Pacific Conservation Biology Pacific Conservation Biology Society
A journal dedicated to conservation and wildlife management in the Pacific region.
RESEARCH ARTICLE

Coyote diet patterns in the Mojave Desert: implications for threatened desert tortoises

Brian L. Cypher A B , Erica C. Kelly A , Tory L. Westall A and Christine L. Van Horn Job A
+ Author Affiliations
- Author Affiliations

A Endangered Species Recovery Program, California State University – Stanislaus, One University Circle, Turlock, CA 95382, USA.

B Corresponding author. Email: bcypher@esrp.csustan.edu

Pacific Conservation Biology - https://doi.org/10.1071/PC17039
Submitted: 21 October 2017  Accepted: 20 December 2017   Published online: 23 January 2018

Abstract

Coyotes (Canis latrans) are generalist predators and are ubiquitous in North America. Occasionally, predation by coyotes can pose a threat to populations of rare species. We assessed diet patterns of coyotes over a 5-year period (2009–14) in a region of the Mojave Desert where high predation rates on threatened desert tortoises (Gopherus agassizii) had been reported. Our goal was to identify primary food items for coyotes and to assess the importance of desert tortoises in the diet. Coyotes primarily consumed rabbits and rodents with rabbits being consumed preferentially and rodents, along with secondary foods including various birds, reptiles, arthropods, and fruits, being consumed more opportunistically. In response to low annual precipitation in the last three years of the study, dietary diversity increased, as did use of anthropogenic food items by coyotes. However, coyotes did not seem to be dependent upon anthropogenic items. Remains of desert tortoises occurred in coyote scats at low frequencies (<6%) in all years and seasons, and use of tortoises appeared to be opportunistic as use varied with tortoise abundance. In the portion of the study area where 571 translocated desert tortoises had been released in 2008, the frequencies of tortoise remains in coyote scats were markedly higher in the two years following the releases (7.5% and 8.8%, respectively). The high predation rates on tortoises reported in this area may have resulted from focussed coyote foraging efforts due to the availability of vulnerable individuals (e.g. disoriented and displaced tortoises) as well as higher tortoise densities.

Additional keywords: California, food habits, hyperpredation, Mojave Desert, precipitation, predator subsidisation, prey availability


References

Aiyadurai, A., and Jhala, Y. V. (2006). Foraging and habitat use by golden jackals (Canis aureus) in the Bhal region, Gujarat, India. Journal of the Bombay Natural History Society 103, 5–12.

Alldredge, J. R., and Ratti, J. T. (1986). Comparison of some statistical techniques for analysis of resource selection. Journal of Wildlife Management 50, 157–165.
Comparison of some statistical techniques for analysis of resource selection.CrossRef |

Allen, B. L., and Leung, L. K.-P. (2012). Assessing predation risk to threatened fauna from their prevalence in predator scats: dingoes and rodents in arid Australia. PLoS One 7, e36426.
Assessing predation risk to threatened fauna from their prevalence in predator scats: dingoes and rodents in arid Australia.CrossRef | 1:CAS:528:DC%2BC38XntlWgsrg%3D&md5=8ce95cc122a05a19086b32c6c6361685CAS |

Allen, B. L., Fleming, P. J. S., Allen, L. R., Engeman, R. M., Ballard, G., and Leung, L. K.-P. (2013). As clear as mud: a critical review of evidence for the ecological roles of Australian dingoes. Biological Conservation 159, 158–174.
As clear as mud: a critical review of evidence for the ecological roles of Australian dingoes.CrossRef |

Beasom, S. L., and Moore, R. A. (1977). Bobcat food habit response to a change in prey abundance. The Southwestern Naturalist 21, 451–457.

Bekoff, M., and Gese, E. M. (2003). Coyotes. In ‘Wild Mammals of North America: Biology, Management, and Conservation’. (Eds G. A. Feldhamer, B. C. Thompson, and J. A. Chapman.) pp. 467–481. (The Johns Hopkins University Press: Baltimore, MD.)

Berry, K. H. (1986). Incidence of gunshot deaths in desert tortoise populations in California. Wildlife Society Bulletin 14, 127–132.

