Fecal samples from 54 Gunnison’s prairie dogs (Cynomys gunnisoni) from Albuquerque, NM were analyzed for the presence of coccidia and all were positive. They were then relocated to an abandoned prairie dog town on the Sevilleta Long Term Ecological Research (LTER) site. Six Eimeria species, E. callospermophili, E. cynomysis, E. pseudospermophili (new host record), E. spermophili, E. ludoviciani and E. vilasi (new host record) were found in Albuquerque animals, but only two species, E. callospermophili and E. vilasi were present in relocated hosts. A significant (P \u3c 0.05) reduction was seen in the prevalence of E. vilasi (72% vs. 13%) and in the prevalence of infections (P \u3c 0.05) with two or more Eimeria species (39% vs. 4%) in pre- and postrelocation animals. To assess the impact of the introduction of C. gunnisoni on the resident rodent population, feces were collected from 6 species of rodents. Five Eimeria species, E. arizonensis (Reithrodontomys), E. chobotari (Dipodomys, Perognathus), E. liomysis (Dipodomys), E. mohavensis (Dipodomys) and E. reedi (Perognathus) were found. We found no evidence of coccidia transfer among introduced and resident rodent species

Decker, K. H.

Duszynski, Donald W.

Ryan, M. M.

English

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Publications from the Harold W. Manter Laboratory of Parasitology Parasitology, Harold W. Manter Laboratory of 2001 Prevalence of Eimeria (Apicomplexa: Eimeriidae) in Reintroduced Gunnison's Prairie Dogs (Cynomys gunnisoni) M. M. Ryan University of New Mexico, mryan@unm.edu K. H. Decker University of New Mexico Donald W. Duszynski University of New Mexico, eimeria@unm.edu Follow this and additional works at: https://digitalcommons.unl.edu/parasitologyfacpubs  Part of the Parasitology Commons Ryan, M. M.; Decker, K. H.; and Duszynski, Donald W., "Prevalence of Eimeria (Apicomplexa: Eimeriidae) in Reintroduced Gunnison's Prairie Dogs (Cynomys gunnisoni)" (2001). Faculty Publications from the Harold W. Manter Laboratory of Parasitology. 635. https://digitalcommons.unl.edu/parasitologyfacpubs/635 This Article is brought to you for free and open access by the Parasitology, Harold W. Manter Laboratory of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications from the Harold W. Manter Laboratory of Parasitology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 409Am. Midl. Nat. 145:409–413Prevalence of Eimeria (Apicomplexa: Eimeriidae) in Reintroduced Gunnison’s PrairieDogs (Cynomys gunnisoni)ABSTRACT.—Fecal samples from 54 Gunnison’s prairie dogs (Cynomys gunnisoni) from Al-buquerque, NM were analyzed for the presence of coccidia and all were positive. They werethen relocated to an abandoned prairiedog town on the Sevilleta Long Term EcologicalResearch (LTER) site. Six Eimeria species, E. callospermophili, E. cynomysis, E. pseudospermo-phili (new host record), E. spermophili, E. ludoviciani and E. vilasi (new host record) werefound in Albuquerque animals, but only 2 species, E. callospermophili and E. vilasi werepresent in relocated hosts. A significant (P , 0.05) reduction was seen in the prevalence ofE. vilasi (72% vs. 13%) and in the prevalence of infections (P , 0.05) with 2 or more Eimeriaspecies (39% vs. 4%) in pre- and postrelocation animals. To assess the impact of the intro-duction of C. gunnisoni on the resident rodent population, feces were collected from 6species of rodents. Five Eimeria species, E. arizonensis (Reithrodontomys), E. chobotari (Dipo-domys, Perognathus), E. liomysis (Dipodomys), E. mohavensis (Dipodomys) and E. reedi (Perog-nathus) were found. We found no evidence of coccidia transfer among introduced and res-ident rodent species.INTRODUCTIONPrairie dogs are an important part of the grassland systems of North America and with 98% of theirhistoric original population already destroyed due, in part, to habitat loss, they are prime candidatesfor relocation efforts (Miller et al., 1994; Long, 1998). Here we document the coccidia fauna of apopulation of Gunnison’s prairie dogs (Cynomys gunnisoni, Baird 1855) that was relocated from Al-buquerque to an abandoned prairie dog town on the University of New Mexico’s (UNM) Long TermEcological Research (LTER) site within the Sevilleta National Wildlife Refuge (SNWR) near Socorro,NM, as well as that of the dominant rodent populations resident near the reoccupied prairie dog townon the Sevillea. Little is known about prairie dog parasite communities and the influence their presencemay have on the parasite communities of sympatric rodent species.Eimeria spp. have a direct life cycle that is easily monitored by the noninvasive examination of fecalpellets, which allows the least interference and stress in a relocated host population. Eimeriid coccidiaare known to be reasonably host specific, transferring easily between