European Journal of Wildlife Research

, Volume 56, Issue 3, pp 421–433 | Cite as

A monitoring program for Patagonian foxes based on power analysis

  • Alejandro Travaini
  • Alejandro Rodríguez
  • Diego Procopio
  • Sonia C. Zapata
  • Juan I. Zanón
  • Rolando Martínez-Peck
Original Paper

Abstract

Culpeo fox (Pseudalopex culpaeus) and gray fox (Pseudalopex griseus) are heavily culled in Patagonia. Fox populations seem to persist thanks to spatial refuges from which hunted areas are repopulated, following a source–sink dynamics. Sustainable use of Patagonian foxes warrants the design of a monitoring program in nature reserves and areas subjected to predator control. During 7 years, we used visitation indices to bait stations in a national park and neighboring sheep ranches of southern Argentina. We operated bait stations during three consecutive nights and calculated seven indices of relative abundance. For each fox species, we compared the power of different monitoring designs and scenarios that combined visitation indices, effort (number of bait station lines and survey frequency) while controlling for type I error, and magnitude of population change during a given period. We looked at the combinations that produced high power (β ≤ 0.24). The operation of bait stations during several nights markedly increased statistical power. Index 7 (recording visits 72 h after activation) exhibited the lowest variation and improved expected power to detect a population trend. Both fox species could be monitored simultaneously, with power >0.76 in the short term (5 years), activating 24 bait station lines. We conclude that monitoring programs for culpeo fox and gray fox based on bait stations are able to detect marked declines but are less useful to reliably detect moderate increases in abundance, especially in sheep ranches.

Keywords

Argentina Bait stations Culpeo fox Gray fox Population management Sustainable use 

