Hostname: page-component-7c8c6479df-r7xzm Total loading time: 0 Render date: 2024-03-28T16:45:21.277Z Has data issue: false hasContentIssue false

Balanites wilsoniana: elephant dependent dispersal?

Published online by Cambridge University Press:  10 July 2009

Lauren J. Chapman
Affiliation:
Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, 02138USA
Colin A. Chapman
Affiliation:
Department of Anthropology, Peabody Museum, Harvard University, Cambridge, Massachusetts, 02138USA
Richard W. Wrangham
Affiliation:
Department of Anthropology, Peabody Museum, Harvard University, Cambridge, Massachusetts, 02138USA

Abstract

This study demonstrates that forest elephants (Loxodonta africana) play a key role as seed dispersal agents for the upper canopy forest tree, Balanites wilsoniana. Seed that passed through elephants had a much greater probability of germinating (50.7%) than seeds from fruits eollected directly from the tree (3%). Of 515 seeds that were collected from under parent trees, 89.1% were rotten at the time of collection, 2.6% had been eaten by forest pigs, 2.8% had been killed by squirrels, and 0.7% had been killed by insect damage. The remaining 4.8% of the seeds were still alive. In 150 hours of focal observations on B. wilsoniana trees, two fruits were seen to be destroyed by squirrels, no fruits were seen to be consumed by potential dispersers, and no evidence of scatter hoarding was found. Experimental seedling stations placed out under parent trees and away from parent trees indicated no significant effect of dispersal on seedling survival. Although elephants are not essential for the successful germination of B. wilsoniana seeds, they do greatly increase probability of germination and play a vital role in their dispersal, suggesting that this is a highly interdependent plant-animal seed dispersal system.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

LITERATURE CITED

Abbiw, D. K. 1990. Useful plants of Ghana. Intermediate Technologies Publications, London.CrossRefGoogle Scholar
Alexandre, D. Y. 1978 Le role disseminateur des elephants en forct de Tai, Cote-D'Ivoire. La Terre et la Vie 32:4772.Google Scholar
Brooks, A. C. & Buss, I. O. 1962. Past and present status of the elephant in Uganda. Journal of Wildlife Management 26:3850.CrossRefGoogle Scholar
Butynski, T. M. 1990. Comparative ecology of blue monkeys (Cercopithecus mitis) in high- and low-density subpopulations. Ecological Monographs 60:126.CrossRefGoogle Scholar
Connell, J. H., Tracey, J. G. & Webb, L. J. 1984. The role of compensatory recruitment, growth, and mortality in maintaining tree diversity. Ecological Monographs 54:141164.CrossRefGoogle Scholar
Dinerstein, E. & Wemmer, C. M. 1988. Fruits Rhinoceros eat: Dispersal of Trewia nudiflora (Euphorbiaceae) in Lowland Nepal. Ecology 69:17681774.CrossRefGoogle Scholar
Douglas-Hamilton, I., Malpas, R., Edroma, E., Holt, P., Laker-Ajok, G., & Weyerhaeuser, R. 1980. Ugandan elephant and wildlife survey. IUCN report.Google Scholar
Hallwachs, W. 1986. Agoutis (Dasyprocta punctata): The Inheritors of Guapinol (Hymaneae courbaril): Leguminosae. Pp. 285304 in Estrada, A., Fleming, T. H. (eds). Frugivores and seed dispersal. Dr W. Junk Publishers, Dordrecht.CrossRefGoogle Scholar
Hardman, R. 1969. Pharmaceutical products from plant steroids. Tropical Science 11:196228.Google Scholar
Herrera, C. M. 1984. A study of avian frugivores, bird-dispersed plants, and their interaction in Mediterranean scrublands. Ecological Monographs 54:123.CrossRefGoogle Scholar
Herrera, C. M. 1985. Determinants of plant-animal coevolution: the case of mutualistic dispersal of seeds by vertebrates. Oikos 44:132141.CrossRefGoogle Scholar
Herrera, C. M. 1986. Vertebrate-dispersed plants: Why they don't behave the way they should. Pp. 518 in Estrada, A., Fleming, T. H. (eds). Frugivores and seed dispersal. Dr. W. Junk Publishers, Dordrecht.CrossRefGoogle Scholar
Howe, H. F. 1984a. Constraints on the evolution of mutualism. American Naturalist. 123:764777.CrossRefGoogle Scholar
Howe, H. F. 1984b. Implications of seed dispersal by animals for tropical reserve management. Biological Conservation 30:261281.CrossRefGoogle Scholar
Howe, H. F. 1985. Gomphothere fruits: A critique. American Naturalist 125:853865.CrossRefGoogle Scholar
Howe, H. F. & Estabrook, G. P. 1977 On intraspecific competition for avian dispersers in tropical trees. American Naturalist 111:817832.CrossRefGoogle Scholar
Howe, H. F. & Smallwood, J. 1982. Ecology of seed dispersal. Annual Review of Ecology and Systematics 13:201228.CrossRefGoogle Scholar
Howe, H. F., Schupp, E. W., & Westley, L. C. 1985. Early consequences of seed dispersal for a neotropical tree (Virola surinamensis). Ecology 66:781791.CrossRefGoogle Scholar
Janzen, D. H. 1978. Complications in interpreting the chemical defenses of trees against tropical arboreal plant-eating vertebrates. Pp. 7384 in Montgomery, G. G. (ed.). The ecology of arboreal folivores, Smithsonian Instituition Press, Washington.Google Scholar
Janzen, D. H. & Martin, P. 1982. Neotropical anachronisms: What the gomphotheres ate. Science 215:1927.CrossRefGoogle ScholarPubMed
Lieberman, D., Lieberman, M. & Martin, C. 1987. Notes on seeds in elephant dung from Bia National Park, Ghana. Biotropica 19:365369.CrossRefGoogle Scholar
McKey, D. 1975. The ecology of coevolved seed dispersal systems. Pp. 158191 in Gilbert, L. E. & Raven, P. (eds.). Coevolution of animals and plants. University of Texas Press, Austin.Google Scholar
Noble, J. C. 1975. The effects of emus (Dromaius novaehollandiae Latham) on the distribution of nitre bush (Nitraria billardieri DC). Journal of Ecology 63:979984.CrossRefGoogle Scholar
Pannell, C. M. 1989. The role of animals in natural regeneration and the management of equatorial rain forests for conservation and timber production. Commonwealth Forestry Review 68:309313.Google Scholar
Patterson, B. 1975. The fossil aardvarks (Mammalia: Tubulidentata). Bulletin of the Museum of Comparative Zoology, Harvard 147:185237.Google Scholar
Rick, C. M. & Bowman, R. I. 1961. Galapagos tomatoes and tortoises. Evolution 15:407417.CrossRefGoogle Scholar
Short, J. 1981. Diet and feeding behaviour of the forest elephant. Mammalia 45:177185.CrossRefGoogle Scholar
Skorupa, J. P. 1988. The effect of selective timber harvesting on rain-forest primates in Kibale Forest, Uganda. PhD Dissertation, University of California, Davis.Google Scholar
Snow, D. W. 1965. A possible selective factor in the evolution of fruiting seasons in tropical forest. Oikos 15:274281.CrossRefGoogle Scholar
Snow, D. W. 1971. Evolutionary aspects of fruit-eating by birds. Ibis 113:194202.CrossRefGoogle Scholar
Struhsaker, T. T. 1975. The red colobus monkey. University of Chicago Press, Chicago.Google Scholar
Temple, S. A. 1977. Plant-animal mutualisms: Coevolution with dodo leads to near extinction of plant. Science 197:885886.CrossRefGoogle ScholarPubMed
Wing, L. D. & Buss, I. O. 1970. Elephants and forest. Wildlife Monographs No. 19.Google Scholar