congenerics (Upton et al., 1992;Seville, 1997; Hnida and Duszynski, 1999), infrequently among confamilials (Todd and Hammond,1968a, b; Wilber et al., 1998) but only rarely between families or orders (De Vos, 1970; Hendricks,1977). The objectives of this study were to: (1) survey the coccidia species infecting C. gunnisoni andthe dominant species of the resident rodent population and (2) compare the prevalence of infectionswith coccidia of C. gunnisoni and the major rodent residents before and after relocation.MATERIAL AND METHODSSixty prairie dogs (54 fecal samples collected) were captured at three localities on 29 March and 16,18 April 1997, within the Albuquerque (Bernalillo County) city limits, marked with a passive integratedtransponder (PIT) and relocated the same day to an abandoned prairie dog colony on the SevilletaLTER in central New Mexico (348129560N, 106847930W, elevation 5 1536 m) (Davidson et al., 1999).Twenty-nine of those prairie dogs (23 fecal samples collected) were recaptured during subsequenttrapping on 15, 16, 17 July. For further details of animal processing and methods of colony reestab-lishment see Davidson et al. (1999).Rodents on the Sevilleta LTER were captured with Tomahawky live traps placed every 10 m in a100 3 100 m grid. Rodents were trapped on 6 grids and feces were collected on 3 prerelocation dates,11, 12, 13 March and 6 postrelocation dates, 6, 7, 8 May, 8 July and 17, 19 September 1997; 3 gridswere located on the prairie dog town (treatment sites) and 3 grids were located across an arroyoapproximately 50–200 m away (reference sites) (Davidson et al., 1999). Animals were presumed to notcross this arroyo.Feces collected from each animal were put into a solution of 2% aqueous (w/v) potassium dichro-410 145(2)THE AMERICAN MIDLAND NATURALISTTABLE 1.—Prevalence (%) of Eimeria spp. in fecal samples of Gunnison’s prairie dogs, Cynomysgunnisoni, in Albuquerque (March 1997) and on the Sevilleta LTER ( July 1997) after 60 animals fromAlbuquerque were relocated to an abandoned prairie dog colony on the LTERCoccidian spp.No. infected hosts (prevalence)March samplesprerelocation (n 5 54)July samplespostrelocation (n 5 23)E. callospermophiliE. cynomysisE. ludovicianaE. pseudospermophiliE. spermophiliE. vilasiUnsporulatedMultiple infections33 (61)2 (4)1 (2)3 (6)1 (2)39 (72)4 (7)25 (44)8 (35)————2 (9)*4 (17)1 (4)*All species 54/54 (100) 15/23 (65)** Postrelocation prevalences were significantly lower (P , 0.05) than those of prerelocation popu-lationmate and taken to the University of New Mexico where oocysts were allowed to sporulate; oocysts wereisolated, identified, measured and stored following Duszynski and Wilber (1997).Prevalence (no. infected hosts/no. hosts collected) of each eimeriid species in the prairie dog androdent sample populations was calculated before and after relocation. A t-test (95% confidence inter-val) for two independent binomial samples was used to assess significant change in eimeriid prevalencebetween pre- and postrelocation populations (Christensen, 1996). We tested the null hypothesis for nodifference in eimerian prevelance between populations.RESULTSAll 54 (100%) fecal samples collected from prairie dogs in Albuquerque in March and April 1997had eimeriid oocysts (Table 1). Because no significant difference was found in eimerian prevalenceamong the original three subpopulations of prairie dogs (P . 0.05), they were combined into a singleprerelocation population in later statistical analysis. Prerelocation prairie dogs had a significantly (P ,0.05) higher prevalence of infection with coccidia than did postrelocation animals. Prevalence of Ei-meria vilasi and of multiple infections also was significantly greater (P , 0.05) in the prerelocationpopulation (Table 1).Fecal samples also were obtained from 391 individual animals of the 6 dominant species of rodentson the Sevilleta LTER, including Dipodomys ordii (21), D. spectabilis (16), Onychomys arenicola (8),Perognathus flavus (320; mean recapture level 5 18%), Peromyscus leucopus (14) and Reithrodontomysmegalotus (12) that were captured on 4 collection dates (March, May, July, September) (Table 2). Fora comprehensive list of all animals captured refer to Davidson et al. (1999). No oocysts were found insamples collected from P. leucopus. Perognathus flavus was the most abundant rodent captured fromboth treatment and reference sites and Eimeria reedi was the most prevalent species of coccidia ob-served. Small sample sizes prevented analytical comparisons for March and May collections and nosignificant difference was found in prevalence of E. reedi between July (4 mo postrelocation) referenceand treatment populations. In September (6 mo postrelocation), E. reedi prevalence was significantlygreater (P , 0.05) in recaptured P. flavus for the reference population than for the treatment popu-lation. Eimeria chobatari and E. reedi oocysts were found in three of the host species in two genera;Dipodomys ordii, D. spectabilis and P. flavus.DISCUSSIONThis survey of Cynomys gunnisoni in New Mexico documents four previously reported species ofeimeriid coccidia, Eimeria callospermophili, E. cynomysis, E. ludoviciani and E. spermophili and two spe-2001 411NOTES AND DISCUSSIONTABLE 2.