analysis of genetic algorithm for rule-set production (garp) modeling approach for predicting distributions of fleas implicated as vectors of plague, yersinia pestis, in california.more than 20 species of fleas in california are implicated as potential vectors of yersinia pestis. extremely limited spatial data exist for plague vectors-a key component to understanding where the greatest risks for human, domestic animal, and wildlife health exist. this study increases the spatial data available for 13 potential plague vectors by using the ecological niche modeling system genetic algorithm for rule-set production (garp) to predict their respective distributions. because the a ...200616506453
no evidence of persistent yersina pestis infection at prairie dog colonies in north-central montana.sylvatic plague is a flea-borne zoonotic disease caused by the bacterium yersinia pestis, which can cause extensive mortality among prairie dogs (cynomys) in western north america. it is unclear whether the plague organism persists locally among resistant host species or elsewhere following epizootics. from june to august 2002 and 2003 we collected blood and flea samples from small mammals at prairie dog colonies with a history of plague, at prairie dog colonies with no history of plague, and fr ...200616699160
mountain plover responses to plague in montana.plague is a bacterial (yersinia pestis) disease that causes epizootic die-offs in black-tailed prairie dog (cynomys ludovicianus) populations in the north american great plains. through their grazing and burrowing, prairie dogs modify vegetation and landscape structure on their colonies in ways that affect other grassland species. plague epizootics on prairie dog colonies can have indirect effects on species associated with colonies. the mountain plover (charadrius montanus) preferentially nests ...201020158330
enzootic plague reduces black-footed ferret (mustela nigripes) survival in ferrets (mustela nigripes) require extensive prairie dog colonies (cynomys spp.) to provide habitat and prey. epizootic plague kills both prairie dogs and ferrets and is a major factor limiting recovery of the highly endangered ferret. in addition to epizootics, we hypothesized that enzootic plague, that is, presence of disease-causing yersinia pestis without any noticeable prairie dog die off, may also affect ferret survival. we reduced risk of plague on portions of two ferret rein ...201020158329
sylvatic plague reduces genetic variability in black-tailed prairie dogs.small, isolated populations are vulnerable to loss of genetic diversity through in-breeding and genetic drift. sylvatic plague due to infection by the bacterium yersinia pestis caused an epizootic in the early 1990s resullting in declines and extirpations of many black-tailed prairie dog (cynomys ludovicianus) colonies in north-central montana, usa. plague-induced population bottlenecks may contribute to significant reductions in genetic variability. in contrast, gene flow maintains genetic vari ...200415362819
flea, rodent, and plague ecology at chuchupate campground, ventura county, california.chuchupate campground in ventura county, california, was closed to the public for 18 years (1982 to 2000) because of uncontrolled vector fleas and persistent plague antibody titers in rodents. the primary purpose of this study was to clarify the plague ecology of chuchupate campground by identifying involved rodents and their vector fleas and by determining many of their ecological parameters: abundance, flea and host preferences and diversities, and flea seasonality. rodents and fleas were iden ...200212125863
the absence of concordant population genetic structure in the black-tailed prairie dog and the flea, oropsylla hirsuta, with implications for the spread of yersinia pestis.the black-tailed prairie dog (cynomys ludovicianus) is a keystone species on the mid- and short-grass prairies of north america. the species has suffered extensive colony extirpations and isolation as a result of human activity including the introduction of an exotic pathogen, yersinia pestis, the causative agent of sylvatic plague. the prairie dog flea, oropsylla hirsuta, is the most common flea on our study colonies in north-central montana and it has been shown to carry y. pestis. we used mic ...201020550633
plague studies in california: a review of long-term disease activity, flea-host relationships and plague ecology in the coniferous forests of the southern cascades and northern sierra nevada mountains.we review 28 years of long-term surveillance (1970-1997) for plague activity among wild rodents from ten locations within three coniferous forest habitat types in the northern sierra nevada and the southern cascade mountains of northeastern california. we identify rodent hosts and their fleas and document long-term plague activity in each habitat type. the highest seroprevalence for yersinia pestis occurred in the chipmunks, tamias senex and t. quadrimaculatus, and the pine squirrel, tamiasciuru ...201020618641
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