References

  1. Ares J, Beeskow AM, Bertiller MB, Rostagno CM, Irisarri MP, Anchorena J, Defossé GE, Meroni CA (1990) Structural and dynamic characteristics of overgrazed lands of Northern Patagonia, Argentina. In: Bremeyer A (ed) Managed grasslands: regional studies. Elsevier, Amsterdam, pp 149–175Google Scholar
  2. Bellati J (1986) Estimación de las pérdidas por zorro colorado de corderos de 1 a 60 días de edad en el departamento de Pilcaniyeu, Río Negro. Presencia 2:43–44Google Scholar
  3. Bellati J, von Thungen J (1990) Lamb predation in Patagonian ranches. In: Davis LR, Marsh RE (eds) Proc 14th Vertebr Pest Conf. Univ California, Davis, pp 263–268Google Scholar
  4. Bertiller MB, Bisigato A (1998) Vegetation dynamics under grazing disturbance. The state-and-transition model for the Patagonian steppes. Ecol Austral 8:191–199Google Scholar
  5. Cavallini P (1994) Faeces count as an index of fox abundance. Acta Theriol 39:417–424Google Scholar
  6. Conner MC, Labisky RF, Progulske DR (1983) Scent-station indices as measures of population abundance for bobcats, raccoons, gray foxes and opossums. Wildl Soc Bull 11:146–152Google Scholar
  7. Crawley MJ (1993) GLIM for ecologists. Blackwell, OxfordGoogle Scholar
  8. Delibes M, Gaona P, Ferreras P (2001) Effects of an attractive sink leading into maladaptive habitat selection. Am Nat 158:277–285CrossRefPubMedGoogle Scholar
  9. Dexter N, Murray A (2009) The impact of fox control on the relative abundance of forest mammals in East Gippsland, Victoria. Wildl Res 36:252–261CrossRefGoogle Scholar
  10. Di Stefano J (2003) How much power is enough? Against the development of an arbitrary convention for statistical power calculations. Funct Ecol 17:707–709CrossRefGoogle Scholar
  11. Diefenbach DR, Conroy MJ, Warren RJ, James WE, Baker LA, Hon T (1994) A test of the scent-station survey technique for bobcats. J Wildl Manage 58:10–17CrossRefGoogle Scholar
  12. Elzinga C, Salzer D, Willoughby J, Gibbs JP (2001) Monitoring plant and animal populations: a handbook for field biologists. Blackwell, LondonGoogle Scholar
  13. Field SA, Tyre AJ, Possingham HP (2005) Optimizing allocation of monitoring effort under economic and observational constraints. J Wildl Manage 69:473–482CrossRefGoogle Scholar
  14. Fleming PJS, Allen LR, Lapidge SJ, Robley A, Saunders GR, Thomson PC (2006) Strategic approach to mitigating the impacts of wild canids: proposed activities of the Invasive Animals Cooperative Research Centre. Aust J Exp Agric 46:753–762CrossRefGoogle Scholar
  15. Funes MC, Novaro JA (1999) Rol de la fauna silvestre en la economía del poblador rural, provincia del Neuquén, Argentina. Rev Argent Prod Anim 19:265–271Google Scholar
  16. Geissler PH, Sauer JR (1990) Topic in route regression analysis. In: Sauer JR, Droege S (eds) Survey designs and statistical methods for the estimation of avian population trends. US Fish Wildl Serv, Biol Report 90(1), pp 54–57Google Scholar
  17. Gibbs JP (1995) Monitor: users manual. Department of Biology, Yale Univ, New HavenGoogle Scholar
  18. Gibbs JP (2000) Monitoring populations. In: Boitani L, Fuller TK (eds) Research techniques in animal ecology. Columbia Univ Press, New York, pp 213–252Google Scholar
  19. Gibbs JP, Melvin SM (1997) Power to detect trends in waterbird abundance with call-response surveys. J Wildl Manage 61:1262–1267CrossRefGoogle Scholar
  20. Gibbs JP, Droege S, Eagle P (1998) Monitoring populations of plants and animals. Bioscience 48:935–940CrossRefGoogle Scholar
  21. Gibbs JP, Snell HL, Causton E (1999) Effective monitoring for adaptive wildlife management: lessons from the Galápagos Islands. J Wildl Manage 63:1055–1065CrossRefGoogle Scholar
  22. Hagan JM, van der Haegen WM, McKinley PS (1996) The early development of forest fragmentation effects on birds. Conserv Biol 10:188–202CrossRefGoogle Scholar
  23. Harris G (1998) A guide to the birds and mammals of coastal Patagonia. Princeton Univ Press, PrincetonGoogle Scholar
  24. Harrison RL, Barr DJ, Dragoo JW (2002) A comparison of population survey techniques for swift foxes (Vulpes velox) in New Mexico. Am Midl Nat 148:320–337CrossRefGoogle Scholar