—Number of fecal samples collected, rodent species and Eimeria spp. found in those samplesfrom each of six rodent species captured at the Sevilleta LTER in 1997Rodent spp.Eimeria spp.No. sampleswithEimeria spp.Rodent spp.Eimeria spp.No. sampleswithEimeria spp.Dipodomys ordiiE. chobotariE. reedi2121Perognathus flavusE. chobotariE. reedi3201110Dipodomys spectabilisE. chobotariE. liomysisE. mohavensisE. reedi161112BothPeromyscus leucopusNoneOnychomys arenicolaUnsporulated (one morph)Reithrodontomys megalotisE. arizonensis114—84122cies that are new host records, E. pseudospermophili and E. vilasi. Previously, Thomas and Stanton(1994), in Utah, found E. callospermophili (and/or E. morainensis), E. beecheyi, E. spermophili, E. bila-mellata (later synonymized with E. cynomysis, Wilber et al., 1998), E. larimerensis and E. cynomysisinfecting C. gunnisoni.Prevalence of infection with Eimeria species declined significantly in the postrelocation populationof Cynomys gunnisoni. Without an established population of C. gunnisoni on the Sevilleta LTER beforerelocation of animals from Albuquerque, we can only postulate probable causes for this decline. Be-cause of the short duration of this experiment it is likely these results are due to the cyclic nature ofthe coccidians. However, the overall prevalence of eimerian infections dropped significantly and notall species of Eimeria contribute equally to this phenomenon.Of the six species of Eimeria originally found within the prairie dog samples, four were relativelyrare and were not recovered from the relocated prairie dogs. The two remaining species, E. callosper-mophili and E. vilasi, had high prevalences within the prerelocated population that decreased afterrelocation, though only E. vilasi showed a significant decrease. Seville and Stanton (1993), workingwith another sciurid (Spermophilus variegatus grammurus) believed high eimerian prevalences indicatedlittle or no host immune response to the eimerian infection.Wilber et al. (1994) found a sharp decline in Eimeria adaensis (5E. vilasi, Wilber et al., 1998) inTownsend’s ground squirrels Spermophilus townsendii during summer months which is consistant withthe decline of E. vilasi in the relocated prairiedog population. However, a significant increase in E.callospermophili also was observed, an event not seen the prairie dog population. These authors attri-buted the patterns to aquired immunity and the seasonal weather cycle. Others have shown that theeffects of stress, such as that caused by decline in host population and changes in the environmentrelating to host diet change, can regulate eimerian prevalences within a host populations (Long, 1982;Crompton, 1987; Allen et al., 1998; Oppliger et al., 1998; Lafferty and Kuris, 1999). One or all of thesehad a significant influence on the prevalences of E. callospermophili and E. vilasi in the prairie dogpopulation.In addition, it is thought that differences in reproductive potentials and responses of infective oocystsunder varying abiotic conditions are mechanisms by which the prevalence of eimerian species varieswithin a host population (Fuller et al., 1995; Stanton et al., 1992). This idea is important when analyzingthe decline we found in prevalences of eimeriid coccidia in prairie dog and Perognathus flavus popu-lations. Within the sympatric rodent community, only P. flavus was caught in numbers great enoughfor statistical analysis. No significant difference of the prevalences in Eimeria reedi was found betweentreatment and reference recaptures until 6 mo after the prairie dog relocation. Because the effects ofspecies variability and host number can be accounted for, this may represent a minimal time frame412 145(2)THE AMERICAN MIDLAND NATURALISTnecessary for an effect of disturbance, such as species introduction, to be detected on eimerian prev-alences.Relocation was associated with a significant decline in the coccidia fauna of the prairie dog Cynomysgunnisoni. This study gives insight into the potential effects of relocating a population of C. gunnisoniand, in particular, revealed no transfer of prairie dog coccidians to the resident rodent population atthe time of this study. While both Eimeria vilasi and E. callospermophili infect multiple genera withinthe Marmotini tribe, they have yet to be found to cross family boundaries (Wilber et al., 1998). Futurelong-term studies that include multiple control and treatment populations are necessary in order thata comprehensive picture of this host-parasite system can be made.Acknowledgments.