Oecologia

, Volume 172, Issue 1, pp 129–140 | Cite as

Variability in temporary emigration rates of individually marked female Weddell seals prior to first reproduction

  • Glenn E. Stauffer
  • Jay J. Rotella
  • Robert A. Garrott
Population ecology - Original research

Abstract

In many species, temporary emigration (TE) is a phenomenon, often indicative of life-history characteristics such as dormancy, skipped reproduction, or partial migration, whereby certain individuals in a population are temporarily unobservable at a particular site. TE may be a flexible condition-dependent strategy that allows individuals to mitigate effects of adverse conditions. Consequently, TE rates ought to be highly variable, but sources of variations are poorly understood for most species. We used data from known-aged female Weddell seals (Leptonychotes weddellii) tagged in Erebus Bay, Antarctica, to investigate sources of variation in TE rates prior to reproduction and to evaluate possible implications for age-specific probability of first reproduction. TE rates were near 1 the year after birth, decreased to an average of 0.15 (\( \widehat{\text{SE}} \) = 0.01) by age 8, and were similar thereafter. TE rates varied substantially from year-to-year and were lower for seals that attended reproductive colonies the previous year than for seals that did not attend (e.g., \( \overline{{\hat{\psi }_{{i,{\text{age}}\,8}}^{\text{UU}} - \hat{\psi }_{{i,\,{\text{age}}\,8}}^{\text{PU}} }} \) = 0.22). Recruitment rates were marginally greater for seals that did attend than for seals that did not attend colonies the previous year. For Weddell seals specifically, our results suggest that (1) motivation to attend colonies varied temporally, (2) as seals grew older they had increased motivation to attend even before reproductive maturity, and (3) seals appear to follow various attendance strategies. More broadly, our results support the idea of TE as a variable, condition-dependent strategy, and highlight the utility of TE models for providing population and life-history insights for diverse taxa.

Keywords

Capture–mark–recapture Colonial breeding Condition-dependent Leptonychotes weddellii Open robust design Recruitment Social learning Trade-offs Unobservable states 

Supplementary material

442_2012_2472_MOESM1_ESM.pdf (869 kb)
Supplementary material 1 (PDF 868 kb)

