Conservation Genetics

, Volume 9, Issue 2, pp 247–255 | Cite as

Effects of poaching on bull mating success in a free ranging African elephant (Loxodonta africana) population in Tarangire National Park, Tanzania

  • D. R. S. Ishengoma
  • A. M. Shedlock
  • C. A. H. Foley
  • L. J. Foley
  • S. K. Wasser
  • S. T. Balthazary
  • B. M. Mutayoba
Research Article

Abstract

Poaching and habitat encroachment for human settlement are the two major factors that caused contraction of elephant populations in Africa. While the effects of poaching on many aspects of elephant social systems have been studied, the impacts on mating patterns are not yet understood and such information is still lacking in most African countries. In this study, we used elephant specific-microsatellite DNA to generate genotypes from 86 elephant samples (84 fresh faeces and two tissue samples) from Tarangire National Park (TNP), Tanzania to assess the mating success of individual males. We also tested whether the oldest bulls are more likely to sire most of the offspring in a severely poached population. Genetic paternity analysis was compared to behavioural observations of matings collected over a 3-year period (1998–2001) to determine the success of bull mating strategy. The genotypes of 26 infants, their known mothers and 10 out of 43 potential breeding bulls in TNP were used to assign 31% of the offspring at 80% confidence level to their potential fathers with simulation assuming that 23% (10/43) of the breeding males were sampled. Mating success of individual bull based on both behavioural and genetic data showed that the oldest remaining bulls performed most of the matings and fathered the majority of infants. We speculate that the lifetime fitness of bulls that have survived poaching may be elevated because their period of dominance increases.

