24 research outputs found
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Reintroducing San Joaquin kit fox (Vulpes macrotis mutica) to vacant or restored lands: identifying optimal source populations and candidate foxes
Endangered San Joaquin kit foxes (Vulpes macrotis mutica) currently persist as a meta- population in central California consisting of 3 core and several satellite populations. Many of these populations are small and the meta-population is highly fragmented, which increases extinction risk. Translocation is a potential strategy for increasing the number of populations. Various factors would need to be considered when selecting source populations and candidate foxes for translocation. One such factor is behavioral attributes of individual foxes, as reflected by level of boldness, particularly in response to novel resources and potential threats. We compared behavioral attributes between and within populations of kit foxes in urban and non-urban habitats, and also examined the relationship of these attributes to survival and fitness. The overall goal of this project was to identify optimal source populations and individual foxes for relocation efforts, and in particular to determine whether urban foxes could be used in such efforts
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Geographic variation and evolutionary history of Dipodomys nitratoides (Rodentia: Heteromyidae), a species in severe decline
We examined geographic patterns of diversification in the highly impacted San Joaquin kangaroo rat, Dipodomys nitratoides, throughout its range in the San Joaquin Valley and adjacent basins in central California. The currently recognized subspecies were distinct by the original set of mensural and color variables used in their formal diagnoses, although the Fresno kangaroo rat (D. n. exilis) is the most strongly differentiated with sharp steps in character clines relative to the adjacent Tipton (D. n. nitratoides) and short-nosed (D. n. brevinasus) races. The latter two grade more smoothly into one another but still exhibit independent, and different, character clines within themselves. At the molecular level, as delineated by mtDNA cytochrome b sequences, most population samples retain high levels of diversity despite significant retraction in the species range and severe fragmentation of local populations in recent decades due primarily to landscape conversion for agriculture and secondarily to increased urbanization. Haplotype apportionment bears no relationship to morphologically defined subspecies boundaries. Rather, a haplotype network is shallow, most haplotypes are single-step variants, and the time to coalescence is substantially more recent than the time of species split between D. nitratoides and its sister taxon, D. merriami. The biogeographic history of the species within the San Joaquin Valley appears tied to mid-late Pleistocene expansion following significant drying of the valley resulting from the rain shadow produced by uplift of the Central Coastal Ranges
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An investigation into the effect of individual personality on reintroduction success, examples from three North American fox species: swift fox, California Channel Island fox and San Joaquin kit fox
Assessing personality in San Joaquin kit fox in situ: efficacy of field-based experimental methods and implications for conservation management
Utilisation of animal personality has potential benefit for conservation management. Due to logistics of robust behavioural evaluation in situ, the majority of studies on wild animals involve taking animals into captivity for testing, potentially compromising results. Three in situ tests for evaluation of boldness in San Joaquin kit fox (Vulpes macrotis mutica) were developed (ENOT: extended novel object test; RNOT: rapid novel object test; TH: trap/handling test). Each test successfully identified variation in boldness within its target age class(es). The TH test was suitable for use across all age classes. Tests were assessed for in situ suitability and for quantity/quality of data yielded. ENOT was rated as requiring high levels of time, cost and labour with greater likelihood of failure. However, it was rated highly for data quantity/quality. The TH test was rated as requiring little time, labour and cost, but yielding lower quality data. RNOT was rated in the middle. Each test had merit and could be adapted to suit project or species constraints. We recommend field-based evaluation of personality, reducing removal of animals from the wild and facilitating routine incorporation of personality assessment into conservation projects
A Serological Survey of Infectious Disease in Yellowstone National Park’s Canid Community
BACKGROUND:Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park (YNP) after a >70 year absence, and as part of recovery efforts, the population has been closely monitored. In 1999 and 2005, pup survival was significantly reduced, suggestive of disease outbreaks. METHODOLOGY/PRINCIPAL FINDINGS:We analyzed sympatric wolf, coyote (Canis latrans), and red fox (Vulpes vulpes) serologic data from YNP, spanning 1991-2007, to identify long-term patterns of pathogen exposure, identify associated risk factors, and examine evidence for disease-induced mortality among wolves for which there were survival data. We found high, constant exposure to canine parvovirus (wolf seroprevalence: 100%; coyote: 94%), canine adenovirus-1 (wolf pups [0.5-0.9 yr]: 91%, adults [>or=1 yr]: 96%; coyote juveniles [0.5-1.5 yrs]: 18%, adults [>or=1.6 yrs]: 83%), and canine herpesvirus (wolf: 87%; coyote juveniles: 23%, young adults [1.6-4.9 yrs]: 51%, old adults [>or=5 yrs]: 87%) suggesting that these pathogens were enzootic within YNP wolves and coyotes. An average of 50% of wolves exhibited exposure to the protozoan parasite, Neospora caninum, although individuals' odds of exposure tended to increase with age and was temporally variable. Wolf, coyote, and fox exposure to canine distemper virus (CDV) was temporally variable, with evidence for distinct multi-host outbreaks in 1999 and 2005, and perhaps a smaller, isolated outbreak among wolves in the interior of YNP in 2002. The years of high wolf-pup mortality in 1999 and 2005 in the northern region of the park were correlated with peaks in CDV seroprevalence, suggesting that CDV contributed to the observed mortality. CONCLUSIONS/SIGNIFICANCE:Of the pathogens we examined, none appear to jeopardize the long-term population of canids in YNP. However, CDV appears capable of causing short-term population declines. Additional information on how and where CDV is maintained and the frequency with which future epizootics might be expected might be useful for future management of the Northern Rocky Mountain wolf population
Recommended from our members
Geographic variation and evolutionary history of Dipodomys nitratoides (Rodentia: Heteromyidae), a species in severe decline
We examined geographic patterns of diversification in the highly impacted San Joaquin kangaroo rat, Dipodomys nitratoides, throughout its range in the San Joaquin Valley and adjacent basins in central California. The currently recognized subspecies were distinct by the original set of mensural and color variables used in their formal diagnoses, although the Fresno kangaroo rat (D. n. exilis) is the most strongly differentiated with sharp steps in character clines relative to the adjacent Tipton (D. n. nitratoides) and short-nosed (D. n. brevinasus) races. The latter two grade more smoothly into one another but still exhibit independent, and different, character clines within themselves. At the molecular level, as delineated by mtDNA cytochrome b sequences, most population samples retain high levels of diversity despite significant retraction in the species range and severe fragmentation of local populations in recent decades due primarily to landscape conversion for agriculture and secondarily to increased urbanization. Haplotype apportionment bears no relationship to morphologically defined subspecies boundaries. Rather, a haplotype network is shallow, most haplotypes are single-step variants, and the time to coalescence is substantially more recent than the time of species split between D. nitratoides and its sister taxon, D. merriami. The biogeographic history of the species within the San Joaquin Valley appears tied to mid-late Pleistocene expansion following significant drying of the valley resulting from the rain shadow produced by uplift of the Central Coastal Ranges