented with neurological signs. one beaver died naturally and despite attempted treatment, the other beaver was euthanatized because of severe clinical signs and poor prognosis. histologic evaluation of the beavers revealed evidence of parasitic migration characterized by several lesions, including eosinophilic granuloma ... | 2017 | 28363038 |
| characterization of the north american beaver (castor canadensis) papillomavirus genome. | the papillomaviruses comprise a large group of viruses that cause proliferations of the stratified squamous epithelium of skin and mucosa in a variety of animals. an earlier report identified a novel papillomavirus of the north american beaver, castor canadensis (ccanpv1) that was associated with cutaneous exophytic lesions. in the current study, we determined the sequence of the complete 7435 basepair genome of ccanpv1. the genome contains an upstream regulatory region located between the end o ... | 2014 | 24309404 |
| a novel papillomavirus isolated from proliferative skin lesions of a wild american beaver (castor canadensis). | cutaneous papillomatosis was diagnosed in an adult american beaver (castor canadensis). gross lesions included numerous exophytic, roughly circular, lightly pigmented lesions on hairless areas of fore and hind feet and the nose. the most significant histopathologic findings were multifocal papilliform hyperplasia of the superficial stratified squamous epithelium, with multifocal koilocytes, and multiple cells with large, darkly basophilic intranuclear inclusion bodies. a virus with properties co ... | 2012 | 22649160 |
| eco-epizootiologic study of francisella tularensis, the agent of tularemia, in québec wildlife. | in canada, francisella tularensis , the zoonotic bacterial agent of tularemia, affects mostly snowshoe hares ( lepus americanus ), muskrats ( ondatra zibethicus ), and beavers ( castor canadensis ). despite numerous studies, the ecologic cycle and natural reservoirs of f. tularensis are not clearly defined. we conducted a cross-sectional study to estimate the prevalence of f. tularensis in snowshoe hares, muskrats, and coyotes ( canis latrans ) in four regions of québec, canada, and to describe ... | 2016 | 26967133 |
| giardia spp. are commonly found in mixed assemblages in surface water, as revealed by molecular and whole-genome characterization. | giardia is the most common parasitic cause of gastrointestinal infections worldwide, with transmission through surface water playing an important role in various parts of the world. giardia duodenalis (synonyms: g. intestinalis and g. lamblia), a multispecies complex, has two zoonotic subtypes, assemblages a and b. when british columbia (bc), a western canadian province, experienced several waterborne giardiasis outbreaks due to unfiltered surface drinking water in the late 1980s, collection of ... | 2015 | 25956776 |
| antigen detection, rabies virus isolation, and q-pcr in the quantification of viral load in a natural infection of the north american beaver (castor canadensis). | all mammals are believed susceptible to rabies virus infection, yet transmission from nonreservoir hosts to humans is uncommon. however, interactions between nonreservoir hosts and humans occur frequently and risk of exposure increases where rabies is enzootic. we describe rabies and apparent pantropism of rabies virus in a beaver (castor canadensis). | 2015 | 25380356 |
| red maple (acer rubrum) inhibits feeding by beaver (castor canadensis). | at many beaver (castor canadensis) sites at allegany state park in new york state, red maple (acer rubrum) is the only or one of the few tree species left standing at the ponds' edges. the relative palatability of red maple (rm) was studied in three ways. (1) at seven beaver sites, the available and utilized trees were recorded and an electivity index (e) computed. of 15 tree species, rm ranked second or fourth lowest. (2) in experiment i, rm, sugar maple (a. saccharum, sm), and quaking aspen (p ... | 1994 | 24242726 |
| mercury in aquatic forage of large herbivores: impact of environmental conditions, assessment of health threats, and implications for transfer across ecosystem compartments. | mercury (hg) is a leading contaminant across u.s. water bodies, warranting concern for wildlife species that depend upon food from aquatic systems. the risk of hg toxicity to large herbivores is little understood, even though some large herbivores consume aquatic vascular plants (macrophytes) that may hyper-accumulate hg. we investigated whether total hg and methylmercury (mehg) in aquatic forage may be of concern to moose (alces alces) and beaver (castor canadensis) by measuring total hg and me ... | 2014 | 24534700 |
| the many faces of population density. | population density, one of the most fundamental demographic attributes, may vary systematically with spatial scale, but this scale-sensitivity is incompletely understood. we used a novel approach-based on fully censused and mapped distributions of eastern grey squirrel (sciurus carolinensis) dreys, beaver (castor canadensis) lodges, and moose (alces alces)--to explore the scale-dependence of population density and its relationship to landscape features. we identified population units at several ... | 2005 | 16001227 |
