Publications by authors named "David Eads"

The consequences of intraguild predation on vulnerable subordinate species are an important consideration in the recovery of endangered species. In prairie ecosystems, coyotes () are the primary predator of endangered black-footed ferrets (; hereafter, ferrets) and presumably compete for prairie dog ( spp.) prey.

View Article and Find Full Text PDF

We evaluated the invasion of plague bacteria into a population of black-tailed prairie dogs (; BTPDs) in South Dakota. We aimed to ascertain if invaded slowly or rapidly, and to determine if vector (flea) control or vaccination of BTPDs assisted in increasing survival rates. We sampled BTPDs in 2007 (before documentation), 2008 (year of confirmed invasion), and 2009 (after invasion).

View Article and Find Full Text PDF
Article Synopsis
  • Plague, caused by the bacterium Yersinia pestis, poses a serious threat to endangered black-footed ferrets and their primary prey, prairie dogs, leading to wildlife biologists using insecticides to control flea populations, which spread the plague.
  • In laboratory tests, lufenuron was administered to prairie dogs without negative health effects, but serum concentrations of the insecticide declined significantly over time, indicating limited effectiveness.
  • Field experiments with bait containing lufenuron and nitenpyram showed increased flea abundance on prairie dogs post-treatment, suggesting that the tested insecticide baits were ineffective for flea control, prompting recommendations for future studies on higher doses and treatment frequency.
View Article and Find Full Text PDF

Sylvatic plague, a primarily flea-borne zoonosis, is a significant threat to prairie dogs ( spp., PDs) and their specialized predators, endangered black-footed ferrets (, BFFs). Host-fed fipronil baits have proven effective in controlling fleas on PDs for the purposes of plague mitigation and BFF conservation.

View Article and Find Full Text PDF

Parasite infrapopulation size - the population of parasites affecting a single host - is a central metric in parasitology. However, parasites are small and elusive such that imperfect detection is expected. Repeated sampling of parasites during primary sampling occasions (e.

View Article and Find Full Text PDF

Plague, caused by the bacterium Yersinia pestis, is a zoonotic disease of mammalian hosts and flea vectors. Fipronil baits have been used to suppress adult fleas for plague mitigation. The degree and duration of flea control may increase if fipronil also kills other stages in the flea life cycle.

View Article and Find Full Text PDF

Sylvatic plague is a widespread, primarily flea-vectored disease in western North America. Because plague is highly lethal to endangered black-footed ferrets (Mustela nigripes, BFFs) and the prairie dogs (Cynomys spp., PDs) on which BFFs depend for habitat and prey, minimizing the impacts of plague is a priority at BFF reintroduction sites.

View Article and Find Full Text PDF

Background: Plague, a widely distributed zoonotic disease of mammalian hosts and flea vectors, poses a significant risk to ecosystems throughout much of Earth. Conservation biologists use insecticides for flea control and plague mitigation. Here, we evaluate the use of an insecticide grain bait, laced with 0.

View Article and Find Full Text PDF

Prairie dogs in the western United States experience periodic epizootics of plague, caused by the flea-borne bacterial pathogen Yersinia pestis. An early study indicated that Oropsylla hirsuta (Baker), often the most abundant prairie dog flea vector of plague, seldom transmits Y. pestis by the classic blocked flea mechanism.

View Article and Find Full Text PDF

Purpose Of Review: In 2020, the Appropriations Committee for the U.S. House of Representatives directed the CDC to develop a national One Health framework to combat zoonotic diseases, including sylvatic plague, which is caused by the flea-borne bacterium .

View Article and Find Full Text PDF

The plague bacterium is lethal to endangered black-footed ferrets (, BFF) and the prairie dogs ( spp., PD) on which they depend for habitat and prey. We assessed the effectiveness of an oral sylvatic plague vaccine delivered in baits to black-tailed PD (, BTPD) from 2013 to 2017 on the Charles M.

View Article and Find Full Text PDF

Scientists collect fleas (Siphonaptera) to survey for , the bacterial agent of plague. When studying fleas parasitizing prairie dogs ( spp.), two primary methods are used: (1) combing fleas from live-trapped prairie dogs and (2) swabbing fleas from burrows with cloth swabs attached to metal cables.

