Reproductive effort and life history strategy of the Aldabran giant tortoise

Abstract

THE Aldabra giant tortoise, Geochelone gigantea Schweigger, has a large body size (19–120 kg)1, long life span (65–90 yr)2, late maturity (females 17–23 yr)3,4 and iteroparity3. The three isolated island populations of different densities on Aldabra show dissimilarity in their reproductive parameters (for example mean clutch size, mean egg weight, proportion of mature females breeding and the number of clutches per female per year) and in the variation of these parameters from year to year through annual changes in rainfall3. Moreover, their reproductive response to these changes in rainfall is rapid; they have a relatively high maximum (potential) rate of natural increase (maximum clutch size 28)3 and mature females in the high density population are half the weight of those in the low density area2,4. I have postulated that the reproductive effort would differ between the different density populations and that this effort would change in relation to changes in food availability. This contention is supported by the results reported here.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1

    Bourn, D. & Coe, M. Phil. Trans. R. Soc., Lond. B (in the press).

  2. 2

    Grubb, P. Phil. Trans. R. Soc., Lond. B260, 327–372 (1971).

    Article  Google Scholar 

  3. 3

    Swingland, I. R. & Coe, M. Phil. Trans. R. Soc., Lond. B (in the press).

  4. 4

    Frazer, J. thesis, Oxford Univ. (1971)

  5. 5

    Coe, M., Bourn, D. & Swingland, I. R. Phil. Trans. R. Soc., B (in the press).

  6. 6

    MacArthur, R. H. & Wilson, E. O. The Theory of Island Biogeography (Princeton University Press, Princeton, 1976).

    Google Scholar 

  7. 7

    Nichols, H. D., Conley, W., Batt, B. & Tipton, A. R. Am. Nat. 110, 995–1005 (1976).

  8. 8

    Pianka, E. R. Am. Nat. 104, 592–597 (1970).

  9. 9

    Wilbur, H. M., Tinkle, D. W. & Collins, J. P. Am. Nat. 108, 805–817 (1974).

    Article  Google Scholar 

  10. 10

    Wilbur, H. M. Am. Nat. 111, 43–68 (1977).

    Article  Google Scholar 

  11. 11

    Hughes, G. M., Gaymer, R., Moore, M. & Woakes, A. J. J. exp. Biol. 55, 651–665 (1971).

    CAS  PubMed  Google Scholar 

Download references

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

SWINGLAND, I. Reproductive effort and life history strategy of the Aldabran giant tortoise. Nature 269, 402–404 (1977). https://doi.org/10.1038/269402a0

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.