—We thank A. Davidson, Dr. B. Parmenter, M. Friggens, J. Aragon, A. Leach, L.Yau and my colleagues in the Duszynski Laboratory for their assistance. Financial support was providedby a NSF (Biotic Survey and Inventory) Grant #DEB 9505025 to DWD. This project was supported bythe UNM Sevilleta LTER Program and is Publication No. 186 (NSF, BSR-88-11906; DEB-95-9411976).LITERATURE CITEDALLEN, P. C., H. D. DANFORTH AND P. C. AUGUSTINE. 1998. Dietary modulation of avian coccidiosis.Inter. J. Parasitol., 28:1131–1140.CHRISTENSEN, R. 1996. Analysis of variance, design, and regression: applied statistical methods, 1st ed.Chapman and Hall, London: New York. 587 p.CROMPTON, D. W. T. 1987. Host diet as a determinant of parasite growth, reproduction and survival.Mammal. Rev., 17:117–126.DAVIDSON, A. D., R. R. PARMENTER AND R. G. GOSZ. 1999. Responses of vegetation and small mammalsto a reintroduction of Gunnison’s prairie dogs. J. Mammal., 80:1311–1324.DE VOS, A. J. 1970. Studies on the host range of Eimeria chinchillae De Vos and Van der Westhuizen,1968. Onderstepoort J. Vet. Res., 37:29–70.DUSZYNSKI, D. W. AND P. G. WILBER. 1997. A guidline for the preparation of species descriptions in theEimeriidae. J. Parasitol., 83:333–336.FULLER, C. A., J. HEFNER AND E. WROSCH. 1995. Oocyst output, periodicity, and immunity of two deermouse (Peromyscus maniculatus) eimerians (Eimeria arizonensis and Eimeria delicata). J. Par-asitol., 81:187–194.HENDRICHS, L. D. 1977. Host range characteristics of the primate coccidian Isospora aratopitheci Rod-hain, 1933 (Protozoa: Eimeriidae). J. Parasitol., 63:32–35.HNIDA, J. A. AND D. W. DUSZYNKSI. 1999. Cross-transmission studies with Eimeria arizonensis, E. arizo-nensis-like oocycst and Eimeria langebarteli: host specifictiy at the genus and species level withinthe Muridae. J. Parasitol., 85:873–877.LAFFERTY, K. D. AND A. M. KURIS. 1999. How environmental stress affects the impacts of parasites. Limn.Oceanogr., 44:925–931.LONG, P. L. 1982. The biology of the coccidia. University Park Press, Baltimore, Maryland. 502 p.LONG, M. E. 1998. The vanishing prairie dog. National Geographic, 194 (April):118–130.MILLER, B., G. CEBALLOS AND R. READING. 1994. The prairie dog and biotic diversity. Conserv. Biol., 8:677–681.OPPLIGER, A., J. CLOBERT, J. LECOMTE, P. LORENZON, K. BOUDJEMADI AND J. H. B. ALDER. 1998. Envi-ronmental stress increases the prevalence and intensity of blood parasite infection in the com-mon lizard Lacerta vivpara. Ecology Letters, 1:129–138.SEVILLE, R. S. 1997. Eimeria spp. (Apicomplexa: Eimeriidae) from Black- and White-tailed Prairie Dogs(Cynomys ludovicianus and Cynomys leucurus) in Central and Southeast Wyoming. J. Parasitol.,83:166–168.——— AND N. L. STANTON. 1993. Eimerian guilds (Apicomplexa: Eimeriidae) in Richardson’s (Sper-mophilus richardsonii) and Wyoming (Spermophilus elegans) ground squirrels. J. Parasitol., 79:973–975.STANTON, N. L., L. M. SHULTS, M. PARKER AND R. S. SEVILLE. 1992. Coccidian assemblages in theWyoming ground squirrel, Spermophilus elegans elegans. J. Parasitol., 78:323–328.THOMAS, D. M. AND N. L. STANTON. 1994. Eimerian species (Apicomplexa: Eimeriina) in Gunnison’s2001 413NOTES AND DISCUSSIONprairie dogs (Cynomys gunnisoni zuniensis) and rock squirrels (Spermophilus variegatus gram-murus) from Southeastern Utah. J. Helm. Soc. Wash., 61:17–21.TODD, K. S., JR. AND D. M. HAMMOND. 1968a. Life cycle and host specificity of Eimeria callospermophiliHenry, 1932 from the Uinta ground squirrel Spermophilus armatus. J. Protozool., 15:1–8.——— AND ———. 1968b. Life cycle and host specificity of Eimeria larimerensis Vetterling, 1964, fromthe Uinta ground squirrel, Spermophilus armatus. J. Protozool., 15:268–275.UPTON, S. L., C. T. MCALLISTER, D. B. BRILLHART, D. W. DUSZYNSKI AND C. W. WASH. 1992. Cross-transmission studies with Eimeria arizonensis-like oocysts (Apicomplexa) in New World rodentsof the genera Baiomys, Neotoma, Onychomys, Peromyscus and Reithrodontomys (Muridae). J.Parasitol., 78:406–413.WILBER, P. G., B. HANELT, B. VAN HORNE AND D. W. DUSZYNSKI. 1994. Two new species and temporalchanges in the prevalence of eimerians in a free-living population of Townsend’s ground squir-rels (Spermophilus townsendii) in Idaho. J. Parasitol., 80:251–259.———, D. W. DUSZYNSKI, S. J. UPTON, R. S. SEVILLE AND J. O. CORLISS. 1998. A revision of the taxonomyand nomenclature of the Eimeria spp. (Apicomplexa; Eimerdiidae) from rodents in the tribeMarmotini (Sciuridae). Syst. Parasitol., 39:113–135.M. M. RYAN1, K. H. DECKER AND D. W. DUSZYNSKI2, Department of Biology, University of NewMexico, Albuquerque 87131.Submitted 13 March 2000; accepted 2 October 2000.1 Corresponding author. e-mail: mryan@unm.edu2 e-mail: eimeria@unm.edu

Prevalence of \u3ci\u3eEimeria\u3c/i\u3e (Apicomplexa: Eimeriidae) in Reintroduced Gunnison\u27s Prairie Dogs (\u3ci\u3eCynomys gunnisoni\u3c/i\u3e)

UNL | Libraries

University of Nebraska - Lincoln 
DigitalCommons@University of Nebraska - Lincoln 
Faculty Publications from the Harold W. Manter 
Laboratory of Parasitology Parasitology, Harold W. Manter Laboratory of 
2001 
Prevalence of Eimeria (Apicomplexa: Eimeriidae) in Reintroduced 
Gunnison's Prairie Dogs (Cynomys gunnisoni) 
M. M. Ryan 
University of New Mexico, mryan@unm.edu 
K. H. Decker 
University of New Mexico 
Donald W. Duszynski 
University of New Mexico, eimeria@unm.edu 
Follow this and additional works at: https://digitalcommons.unl.edu/parasitologyfacpubs 
 Part of the Parasitology Commons 
Ryan, M. M.; Decker, K. H.; and Duszynski, Donald W., "Prevalence of Eimeria (Apicomplexa: Eimeriidae) in 
Reintroduced Gunnison's Prairie Dogs (Cynomys gunnisoni)" (2001). Faculty Publications from the Harold 
W. Manter Laboratory of Parasitology. 635. 
https://digitalcommons.unl.edu/parasitologyfacpubs/635 
This Article is brought to you for free and open access by the Parasitology, Harold W. Manter Laboratory of at 
DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications from 
the Harold W. Manter Laboratory of Parasitology by an authorized administrator of DigitalCommons@University of 
Nebraska - Lincoln. 
409
Am. Midl. Nat. 145:409–413
Prevalence of Eimeria (Apicomplexa: Eimeriidae) in Reintroduced Gunnison’s Prairie
Dogs (Cynomys gunnisoni)
ABSTRACT.—Fecal samples from 54 Gunnison’s prairie dogs (Cynomys gunnisoni) from Al-
buquerque, NM were analyzed for the presence of coccidia and all were positive. They were
then relocated to an abandoned prairiedog town on the Sevilleta Long Term Ecological
Research (LTER) site. Six Eimeria species, E. callospermophili, E. cynomysis, E. pseudospermo-
phili (new host record), E. spermophili, E. ludoviciani and E. vilasi (new host record) were
found in Albuquerque animals, but only 2 species, E. callospermophili and E. vilasi were
present in relocated hosts. A significant (P , 0.05) reduction was seen in the prevalence of
E. vilasi (72% vs. 13%) and in the prevalence of infections (P , 0.05) with 2 or more Eimeria
species (39% vs. 4%) in pre- and postrelocation animals. To assess the impact of the intro-
duction of C. gunnisoni on the resident rodent population, feces were collected from 6
species of rodents. Five Eimeria species, E. arizonensis (Reithrodontomys), E. chobotari (Dipo-
domys, Perognathus), E. liomysis (Dipodomys), E. mohavensis (Dipodomys) and E. reedi (Perog-
nathus) were found. We found no evidence of coccidia transfer among introduced and res-
ident rodent species.
INTRODUCTION
Prairie dogs are an important part of the grassland systems of North America and with 98% of their
historic original population already destroyed due, in part, to habitat loss, they are prime candidates
for relocation efforts (Miller et al., 1994; Long, 1998). Here we document the coccidia fauna of a
population of Gunnison’s prairie dogs (Cynomys gunnisoni, Baird 1855) that was relocated from Al-
buquerque to an abandoned prairie dog town on the University of New Mexico’s (UNM) Long Term
Ecological Research (LTER) site within the Sevilleta National Wildlife Refuge (SNWR) near Socorro,
NM, as well as that of the dominant rodent populations resident near the reoccupied prairie dog town
on the Sevillea. Little is known about prairie dog parasite communities and the influence their presence
may have on the parasite communities of sympatric rodent species.
Eimeria spp. have a direct life cycle that is easily monitored by the noninvasive examination of fecal
pellets, which allows the least interference and stress in a relocated host population. Eimeriid coccidia
are known to be reasonably host specific, transferring easily between congenerics (Upton et al., 1992;
Seville, 1997; Hnida and Duszynski, 1999), infrequently among confamilials (Todd and Hammond,
1968a, b; Wilber et al., 1998) but only rarely between families or orders (De Vos, 1970; Hendricks,
1977). The objectives of this study were to: (1) survey the coccidia species infecting C. gunnisoni and
the dominant species of the resident rodent population and (2) compare the prevalence of infections
with coccidia of C. gunnisoni and the major rodent residents before and after relocation.
MATERIAL AND METHODS
Sixty prairie dogs (54 fecal samples collected) were captured at three localities on 29 March and 16,
18 April 1997, within the Albuquerque (Bernalillo County) city limits, marked with a passive integrated
transponder (PIT) and relocated the same day to an abandoned prairie dog colony on the Sevilleta