Berry, K. H., Bailey, T. Y., and Anderson, K. M. (2006). Attributes of desert tortoise populations at the National Training Center, central Mojave Desert, California, USA. Journal of Arid Environments 67, 165–191.
Attributes of desert tortoise populations at the National Training Center, central Mojave Desert, California, USA.CrossRef |

Boarman, W. I. (1992). Problems with management of a native predator on a threatened species: raven predation on desert tortoises. Proceedings of the Vertebrate Pest Conference 15, 48–52.

Boarman, W. I., Patten, M. A., Camp, R. J., and Collis, S. J. (2006). Ecology of a population of subsidized predators: common ravens in the central Mojave Desert, California. Journal of Arid Environments 67, 248–261.
Ecology of a population of subsidized predators: common ravens in the central Mojave Desert, California.CrossRef |

Brower, J. E., and Zar, J. H. (1984). ‘Field and Laboratory Methods for General Ecology.’ (Wm. C. Brown Publishers: Dubuque, IA.)

Brown, J. H., and Harney, B. A. (1993). Populations and community ecology of heteromyid rodents in temperate habitats. In ‘Biology of the Heteromyidae’. American Society of Mammalogists Special Publication No. 10. (Eds H. H. Genoways and J. H. Brown.) pp. 618–651. (Brigham Young University: Provo, UT.)

Butchko, P. H. (1990). Predator control for the protection of endangered species in California. Proceedings of the Vertebrate Pest Conference 14, 237–240.

California Department of Fish and Game (2008). California species of special concern. Available at: http://www.wildlife.ca.gov/Conservation/ SSC [accessed 25 September 2017].

Clark, F. W. (1972). Influence of jackrabbit density on coyote population change. Journal of Wildlife Management 36, 343–356.
Influence of jackrabbit density on coyote population change.CrossRef |

Corbett, L. (1995). ‘The Dingo.’ (Cornell University Press: Ithaca, NY.)

Cypher, B. L., Spencer, K. A., and Scrivner, J. H. (1994). Food-item use by coyotes at the Naval Petroleum Reserves in California. The Southwestern Naturalist 39, 91–95.
Food-item use by coyotes at the Naval Petroleum Reserves in California.CrossRef |

Cypher, B. L., Warrick, G. D., Otten, M. R. M., O’Farrell, T. P., Berry, W. H., Harris, C. E., Kato, T. T., McCue, P. M., Scrivner, J. H., and Zoellick, B. W. (2000). Population dynamics of San Joaquin kit foxes at the Naval Petroleum Reserves in California. Wildlife Monographs 45, 1–43.

Danner, D. A., and Smith, N. S. (1980). Coyote home range, movement, and relative abundance near a cattle feedyard. Journal of Wildlife Management 44, 484–487.
Coyote home range, movement, and relative abundance near a cattle feedyard.CrossRef |

Delibes, M. (1980). Feeding ecology of the Spanish lynx in the Coto Doñana. Acta Theriologica 25, 309–324.
Feeding ecology of the Spanish lynx in the Coto Doñana.CrossRef |

Di Stefano, J. (2003). How much power is enough? Against the development of an arbitrary convention for statistical power calculations. Functional Ecology 17, 707–709.
How much power is enough? Against the development of an arbitrary convention for statistical power calculations.CrossRef |

Duda, J. J., Krzysik, A. J., and Freilich, J. E. (1999). Effects of drought on desert tortoise movement and activity. Journal of Wildlife Management 63, 1181–1192.
Effects of drought on desert tortoise movement and activity.CrossRef |

Errington, P. L. (1937). Food habits of Iowa red foxes during a drought summer. Ecology 18, 53–61.
Food habits of Iowa red foxes during a drought summer.CrossRef |

Esque, T. C., Nussear, K. E., and Medica, P. A. (2005). Desert tortoise translocation plan for Fort Irwin’s land expansion program at the U.S. Army National Training Center (NTC) at Fort Irwin. U.S. Geological Survey, Las Vegas, NV. Available at: https://tortoise.org/conservation/FtIrwinTranslocationPlan.pdf [accessed 4 December 2017].

Esque, T. C., Nussear, K. E., Drake, K. K., Berry, K. H., Medica, P. A., and Heaton, J. S. (2009). Amendment to Desert Tortoise Translocation Plan for Fort Irwin’s Land Expansion Program at the U.S. Army National Training Center (NTC) & Fort Irwin. U.S. Geological Survey, Las Vegas, NV. Available at: http://www.ww.w.gosolarcalifornia.org/sitingcases/genesis_solar/documents/others/testimony_centr_biological_diversity/exhibits/Exh.%20813.%20Esque%20et%20al.%202009.%20%20Amendment%20to%20DT%20trans.%20Plan.pdf [accessed 4 December 2017].

Esque, T. C., Nussear, K. E., Drake, K. K., Walde, A. D., Berry, K. H., Averill-Murray, R. C., Woodman, A. P., Boarman, W. I., Medica, P. A., Mack, J., and Heaton, J. S. (2010). Effects of subsidized predators, resource variability, and human population density on desert tortoise populations in the Mojave Desert, USA. Endangered Species Research 12, 167–177.
Effects of subsidized predators, resource variability, and human population density on desert tortoise populations in the Mojave Desert, USA.CrossRef |

Fedriani, J. M., Fuller, T. K., and Sauvajot, R. M. (2001). Does availability of anthropogenic food enhance densities of omnivorous mammals? An example with coyotes in southern California. Ecography 24, 325–331.
Does availability of anthropogenic food enhance densities of omnivorous mammals? An example with coyotes in southern California.CrossRef |

Ferrel, C. M., Leach, H. R., and Tillotson, D. R. (1953). Food habits of the coyote in California. California Fish and Game 39, 301–341.

Germano, D. J., Rathbun, G. B., and Saslaw, L. R. (2012). Effects of grazing and invasive grasses on desert vertebrates in California. Journal of Wildlife Management 76, 670–682.
Effects of grazing and invasive grasses on desert vertebrates in California.CrossRef |

Glass, B. P. (1981). ‘Key to the Skulls of North American Mammals.’ (Oklahoma State University: Stillwater, OK.)

Gross, J. E., Stoddart, L. C., and Wagner, F. H. (1974). Demographic analysis of a northern Utah jackrabbit population. Wildlife Monographs 40, 1–68.

Kelly, E. C. (2017). Desert kit fox (Vulpes macrotis arsipus) food habits and competitive interactions with coyotes (Canis latrans) in the Mojave Desert. M.Sc. Thesis, California State University, Bakersfield.

Kelt, D. A. (2011). Comparative ecology of desert small mammals: a selective review of the past 30 years. Journal of Mammalogy 92, 1158–1178.
Comparative ecology of desert small mammals: a selective review of the past 30 years.CrossRef |

Kristan, W. B., and Boarman, W. I. (2003). Spatial pattern of risk of common raven predation on desert tortoises. Ecology 84, 2432–2443.
Spatial pattern of risk of common raven predation on desert tortoises.CrossRef |

Legendre, P., and Legendre, L. (1998). ‘Numerical Ecology.’ 2nd edn. (Elsevier: Amsterdam.)

Longshore, K. M., Jaeger, J. R., and Sappington, J. M. (2003). Desert tortoise (Gopherus agassizii) survival at two eastern Mojave Desert sites: death by short-term drought? Journal of Herpetology 37, 169–177.
Desert tortoise (Gopherus agassizii) survival at two eastern Mojave Desert sites: death by short-term drought?CrossRef |

Lovich, J. E., Yackulic, C. B., Freilich, J., Agha, M., Austin, M., Meyer, K. P., Arundel, T. R., Hansen, J., Vamstad, M. S., and Root, S. A. (2014). Climatic variation and tortoise survival: has a desert species met its match? Biological Conservation 169, 214–224.
Climatic variation and tortoise survival: has a desert species met its match?CrossRef |

MacCracken, J. G., and Hansen, R. M. (1987). Coyote feeding strategies in southeastern Idaho: optimal foraging by an opportunistic predator. Journal of Wildlife Management 51, 278–285.
Coyote feeding strategies in southeastern Idaho: optimal foraging by an opportunistic predator.CrossRef |

McClure, M. F., Smith, N. S., and Shaw, W. W. (1995). Diets of coyotes near the boundary of Saguaro National Monument and Tucson, Arizona. The Southwestern Naturalist 40, 101–125.

