Skip to main content

Removal of black palm (Astrocaryum standleyanum) seeds by spiny rats (Proechimys semispinosus)

  • Gregory A. Hoch (a1) and Gregory H. Adler (a2)

A seed-removal experiment was conducted to assess the role of Proechimys semispinosus (Central American spiny rat) as potential predator and disperser of Astrocaryum standleyanum (black palm) seeds. One hundred fresh ripe A. standleyanum fruits were placed in semipermeable cages on each of 14 small islands in Panama, and seed disappearance rates were calculated for each island. Spiny rat density and biomass were determined by live-trapping on each island for 5 consecutive days and 4 nights. Censuses of fruiting trees were conducted on each island to control for effects of food availability on removal of palm fruits. Disappearance rates were related positively to total spiny rat density, density of adult and subadult spiny rats, and spiny rat biomass, but the density of fruiting trees accounted for very little variation. Spiny rats evidently prey heavily on A. standleyanum seeds, based on the high removal rates and on feeding observations of captive individuals. Since spiny rats may scatterhoard A. standleyanum seeds, they may also function as effective seed dispersers if seeds are removed to favourable germination sites unavailable to other seed predators. Results indicate that spiny rats, because of their abundance and wide distribution, may be important but overlooked predators and dispersers of A. standleyanum seeds and of other large-seeded tree species.

Corresponding author
2 Author to whom all correspondence should be sent.
Hide All
Adler, G. H. 1995. Fruit and seed exploitation by Central American spiny rats, Protchimys semispinosus. Studies on Neotropical Fauna and Environment 30:237244.
Adler, G. H., Endries, M. & Piotter, S. 1996. Spacing patterns within populations of a tropical forest rodent, Proechimys semispinosus, on five Panamanian islands. Journal of Zoology (London), in press.
Adler, G. H. & Seamon, J. O. 1991. Distribution and abundance of a tropical rodent, the spiny rat, on islands in Panama. Journal of Tropical Ecology 7:349360.
Connell, J. H. 1971. On the role of natural enemies in preventing competitive exclusion in some marine animals and in rain forest trees. Pp. 298312 in den Boer, P. J. & Gradwell, G. R. (eds.). Dynamics of numbers in populations. Center for Agricultural Publication and Documentation, Wageningen, Netherlands.
Croat, T. B. 1978. Flora of Barro Colorado Island. Stanford University Press, Stanford, CA, USA.
De Steven, D., Windsor, D. M., Putz, F. E. & De Leon, B. 1987. Vegetative and reproductive phenologies of a palm assemblage in Panama. Biotropica 19:342356.
Dietrich, W. E., Windsor, D. M. & Dunne, T. 1982. Geology, climate, and hydrology of Barro Colorado Island. Pp. 2146 in Leigh, E. G. Jr, Rand, A. S. & Windsor, D. M. (eds.). The ecology of a tropical forest: seasonal rhythms and long-term changes. Smithsonian Institution, Press, Washington, D.C., USA.
Fleming, T. H. 1971. Population ecology of three species of Neotropical rodents. Miscellaneous Publications of the Museum of Zoology, University of Michigan, No. 143, pp. 177.
Forget, P.-M. 1990. Seed dispersal of Vouacapoua americana Aublet (Caesalpiniaceae) by caviomorph rodents in French Guiana. Journal of Tropical Ecology 6:459468.
Forget, P.-M. 1991. Scatterhoarding of Astrocaryum paramaca by Proechimys in French Guiana: comparison with Myoprocta exilis. Tropical Ecology 32:155167.
Forget, P.-M. 1994. Recruitment pattern of Vouacapoua americana (Caesalpiniaceae), a rodent-dispersed tree species in French Guiana. Biotropica 26:408419.
Forget, P.-M., Munoz, E. & Leigh, E. G. Jr., 1994. Predation by rodents and bruchid beetles on seeds of Scheelea palms on Barro Colorado Island, Panama. Biotropica 26:420426.
Glanz, W. E., JrThorington, R. W., Giacalone-Madden, J. & Heaney, L. R. 1982. Seasonal food use and demographic trends in Sciurus granatensis. Pp. 239252 in Leigh, E. G. Jr, Rand, A. S. & Windsor, D. M. (eds.). The ecology of a tropical forest: seasonal rhythms and long-term changes. Smithsonian Institution Press, Washington, D.C., USA.
Gliwicz, J. 1984. Population dynamics of the spiny rat Proechimys semispinosus on Orchid Island (Panama). Biotropica 16:7378.
Janzen, D. H. 1970. Herbivores and the number of tree species in tropical forests. American Naturalist 104:501528.
Janzen, D. H. 1971. The fate of Scheelea rostrata fruits beneath the parent tree: predispersal attack by bruchids. Principes 15:89101.
Kiltie, R. A. 1981. Distribution of palm fruits on a rain forest floor: why white-lipped peccaries forage near objects. Biotropica 13:141145.
Leigh, E. G. Jr, Wright, S. J., Putz, F. E. & Herre, E. A. 1993. The decline of tree diversity on newly isolated tropical islands: a test of a null hypothesis and some implications. Evolutionary Ecology 7:76102.
Maliniak, E. & Eisenberg, J. F. 1971. Breeding spiny rats, Proechimys semispinosus in captivity. International Zoo Year Book 11:9398.
Smythe, N. 1978. The natural history of the Central American agouti (Dasyprocta punctata). Smithsonian Contributions to Zoology 257:152.
Smythe, N. 1989. Seed survival in the palm A. standleyanum: evidence for dependence upon its seed dispersers. Biotropica 21:5056.
Smythe, N., Glanz, W. E. & Leigh, E. G. Jr., 1982. Population regulation in some terrestrial frugivores. Pp. 227238 in Leigh, E. G. Jr, Rand, A. S. & Windsor, D. M. (eds). The ecology of a tropical forest: seasonal rhythms and long-term changes. Smithsonian Institution Press, Washington, D.C., USA.
Terborgh, J., Losos, E., Riley, M. P. & Bolanos Riley, M. 1993. Predation by vertebrates and invertebrates on the seeds of five canopy tree species of an Amazonian forest. Vegetatio 107/108:375386.
Vandermeer, J. H. 1979. Hoarding behaviour of captive Heteromys desmarestianus (Rodentia) on the fruits of Welfia georgii. Tropical Ecology 20:1726.
Windsor, D. M. 1990. Climate and moisture variability in a tropical forest: long-term records from Barro Colorado Island, Panama. Smithsonian Contributions to the Earth Sciences 29:1145.
Wright, S. J. 1979. Competition between insectivorous lizards and birds in central Panama. American Zoologist 19:11451156.
Wright, S. J. 1983. The dispersion of eggs by a bruchid beetle among Scheelea palm seeds and the effect of distance to the parent palm. Ecology 64:10161021.
Wright, S. J. 1985. How isolation affects rates of turnover of species on islands. Oikos 44:331338.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Tropical Ecology
  • ISSN: 0266-4674
  • EISSN: 1469-7831
  • URL: /core/journals/journal-of-tropical-ecology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed