Environmental Management

, Volume 51, Issue 3, pp 786–800 | Cite as

A Strategy for Prioritizing Threats and Recovery Actions for At-Risk Species

  • Catherine R. Darst
  • Philip J. Murphy
  • Nathan W. Strout
  • Steven P. Campbell
  • Kimberleigh J. Field
  • Linda Allison
  • Roy C. Averill-Murray


Ensuring the persistence of at-risk species depends on implementing conservation actions that ameliorate threats. We developed and implemented a method to quantify the relative importance of threats and to prioritize recovery actions based on their potential to affect risk to Mojave desert tortoises (Gopherus agassizii). We used assessments of threat importance and elasticities of demographic rates from population matrix models to estimate the relative contributions of threats to overall increase in risk to the population. We found that urbanization, human access, military operations, disease, and illegal use of off highway vehicles are the most serious threats to the desert tortoise range-wide. These results suggest that, overall, recovery actions that decrease habitat loss, predation, and crushing will be most effective for recovery; specifically, we found that habitat restoration, topic-specific environmental education, and land acquisition are most likely to result in the greatest decrease in risk to the desert tortoise across its range. In addition, we have developed an application that manages the conceptual model and all supporting information and calculates threat severity and potential effectiveness of recovery actions. Our analytical approach provides an objective process for quantifying threats, prioritizing recovery actions, and developing monitoring metrics for those actions for adaptive management of any at-risk species.


Threats assessment Conservation planning Species recovery Endangered species Adaptive management Mojave desert tortoise 