McGee, B. K., Ballard, W. B., Nicholson, K. L., Cypher, B. L., Lemons, P. R., and Kamler, J. F. (2006). Effects of artificial escape dens on swift fox populations in northwest Texas. Wildlife Society Bulletin 34, 821–827.
Effects of artificial escape dens on swift fox populations in northwest Texas.CrossRef |

McKinney, T., and Smith, T. W. (2007). Diets of sympatric bobcats and coyotes during years of varying rainfall in central Arizona. Western North American Naturalist 67, 8–15.
Diets of sympatric bobcats and coyotes during years of varying rainfall in central Arizona.CrossRef |

Moore, G. C., and Parker, G. R. (1992). Colonization by the eastern coyote (Canis latrans). In ‘Ecology and Management of the Eastern Coyote’. (Ed. A. H. Boer.) pp. 23–38. (Wildlife Research Unit, University of New Brunswick: Fredericton, NB.)

Moore, J. A., Engeman, R. M., Smith, H. T., and Woolard, J. (2006). Gopherus polyphemus (Gopher tortoise) coyote predation. Herpetological Review 37, 78–79.

Moore, T. D., Spencer, L. E., and Dugnolle, C. E. (1974). Identification of the dorsal guard hairs of some mammals of Wyoming. Wyoming Game and Fish Department Bulletin 14, 1–177.

Nagy, K. A., and Medica, P. A. (1986). Physiological ecology of desert tortoises in southern Nevada. Herpetologica 42, 73–92.

Otten, M. R. M., and Holmstead, G. L. (1996). Effect of seeding burned lands on the abundance of rodents and leporids on Naval Petroleum Reserve No. 1, Kern County, California. The Southwestern Naturalist 41, 129–135.

Page, G. W., Stenzel, L. E., Winkler, D. W., and Swarth, C. W. (1983). Spacing out at Mono Lake: breeding success, nest density, and predation in the snowy plover. The Auk 100, 13–24.

Palmer, R., and Fairall, N. (1988). Caracal and African wild cat diet in the Karoo National Park and the implications thereof for hyrax. South African Journal of Wildlife Research 18, 30–34.

Paltridge, R. (2002). The diets of cats, foxes and dingoes in relation to prey availability in the Tanami Desert, Northern Territory. Wildlife Research 29, 389–403.
The diets of cats, foxes and dingoes in relation to prey availability in the Tanami Desert, Northern Territory.CrossRef |

Peterson, C. C. (1994). Different rates and causes of high mortality in two populations of the threatened desert tortoise Gopherus agassizii. Biological Conservation 70, 101–108.
Different rates and causes of high mortality in two populations of the threatened desert tortoise Gopherus agassizii.CrossRef |

Pianka, E. R. (1978). ‘Evolutionary Ecology.’ (Harper and Row Publishers: New York.)

Riedle, J. D., Averill-Murray, R. C., and Grandmaison, D. D. (2010). Seasonal variation in survivorship and mortality of desert tortoises in the Sonoran Desert, Arizona. Journal of Herpetology 44, 164–167.
Seasonal variation in survivorship and mortality of desert tortoises in the Sonoran Desert, Arizona.CrossRef |

Roest, A. I. (1986). ‘A Key-guide to Mammal Skulls and Lower Jaws.’ (Mad River Press: Eureka, CA.)

Rotenberry, J. T., and Wiens, J. A. (1985). Statistical power analysis and community-wide patterns. American Naturalist 125, 164–168.
Statistical power analysis and community-wide patterns.CrossRef |

Scherer, R. D., and Tracey, J. A. (2011). A power analysis for the use of counts of egg masses to monitor wood frog (Lithobates sylvaticus) populations. Herpetological Conservation and Biology 6, 81–90.

Spencer, E. E., Newsome, T. M., and Dickman, C. R. (2017). Prey selection and dietary flexibility of three species of mammalian predator during an irruption of non-cyclic prey. Royal Society Open Science 4, 170317.
Prey selection and dietary flexibility of three species of mammalian predator during an irruption of non-cyclic prey.CrossRef |

Steidl, R. J., Hayes, J. P., and Schauber, E. (1997). Statistical power analysis in wildlife research. Journal of Wildlife Management 61, 270–279.
Statistical power analysis in wildlife research.CrossRef |

Stephens, D. W., and Krebs, J. R. (1986). ‘Foraging Theory.’ (Princeton University Press: Princeton, NJ.)

Taylor, B. L., and Gerrodette, T. (1993). The uses of statistical power in conservation biology: the vaquita and northern spotted owl. Conservation Biology 7, 489–500.
The uses of statistical power in conservation biology: the vaquita and northern spotted owl.CrossRef |

Turner, R. M. (1994). Mojave desert scrub. In ‘Biotic Communities, Southwestern United States and Northwestern Mexico’. (Ed. D. E. Brown.) pp. 157–168. (University of Utah Press: Salt Lake City, UT.)

Turner, F. B., Medica, P. A., and Lyons, C. L. (1984). Reproduction and survival of the desert tortoise (Scaptochelys agassizii) in Ivanpah Valley, California. Copeia 1984, 811–820.
Reproduction and survival of the desert tortoise (Scaptochelys agassizii) in Ivanpah Valley, California.CrossRef |

US Climate Data (2014). Precipitation data for Barstow, CA. Available at: http://www.usclimatedata.com/climate/barstow/california/united-states/usca0069/2014/8 [accessed 4 December 2017].

US Fish and Wildlife Service (1994). Desert tortoise (Mojave population) recovery plan. U.S. Fish and Wildlife Service, Portland, Oregon. Available at: https://www.fws.gov/nevada/desert_tortoise/documents/recovery_plan/1994_dtrp.pdf [accessed 4 December 2017].

US Fish and Wildlife Service (2007). Western snowy plover (Charadrius alexandrinus nivosus) Pacific coast population recovery plan. U.S. Fish and Wildlife Service, Sacramento, California. Available at: https://www.fws.gov/carlsbad/SpeciesStatusList/RP/20070813_RP_WSP.pdf [accessed 4 December 2017].

US Fish and Wildlife Service (2011). Revised recovery plan for the Mojave population of the desert tortoise (Gopherus agassizii). U.S. Fish and Wildlife Service, Sacramento, California. Available at: http://www.fwspubs.org/doi/suppl/10.3996/022015-JFWM-013/suppl_file/022015-jfwm-013.s7.pdf?code=ufws-site [accessed 4 December 2017].

US Fish and Wildlife Service (2016). Range-wide monitoring of the Mojave Desert tortoise (Gopherus agassizii): 2015 and 2016 annual reporting. Report by the Desert Tortoise Recovery Office, U.S. Fish and Wildlife Service, Reno, Nevada. Available at: https://www.fws.gov/nevada/desert_tortoise/documents/reports/2015/201516_rangewide-mojave-desert-tortoise-monitoring.pdf [accessed 4 December 2017].

Voigt, D. R., and Berg, W. E. (1987). Coyote. In ‘Wild Furbearer Management and Conservation in North America’. (Eds M. Novak, J. A. Baker, M. E. Obbard and B. Malloch.) pp. 344–357. (Ontario Ministry of Natural Resources: Toronto, ON.)

Whitford, W. G., and Creusere, F. M. (1977). Seasonal and yearly fluctuations in Chihuahuan Desert lizard communities. Herpetologica 33, 54–65.

Woodbury, A. M., and Hardy, R. (1948). Studies of the desert tortoise, Gopherus agassizii. Ecological Monographs 18, 145–200.
Studies of the desert tortoise, Gopherus agassizii.CrossRef |

Young, J. A., and Young, C. G. (1992). ‘Seeds of Woody Plants in North America.’ (Dioscorides Press: Portland, OR.)

Zar, J. H. (1984). ‘Biostatistical Analysis.’ 2nd edn. (Prentice-Hall: Englewood Cliffs, NJ.)

Zimmerman, L. C., O’Connor, M. P., Bulova, S. J., Spotila, J. R., Kemp, S. J., and Salice, C. J. (1994). Thermal ecology of desert tortoises in the eastern Mojave Desert: seasonal patterns of operative and body temperatures, and microhabitat utilization. Herpetological Monograph 8, 45–59.
Thermal ecology of desert tortoises in the eastern Mojave Desert: seasonal patterns of operative and body temperatures, and microhabitat utilization.CrossRef |



Export Citation