| substrate-driven convergence of the microbial community in lignocellulose-amended enrichments of gut microflora from the canadian beaver (castor canadensis) and north american moose (alces americanus). | strategic enrichment of microcosms derived from wood foragers can facilitate the discovery of key microbes that produce enzymes for the bioconversion of plant fiber (i.e., lignocellulose) into valuable chemicals and energy. in this study, lignocellulose-degrading microorganisms from the digestive systems of canadian beaver (castor canadensis) and north american moose (alces americanus) were enriched under methanogenic conditions for over 3 years using various wood-derived substrates, including ( ... | 2016 | 27446004 |
| alternative prey use affects helminth parasite infections in grey wolves. | predators affect prey populations not only through direct predation, but also by acting as definitive hosts for their parasites and completing parasite life cycles. understanding the affects of parasitism on prey population dynamics requires knowing how their predators' parasite community is affected by diet and prey availability. ungulates, such as moose (alces americanus) and white-tailed deer (odocoileus virginianus), are often important prey for wolves (canis lupus), but wolves also consume ... | 2016 | 27155132 |
| responses of beaver (castor canadensis kuhl) to predator chemicals. | free-ranging beaver (castor canadensis) in two different beaver populations in new york state were exposed to predator chemicals to test feeding inhibition. solvent extracts of feces were applied to stem sections of aspen, the preferred food tree of beavers, permitting smelling and tasting the samples. predator odors were from wolf (canis lupus), coyote (canis latrans), dog (canis familiaris), black bear (ursus americanus), river otter (lutra canadensis), lynx (lynx canadensis), and african lion ... | 1995 | 24234632 |
| avian vacuolar myelinopathy outbreaks at a southeastern reservoir. | avian vacuolar myelinopathy (avm) is a neurologic disease of unknown etiology that affects bald eagles (haliaeetus leucocephalus), american coots (fulica americana), and several species of waterfowl. an unidentified neurotoxin is suspected as the cause of avm, which has been documented at several reservoirs in the southeastern united states. we conducted diagnostic and epidemiologic studies annually during october-march from 1998-2004 at clarks hill/strom thurmond lake on the georgia/south carol ... | 2006 | 17092880 |
| where and how wolves (canis lupus) kill beavers (castor canadensis). | beavers (castor canadensis) can be a significant prey item for wolves (canis lupus) in boreal ecosystems due to their abundance and vulnerability on land. how wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. we inferred how wolves hunt beavers by identifying kill sites using clusters of locations from gps-collared wolves in voyageurs national park, minnesota. we identified 22 sites where wolves from 4 different packs killed beavers. we ... | 2016 | 27992441 |
| de novo genome and transcriptome assembly of the canadian beaver (castor canadensis). | the canadian beaver (castor canadensis) is the largest indigenous rodent in north america. we report a draft annotated assembly of the beaver genome, the first for a large rodent and the first mammalian genome assembled directly from uncorrected and moderate coverage (< 30 ×) long reads generated by single-molecule sequencing. the genome size is 2.7 gb estimated by k-mer analysis. we assembled the beaver genome using the new canu assembler optimized for noisy reads. the resulting assembly was re ... | 2017 | 28087693 |
| beaver colony density trends on the chequamegon-nicolet national forest, 1987 - 2013. | the north american beaver (castor canadensis) is a managed species in the united states. in northern wisconsin, as part of the state-wide beaver management program, the chequamegon-nicolet national forest removes beavers from targeted trout streams on u.s. forest service lands. however, the success of this management program has not been evaluated. targeted removals comprise only 3% of the annual beaver harvest, a level of effort that may not affect the beaver population. we used colony location ... | 2017 | 28081271 |
| eurasian beaver activity increases water storage, attenuates flow and mitigates diffuse pollution from intensively-managed grasslands. | beavers are the archetypal keystone species, which can profoundly alter ecosystem structure and function through their ecosystem engineering activity, most notably the building of dams. this can have a major impact upon water resource management, flow regimes and water quality. previous research has predominantly focused on the activities of north american beaver (castor canadensis) located in very different environments, to the intensive lowland agricultural landscapes of the united kingdom and ... | 2017 | 27792958 |