  1. Abbitt RJF, Scott JM (2001) Examining differences between recovered and declining endangered species. Conserv Biol 15:1274–1284CrossRefGoogle Scholar
  2. Aipanjigul S, Jacobson SK, Flamm R (2003) Conserving manatees: knowledge, attitudes, and intentions of boaters in Tampa Bay, Florida. Conserv Biol 17:1098–1105CrossRefGoogle Scholar
  3. Averill-Murray RC, Darst CR, Field KJ, Allison LJ (2012) A new approach to conservation of the Mojave desert tortoise. Bioscience 62:893–899CrossRefGoogle Scholar
  4. Balmford A, Carey P, Kapos V, Manica A, Rodrigues ASL, Sharlemann JPW, Green RE (2009) Capturing the many dimensions of threat: comment on Salafsky et al. Conserv Biol 23:482–487CrossRefGoogle Scholar
  5. Boarman WI (2002) Threats to desert tortoise populations: a critical review of the literature. US Geological Survey, Western Ecological Research Center, Sacramento. http://www.werc.usgs.gov/ProductDetails.aspx?ID=2574. Accessed Jan 2012
  6. Boarman WI, Kristan WB (2006) Evaluation of evidence supporting the effectiveness of desert tortoise recovery actions: US geological survey scientific investigations report 2006–5143, 27 p. http://pubs.usgs.gov/sir/2006/5143/sir_2006-5143.pdf. Accessed Jan 2012
  7. Bolten AB, Crowder LB, Dodd MG, MacPherson SL, Musick JA, Schroeder BA, Witherington BE, Long KJ, Snover ML (2011) Quantifying multiple threats to endangered species: an example from loggerhead sea turtles. Front Ecol Environ 9:295–301CrossRefGoogle Scholar
  8. Brooks ML (1998) Ecology of a biological invasion: alien annual plants in the Mojave desert. Ph.D. Dissertation, University of California, Riverside. 186 pGoogle Scholar
  9. Brooks ML (2009) Spatial and temporal distribution of nonnative plants in upland areas of the Mojave desert. In: Webb RH, Fenstermaker LF, Heaton JS, Hughson DL, McDonald EV, Miller DM (eds) The Mojave desert: ecosystem processes and sustainability. University of Nevada Press, Reno, pp 101–124Google Scholar
  10. Brooks ML, Esque TC (2002) Alien plants and fire in desert tortoise (Gopherus agassizii) habitat of the Mojave and Colorado deserts. Chelonian Conserv Biol 4:330–340Google Scholar
  11. Brown DE, Minnich RA (1986) Fire and changes in creosote bush scrub of the western Sonoran desert, California. Am Midl Nat 116:411–422CrossRefGoogle Scholar
  12. Burgman MA, Ferson S, Akçakaya HR (1993) Risk assessment in conservation biology. Chapman and Hall, LondonGoogle Scholar
  13. Clark JA, Hoekstra JM, Boersma PD, Kareiva P (2002) Improving U.S. endangered species act recovery plans: key findings and recommendations of the SCB recovery plan project. Conserv Biol 16:1510–1519CrossRefGoogle Scholar
  14. Conservation Management Partnership [CMP] (2003) The open standards for the practice of conservation. CMP, Washington, DC. http://www.conservationmeasures.org. Accessed Jan 2012
  15. Cooper JC (1863) Description of Xerobates agassizii. Proc Calif Acad Sci 2:120–121Google Scholar
  16. Doak D, Kareiva P, Klepetka B (1994) Modeling population viability for the desert tortoise in the western Mojave desert. Ecol Appl 4:446–460CrossRefGoogle Scholar
  17. Donlan CJ, Wingfield DK, Crowder LB, Wilcox C (2010) Using expert opinion surveys to rank threats to endangered species: a case study with sea turtles. Conserv Biol 24:1586–1595CrossRefGoogle Scholar
  18. Doremus H, Pagel JE (2001) Why listing may be forever: perspectives on delisting under the U.S. endangered species act. Conserv Biol 15:1258–1268CrossRefGoogle Scholar
  19. Efroymson R, Jager H, Dale V, Westervelt J (2009) A framework for developing management goals for species at risk with examples from military installation in the United States. Environ Manage 44:1163–1179CrossRefGoogle Scholar
  20. General Accounting Office [GAO] (2002) Endangered species: research strategy and long-term monitoring needed for the Mojave desert tortoise recovery program. GAO-03 23, Washington DCGoogle Scholar
  21. Halpern BS, Selkoe KA, Micheli F, Kappel CV (2007) Evaluating and ranking the vulnerability of global marine ecosystems to anthropogenic threats. Conserv Biol 21:1301–1315CrossRefGoogle Scholar
  22. World Conservation Union [IUCN] (2005) Threats authority file. Version 2.1. IUCN Species Survival Commission, Cambridge, United Kingdom. http://www.iucn.org/about/work/programmes/species/red_list/resources/technical_documents/authority_files/. Accessed Jan 2012
  23. Kiker GA, Bridges TS, Varghese A, Seager TP, Linkov L (2005) Application of multicriteria decision analysis in environmental decision making. Integr Environ Assess Manage 1:95–108CrossRefGoogle Scholar
  24. Lawler JJ, Campbell S, Guerry AD, Kolozsvary MB, O’Connor RJ, Seward L (2002) The scope and treatment of threats in endangered species recovery plans. Ecol Appl 12:663–667CrossRefGoogle Scholar
  25. Malczewski J (1999) GIS and multicriteria decision analysis. Wiley, New York, p 392Google Scholar
  26. Margoluis R, Stem C, Salafsky N, Brown M (2009) Using conceptual models as a planning and evaluation tool in conservation. Eval Progr Plan 32:138–147CrossRefGoogle Scholar
  27. Martin TG, Burgman MA, Fidler F, Kuhnert PM, Low-Choy S, McBride M, Mengersen K (2012) Eliciting expert knowledge in conservation science. Conserv Biol 26:29–38CrossRefGoogle Scholar
  28. Medica PA, Bury RB, Turner FB (1975) Growth of the desert tortoise (Gopherus agassizii) in Nevada. Copeia 1975:639–643CrossRefGoogle Scholar