References

  1. Ainley DG (2002) The Ross Sea, Antarctica, where all ecosystem processes still remain for study, but maybe not for long. Mar Ornithol 30:55–62Google Scholar
  2. Arrigo KR, van Dijken GL (2003) Impact of iceberg C-19 on Ross Sea primary production. Geophys Res Lett. doi:10.1029/2003GL017721 Google Scholar
  3. Arrigo KR, van Dijken GL, Ainley DG, Fahnestock MA, Markus T (2002) Ecological impact of a large Antarctic iceberg. Geophys Res Lett. doi:10.1029/2001GL014160 Google Scholar
  4. Aubry LM, Koons DN, Monnat J-Y, Cam E (2009) Consequences of recruitment decisions and heterogeneity on age-specific breeding success in a long-lived seabird. Ecology 90:2491–2502. doi:10.1890/08-1475.1 PubMedCrossRefGoogle Scholar
  5. Bailey LL, Kendall WL, Church DR, Wilbur HM (2004) Estimating survival and breeding probability for pond-breeding amphibians: a modified robust design. Ecology 85:2456–2466. doi:10.1890/03-0539 CrossRefGoogle Scholar
  6. Bailey LL, Converse SJ, Kendall WL (2010) Bias, precision, and parameter redundancy in complex multistate models with unobservable states. Ecology 91:1598–1604. doi:10.1890/09-1633.1 PubMedCrossRefGoogle Scholar
  7. Baker JD, Thompson PM (2007) Temporal and spatial variation in age-specific survival rates of a long-lived mammal, the Hawaiian monk seal. Proc R Soc Lond B 274:407–415. doi:10.1098/rspb.2006.3737 CrossRefGoogle Scholar
  8. Beauplet G, Barbraud C, Chambellant M, Guinet C (2005) Interannual variation in the post-weaning and juvenile survival of subantarctic fur seals: influence of pup sex, growth rate and oceanographic conditions. J Anim Ecol 74:1160–1172. doi:10.1111/j.1365-2656.2005.01016.x CrossRefGoogle Scholar
  9. Beauplet G, Barbraud C, Dabin W, Küssener C, Guinet C (2006) Age-specific survival and reproductive performances in fur seals: evidence of senescence and individual quality. Oikos 112:430–441. doi:10.1111/j.0030-1299.2006.14412.x CrossRefGoogle Scholar
  10. Bjorndal KA, Bolten AB, Dellinger T, Delgado C, Martins HR (2003) Compensatory growth in oceanic loggerhead sea turtles: response to a stochastic environment. Ecology 84:1237–1249. doi:10.1890/0012-9658(2003)084[1237:CGIOLS]2.0.CO;2 CrossRefGoogle Scholar
  11. Boyle WA (2008) Partial migration in birds: tests of three hypotheses in a tropical lekking frugivore. J Anim Ecol 77:1122–1128. doi:10.1111/j.1365-2656.2008.01451.x PubMedCrossRefGoogle Scholar
  12. Bradford AL, Wade PR, Weller DW, Burdin AM, Ivashchenko YV, Tsidulko GA, VanBlaricom GR, Brownell RLB Jr (2006) Survival estimates of western gray whales Eschrichtius robustus incorporating individual heterogeneity and temporary emigration. Mar Ecol Prog Ser 315:293–307. doi:10.3354/meps315293 CrossRefGoogle Scholar
  13. Brierley AS, Fernandes PG, Brandon MA, Armstrong F, Millard NW, McPhail SD, Stevenson P, Pebody M, Perrett J, Squires M, Bone DG, Griffiths G (2002) Antarctic krill under sea ice: elevated abundance in a narrow band just south of ice edge. Science 295:1890–1892. doi:10.1126/science.1068574 PubMedCrossRefGoogle Scholar
  14. Brodersen J, Nilsson PA, Hansson L-A, Skov C, Brönmark C (2008) Condition-dependent individual decision-making determines cyprinid partial migration. Ecology 89:1195–1200. doi:10.1890/07-1318.1 PubMedCrossRefGoogle Scholar
  15. Burnham KP, Anderson DR (2002) Model Selection and Multimodel Inference; A Practical Information-theoretic Approach, 2nd edn. Springer, New YorkGoogle Scholar
  16. Cam E, Monnat J-Y, Hines JE (2003) Long-term fitness consequences of early conditions in the kittiwake. J Anim Ecol 72:411–424. doi:10.1046/j.1365-2656.2003.00708.x CrossRefGoogle Scholar
  17. Cameron MF, Siniff DB (2004) Age-specific survival, abundance, and immigration rates of a Weddell seal (Leptonychotes weddellii) population in McMurdo Sound, Antarctica. Can J Zool 82:601–615. doi:10.1139/z04-025 CrossRefGoogle Scholar