| alteration of hydrogeomorphic processes by invasive beavers in southern south america. | the north american beaver (castor canadensis) is an invasive species in southern patagonia, introduced in 1946 as part of a program by the argentine government to augment furbearers. research focus has turned from inventorying the beaver's population and ecosystem impacts toward eradicating it from the region and restoring degraded areas. successful restoration, however, requires a fuller determination of how beavers have altered physical landscape characteristics, and of what landscape features ... | 2017 | 27636003 |
| do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains? | beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. our intent in this paper is ... | 2016 | 27635357 |
| bacterial and archaeal diversity in the gastrointestinal tract of the north american beaver (castor canadensis). | the north american beaver (castor canadensis) is the second largest living rodent and an iconic symbol of canada. the beaver is a semi-aquatic browser whose diet consists of lignocellulose from a variety of plants. the beaver is a hindgut fermenter and has an enlarged ceacum that houses a complex microbiome. there have been few studies examining the microbial diversity in gastrointestinal tract of hindgut fermenting herbivores. to examine the bacterial and archaeal communities inhabiting the gas ... | 2016 | 27227334 |
| persistence at distributional edges: columbia spotted frog habitat in the arid great basin, usa. | a common challenge in the conservation of broadly distributed, yet imperiled species is understanding which factors facilitate persistence at distributional edges, locations where populations are often vulnerable to extirpation due to changes in climate, land use, or distributions of other species. for columbia spotted frogs (rana luteiventris) in the great basin (usa), a genetically distinct population segment of conservation concern, we approached this problem by examining (1) landscape-scale ... | 2015 | 26380699 |
| mites of the genus schizocarpus trouessart, 1896 (acariformes: chirodiscidae) from the north american beavers (castor canadensis) in russia. | four native species of parasitic mites belonging to the genus schizocarpus trouessart, 1896 (acariformes: chirodiscidae) are recorded on the north american beaver castor canadensis kuhl, 1820 (rodentia: castoridae) from russia. totally ten beavers from all three main geographically isolated populations of in russia (leningrad province, voronezh biosphere reserve (beaver farm) and khabarovsk territory) were examined. additionally, in captivity (voronezh beaver farm) eight species were recorded sw ... | 2015 | 25936168 |
| iodine status of eeyou istchee community members of northern quebec, canada, and potential sources. | a multi community environment-and-health study among six of the nine communities of eeyou istchee in northern quebec, canada provided greater insight into iodine intake levels among these cree first nation communities. using data from this large population-based study, descriptive statistics of measured urinary iodine concentrations (uics) and iodine-creatinine ratios (stratified by age, sex, community of residence, and water consumption) were calculated, and the associations between independent ... | 2015 | 25764377 |
| beaver-mediated methane emission: the effects of population growth in eurasia and the americas. | globally, greenhouse gas budgets are dominated by natural sources, and aquatic ecosystems are a prominent source of methane (ch(4)) to the atmosphere. beaver (castor canadensis and castor fiber) populations have experienced human-driven change, and ch(4) emissions associated with their habitat remain uncertain. this study reports the effect of near extinction and recovery of beavers globally on aquatic ch4 emissions and habitat. resurgence of native beaver populations and their introduction in o ... | 2015 | 25515021 |
| assessment of a new bacteroidales marker targeting north american beaver (castor canadensis) fecal pollution by real-time pcr. | in many settings wildlife can be a significant source of fecal pathogen input into surface water. the north american beaver (castor canadensis) is a zoonotic reservoir for several human pathogens including cryptosporidium spp. and giardia spp. in order to specifically detect fecal pollution by beavers, we have developed and validated a beaver-specific bacteroidales marker, designated beapol01, based on the 16s rrna gene. the marker is suitable for quantifying pollution using real-time pcr. the s ... | 2013 | 23999275 |