  29. Murphy RW, Berry KH, Edwards T, Leviton AE, Lathrop A, Riedle JD (2011) The dazed and confused identity of Agassiz’s land tortoise, Gopherus agassizii (Testudines, Testudinidae) with the description of a new species, and its consequences for conservation. ZooKeys 113:39–71CrossRefGoogle Scholar
  30. Nagy KA, Henen BT, Vyas DB (1998) Nutritional quality of native and introduced food plants of wild desert tortoises. J Herpetol 32:260–267CrossRefGoogle Scholar
  31. National Marine Fisheries Service [NMFS] (2007) Interim endangered and threatened species recovery planning guidance, ver 103. http://www.nmfs.noaa.gov/pr/pdfs/recovery/guidance.pdf. Accessed Jan 2012
  32. Oftedal OT (2002) The nutritional ecology of the desert tortoise in the Mojave and Sonoran deserts. In: Van Devender TR (ed) The Sonoran desert tortoise; natural history. Biology and conservation. University of Arizona Press, Tucson, pp 194–241Google Scholar
  33. Oftedal OT, Hillard S, Morafka DJ (2002) Selective spring foraging by juvenile desert tortoises (Gopherus agassizii) in the Mojave Desert: Evidence of an adaptive nutritional strategy. Chelonian Conserv Biol 4:341–352Google Scholar
  34. Reed JM, Fefferman N, Averill-Murray RC (2009) Vital rate sensitivity analysis as a tool for assessing management actions for the Desert Tortoise. Biol Conserv 142:2710–2717CrossRefGoogle Scholar
  35. Runge MC (2011) An introduction to adaptive management for threatened and endangered species. J Fish Wildl Manage 2:220–233CrossRefGoogle Scholar
  36. Salafsky N, Margoluis R, Redford K, Robinson JG (2002) Improving the practice of conservation: a conceptual framework and research agenda for conservation science. Conserv Biol 16:1469–1479CrossRefGoogle Scholar
  37. Salafsky N, Salzer D, Stattersfield AJ, Hilton-Taylor C, Neugarten R, Butchart SH, Collen B, Cox N, Master LL, O’Connor S, Wilkie D (2008) A standard lexicon for biodiversity conservation: unified classifications of threats and actions. Conserv Biol 22:897–911CrossRefGoogle Scholar
  38. Salafsky N, Butchart SH, Salzer D, Stattersfield AJ, Neugarten R, Hilton-Taylor C, Collen B, Master LL, O’Connor S, Wilkie D (2009) Pragmatism and practice in classifying threats: reply to Balmford et al. Conserv Biol 23:488–493CrossRefGoogle Scholar
  39. Scott JM, Goble DD, Wiens JA, Wilcove DS, Bean M, Male T (2005) Recovery of imperiled species under the endangered species act: The need for a new approach. Front Ecol Environ 3:383–389CrossRefGoogle Scholar
  40. Scott JM, Goble DD, Svancara LK, Pidgorna A (2006) By the numbers. In: Scott JM, Goble DD, Davis FW (eds) The endangered species act at thirty: renewing the conservation promise. Island Press, Washington, DC, pp 16–35Google Scholar
  41. Scott JM, Goble DD, Haines AM, Wiens JA, Neel MC (2010) Conservation-reliant species and the future of conservation. Conserv Lett 3:91–97CrossRefGoogle Scholar
  42. Starfield AM (1997) A pragmatic approach to modeling for wildlife management. J Wildl Manage 61:261–270CrossRefGoogle Scholar
  43. TNC (2000) The Five-S framework for site conservation: a practitioner’s handbook for site conservation planning and measuring conservation success. Vol I, 2nd edn. The Nature Conservancy, ArlingtonGoogle Scholar
  44. Tracy CR, Zimmerman LC, Tracy C, Dean-Bradley K, Castle K (2006) Rates of food passage in the digestive tract of young desert tortoises: Effects of body size and diet quality. Chelonian Conserv Biol 5:269–273CrossRefGoogle Scholar
  45. Turner FB, Hayden P, Burge BL, Roberson JB (1986) Egg production by the desert tortoise (Gopherus agassizii) in California. Herpetologica 42:93–104Google Scholar
  46. US Fish and Wildlife Service [USFWS] (1990) Endangered and threatened wildlife and plants; determination of threatened status for the Mojave population of the desert tortoise. Fed Reg 55:12178–12191. http://ecos.fws.gov/docs/federal_register/fr1673.pdf. Accessed Jan 2012
  47. US Fish and Wildlife Service [USFWS] (1994) Desert tortoise (Mojave population) recovery plan. US Fish and Wildlife Service, Portland. http://ecos.fws.gov/docs/recovery_plans/1994/940628.pdf. Accessed Jan 2012
  48. US Fish and Wildlife Service [USFWS] (2010) Mojave population of the desert tortoise (Gopherus agassizii) 5-year review: summary and evaluation. US Fish and Wildlife Service, Sacramento. http://ecos.fws.gov/docs/five_year_review/doc3572.DT%205Year%20Review_FINAL.pdf. Accessed Jan 2012
  49. US Fish and Wildlife Service [USFWS] (2011) Revised recovery plan for the Mojave population of the desert tortoise (Gopherus agassizii). US Fish and Wildlife Service, Sacramento. http://ecos.fws.gov/docs/recovery_plan/RRP%20for%20the%20Mojave%20Desert%20Tortoise%20-%20May%202011_1.pdf. Accessed Jan 2012

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Catherine R. Darst
    • 1
  • Philip J. Murphy
    • 2
  • Nathan W. Strout
    • 2
  • Steven P. Campbell
    • 3
  • Kimberleigh J. Field
    • 4
  • Linda Allison
    • 4
  • Roy C. Averill-Murray
    • 4
  1. 1.Desert Tortoise Recovery Office, U.S. Fish and Wildlife ServiceVenturaUSA
  2. 2.Redlands Institute, University of RedlandsRedlandsUSA
  3. 3.School of Natural Resources and the Environment, University of ArizonaTucsonUSA
  4. 4.Desert Tortoise Recovery Office, U.S. Fish and Wildlife ServiceRenoUSA

Personalised recommendations