Geology topics

Shelli A. Dubay

Publications and source records attributed to Shelli A. Dubay.

6 recordsLinked to original sources

USGS2026

Fipronil baits as emerging tools for flea control and plague mitigation: Experiments with cricetid mice on prairie dog colonies

Plague is a zoonotic disease of mammalian hosts and flea vectors. Wildlife biologists most commonly mitigate plague by controlling flea populations. We evaluated the efficacy of edible baits for systemic flea control with two cricetid species on colonies of black-tailed prairie dogs ( Cynomys ludovicianus ): the western deer mouse ( Peromyscus sonoriensis ) and the northern grasshopper mouse ( Onychomys leucogaster ). We tested grain bait with 0.005% fipronil by weight and “FipBit” pellets with 0.46–1.52 mg of fipronil/pellet. Flea prevalence was assessed via combing of live-trapped mice. In one experiment with fipronil grain bait and FipBits ( n =564 combings), flea prevalence declined from 74% (grain) and 45% (FipBits) before treatments to 0% for both treatments from 30–44 d and from 324–413 d after treatments. During a second experiment with FipBits ( n =299 combings), flea prevalence declined from 13% to 32% before treatments to 0% from 11–15 d after treatments, but increased to 29–56% from 349–378 d after treatments. Results herein suggest annual fipronil bait treatments may be most effective for flea control.

Journal of Wildlife Diseases↗

USGS2021

Gapeworm (Syngamus spp.) prevalence in Wisconsin greater prairie chickens (Tympanuchus cupido pinnatus)

Under Wisconsin state law, the greater prairie chicken (GRPC; Tympanuchus cupido pinnatus ) has been listed as a threatened species since 1976. In 2014–15, we conducted a pilot study to determine the prevalence and intensity of gapeworms ( Syngamus spp.) in female Wisconsin GRPCs collected from 2 monitored populations. We captured 62 female GRPCs using walk-in-style traps for females and night lighting for juveniles ≥45 days of age. From these individuals, we collected 15 carcasses of radio-marked birds, most of whom died due to predation events. Through dissection, we identified gapeworm in 20% of examined carcasses and report an intensity ranging between 4 and 74 worms.

Wisconsin↗

USGS2018

Nest tree use by Southern flying squirrels in fragmented midwestern landscapes

Southern flying squirrels ( Glaucomys volans ; SFS) nest in naturally formed cavities in snags and hardwoods found in mature, oak ( Quercus spp.)–hickory ( Carya spp.) forests. Intensive forest fragmentation of the Midwest United States limits the number of available nesting trees. We quantified annual nest‐site selection patterns by southern flying squirrels across fragmented landscapes of west‐central Illinois, USA. We used radiotelemetry to measure nest‐tree use by 55 SFS (30 males, 25 females) captured during 2014–2016. Of 105 nest trees used by SFS, live trees and snags comprised 75% and 25%, respectively. Probability of diurnal nest‐tree use increased 1.08/1.00‐cm increase in diameter‐breast‐height and by 1.50/1‐unit increase in the number of overstory mast trees between random and nest‐tree habitat areas (i.e., 300‐m 2 circular plots). Similarly, probability of diurnal nest‐tree use increased 1.29/1‐unit increase in the number of snags between random and nest‐tree habitat areas. Our results revealed no intersexual differences in patterns of nest‐site selection, which may reflect the tendency for SFS to compensate for reduced availability of key structural attributes (i.e., snags, overstory trees) across fragmented forests by exhibiting similar intersexual patterns of nest‐tree use. Use of natural cavities for denning is encouraging, but also underscores the importance of unharvested oak–hickory forests in contributing essential habitat to SFS populations in fragmented Midwestern landscapes.

