1. Fleas of Kit Foxes (Vulpes macrotis) at Dugway Proving Ground, Utah Helen K. Pigage1, Bryan M. Kluever2, Jon C. Pigage1, and Eric M. Gese3 1Biology Department, University of Colorado Colorado Springs, 1420 Austin Bluffs Parkway, Colorado Springs, CO USA 2Fort Carson Wildlife Program, DPW Environmental Division, 1626 Evans Street, Building 1219, Fort Carson, CO USA 3United States Dept. of Agriculture, Wildlife Services, National Wildlife Research Center, Department of Wildland Resources, Utah State University, Logan, UT USA
Abstract
Fifty-five kit foxes (Vulpes macrotis), 25 females and 30 males, were sampled at Dugway Proving Ground, Utah in 2012 and Foxes were examined, sexed, measured, fitted with radio collars, and combed for ectoparasites. A total of 575 fleas of 5 species were collected as well as approximately 100 ticks, not yet identified. Fleas identified included Pulex irritans (568), Meringis parkeri (4), Aetheca wagneri (1), Foxella ignota utahensis (1) and Peromyscopsyllus hesperomys adelpha (1). Mean intensity and prevalence of flea infestation were examined over three 4-month intervals of the year designated breeding, pup rearing, and dispersal. There was no difference in mean intensity of fleas on foxes over the year as determined by a χ2 test.
Results
Table 1. Fleas found on kit foxes at Dugway Proving Ground in
Flea Species
Number
Males
Females
% Total
Aetheca wagneri 1
0.002%
Foxella ignota utahensis
Meringis parkeri 4* 3
0.007%
Peromyscopsylla hesperomys adelpha
Pulex irritans
568
210
358
98.800%
*One broken
The number of fleas observed on individual kit foxes averaged 10.4 (SD = 11.2) and ranged from 0 to 48. The average number of fleas observed on adult and juvenile foxes was 12.7 (SD = 11.5) and 6.1 (SD = 9.28), respectively.
Table 2. Mean Intensity (# fleas/infested host) and Prevalence (# infested hosts/# hosts examined) of fleas on kit foxes . Breeding = 15 Dec.-14 Apr., Pup Rearing = 15 Apr.-14 Aug. , and Dispersal = 15 Aug.-14 Dec.
Figure 4. Mean intensity of flea infestation by biological
season on adult and juvenile kit foxes over 2 years ( ).
Materials and Methods
Kit foxes (Figure 1) were captured in 25x25x80 cm box traps baited with hot dogs on the U.S. Army Dugway Proving Ground and adjacent BLM land (Figure 2). Captured foxes were immobilized, examined, sexed, weighed, ear-tagged and fitted with a g radio collar (Advanced Telemetry Systems, Isanti, MN). In addition, foxes were combed from nose to tail for 2 minutes to remove ectoparasites. These were placed in plastic bags and frozen until identification.
Fleas were transferred to 100% EtOH, counted, identified, and some were permanently mounted on slides using standard procedures (Tables 1 and 2). Permanent mounts were entered into the parasite collection at University of Colorado Colorado Springs (Figure3).
Season
# hosts
# fleas
Range
(infested foxes)
Mean Intensity
Prevalence
2012
Breeding 4 41
5-14
10.25
1.00
Pup 13 57
1-29
4.38
0.46
Dispersal 11
120
10.91
2013 16
283
1-48
17.68
0.94 9 65
1-24
7.22
0.50 2 —
4.5
Discussion
Our findings are similar to previous investigations with respect to flea species observed on kit foxes. Our results (Figure 4) suggest that age (juvenile versus adult) may influence flea intensity, but further analytical explorations are needed to verify. The effects of flea infestations on kit fox space use and demography remain largely unexplored. Previous researchers have suggested that heavy flea infestations of dens are a principal factor for foxes changing dens. This hypothesis remains untested for kit foxes and other members of Canidae that exhibit high levels of den use. Numbers of fleas observed on kit foxes exceeded those observed on coyotes from the same study area, suggesting that the semi-fossorial lifestyle exhibited by kit foxes in order to reduce predation risk may carry with it an unintended negative consequence in the form of increased flea load intensity. A
Acknowledgements
Steve Dempsey, Robbie Knight, Clint Perkins, Shawn McEachin, John DeCotis, Wilson Wright, Will Knowlton, Joseph Fasig, Marleen Richmond, Utah State University Department of Wildland Resources, S.J & Jessie E. Quinney Foundation, Utah Division of Wildlife, T & E Inc., American Society of Mammologists, Dugway Proving Ground Environmental Division, The Wildlife Society – Utah Chapter, and the Biology Department, University of Colorado Colorado Springs. B
Figure 3. Pulex irritans female (A) and male (B) fleas, shown at the same magnification, are commonly found on canids, such as the kit fox, at the right.
Figure 2. Map of Utah, Dugway
Proving Ground and Study
Area (1127 km2).
Figure 1. Kit fox showing ear tag (left ear) and radio collar with antenna.