Abundance of fleas is thought to drive rates of plague transmission in the wild. In the complex process of plague maintenance and transmission, fleas as vectors are a potentially weak link in the system that can be exploited. To date, exploiting this link has provided the only stand-alone tools that are operationally effective for managing plague in the black-footed ferret/prairie dog community (i.e., use of various insecticides for flea control).
FORT scientists are addressing the question of how to most efficiently use these tools by conducting studies of flea ecology that examine the influences of colony age, soil characteristics, microclimates in burrows, weather patterns, and differences among flea species.
This research concentrates on fleas that parasitize black-tailed prairie dogs and the conservation implications of flea ecology in prairie dog habitats. Specifically, flea ecology will be compared among colonies with of differing ages and soil characteristics. Prairie dog fleas spend all life stages in close association with soils in prairie dog burrows. As prairie dogs construct a burrow system, soil is manipulated and organic matter, upon which fleas can feed (e.g., feces), accumulates. Also, burrow depth can increase, and the burrow microclimate can become more stable. This suggests temporal changes in the suitability of burrow environments for fleas as prairie dogs construct and modify burrows. Local environmental factors are also of extreme importance to fleas. Two factors, temperature and soil attributes, seem particularly important. Temperature can influence flea egg production and egg laying, and survival and development of fleas. Soil attributes are important because they influence moisture retention and humidity in burrows (another important factor) and abrasive soils can damage the flea exoskeleton. The purpose of this research is to investigate factors that influence the abundance and dispersion of different flea species in prairie dog habitats and in particular at translocation sites with colonies of differing time-since-colonization. Insight into flea dynamics at these sites could provide insight into development of plague risk at translocation sites increasingly used in conservation of prairie dogs and associated species, such as the federally endangered black-footed ferret.
Below are publications associated with this project.
Using occupancy models to investigate the prevalence of ectoparasitic vectors on hosts: an example with fleas on prairie dogs
Landscape features influence postrelease predation on endangered black-footed ferrets
Vector control improves survival of three species of prairie dogs (Cynomys) in areas considered enzootic for plague
Enzootic plague reduces black-footed ferret (Mustela nigripes) survival in Montana
Morning ambush attacks by black-footed ferrets on emerging prairie dogs
A review of plague persistence with special emphasis on fleas
Aboveground predation by an American badger (Taxidea taxus) on black-tailed prairie dogs (Cynomys ludovicianus)
Influences of introduced plague on North American mammals: Implications from ecology of plague in Asia
- Overview
Abundance of fleas is thought to drive rates of plague transmission in the wild. In the complex process of plague maintenance and transmission, fleas as vectors are a potentially weak link in the system that can be exploited. To date, exploiting this link has provided the only stand-alone tools that are operationally effective for managing plague in the black-footed ferret/prairie dog community (i.e., use of various insecticides for flea control).
FORT scientists are addressing the question of how to most efficiently use these tools by conducting studies of flea ecology that examine the influences of colony age, soil characteristics, microclimates in burrows, weather patterns, and differences among flea species.
This research concentrates on fleas that parasitize black-tailed prairie dogs and the conservation implications of flea ecology in prairie dog habitats. Specifically, flea ecology will be compared among colonies with of differing ages and soil characteristics. Prairie dog fleas spend all life stages in close association with soils in prairie dog burrows. As prairie dogs construct a burrow system, soil is manipulated and organic matter, upon which fleas can feed (e.g., feces), accumulates. Also, burrow depth can increase, and the burrow microclimate can become more stable. This suggests temporal changes in the suitability of burrow environments for fleas as prairie dogs construct and modify burrows. Local environmental factors are also of extreme importance to fleas. Two factors, temperature and soil attributes, seem particularly important. Temperature can influence flea egg production and egg laying, and survival and development of fleas. Soil attributes are important because they influence moisture retention and humidity in burrows (another important factor) and abrasive soils can damage the flea exoskeleton. The purpose of this research is to investigate factors that influence the abundance and dispersion of different flea species in prairie dog habitats and in particular at translocation sites with colonies of differing time-since-colonization. Insight into flea dynamics at these sites could provide insight into development of plague risk at translocation sites increasingly used in conservation of prairie dogs and associated species, such as the federally endangered black-footed ferret.
- Publications
Below are publications associated with this project.
Using occupancy models to investigate the prevalence of ectoparasitic vectors on hosts: an example with fleas on prairie dogs
Ectoparasites are often difficult to detect in the field. We developed a method that can be used with occupancy models to estimate the prevalence of ectoparasites on hosts, and to investigate factors that influence rates of ectoparasite occupancy while accounting for imperfect detection. We describe the approach using a study of fleas (Siphonaptera) on black-tailed prairie dogs (Cynomys ludovicianLandscape features influence postrelease predation on endangered black-footed ferrets
Predation can be a critical factor influencing recovery of endangered species. In most recovery efforts lethal and nonlethal influences of predators are not sufficiently understood to allow prediction of predation risk, despite its importance. We investigated whether landscape features could be used to model predation risk from coyotes (Canis latrans) and great horned owls (Bubo virginianus) on thVector control improves survival of three species of prairie dogs (Cynomys) in areas considered enzootic for plague
Plague causes periodic epizootics that decimate populations of prairie dogs (PDs) (Cynomys), but the means by which the causative bacterium (Yersinia pestis) persists between epizootics are poorly understood. Plague epizootics in PDs might arise as the result of introductions of Y. pestis from sources outside PD colonies. However, it remains possible that plague persists in PDs during interepizootEnzootic plague reduces black-footed ferret (Mustela nigripes) survival in Montana
Black-footed 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 doMorning ambush attacks by black-footed ferrets on emerging prairie dogs
Black-footed ferrets (Mustela nigripes) often hunt at night, attacking normally diurnal prairie dogs (Cynomys spp.) in underground burrow systems. While monitoring black-footed ferrets in South Dakota during morning daylight hours, we observed an adult female ferret ambush a black-tailed prairie dog (C. ludovicianus) emerging from a burrow. On a neighboring colony, we observed a second adult femalA review of plague persistence with special emphasis on fleas
Sylvatic plague is highly prevalent during infrequent epizootics that ravage the landscape of western North America. During these periods, plague dissemination is very efficient. Epizootics end when rodent and flea populations are decimated and vectored transmission declines. A second phase (enzootic plague) ensues when plague is difficult to detect from fleas, hosts or the environment, and presenAboveground predation by an American badger (Taxidea taxus) on black-tailed prairie dogs (Cynomys ludovicianus)
During research on black-tailed prairie dogs (Cynomys ludovicianus), we repeatedly observed a female American badger (Taxidea taxus) hunting prairie dogs on a colony in southern Phillips County, Montana. During 1-14 June 2006, we observed 7 aboveground attacks (2 successful) and 3 successful excavations of prairie dogs. The locations and circumstances of aboveground attacks suggested that the badgInfluences of introduced plague on North American mammals: Implications from ecology of plague in Asia
Intercontinental movements of invasive species continue to modify the world's ecosystems. The plague bacterium (Yersinia pestis) has colonized and altered animal communities worldwide but has received much more attention as a human pathogen. We reviewed studies on the ecology of Y. pestis in ancient foci of central Asia and in western North America, where the bacterium apparently has become establ