LTER in central New Mexico (348129560N, 106847930W, elevation 5 1536 m) (Davidson et al., 1999).
Twenty-nine of those prairie dogs (23 fecal samples collected) were recaptured during subsequent
trapping on 15, 16, 17 July. For further details of animal processing and methods of colony reestab-
lishment see Davidson et al. (1999).
Rodents on the Sevilleta LTER were captured with Tomahawky live traps placed every 10 m in a
100 3 100 m grid. Rodents were trapped on 6 grids and feces were collected on 3 prerelocation dates,
11, 12, 13 March and 6 postrelocation dates, 6, 7, 8 May, 8 July and 17, 19 September 1997; 3 grids
were located on the prairie dog town (treatment sites) and 3 grids were located across an arroyo
approximately 50–200 m away (reference sites) (Davidson et al., 1999). Animals were presumed to not
cross this arroyo.
Feces collected from each animal were put into a solution of 2% aqueous (w/v) potassium dichro-
410 145(2)THE AMERICAN MIDLAND NATURALIST
TABLE 1.—Prevalence (%) of Eimeria spp. in fecal samples of Gunnison’s prairie dogs, Cynomys
gunnisoni, in Albuquerque (March 1997) and on the Sevilleta LTER ( July 1997) after 60 animals from
Albuquerque were relocated to an abandoned prairie dog colony on the LTER
Coccidian spp.
No. infected hosts (prevalence)
March samples
prerelocation (n 5 54)
July samples
postrelocation (n 5 23)
E. callospermophili
E. cynomysis
E. ludoviciana
E. pseudospermophili
E. spermophili
E. vilasi
Unsporulated
Multiple infections
33 (61)
2 (4)
1 (2)
3 (6)
1 (2)
39 (72)
4 (7)
25 (44)
8 (35)
—
—
—
—
2 (9)*
4 (17)
1 (4)*
All species 54/54 (100) 15/23 (65)*
* Postrelocation prevalences were significantly lower (P , 0.05) than those of prerelocation popu-
lation
mate and taken to the University of New Mexico where oocysts were allowed to sporulate; oocysts were
isolated, identified, measured and stored following Duszynski and Wilber (1997).
Prevalence (no. infected hosts/no. hosts collected) of each eimeriid species in the prairie dog and
rodent sample populations was calculated before and after relocation. A t-test (95% confidence inter-
val) for two independent binomial samples was used to assess significant change in eimeriid prevalence
between pre- and postrelocation populations (Christensen, 1996). We tested the null hypothesis for no
difference in eimerian prevelance between populations.
RESULTS
All 54 (100%) fecal samples collected from prairie dogs in Albuquerque in March and April 1997
had eimeriid oocysts (Table 1). Because no significant difference was found in eimerian prevalence
among the original three subpopulations of prairie dogs (P . 0.05), they were combined into a single
prerelocation population in later statistical analysis. Prerelocation prairie dogs had a significantly (P ,
0.05) higher prevalence of infection with coccidia than did postrelocation animals. Prevalence of Ei-
meria vilasi and of multiple infections also was significantly greater (P , 0.05) in the prerelocation
population (Table 1).
Fecal samples also were obtained from 391 individual animals of the 6 dominant species of rodents
on the Sevilleta LTER, including Dipodomys ordii (21), D. spectabilis (16), Onychomys arenicola (8),
Perognathus flavus (320; mean recapture level 5 18%), Peromyscus leucopus (14) and Reithrodontomys
megalotus (12) that were captured on 4 collection dates (March, May, July, September) (Table 2). For
a comprehensive list of all animals captured refer to Davidson et al. (1999). No oocysts were found in
samples collected from P. leucopus. Perognathus flavus was the most abundant rodent captured from
both treatment and reference sites and Eimeria reedi was the most prevalent species of coccidia ob-
served. Small sample sizes prevented analytical comparisons for March and May collections and no
significant difference was found in prevalence of E. reedi between July (4 mo postrelocation) reference
and treatment populations. In September (6 mo postrelocation), E. reedi prevalence was significantly
greater (P , 0.05) in recaptured P. flavus for the reference population than for the treatment popu-
lation. Eimeria chobatari and E. reedi oocysts were found in three of the host species in two genera;
Dipodomys ordii, D. spectabilis and P. flavus.
DISCUSSION
This survey of Cynomys gunnisoni in New Mexico documents four previously reported species of
eimeriid coccidia, Eimeria callospermophili, E. cynomysis, E. ludoviciani and E. spermophili and two spe-
2001 411NOTES AND DISCUSSION
TABLE 2.—Number of fecal samples collected, rodent species and Eimeria spp. found in those samples
from each of six rodent species captured at the Sevilleta LTER in 1997
Rodent spp.
Eimeria spp.
No. samples
with
Eimeria spp.
Rodent spp.
Eimeria spp.
No. samples
with
Eimeria spp.
Dipodomys ordii