| manipulating beaver (castor canadensis) feeding responses to invasive tamarisk (tamarix spp.). | to evaluate methods for promoting consumption of tamarisk plants by beavers (castor canadensis), we determined the feeding responses by captive beavers to diets that contained tannins and sodium chloride (hereafter referred to as tamarisk diet). in two-choice tests, beavers consumed equivalent quantities of tamarisk diet and control diet. treatment with polyethylene glycol and fructose did not increase beaver preferences for the tamarisk diet. when offered the choice of control diet and casein h ... | 2008 | 18581180 |
| isolation and characterization of microsatellite loci in the beaver (castor canadensis). | we have isolated and characterized 10 microsatellite loci in the beaver (castor canadensis). sixty individuals from southern and central illinois were screened at each locus. all loci exhibited moderate levels of polymorphism, ranging from five to 13 alleles per locus with average heterozygosity ranging from 0.317 to 0.867. locus cca5 deviated significantly from hwe (p < 0.001). the locus pair cca4/cca5 was shown to be in linkage disequilibrium in southern illinois, but not in the central illino ... | 2008 | 21585849 |
| stream flow, salmon and beaver dams: roles in the structuring of stream fish communities within an anadromous salmon dominated stream. | the current paradigm of fish community distribution is one of a downstream increase in species richness by addition, but this concept is based on a small number of streams from the mid-west and southern united states, which are dominated by cyprinids. further, the measure of species richness traditionally used, without including evenness, may not be providing an accurate reflection of the fish community. we hypothesize that in streams dominated by anadromous salmonids, fish community diversity w ... | 2007 | 17922703 |
| ecosystem engineering by invasive exotic beavers reduces in-stream diversity and enhances ecosystem function in cape horn, chile. | species invasions are of global significance, but predicting their impacts can be difficult. introduced ecosystem engineers, however, provide an opportunity to test the underlying mechanisms that may be common to all invasive engineers and link relationships between changes in diversity and ecosystem function, thereby providing explanatory power for observed ecological patterns. here we test specific predictions for an invasive ecosystem engineer by quantifying the impacts of habitat and resourc ... | 2007 | 17587063 |
| beaver herbivory on aquatic plants. | herbivores have strong impacts on marine and terrestrial plant communities, but their impact is less well studied in benthic freshwater systems. for example, north american beavers (castor canadensis) eat both woody and non-woody plants and focus almost exclusively on the latter in summer months, yet their impacts on non-woody plants are generally attributed to ecosystem engineering rather than herbivory. here, we excluded beavers from areas of two beaver wetlands for over 2 years and demonstrat ... | 2007 | 17180372 |
| hypsodontia in castor canadensis: an anatomical and histological study. | the aim of this original study is to describe the dental morphology and anatomy of castor canadensis and to compare results with existing data in the literature relating to this mammal. this will give us a better knowledge of its very distinctive dental system, representative of rodent typology. | 2006 | 16929819 |
| comparative morphological study on the stereo-structure of the lingual papillae and their connective tissue cores of the american beaver (castor canadensis). | the lingual papillae and the connective tissue cores (ctc) of the american beaver were examined by light and scanning electron microscopy. the tongue of american beaver was about 9 cm in length, 3.5 cm in width, and has a lingual prominence. four types of papillae (filiform, fungiform, vallate and foliate papillae) were observed. the filiform papillae can be classified into three types (filiform, large filiform and dorm-like papillae). filiform papillae distributed on the anterior tongue and pos ... | 2006 | 16526571 |
| a case of maloccluded incisor teeth in a beaver: castor canadensis. | a three-year-old female beaver (castor canadensis) was referred to the veterinary teaching hospital of chungbuk national university. it had been raised in the cheong-ju zoo and had a history of malocclusion caused by improper feeding. general anesthesia was induced, and preoperative intraoral dental radiographs of the rostal maxillary and mandibular dentition were taken and lateral and ventrodorsal extraoral radiographs of the cheek teeth were also taken. the radiographs were negative for apical ... | 2005 | 15933441 |
| marine-derived nitrogen and carbon in freshwater-riparian food webs of the copper river delta, southcentral alaska. | after rearing to adulthood at sea, coho salmon (oncorhynchus kisutch) return to freshwater to spawn once and then die on or near their spawning grounds. we tested the hypothesis that spawning coho salmon return marine n and c to beaver (castor canadensis) ponds of the copper river delta (crd), cordova, southcentral alaska, thereby enhancing productivity of the aquatic food webs that support juvenile coho salmon. we sampled three types of pond treatment: (1) natural enrichment by spawning salmon, ... | 2005 | 15891853 |