Keywords

Elephants Poaching Microsatellites Tanzania 

References

  1. Archie EA, Moss CJ, Alberts SC (2006) The ties that bind: genetic relatedness predicts the fission and fusion of social groups in wild African elephants. Proc Biol Sci 273(1586):513–522PubMedCrossRefGoogle Scholar
  2. Barnes RFW, Kapela EB (1991) Changes in the Ruaha elephant population caused by poaching. Afr J Ecol 29:289–294CrossRefGoogle Scholar
  3. Barnes RW, Craig GC, Dublin HT et al (1999) African Elephant Database 1998. IUCN, Gland, Switzerland and CambridgeGoogle Scholar
  4. Comstock KE, Wasser SK, Ostrander EA (2000) Polymorphic microsatellite DNA loci identified in the African elephant (Loxodonta africana). Mol Ecol 9(7):1004–1006PubMedCrossRefGoogle Scholar
  5. Comstock KE, Georgiadis N, Pecon-Slattery J et al (2002) Patterns of molecular genetic variation among African elephant populations. Mol Ecol 11(12):2489–2498PubMedCrossRefGoogle Scholar
  6. Cumming DHM, Du Toit RF, Stuart SN (1990) African elephants and rhino status survey and conservation action plan. IUCN, Gland, SwitzerlandGoogle Scholar
  7. Douglas-Hamilton I (1987) African elephants: population trends and their causes. Oryx 21:11–24CrossRefGoogle Scholar
  8. Douglas-Hamilton I (1972) On the ecology and behaviour of the African elephant: the elephants of Manyara. Oxford University, Oxford, UK. DPhilGoogle Scholar
  9. Eggert LS, Rasner CA, Woodruff DS (2002) The evolution and phylogeography of the African elephant inferred from mitochondrial DNA sequence and nuclear microsatellite markers. Proc Biol Sci 269(1504):1993–2006PubMedCrossRefGoogle Scholar
  10. Foley CAH, Papageorge S, Wasser SK (2001) Non-invasive stress and reproduction measures of social and ecological pressure in free-ranging African elephants. Cons Biol 15(4):1134–1142CrossRefGoogle Scholar
  11. Foley CAH (2002) The effects of poaching on elephant social system. PhD thesis, Princeton UniversityGoogle Scholar
  12. Frantzen MA, Silk JB, Ferguson JWH et al (1998) Empirical evaluation of preservation methods for faecal DNA. Mol Ecol 7:1423–1428PubMedCrossRefGoogle Scholar
  13. Kangwana K (1995) Human-elephant conflict: the challenge ahead. Pachyderm 19:11–15Google Scholar
  14. Kellogg DE, Rybalkin I, Chen S et al (1994) TaqStart Antibody: hotstart PCR facilitated by a neutralizing monoclonal antibody directed against TaqDNA polymerase. Bio Techniques 16:1134–1137Google Scholar
  15. Kohn HM, Wayne RK (1997) Facts from faeces revisited. Trends Ecol Evol 12(6):223–227CrossRefGoogle Scholar
  16. Laws RM (1966) Age criteria for the African elephant, Loxodonta a.africana. E Afr Wildl J 4:1–37Google Scholar
  17. Marshall TC, Slate J, Kruuk LEB, Pemberton JM (1998) Statistical confidence for likelihood-based paternity inference in natural populations. Mol Ecol 7:639–655PubMedCrossRefGoogle Scholar
  18. Moss CJ (1983) Oestrous behaviour and female choice in African elephant. Behaviour 86:167–196CrossRefGoogle Scholar
  19. Moss C (1988) Elephant memories. William Morrow, New YorkGoogle Scholar
  20. Moss CJ (1990) Elephants in Tarangire. Pachyderm 13:26–30Google Scholar
  21. Moss C (1996) Getting to know a population. In: Kangwana K (ed) Studying elephants. African Wildlife Foundation, Nairobi, p 58Google Scholar
  22. Moss CJ (2001) The demography of an African Elephants (Loxodonta africana) population in Amboseli, Kenya. J Zool Lond 255:145–156CrossRefGoogle Scholar
  23. Murphy MA, Waits LP, Kendall KC et al (2002) Evaluation of long-term preservation methods for brown bear (Ursus arctos) faecal DNA samples. Cons Genet 3:435–440CrossRefGoogle Scholar
  24. Nyakaana S, Arctander P, Siegismund HR (2002) Population structure of the African savannah elephant inferred from mitochondrial control region sequences and nuclear microsatellite loci. Heredity 89(2):90–8PubMedCrossRefGoogle Scholar
  25. Poole JH (1987) Rutting behaviour in African elephants: The phenomenon of musth. Behaviour 102:283–316CrossRefGoogle Scholar
  26. Poole JH (1989a) Mate guarding, reproductive success and female choice in African elephants. Anim Behav 37:842–849CrossRefGoogle Scholar
  27. Poole JH (1989b) Announcing intent: the aggressive state of musth in African elephants. Anim Behav 37:140–152CrossRefGoogle Scholar
  28. Slate J, Marshall T, Pemberton J (2000) A retrospective assessment of the accuracy of the paternity inference program CERVUS. Mol Ecol 9:801–808PubMedCrossRefGoogle Scholar
  29. Taberlet P, Griffin S, Goossens B et al (1996) Reliable genotyping of samples with very low DNA quantities using PCR. Nucl Acid Res 24(16):3189–3194CrossRefGoogle Scholar
  30. Taberlet P, Waits LP, Luikart G (1999) Non-invasive genetic sampling: look before you leap. Trends Ecol Evol 14(8):323–327PubMedCrossRefGoogle Scholar
  31. Wasser SK, Houston CS, Koehler GM et al (1997) Techniques for application of faecal DNA methods to field studies of Ursids. Mol Ecol 6:1091–1097PubMedCrossRefGoogle Scholar
  32. Wasser SK, Hunt KE, Clarke CM (2002) Assessing stress and population genetics through non-invasive means. In: Aguirre AA, Ostfeld RS, Tabor GM et al (eds) Conservation medicine: ecological health in practice. Oxford University Press, New York, p 130Google Scholar
  33. Wasser SK, Shedlock AM, Comstock K, Ostrander EA et al (2004) Assigning African elephant DNA to geographic region of origin: applications to the ivory trade. Proc Natl Acad Sci USA 101(41):14847–14852PubMedCrossRefGoogle Scholar
  34. Whitehouse AM, Hall-Martin JA (2000) Elephants in Addo National Park, South Africa: reconstruction of the population’s history. Oryx 34:46–55CrossRefGoogle Scholar
  35. Watve MG, Sukumar R (1997) Asian elephants with longer tusks have lower parasite loads. Curr Sci 72:885–889Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • D. R. S. Ishengoma
    • 1
    • 5
  • A. M. Shedlock
    • 3
    • 4
  • C. A. H. Foley
    • 2
  • L. J. Foley
    • 2
  • S. K. Wasser
    • 3
  • S. T. Balthazary
    • 1
  • B. M. Mutayoba
    • 1
  1. 1.Department of Veterinary Physiology, Biochemistry, Pharmacology and ToxicologySokoine University of AgricultureMorogoroTanzania
  2. 2.Tarangire Elephant ProjectArushaTanzania
  3. 3.Department of BiologyCentre for Conservation Biology, University of WashingtonSeattleUSA
  4. 4.Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeUSA
  5. 5.National Institute for Medical ResearchTangaTanzania

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