  18. Cameron MF, Siniff DB, Proffitt KM, Garrott RA (2007) Site fidelity of Weddell seals: the effects of sex and age. Antarct Sci 19:149–155. doi:10.1017/S0954102007000223 CrossRefGoogle Scholar
  19. Conn PB, Cooch EG (2009) Multistate capture–recapture analysis under imperfect state observation: an application to disease models. J Appl Ecol 46:486–492. doi:10.1111/j.1365-2664.2008.01597.x CrossRefGoogle Scholar
  20. Converse SJ, Kendall WL, Doherty PF, Ryan PG (2009) Multistate models for estimation of survival and reproduction in the grey-headed albatross (Thalassarche chrysostoma). Auk 126:77–88. doi:10.1525/auk.2009.07189 CrossRefGoogle Scholar
  21. Crespin L, Harris MP, Lebreton J-D, Frederiksen M, Wanless S (2006) Recruitment to a seabird population depends on environmental factors and on population size. J Anim Ecol 75:228–238. doi:10.1111/j.1365-2656.2006.01035.x PubMedCrossRefGoogle Scholar
  22. Danchin E, Giraldeau L-A, Valone TJ, Wagner RH (2004) Public information: from nosy neighbors to cultural evolution. Science 305:487–491. doi:10.1126/science.1098254 PubMedCrossRefGoogle Scholar
  23. de Bruyn PJN, Tosh CA, Bester MN, Cameron EZ, McIntyre T, Wilkinson IS (2011) Sex at sea: alternative mating system in an extremely polygynous mammal. Anim Behav 82:445–451. doi:10.1016/j.anbehav.2011.06.006 CrossRefGoogle Scholar
  24. Deutsch JC, Nefdt RJC (1992) Olfactory cues influence female choice in two lek-breeding antelopes. Nature 356:596–598. doi:10.1038/356596a0 PubMedCrossRefGoogle Scholar
  25. Dingle H (1996) Migration: The Biology of Life on the Move. Oxford University Press, New YorkGoogle Scholar
  26. Dobson FS, Jones WT (1985) Multiple causes of dispersal. Am Nat 126:855–858CrossRefGoogle Scholar
  27. Doherty PF, White GC, Burnham KP (2010) Comparison of model building and selection strategies. J Ornithol. doi:10.1007/s10336-010-0598-5 Google Scholar
  28. Doligez B, Danchin E, Clobert J (2002) Public information and breeding habitat selection in a wild bird population. Science 297:1168–1170. doi:10.1126/science.1072838 PubMedCrossRefGoogle Scholar
  29. Dugger KM, Ainley DG, Lyver PO, Barton K, Ballard G (2010) Survival differences and the effect of environmental instability on breeding dispersal in an Adélie penguin meta-population. Proc Natl Acad Sci USA 107:12375–12380. doi:10.1073/pnas.1000623107 PubMedCrossRefGoogle Scholar
  30. Eisert R, Oftedal OT, Lever M, Ramdohr S, Breier BH, Barrell GK (2005) Detection of food intake in a marine mammal using marine osmolytes and their analogues as dietary biomarkers. Mar Ecol Prog Ser 300:213–228. doi:10.3354/meps300213 CrossRefGoogle Scholar
  31. Forcada J, Trathan PN, Murphy EJ (2008) Life history buffering in Antarctic mammals and birds against changing patterns of climate and environmental variation. Glob Change Biol 14:2473–2488. doi:10.1111/j.1365-2486.2008.01678.x Google Scholar
  32. Forchhammer MC, Clutton-Brock TH, Lindström J, Albon SD (2001) Climate and population density induce long-term cohort variation in a northern ungulate. J Anim Ecol 70:721–729. doi:10.1046/j.0021-8790.2001.00532.x CrossRefGoogle Scholar
  33. Frederiksen M, Bregnballe T (2000) Diagnosing a decline in return rate of 1-year-old cormorants: mortality, emigration or delayed return? J Anim Ecol 69:753–761. doi:10.1046/j.1365-2656.2000.00436.x CrossRefGoogle Scholar
  34. Fujiwara M, Caswell H (2002) A general approach to temporary emigration in mark-recapture analysis. Ecology 83:3266–3275. doi:10.1890/0012-9658(2002)083[3266:AGATTE]2.0.CO;2 Google Scholar
  35. Gaillard J-M, Boutin J-M, Delorme D, Van Laere G, Duncan P, Lebreton J-D (1997) Early survival in roe deer: causes and consequences of cohort variation in two contrasted populations. Oecologia 112:502–513CrossRefGoogle Scholar
  36. Garrott RA, Rotella JJ, Siniff DB, Parkinson CL, Stauffer GE (2012) Environmental variation and cohort effects in an Antarctic predator. Oikos 121:1027–1040. doi:10.1111/j.1600-0706.2011.19673.x CrossRefGoogle Scholar