| odontoplasty for the treatment of malocclusion of the incisor teeth in a beaver (castor canadensis). | | 2005 | 15704553 |
| changes in distribution and abundance of mosquito populations in an ecological research tract over a 35-year period. | marked changes in species and numbers of mosquitoes have occurred over a 35-year period. changes relate to alteration of available larval development sites by beaver (castor canadensis), variation in winter and spring precipitation, and differences in feeding behaviors. | 2004 | 15532936 |
| comparison of isoflurane and sevoflurane for anesthesia in beaver. | we compared the hemodynamic and respiratory effects, recovery time, and cost of two gas inhalants (isoflurane and sevoflurane) for anesthetic induction and maintenance of beaver (castor canadensis) during surgery to implant radio transmitters in the peritoneal cavity. heart rate, respiratory rate, relative hemoglobin saturation with oxygen (spo2), and body temperature were measured every 5 min for the first 45 min, and arterial blood gas was measured once, 25 min into the anesthetic procedure. i ... | 2003 | 12910766 |
| giardia in beaver (castor canadensis) and nutria (myocastor coypus) from east texas. | we examined the prevalence of giardia sp. infection in nuisance beaver (castor canadensis) and nutria (myocastor coypus) in east texas. from october 1992 through september 1993, 100 beaver and 30 nutria were collected in routine wildlife management activities conducted by the u.s. department of agriculture-animal and plant health inspection service-texas animal damage control service. fecal and duodenal mucoid samples were preserved from each animal. fecal samples were examined for the occurrenc ... | 2002 | 12537124 |
| research: attitudes of private- and public-land managers in wyoming, usa, toward beaver. | / a mail survey concerning beaver (castor canadensis) management in wyoming, usa, was sent to 5265 private-land managers and 124 public-land managers during 1993. the survey was developed in response to increasing interest in beaver management and beaver reintroduction possibilities. private-land managers responding to the survey supplied information on 62,859 km2 of land area and 20,037 km of streams. primary concerns about beaver damage centered on (in decreasing order of importance) blocked i ... | 1999 | 9817774 |
| beaver response to recurrent alien scents: scent fence or scent match? | by repeatedly presenting an alien scent to territory-owning beavers, castor canadensis, we tested two competing hypotheses about the function of scent marking: scent fence and scent matching. the scent-fence hypothesis predicts that territory owners should respond increasingly strongly over time towards a recurrent alien scent because of the ineffectiveness of previous responses. the scent-matching hypothesis predicts that the intensity of response should be the same or decrease because, without ... | 1998 | 9641998 |
| energy requirements of beavers (castor canadensis) swimming underwater. | energy requirements of beavers (castor canadensis) swimming voluntarily underwater were investigated in neumünster zoo (germany) in a covered, still-water swim channel with oxygen and carbon dioxide respirometry. during the experiments, all activities of the beavers were monitored and recorded. while at rest within their thermoneutral zone on land (17 degrees c), beavers had a respiratory quotient of 0.95 and a resting metabolic rate of 1.58 w kg-1. when resting in water, energy requirements ros ... | 2006 | 9237306 |
| unusual fatty acids in the depot fat of the canadian beaver (castor canadensis). | unusual fatty acids in the adipose tissue of the canadian beaver were analysed by argentation thin-layer chromatography, gas-liquid chromatography and gas chromatography-mass spectrometry of several adducts and spectroscopic measurements. the total proportion of trans-octadecenoic fatty acids and the distribution of double bonds in these acids resembled those of ruminant fats. because trans-11-18:1 was the main trans-18:1 isomer of beaver fat and a conjugated diene cis-9, trans-11-18:2 was also ... | 1996 | 8829812 |
| neutral compounds from male castoreum of north american beaver,castor canadensis. | north american beavers (castor canadensis) mark their territories with castoreum, the strong-smelling paste in their castor sacs. in their own territories, beavers respond with scent marking to experimental scent marks that consist of strange castoreum (or selected components). in part, the unique odor of castoreum is due to large amounts of phenolic compounds and neutral compounds. purified neutral compounds were analyzed by gc. gc-ms, and nmr; identities of the neutral compounds were confirmed ... | 1995 | 24233827 |