View Article and Find Full Text PDF

Rodents characteristically benefit from increased precipitation, especially in typically dry habitats; "good years" of high precipitation improve their forage and water balance. However, (plague), a flea-borne pathogen of mammals that was introduced to western North America, has the greatest negative impact on at least some species of rodents during years of above-average precipitation. In the absence of plague mitigation, negative effects of plague in wet years might overwhelm the otherwise beneficial effects of increased moisture.

View Article and Find Full Text PDF

In western North America, sylvatic plague (a flea-borne disease) poses a significant risk to endangered black-footed ferrets (Mustela nigripes) and their primary prey, prairie dogs (Cynomys spp.). Pulicides (flea-killing agents) can be used to suppress fleas and thereby manage plague.

View Article and Find Full Text PDF

The plague bacterium, , is a generalist pathogen of flea (Siphonaptera) vectors and mammalian hosts. In colonies of prairie dogs (PDs, spp.), causes occasional epizootics, killing ≥90% of PDs within weeks to several months.

View Article and Find Full Text PDF

Plague originated in Asia as a flea-borne zoonosis of mammalian hosts. Today, the disease is distributed nearly worldwide. In western United States of America, plague is maintained, transmitted, and amplified in diverse communities of rodents and fleas.

View Article and Find Full Text PDF

Human health practitioners and wildlife biologists use insecticides to manage plague by suppressing fleas (Siphonaptera), but insecticides can also kill other ectoparasites. We investigated effects of deltamethrin and fipronil on ectoparasites from black-tailed prairie dogs (Cynomys ludovicianus, BTPDs). In late July, 2018, we treated three sites with 0.

View Article and Find Full Text PDF

Plague is a bacterial zoonosis of mammalian hosts and flea vectors. The disease is capable of ravaging rodent populations and transforming ecosystems. Because plague mortality is likely to be predicted by flea parasitism, it is critical to understand vector dynamics.

View Article and Find Full Text PDF

Plague is a flea-borne disease of mammalian hosts. On the grasslands of western North America, plague stifles populations of Cynomys spp. prairie dogs (PDs).

View Article and Find Full Text PDF

Plague (caused by the bacterium ) is a deadly flea-borne disease that remains a threat to public health nearly worldwide and is particularly disruptive ecologically where it has been introduced. We review hypotheses regarding maintenance and transmission of , emphasizing recent data from North America supporting maintenance by persistent transmission that results in sustained non-epizootic (but variable) rates of mortality in hosts. This maintenance mechanism may facilitate periodic epizootic eruptions "in place" because the need for repeated reinvasion from disjunct sources is eliminated.

View Article and Find Full Text PDF

Plague, a flea-borne disease, hampers efforts to restore populations of black-footed ferrets (), which occupy colonies of prairie dogs ( spp.) in North America. Plague is managed by infusing prairie dog burrows with DeltaDust 0.

View Article and Find Full Text PDF

The insecticide fipronil can be metabolized to its sulfone in mammalian species. Two camel single-domain antibodies (VHHs) F1 and F6, selective to fipronil and fipronil-sulfone, respectively, were generated and used to develop enzyme linked immunosorbent assays (ELISAs) for the detection of the two compounds in the sera of black-tailed prairie dogs and rats. The limits of detection of fipronil and fipronil-sulfone in the rodent sera by the corresponding ELISAs were 10 and 30 ng mL, and the linear ranges were 30-1000 and 75-2200 ng mL.

View Article and Find Full Text PDF

The following study investigates louse parasitism of black-tailed prairie dogs (Cynomys ludovicianus (Ord, Rodentia: Sciuridae)) on 20 plots at 13 colonies in the short-grass prairie of New Mexico, USA, June-August, 2011-2012. Among 124 lice collected from 537 prairie dogs during 1,207 sampling events in which anesthetized animals were combed for ectoparasites, all of the lice were identified as Linognathoides cynomyis (Kim, Phthiraptera: Polyplacidae). Data were analyzed under an information-theoretic approach to identify factors predicting louse parasitism.

View Article and Find Full Text PDF

Sylvatic plague poses a substantial risk to black-tailed prairie dogs ( Cynomys ludovicianus) and their obligate predator, the black-footed ferret ( Mustela nigripes). The effects of plague on prairie dogs and ferrets are mitigated using a deltamethrin pulicide dust that reduces the spread of plague by killing fleas, the vector for the plague bacterium. In portions of Conata Basin, Buffalo Gap National Grassland, and Badlands National Park, South Dakota, US, 0.

View Article and Find Full Text PDF