  25. Hayes JP, Steidl RJ (1997) Statistical power analysis and amphibian population trends. Conserv Biol 11:173–275CrossRefGoogle Scholar
  26. Herfindal I, Linnell JDC, Moa PF, Odden J, Austmo LB, Andersen R (2005) Does recreational hunting of lynx reduce depredation losses of domestic sheep? J Wildl Manage 69:1034–1042CrossRefGoogle Scholar
  27. Hewson R, Kolb HH (1973) Changes in the numbers and distribution of foxes (Vulpes vulpes) killed in Scotland from 1948–1970. J Zool 171:345–365CrossRefGoogle Scholar
  28. Linhart SB, Knowlton FF (1975) Determining the relative abundance of coyotes by scent station lines. Wildl Soc Bull 3:119–124Google Scholar
  29. Linscombe G, Kinler N, Wright V (1983) An analysis of scent station response in Louisiana. Proc Ann Conf Southeast Assoc Fish Wildl Agencies 37:190–200Google Scholar
  30. Lougheed LW, Breault A, Lank DB (1999) Estimating statistical power to evaluate ongoing waterfowl population monitoring. J Wildl Manage 63:1359–1369CrossRefGoogle Scholar
  31. Mapstone BD (1995) Scalable decision rules for environmental impact studies: effects size, type I, and type II errors. Ecol Appl 5:401–410CrossRefGoogle Scholar
  32. Mares MA, Ojeda RA (1984) Faunal commercialization and conservation in South America. Bioscience 34:580–584CrossRefGoogle Scholar
  33. McDonald RA, Harris S (1999) The use of trapping records to monitor populations of stoats Mustela erminea and weasels M nivalis: the importance of trapping effort. J Appl Ecol 36:679–688CrossRefGoogle Scholar
  34. Myrberget S (1988) Hunting statistics as indicators of game population size and composition. Stat J UN Econ Comm Eur 5:289–301Google Scholar
  35. Novaro AJ (1993) Culpeo foxes in Patagonia. Canid News 1:15–17Google Scholar
  36. Novaro AJ (1995) Sustainability of harvest of culpeo foxes in Patagonia. Oryx 29:18–22CrossRefGoogle Scholar
  37. Novaro AJ (1997a) Source-sink dynamics induced by hunting: case study of culpeo foxes on rangelands in Patagonia, Argentina. Dissertation, Univ Florida, GainesvilleGoogle Scholar
  38. Novaro AJ (1997b) Pseudalopex culpaeus. Mammal Spec 558:1–8CrossRefGoogle Scholar
  39. Novaro AJ, Funes MC (1994) Impact of hunting on Argentinean foxes. Canid News 2:19–20Google Scholar
  40. Novaro AJ, Funes MC, Rambeaud C, Monsalvo O (2000) Calibración del índice de estaciones odoríferas para estimar tendencias poblacionales del zorro colorado (Pseudalopex culpaeus) en Patagonia. Mastozool Neotrop 7:81–88Google Scholar
  41. Novaro JA, Funes MC, Walker RS (2005) An empirical test of source-sink dynamics induced by hunting. J Appl Ecol 42:910–920CrossRefGoogle Scholar
  42. Ojeda RA, Mares MA (1982) Conservation of South American mammals: Argentina as a paradigm. In: Mares MA, Genoways HH (eds) Mammalian biology in South America. Pymatuning Laboratory of Ecology Special Publication, vol 6. Pymatuning Laboratory of Ecology, Linesville, pp 505–521Google Scholar
  43. Olrog CH (1980) Alarmante escasez de rapaces en el sur argentino. Hornero 12:82–84Google Scholar
  44. Peterman RM (1990) The importance of reporting statistical power: the forest decline and acidic deposition example. Ecology 71:2024–2027CrossRefGoogle Scholar
  45. Redford KH, Eisenberg JF (1992) Mammals of the neotropics. The southern cone: Chile, Argentina, Uruguay, Paraguay, 2. Univ Chicago Press, ChicagoGoogle Scholar
  46. Rice CG, Rohlman J, Beecham J, Pozzanghera S (2001) Power analysis of bait station surveys in Idaho and Washington. Ursus 12:227–236Google Scholar
  47. Robinson HS, Wielgus RB, Cooley HS, Cooley SW (2008) Sink populations in carnivore management: cougar demography and immigration in a hunted population. Ecol Appl 18:1028–1037CrossRefPubMedGoogle Scholar
  48. Roughton RD, Sweeny MW (1982) Refinements in scent-station methodology for assessing trends in carnivore populations. J Wildl Manage 46:217–229CrossRefGoogle Scholar
  49. Ruette S, Stahl P, Albaret M (2003) Applying distance-sampling methods to spotlight counts of red foxes. J Appl Ecol 40:32–43CrossRefGoogle Scholar
  50. Salzer D, Salafsky N (2006) Allocation resources between taking action, assessing status, and measuring effectiveness of conservation actions. Nat Areas J 26:310–316CrossRefGoogle Scholar