| bioactivity of beaver castoreum constituents using principal components analysis. | north american beaver (castor canadensis) were observed to sniff from the water and make land visits to some synthetic chemical components of castoreum placed on experimental scent mounds (esm). in previous analysis, the elicitation (presence/absence), completeness, and/or strength (number, duration) of these key responses served as separate measures of biological activity. in this paper, we used principal components analysis (pca) to combine linearly six related measures of observed response an ... | 1995 | 24234411 |
| beaver (castor canadensis) responses to major phenolic and neutral compounds in castoreum. | north american beaver (castor canadensis) mark their territories with castoreum, a chemically complex secretion from their castor sacs. the phenolic and neutral fractions of castoreum have been shown to elicit specific behavioral responses from beavers in a field setting. our objective was to identify compounds/mixtures that evoked responses similar to those stimulated by castoreum. we assayed recently identified phenolic compounds, some phenolics that had been determined to be biologically acti ... | 1994 | 24241977 |
| controlling forest damage by dispersive beaver populations: centralized optimal management strategy. | the beaver (castor canadensis) population in the united states has caused severe damage to valuable timberland through dam-building and flooding of bottomland forest. traditionally, beavers have provided a source of livelihood to a small group of people. however, recent low pelt prices have failed to stimulate adequate trapping pressure, and thus have resulted in increased beaver populations and damage losses. the low trapping pressure has left the burden of nuisance control on property owners. ... | 1993 | 27759239 |
| phenolic compounds from male castoreum of the north american beaver,castor canadensis. | north american beaver (castor canadensis) mark their territories with castoreum, the contents of their castor sacs. in their territories, beaver respond with scent marking to experimental scent marks consisting of castoreum, or selected single components. in part, the unique odor of castoreum is due to large amounts of phenolic compounds. purified phenolic components were analyzed by gc, gc-ms, and nmr; identifications were confirmed by comparing the spectra of synthetic phenols with those of th ... | 1993 | 24249178 |
| age and proximity to local ore-smelters as determinants of tissue metal levels in beaver (castor canadensis) of the sudbury (ontario) area. | an examination of tissue metal levels in sudbury-area beaver (castor canadensis) revealed that animals in the vicinity of the local ore-smelters contained elevated burdens of ni and pb in the liver and kidneys. tissue concentrations averaged 1.5- to 2.5-fold higher than background values and are believed to reflect accumulations resulting through food chain contamination. tissue levels of cu, cd and zn did not vary in relation to distance from source. tissue cd levels were uniformly elevated thr ... | 1993 | 15091874 |
| changes in local mosquito fauna following beaver (castor canadensis) activity--an update. | drastic reduction of populations of univoltine temporary pool mosquitoes followed impoundment of breeding areas by beavers. mosquito populations persist at very low levels over a 10-year period with no evidence of mosquito development in the impoundment. | 1992 | 1357092 |
| cardiovascular effects of halothane anesthesia after diazepam and ketamine administration in beavers (castor canadensis) during spontaneous or controlled ventilation. | fourteen adult beavers (castor canadensis) weighing 16.5 +/- 4.14 kg (mean +/- sd) were anesthetized for surgical implantation of radio telemetry devices. beavers were anesthetized with diazepam (0.1 mg/kg) and ketamine (25 mg/kg) administered im, which provided smooth anesthetic induction and facilitated tracheal intubation. anesthesia was maintained with halothane in oxygen via a semiclosed circle anesthetic circuit. values for heart rate, respiratory rate, esophageal temperature, direct arter ... | 1991 | 1906691 |
| pheromonal activity of single castoreum constituents in beaver,castor canadensis. | behavioral activity of single components of beaver castoreum was demonstrated for the first time. in four experiments samples were presented to free-ranging beaver in their family territories. first, responses to whole castoreum and anal gland secretion (ags) from males and females were tested. second, 24 compounds, known to be constituents of beaver castoreum, were individually screened for activity. four of these consistently released immediate responses during the observation periods. these a ... | 1991 | 24258917 |