  37. Gelatt TS, Davis CS, Siniff DB, Strobeck C (2001) Molecular evidence for twinning in Weddell seals (Leptonychotes weddellii). J Mammal 82:491–499. doi:10.1644/1545-1542(2001)082<0491:MEFTIW>2.0.CO;2 CrossRefGoogle Scholar
  38. Hadley GL, Rotella JJ, Garrott RA, Nichols JD (2006) Variation in probability of first reproduction of Weddell seals. J Anim Ecol 75:1058–1070. doi:10.1111/j.1365-2656.2006.01118.x PubMedCrossRefGoogle Scholar
  39. Hadley GL, Rotella JJ, Garrott RA (2007a) Influence of maternal characteristics and oceanographic conditions on survival and recruitment probabilities of Weddell seals. Oikos 116:601–613. doi:10.1111/j.0030-1299.2007.15528.x CrossRefGoogle Scholar
  40. Hadley GL, Rotella JJ, Garrott RA (2007b) Evaluation of reproductive costs for Weddell seals in Erebus Bay, Antarctica. J Anim Ecol 76:448–458. doi:10.1111/j.1365-2656.2007.01219.x PubMedCrossRefGoogle Scholar
  41. Hindell MA (1991) Some life-history parameters of a declining population of southern elephant seals, Mirounga leonina. J Anim Ecol 60:119–134. doi:10.2307/5449 CrossRefGoogle Scholar
  42. Holyoak M, Casagrandi R, Nathan R, Revilla E, Spiegel O (2008) Trends and missing parts in the study of movement ecology. Proc Natl Acad Sci USA 105:19060–19065. doi:10.1073/pnas.0800483 PubMedCrossRefGoogle Scholar
  43. Hoover JP (2003) Decision rules for site fidelity in a migratory bird, the prothonotary warbler. Ecology 84:416–430. doi:10.1890/0012-9658(2003)084[0416:DRFSFI]2.0.CO;2 CrossRefGoogle Scholar
  44. Ims RA, Hjermann DØ (2001) Condition-dependent dispersal. In: Clobert J, Danchin E, Dhondt AA, Nichols JD (eds) Dispersal. Oxford University Press, New York, pp 452–465Google Scholar
  45. Jahn AE, Levey DJ, Hostetler JA, Mamani AM (2010) Determinants of partial bird migration in the Amazon Basin. J Anim Ecol 79:983–992. doi:10.1111/j.1365-2656.2010.01713.x PubMedCrossRefGoogle Scholar
  46. Kendall WL (2004) Coping with unobservable and mis-classified states in capture-recapture studies. Anim Biodivers Cons 27:97–107Google Scholar
  47. Kendall WL (2006) The Robust Design. In: Cooch EG, White GC (eds) Program MARK: A Gentle Introduction, 9th edn. http://www.phidot.org/software/mark/docs/book/
  48. Kendall WL, Bjorkland R (2001) Using open robust design models to estimate temporary emigration from capture-recapture data. Biometrics 57:1113–1122. doi:10.1111/j.0006-341X.2001.01113.x PubMedCrossRefGoogle Scholar
  49. Kendall WL, Nichols JD (2002) Estimating state-transition probabilities for unobservable states using capture-recapture/resighting data. Ecology 83:3276–3284. doi:10.1890/0012-9658(2002)083[3276:ESTPFU]2.0.CO;2 Google Scholar
  50. Kendall WL, Nichols JD, Hines JE (1997) Estimating temporary emigration using capture–recapture data with Pollock’s robust design. Ecology 78:563–578. doi:10.1890/0012-9658(1997)078[0563:ETEUCR]2.0.CO;2 Google Scholar
  51. Kéry M, Gregg KB, Schaub M (2005) Demographic estimation methods for plants with unobservable life-states. Oikos 108:307–320. doi:10.1111/j.0030-1299.2005.13589.x CrossRefGoogle Scholar
  52. Kooyman GL, Ainley DG, Ballard G, Ponganis PJ (2007) Effects of giant icebergs on two emperor penguin colonies in the Ross Sea, Antarctica. Antarct Sci 19:31–38. doi:10.1017/S0954102007000065 CrossRefGoogle Scholar
  53. Laake JL (2010) RMark: R Code for MARK Analysis. R package version 1.9.6Google Scholar
  54. Lake SE, Burton HR, Barker RJ, Hindell MA (2008) Annual reproductive rates of Weddell seals in eastern Antarctica from 1973 to 2000. Mar Ecol Prog Ser 366:259–270. doi:10.3354/meps07502 CrossRefGoogle Scholar
  55. Langtimm CA (2009) Non-random temporary emigration and the robust design: conditions for bias at the end of a time series. Environ Ecol Stat 3:745–761. doi:10.1007/978-0-387-78151-8_34 Google Scholar