E. chobotari
E. reedi
21
2
1
Perognathus flavus
E. chobotari
E. reedi
320
1
110
Dipodomys spectabilis
E. chobotari
E. liomysis
E. mohavensis
E. reedi
16
1
1
1
2
Both
Peromyscus leucopus
None
Onychomys arenicola
Unsporulated (one morph)
Reithrodontomys megalotis
E. arizonensis
1
14
—
8
4
12
2
cies that are new host records, E. pseudospermophili and E. vilasi. Previously, Thomas and Stanton
(1994), in Utah, found E. callospermophili (and/or E. morainensis), E. beecheyi, E. spermophili, E. bila-
mellata (later synonymized with E. cynomysis, Wilber et al., 1998), E. larimerensis and E. cynomysis
infecting C. gunnisoni.
Prevalence of infection with Eimeria species declined significantly in the postrelocation population
of Cynomys gunnisoni. Without an established population of C. gunnisoni on the Sevilleta LTER before
relocation of animals from Albuquerque, we can only postulate probable causes for this decline. Be-
cause of the short duration of this experiment it is likely these results are due to the cyclic nature of
the coccidians. However, the overall prevalence of eimerian infections dropped significantly and not
all species of Eimeria contribute equally to this phenomenon.
Of the six species of Eimeria originally found within the prairie dog samples, four were relatively
rare and were not recovered from the relocated prairie dogs. The two remaining species, E. callosper-
mophili and E. vilasi, had high prevalences within the prerelocated population that decreased after
relocation, though only E. vilasi showed a significant decrease. Seville and Stanton (1993), working
with another sciurid (Spermophilus variegatus grammurus) believed high eimerian prevalences indicated
little or no host immune response to the eimerian infection.
Wilber et al. (1994) found a sharp decline in Eimeria adaensis (5E. vilasi, Wilber et al., 1998) in
Townsend’s ground squirrels Spermophilus townsendii during summer months which is consistant with
the decline of E. vilasi in the relocated prairiedog population. However, a significant increase in E.
callospermophili also was observed, an event not seen the prairie dog population. These authors attri-
buted the patterns to aquired immunity and the seasonal weather cycle. Others have shown that the
effects of stress, such as that caused by decline in host population and changes in the environment
relating to host diet change, can regulate eimerian prevalences within a host populations (Long, 1982;
Crompton, 1987; Allen et al., 1998; Oppliger et al., 1998; Lafferty and Kuris, 1999). One or all of these
had a significant influence on the prevalences of E. callospermophili and E. vilasi in the prairie dog
population.
In addition, it is thought that differences in reproductive potentials and responses of infective oocysts
under varying abiotic conditions are mechanisms by which the prevalence of eimerian species varies
within a host population (Fuller et al., 1995; Stanton et al., 1992). This idea is important when analyzing
the decline we found in prevalences of eimeriid coccidia in prairie dog and Perognathus flavus popu-
lations. Within the sympatric rodent community, only P. flavus was caught in numbers great enough
for statistical analysis. No significant difference of the prevalences in Eimeria reedi was found between
treatment and reference recaptures until 6 mo after the prairie dog relocation. Because the effects of
species variability and host number can be accounted for, this may represent a minimal time frame
412 145(2)THE AMERICAN MIDLAND NATURALIST
necessary for an effect of disturbance, such as species introduction, to be detected on eimerian prev-
alences.
Relocation was associated with a significant decline in the coccidia fauna of the prairie dog Cynomys
gunnisoni. This study gives insight into the potential effects of relocating a population of C. gunnisoni
and, in particular, revealed no transfer of prairie dog coccidians to the resident rodent population at
the time of this study. While both Eimeria vilasi and E. callospermophili infect multiple genera within
the Marmotini tribe, they have yet to be found to cross family boundaries (Wilber et al., 1998). Future
long-term studies that include multiple control and treatment populations are necessary in order that
a comprehensive picture of this host-parasite system can be made.
Acknowledgments.—We thank A. Davidson, Dr. B. Parmenter, M. Friggens, J. Aragon, A. Leach, L.
Yau and my colleagues in the Duszynski Laboratory for their assistance. Financial support was provided
by a NSF (Biotic Survey and Inventory) Grant #DEB 9505025 to DWD. This project was supported by
the UNM Sevilleta LTER Program and is Publication No. 186 (NSF, BSR-88-11906; DEB-95-9411976).
LITERATURE CITED