| 226ra and other radionuclides in water, vegetation, and tissues of beavers (castor canadensis) from a watershed containing u tailings near elliot lake, canada. | radionuclide levels were measured in tissues, gut contents, diet items, and water at site of capture, of adult beavers from the serpent river drainage basin which contains u tailings at elliot lake, ontario, and from nearby control sites. levels of (226)ra in beaver bone, muscle and kidney were highest in animals from locations close to u tailings; liver levels did not vary by site. environmental (226)ra levels were within ranges previously reported at these or similar locations elsewhere; level ... | 1991 | 15092150 |
| experimental habitat scenting inhibits colonization by beaver,castor canadensis. | unoccupied beaver (castor canadensis) sites in new york state were for two years experimentally scented with a mixture of beaver castoreum and anal gland secretion. these sites were colonized less often than unscented control sites. the beaver is the first mammal to have been shown experimentally to use intraspecific odor cues when settling in vacant habitat. territorial pheromones may be useful as repellents for beaver or other rodents. | 1989 | 24271891 |
| optimal central-place foraging by beavers: tree-size selection in relation to defensive chemicals of quaking aspen. | at a newly occupied pond, beavers preferentially felled aspen smaller than 7.5 cm in diameter and selected against larger size classes. after one year of cutting, 10% of the aspen had been cut and 14% of the living aspen exhibited the juvenile growth form. a phenolic compound which may act as a deterrent to beavers was found in low concentrations in aspen bark, and there was no significant regression of relative concentration of this compound on tree diameter. at a pond which had been intermitte ... | 1988 | 28312207 |
| heart rates in the captive, free-ranging beaver. | 1. heart rates of beaver (castor canadensis) under free-ranging captive conditions for active behaviors and resting in water (approximately 121 beats/min) were significantly (p less than 0.01) higher than for resting on land (100 beats/min). 2. although no transient recovery tachycardia was evident in swimming heart rates following diving, average swimming heart rates were higher (127 beats/min) after diving than after other precursor behaviors (123 beats/min). 3. beaver exhibited bradycardia wh ... | 1988 | 2906827 |
| changes in local mosquito fauna following beaver (castor canadensis) activity. | a marked decrease in anthropophilic temporary water mosquito populations subsequent to impoundment of extensive areas of larval development by beavers is documented. absence to date of development of other mosquito species in the permanent water thus established is noted and discussed relative to current characteristics of the site. | 1986 | 2906976 |
| structure and function of a benthic invertebrate stream community as influenced by beaver (castor canadensis). | beaver (castor canadensis) affect the benthic invertebrate community of small woodland streams in quebec through habitat modifications. their activities influence community structure through the replacement of lotic taxa by lentic forms and community function by increasing the absolute importance of collectors and predators while decreasing the relative importance of shredders and scrapers in impounded sites. at our study site during the 1983 ice-free season, standing stocks of coarse particulat ... | 1986 | 28311700 |
| central place foraging by beavers (castor canadensis): a test of foraging predictions and the impact of selective feeding on the growth form of cottonwoods (populus fremontii). | several predictions of central place foraging theory were tested. as predicted, beavers foraged more selectively at increasing distance from the central place. with increasing distance from the river's edge, beavers cut fewer branches and deleted small branches from their diet. large branches were favored at all distances, which differs from patterns observed in previous studies of beaver foraging. this difference, however, is expected and supports schoener's (1979) predictions which are based o ... | 1985 | 28310799 |
| the subplacenta of the beaver (castor canadensis). | | 2003 | 4059183 |
| nitrogen budget of a subarctic stream altered by beaver (castor canadensis). | beaver (castor canadensis) influence stream ecosystems through their wood cutting and dam building activities. to quantify this influence we have used measured rates of nitrogen dynamics to construct a nitrogen budget for a section of a second order stream in eastern québec and a beaver dam in that stream. the budget demonstrates the importance of sediment accumulations and an expanded wetted area to the annual nitrogen economy and to pathways of nitrogen cycling. major changes after impoundment ... | 1984 | 28310707 |
| castor sacs and anal glands of the north american beaver (castor canadensis): their histology, development, and relationship to scent communication. | both sexes of beavers possess a pair of castor sacs and a pair of anal glands located in paired subcutaneous cavities between the pelvis and the base of the tail. the castor sacs are not glandular in the histological sense, hence references to these structures as preputial glands or castor glands are misnomers. the wall of the castor sacs is plicate and comprised of three distinct zones: an outer layer of vascular connective tissue, a two-to five-cell-thick layer of mitotic epithelial cells, and ... | 1982 | 24415179 |