  56. Langvatn R, Mysterud A, Stenseth NC, Yoccoz NG (2004) Timing and synchrony of ovulation in red deer constrained by short northern summers. Am Nat 163:763–772. doi:10.1086/383594 PubMedCrossRefGoogle Scholar
  57. Laws RM (1956) Growth and sexual maturity in aquatic mammals. Nature 178:193–194. doi:10.1038/178193a0 CrossRefGoogle Scholar
  58. Lebreton JD, Burnham KP, Clobert J, Anderson DR (1992) Modeling survival and testing biological hypotheses using marked animals—a unified approach with case-studies. Ecol Monogr 62:67–118CrossRefGoogle Scholar
  59. Lebreton J-D, Nichols JD, Barker RJ, Pradel R, Spendelow JA (2009) Modeling individual animal histories with multistate capture-recapture models. Adv Ecol Res 41:87–173. doi:10.1016/S0065-2504(09)00403-6 CrossRefGoogle Scholar
  60. Lescroël A, Ballard G, Toniolo V, Barton KJ, Wilson PR, Lyver POB, Ainley DG (2010) Working less to gain more: when breeding quality relates to foraging efficiency. Ecology 91:2044–2055. doi:10.1890/09-0766.1 PubMedCrossRefGoogle Scholar
  61. Lindström J (1999) Early development and fitness in birds and mammals. Trends Ecol Evol 14:343–348. doi:10.1016/S0169-5347(99)01639-0 PubMedCrossRefGoogle Scholar
  62. Lunn NJ, Boyd IL, Croxall JP (1994) Reproductive performance of female Antarctic fur seals: the influence of age, breeding experience, environmental variation and individual quality. J Anim Ecol 63:827–840CrossRefGoogle Scholar
  63. McClintock MK (1978) Estrous synchrony and its mediation by airborne chemical communication (Rattus norvegicus). Horm Behav 10:264–276. doi:10.1016/0018-506X(78)90071-5 PubMedCrossRefGoogle Scholar
  64. McMahon TE, Matter WJ (2006) Linking habitat selection, emigration and population dynamics of freshwater fishes: a synthesis of ideas and approaches. Ecol Freshw Fish 15:200–210. doi:10.1111/j.1600-0633.2006.00130.x CrossRefGoogle Scholar
  65. McMahon CR, Burton HR, Bester MN (2003) A demographic comparison of two southern elephant seal populations. J Anim Ecol 72:61–74. doi:10.1046/j.1365-2656.2003.00685.x CrossRefGoogle Scholar
  66. Muths E, Scherer RD, Corn PS, Lambert BA (2006) Estimation of temporary emigration in male toads. Ecology 87:1048–1056. doi:10.1890/0012-9658(2006)87[1048:EOTEIM]2.0.CO;2 PubMedCrossRefGoogle Scholar
  67. Nevoux M, Barbraud C (2005) Relationships between sea ice concentration, sea surface temperature and demographic traits of thin-billed prions. Polar Biol 29:445–453. doi:10.1007/s00300-005-0075-4 CrossRefGoogle Scholar
  68. Nevoux M, Barbraud C (2006) Do demographic responses to climate change depend on life history strategies? J Ornithol 147:25Google Scholar
  69. Nichols JD, Kaiser A (1999) Quantitative studies of bird movement: a methodological review. Bird Study 46:S289–S298. doi:10.1080/00063659909477256 CrossRefGoogle Scholar
  70. Pfister CA (1998) Patterns of variance in stage-structured populations: evolutionary predictions and ecological implications. Proc Natl Acad Sci USA 95:213–218PubMedCrossRefGoogle Scholar
  71. Pomeroy PP, Anderson SS, Twiss SD, McConnell BJ (1994) Dispersion and site fidelity of breeding female grey seals (Halichoerus grypus) on North Rona, Scotland. J Zool 233:429–447. doi:10.1111/j.1469-7998.1994.tb05275.x CrossRefGoogle Scholar
  72. Proffitt KM, Garrott RA, Rotella JJ (2008) Long-term evaluation of body mass at weaning and postweaning survival rates of Weddell seals in Erebus Bay, Antarctica. Mar Mammal Sci 24:677–689. doi:10.1111/j.1748-7692.2008.00207.x CrossRefGoogle Scholar
  73. R Development Core Team (2012) R: A language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria. ISBN 3-900051-07-0. URL http://www.R-project.org
  74. Reid JM, Bignal EM, Bignal S, McCracken DI, Monaghan P (2003) Environmental variability, life-history covariation and cohort effects in the red-billed chough Pyrrhocorax pyrrhocorax. J Anim Ecol 72:36–46. doi:10.1046/j.1365-2656.2003.00673.x CrossRefGoogle Scholar