ALLEN, P. C., H. D. DANFORTH AND P. C. AUGUSTINE. 1998. Dietary modulation of avian coccidiosis.
Inter. J. Parasitol., 28:1131–1140.
CHRISTENSEN, R. 1996. Analysis of variance, design, and regression: applied statistical methods, 1st ed.
Chapman and Hall, London: New York. 587 p.
CROMPTON, D. W. T. 1987. Host diet as a determinant of parasite growth, reproduction and survival.
Mammal. Rev., 17:117–126.
DAVIDSON, A. D., R. R. PARMENTER AND R. G. GOSZ. 1999. Responses of vegetation and small mammals
to a reintroduction of Gunnison’s prairie dogs. J. Mammal., 80:1311–1324.
DE VOS, A. J. 1970. Studies on the host range of Eimeria chinchillae De Vos and Van der Westhuizen,
1968. Onderstepoort J. Vet. Res., 37:29–70.
DUSZYNSKI, D. W. AND P. G. WILBER. 1997. A guidline for the preparation of species descriptions in the
Eimeriidae. J. Parasitol., 83:333–336.
FULLER, C. A., J. HEFNER AND E. WROSCH. 1995. Oocyst output, periodicity, and immunity of two deer
mouse (Peromyscus maniculatus) eimerians (Eimeria arizonensis and Eimeria delicata). J. Par-
asitol., 81:187–194.
HENDRICHS, L. D. 1977. Host range characteristics of the primate coccidian Isospora aratopitheci Rod-
hain, 1933 (Protozoa: Eimeriidae). J. Parasitol., 63:32–35.
HNIDA, J. A. AND D. W. DUSZYNKSI. 1999. Cross-transmission studies with Eimeria arizonensis, E. arizo-
nensis-like oocycst and Eimeria langebarteli: host specifictiy at the genus and species level within
the Muridae. J. Parasitol., 85:873–877.
LAFFERTY, K. D. AND A. M. KURIS. 1999. How environmental stress affects the impacts of parasites. Limn.
Oceanogr., 44:925–931.
LONG, P. L. 1982. The biology of the coccidia. University Park Press, Baltimore, Maryland. 502 p.
LONG, M. E. 1998. The vanishing prairie dog. National Geographic, 194 (April):118–130.
MILLER, B., G. CEBALLOS AND R. READING. 1994. The prairie dog and biotic diversity. Conserv. Biol., 8:
677–681.
OPPLIGER, A., J. CLOBERT, J. LECOMTE, P. LORENZON, K. BOUDJEMADI AND J. H. B. ALDER. 1998. Envi-
ronmental stress increases the prevalence and intensity of blood parasite infection in the com-
mon lizard Lacerta vivpara. Ecology Letters, 1:129–138.
SEVILLE, R. S. 1997. Eimeria spp. (Apicomplexa: Eimeriidae) from Black- and White-tailed Prairie Dogs
(Cynomys ludovicianus and Cynomys leucurus) in Central and Southeast Wyoming. J. Parasitol.,
83:166–168.
——— AND N. L. STANTON. 1993. Eimerian guilds (Apicomplexa: Eimeriidae) in Richardson’s (Sper-
mophilus richardsonii) and Wyoming (Spermophilus elegans) ground squirrels. J. Parasitol., 79:
973–975.
STANTON, N. L., L. M. SHULTS, M. PARKER AND R. S. SEVILLE. 1992. Coccidian assemblages in the
Wyoming ground squirrel, Spermophilus elegans elegans. J. Parasitol., 78:323–328.
THOMAS, D. M. AND N. L. STANTON. 1994. Eimerian species (Apicomplexa: Eimeriina) in Gunnison’s
2001 413NOTES AND DISCUSSION
prairie dogs (Cynomys gunnisoni zuniensis) and rock squirrels (Spermophilus variegatus gram-
murus) from Southeastern Utah. J. Helm. Soc. Wash., 61:17–21.
TODD, K. S., JR. AND D. M. HAMMOND. 1968a. Life cycle and host specificity of Eimeria callospermophili
Henry, 1932 from the Uinta ground squirrel Spermophilus armatus. J. Protozool., 15:1–8.
——— AND ———. 1968b. Life cycle and host specificity of Eimeria larimerensis Vetterling, 1964, from
the Uinta ground squirrel, Spermophilus armatus. J. Protozool., 15:268–275.
UPTON, S. L., C. T. MCALLISTER, D. B. BRILLHART, D. W. DUSZYNSKI AND C. W. WASH. 1992. Cross-
transmission studies with Eimeria arizonensis-like oocysts (Apicomplexa) in New World rodents
of the genera Baiomys, Neotoma, Onychomys, Peromyscus and Reithrodontomys (Muridae). J.
Parasitol., 78:406–413.
WILBER, P. G., B. HANELT, B. VAN HORNE AND D. W. DUSZYNSKI. 1994. Two new species and temporal
changes in the prevalence of eimerians in a free-living population of Townsend’s ground squir-
rels (Spermophilus townsendii) in Idaho. J. Parasitol., 80:251–259.
———, D. W. DUSZYNSKI, S. J. UPTON, R. S. SEVILLE AND J. O. CORLISS. 1998. A revision of the taxonomy
and nomenclature of the Eimeria spp. (Apicomplexa; Eimerdiidae) from rodents in the tribe
Marmotini (Sciuridae). Syst. Parasitol., 39:113–135.
M. M. RYAN1, K. H. DECKER AND D. W. DUSZYNSKI2, Department of Biology, University of New
Mexico, Albuquerque 87131.
Submitted 13 March 2000; accepted 2 October 2000.
1 Corresponding author. e-mail: mryan@unm.edu
2 e-mail: eimeria@unm.edu


https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1645&amp;context=parasitologyfacpubs

Prevalence of \u3ci\u3eEimeria\u3c/i\u3e (Apicomplexa: Eimeriidae) in Reintroduced Gunnison\u27s Prairie Dogs (\u3ci\u3eCynomys gunnisoni\u3c/i\u3e)

Abstract

Similar works

Full text

Available Versions

DigitalCommons@University of Nebraska

UNL | Libraries