| cardiovascular adjustments to laboratory diving in beavers and nutria. | beavers (castor canadensis) and nutria (myocastor coypus) were anesthetized with halothane and catheters placed in the left ventricle, aorta and pulmonary artery, right ventricle or right atrium. the animals were strapped to a board and following recovery from anesthesia the following measurements were taken: regional distribution of blood flow, cardiac output, o2 consumption, arterial and venous blood gases, and ph. the animal was then immersed in 15-20 degrees c water for up to 2.75 min (nutri ... | 1982 | 7081467 |
| anatomy of the heart in the north american beaver (castor canadensis). | the gross anatomy of the heart of the north american beaver (castor canadensis) is described following the dissection of nine specimens of both sexes ranging in body weight from 10 to 26 kg. the general characteristics of the beaver heart are similar to those of other mammals. however, variations in details of anatomy exist, especially for the right atrium. the right auricle is divided into 2 appendages, one on each side of the ascending aorta. the orifices of the 3 venae cavae are guarded by a ... | 1982 | 7103113 |
| heart rate values for beaver, mink and muskrat. | 1. implanted ecg transmitters were used to determine heart rates for several activities of beaver (castor canadensis), mink (mustela vison), and muskrat (ondatra zibethicus) under free-ranging laboratory conditions within an aquatic tank. 2. all three species exhibited bradycardia when diving but mink heart rates returned to pre-dive levels if the dive lasted greater than 30 sec. 3. heart rates for all other behaviours were significantly (p less than 0.05) higher than for diving and averaged abo ... | 1982 | 6128113 |
| gross anatomy of the cardiac blood vessels in the north american beaver (castor canadensis). | the cardiac arteries and veins are described in the north american beaver (castor canadensis) following the injection of the vessels of 15 hearts with either latex, vinyl plastic or barium sulfate. the left coronary artery gives off the typical circumflex and paraconal interventricular branches which supply the left atrium and ventricle and part of the right ventricle and interventricular septum. the right coronary artery vascularizes the right atrium and ventricule and by means of its subsinuos ... | 1981 | 7305001 |
| gross anatomy of the arterial supply of the stomach of the north american beaver (castor canadensis). | the arterial pattern of the stomach of the north american beaver is studied by dissection of height specimens. the arrangement of the arteries resembles the typical mammalian pattern, although some variations are described. for example, the celiac artery gives off two large vessels, the cardiac and fundic arteries, which supply the corresponding regions of the stomach. also, the right gastric artery originates from the gastroduodenal vessel instead of the hepatic artery. | 1979 | 442965 |
| spontaneous renal disease in beaver in louisiana. | interstitial nephritis was present in 13 of 25 adult beavers (castor canadensis). results of serum chemistry, serotyping, and culture for leptospires were compared with the extent of renal lesions. although the pathogenesis of the nephritis was not determined, the survey provided baseline information on spontaneous renal disease in beavers. | 1978 | 650793 |
| [arterial vascularization of the intestines of american beaver (castor canadensis, kuhl)]. | | 1976 | 1015064 |
| some morphological, physiological and behavioral specializations in north american beavers (castor canadensis). | in order to gain insight into the functional properties of the tail in north american beavers (castor canadensis) we (1) examined morphological features of skeletal, muscular, vascular, cutaneous and neural structures; (2) determined the segmental organization of spinal roots and certain stimulus-response features of receptive fields of single dorsal root fibers; (3) mapped the main somatic sensory area (si) of the cerebral neocortex, and (4) attempted to relate these findings to observations of ... | 1976 | 990911 |
| life cycle of dipetalonema sprenti anderson (nematoda: filarioidea) of beaver (castor canadensis). | | 1973 | 4735888 |
| [proof of amoeba in focal organ necrosis in a young canadian beaver (castor canadensis)]. | | 1973 | 4149685 |
| placentation in the american beaver (castor canadensis). | | 1971 | 5575888 |
| psorobia castoris spec. nov. (acarina: psorergatidae), a new itch mite from the beaver, castor canadensis. | | 1970 | 5533912 |
| eimeria sprehni yakimoff, 1934, and e. causeyi sp. n. (protozoa: eimeridae) from the canadian beaver, castor canadensis. | | 1970 | 5461094 |