  75. Remy J-P, Becquevort S, Haskell TG, Tison J-L (2008) Impact of the B-15 iceberg “stranding event” on the physical and biological properties of sea ice in McMurdo Sound, Ross Sea, Antarctica. Antarct Sci 20:593–604. doi:10.1017/S0954102008001284 CrossRefGoogle Scholar
  76. Rivalan P, Prévot-Julliard A-C, Choquet R, Pradel R, Jacquemin B, Girondot M (2005) Trade-off between current reproductive effort and delay to next reproduction in the leatherback sea turtle. Oecologia 145:564–574. doi:10.1007/s00442-005-0159-4 PubMedCrossRefGoogle Scholar
  77. Rödel HG, von Holst D, Kraus C (2009) Family legacies: short- and long-term fitness consequences of early-life conditions in female European rabbits. J Anim Ecol 78:789–797. doi:10.1111/j.1365-2656.2009.01537.x PubMedCrossRefGoogle Scholar
  78. Rotella JJ, Link WA, Nichols JD, Hadley GL, Garrott RA, Proffitt KM (2009) An evaluation of density-dependent and density-independent influences on population growth rates in Weddell seals. Ecology 90:975–984. doi:10.1890/08-0971.1 PubMedCrossRefGoogle Scholar
  79. Rotella JJ, Link WA, Chambert T, Stauffer GE, Garrott RA (2012) Evaluating the demographic buffering hypothesis with vital rates estimated for Weddell seals from 30 years of mark–recapture data. J Anim Ecol 81:162–173. doi:10.1111/j.1365-2656.2011.01902.x PubMedCrossRefGoogle Scholar
  80. Schaub M, Gimenez O, Schmidt BR, Pradel R (2004) Estimating survival and temporary emigration in the multistate capture-recapture framework. Ecology 85:2107–2113. doi:10.1890/03-3110 CrossRefGoogle Scholar
  81. Schjørring S, Gregersen J, Bregnballe T (1999) Prospecting enhances breeding success of first-time breeders in the great cormorant, Phalacrocorax carbo sinensis. Anim Behav 57:647–654. doi:10.1006/anbe.1998.0993 PubMedCrossRefGoogle Scholar
  82. Schwarz CJ, Stobo WT (1997) Estimating temporary migration using the robust design. Biometrics 53:178–194CrossRefGoogle Scholar
  83. Siniff DB, DeMaster DP, Hofman RJ, Eberhardt LL (1977) An analysis of the dynamics of a Weddell seal population. Ecol Monogr 47:319–335. doi:10.2307/1942520 CrossRefGoogle Scholar
  84. Stirling I (1969) Ecology of the Weddell seal in McMurdo Sound, Antarctica. Ecology 50:573–586. doi:10.2307/1936247 CrossRefGoogle Scholar
  85. Sydeman WJ, Huber HR, Emslie SD, Ribic CA, Nur N (1991) Age-specific weaning success of northern elephant seals in relation to previous breeding experience. Ecology 72:2204–2217. doi:10.2307/1941571 CrossRefGoogle Scholar
  86. Testa JW (1994) Over-winter movements and diving behavior of female Weddell seals (Leptonychotes weddellii) in the southwestern Ross Sea, Antarctica. Can J Zool 72:1700–1710. doi:10.1139/z94-229 CrossRefGoogle Scholar
  87. Testa JW, Siniff DB (1987) Population dynamics of Weddell seals (Leptonychotes weddellii) in McMurdo Sound, Antarctica. Ecol Monogr 57:149–165. doi:10.2307/1942622 CrossRefGoogle Scholar
  88. Testa JW, Siniff DB, Ross MJ, Winter JD (1985) Weddell seal—Antarctic cod interactions in McMurdo Sound. In: Siegfried WR, Condy PR, Laws RM (eds) Antarctic nutrient cycles and food webs. Proceedings of the 4th SCAR Symposium on Antarctic Biology. Springer, New York, pp 561–565Google Scholar
  89. White GC, Burnham KP (1999) Program MARK: survival estimation from populations of marked animals. Bird Study 46 (Suppl):120–138CrossRefGoogle Scholar
  90. White PJ, Davis TL, Barnowe-Meyer KK, Crabtree RL, Garrott RA (2007) Partial migration and philopatry of Yellowstone pronghorn. Biol Conserv 135:502–510. doi:10.1016/j.biocon.2006.10.041 CrossRefGoogle Scholar
  91. Williams BK, Nichols JD, Conroy MJ (2002) Analysis and management of animal populations; modeling, estimation, and decision making. Academic, San DiegoGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Glenn E. Stauffer
    • 1
  • Jay J. Rotella
    • 1
  • Robert A. Garrott
    • 1
  1. 1.Department of EcologyMontana State UniversityBozemanUSA

Personalised recommendations