Wildlife Society Bulletin↗

USGS2017

Influence of trap modifications and environmental predictors on capture success of southern flying squirrels

Sherman traps are the most commonly used live traps in studies of small mammals and have been successfully used in the capture of arboreal species such as the southern flying squirrel ( Glaucomys volans ). However, southern flying squirrels spend proportionately less time foraging on the ground, which necessitates above-ground trapping methods and modifications of capture protocols. Further, quantitative estimates of the factors affecting capture success of flying squirrel populations have focused solely on effects of trapping methodologies. We developed and evaluated the efficacy of a portable Sherman trap design for capturing southern flying squirrels during 2015–2016 at the Alice L. Kibbe Field Station, Illinois, USA. Additionally, we used logistic regression to quantify potential effects of time-dependent (e.g., weather) and time-independent (e.g., habitat, extrinsic) factors on capture success of southern flying squirrels. We recorded 165 capture events (119 F, 44 M, 2 unknown) using our modified Sherman trap design. Probability of capture success decreased 0.10/1° C increase in daily maximum temperature and by 0.09/unit increase (km/hr) in wind speed. Conversely, probability of capture success increased by 1.2/1° C increase in daily minimum temperature. The probability of capturing flying squirrels was negatively associated with trap orientation. When tree-mounted traps are required, our modified trap design is a safe, efficient, and cost-effective method of capturing animals when moderate weather (temp and wind speed) conditions prevail. Further, we believe that strategic placement of traps (e.g., northeast side of tree) and quantitative information on site-specific (e.g., trap location) characteristics (e.g., topographical features, slope, aspect, climatologic factors) could increase southern flying squirrel capture success. © 2017 The Wildlife Society.

Illinois↗

USGS2017

Associations among habitat characteristics and meningeal worm prevalence in eastern South Dakota, USA

Few studies have evaluated how wetland and forest characteristics influence the prevalence of meningeal worm ( Parelaphostrongylus tenuis ) infection of deer throughout the grassland biome of central North America. We used previously collected, county-level prevalence data to evaluate associations between habitat characteristics and probability of meningeal worm infection in white-tailed deer ( Odocoileus virginianus ) across eastern South Dakota, US. The highest-ranked binomial regression model for detecting probability of meningeal worm infection was spring temperature + summer precipitation + percent wetland; weight of evidence ( w i =0.71) favored this model over alternative models, though predictive capability was low (Receiver operating characteristic=0.62). Probability of meningeal worm infection increased by 1.3- and 1.6-fold for each 1-cm and 1-C increase in summer precipitation and spring temperature, respectively. Similarly, probability of infection increased 1.2-fold for each 1% increase in wetland habitat. Our findings highlight the importance of wetland habitat in predicting meningeal worm infection across eastern South Dakota. Future research is warranted to evaluate the relationships between climatic conditions (e.g., drought, wet cycles) and deer habitat selection in maintaining P. tenuis along the western boundary of the parasite.

Journal of Wildlife Diseases↗

USGS2015

Influence of ecological factors on prevalence of meningeal worm ( Parelaphostrongylus tenuis infection in South Dakota, USA

The meningeal worm ( Parelaphostrongylus tenuis ) is a nematode parasite that commonly infects white-tailed deer ( Odocoileus virginianus ; WTD) throughout the deciduous forest biome and deciduous-coniferous ecotone of eastern and central North America; the species is not known to occur west of the grassland biome of central North America. We used county-specific prevalence data to evaluate potential effects of landscape and climatologic factors on the spatial distribution of meningeal worm infection in South Dakota, US. Probability of infection increased 4-fold between eastern and western South Dakota and 1.3-fold for each 1-cm increase in summer precipitation. Sixty-three percent of WTD had only a single worm in the cranium. Expansion of meningeal worm infection across western South Dakota may be inherently low due to the combined effects of arid climate and potential attributes of the Missouri River that limit regional movements by infected WTD. Use of landscape genetic analyses to identify potential relationships between landscape features and population genetic structure of infected deer and parasites may contribute to a greater understanding of regional heterogeneity in meningeal worm infection rates across South Dakota, particularly in counties adjacent to the Missouri River. Future research evaluating heterogeneity in prevalence and intensity of infection between fawn and yearling deer, and the potential role of yearling male deer as dispersal agents of meningeal worms across the Missouri River, also is warranted.

South Dakota↗