  51. Sargeant GA, Johnson DH, Berg WE (1998) Interpreting carnivore scent-station surveys. J Wildl Manage 62:1235–1245CrossRefGoogle Scholar
  52. Sargeant GA, Johnson DH, Berg WE (2003) Sampling designs for carnivore scent-station surveys. J Wildl Manage 67:289–298CrossRefGoogle Scholar
  53. Smith WP, Borden DL, Endres KM (1994) Scent-station visits as an index to abundance of raccoons: an experimental manipulation. J Mammal 75:637–647CrossRefGoogle Scholar
  54. Sobrino R, Acevedo P, Escudero MA, Marco J, Gortázar C (2009) Carnivore population trends in Spanish agrosystems after the reduction in food availability due to rabbit decline by rabbit haemorrhagic disease and improved waste management. Eur J Wildl Res 55:161–165CrossRefGoogle Scholar
  55. Soriano A (1983) Deserts and semi-deserts of Patagonia. In: West NE (ed) Temperate deserts and semideserts. Elsevier, Amsterdam, pp 423–459Google Scholar
  56. Steidl RJ, Hayes JP, Schauber E (1997) Statistical power analysis in wildlife research. J Wildl Manage 61:270–279CrossRefGoogle Scholar
  57. Stem C, Margoluis R, Salafsky N, Brown M (2005) Monitoring and evaluation in conservation: a review of trends and approaches. Conserv Biol 19:295–309CrossRefGoogle Scholar
  58. Taylor BL, Gerrodette T (1993) The uses of statistical power in conservation biology: the Vaquita and northern Spotted Owl. Conserv Biol 7:489–500CrossRefGoogle Scholar
  59. Thomas L, Juanes F (1996) The importance of statistical power analysis: an example from animal behaviour. Anim Behav 52:856–859CrossRefGoogle Scholar
  60. Thomas L, Krebs CJ (1997) A review of statistical power analysis software. Bull Ecol Soc Am 78:126–139Google Scholar
  61. Thompson WL, White GC, Gowan C (1998) Monitoring vertebrate populations. Academic Press, San DiegoGoogle Scholar
  62. Travaini A, Laffitte R, Delibes M (1996) Determining the relative abundance of European red foxes by scent-station methodology. Wildl Soc Bull 24:500–504Google Scholar
  63. Travaini A, Zapata SC, Martínez-Peck R, Delibes M (2000) Percepción y actitud humanas hacia la predación de ganado ovino por el zorro colorado (Pseudalopex culpaeus) en Santa Cruz, Patagonia Argentina. Mastozool Neotrop 7:117–129Google Scholar
  64. Travaini A, Martínez-Peck R, Zapata SC (2001) Selection of odor attractants and meat delivery methods to control Culpeo foxes (Pseudalopex culpaeus) in Patagonia. Wildl Soc Bull 29:1089–1096Google Scholar
  65. Travaini A, Zapata SC, Zoratti C, Soria G, Escobar F, Aguilera G, Collavino P (2003a) Diseño de un programa de seguimiento de poblaciones de cánidos silvestres en ambientes esteparios de la Patagonia, Argentina. Acta Zool Mex 90:1–14Google Scholar
  66. Travaini A, Pereira J, Martínez-Peck R, Zapata SC (2003b) Monitoreo de zorros colorados (Pseudalopex culpaeus) y grises (Pseudalopex griseus) en Patagonia: diseño y comparación de dos métodos alternativos. Mastozool Neotrop 10:277–291Google Scholar
  67. Travaini A, Bustamante J, Rodríguez A, Zapata S, Procopio D, Pedrana J, Martínez-Peck R (2007) An integrated framework to map animal distributions in large and remote regions. Divers Distrib 13:289–298CrossRefGoogle Scholar
  68. Webbon CC, Baker PJ, Harris S (2004) Faecal density counts for monitoring changes in red fox numbers in rural Britain. J Appl Ecol 41:768–779CrossRefGoogle Scholar
  69. Zielinski WJ, Stauffer HB (1996) Monitoring Martes populations in California: survey design and power analysis. Ecol Appl 6:1254–1267CrossRefGoogle Scholar
  70. Zielinski WJ, Truex RL, Schlexer FV, Campbell LA, Carroll C (2005) Historical and contemporary distributions of carnivores in forests of the Sierra Nevada, California, USA. J Biogeogr 32:1385–1407Google Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Alejandro Travaini
    • 1
  • Alejandro Rodríguez
    • 2
  • Diego Procopio
    • 1
  • Sonia C. Zapata
    • 1
  • Juan I. Zanón
    • 1
  • Rolando Martínez-Peck
    • 1
  1. 1.Centro de Investigaciones de Puerto DeseadoUniversidad Nacional de la Patagonia Austral, CONICETPuerto DeseadoArgentina
  2. 2.Department of Conservation BiologyEstación Biológica de Doñana, CSICSevillaSpain

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