Impact of a catastrophic hurricane on island populations

Science

Volumn 281, Issue 5377, 1998, Pages 695-697

  Spiller, David A ^a   Losos, Jonathan B ^b   Schoener, Thomas W ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b WASHINGTON UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ENVIRONMENTAL IMPACT; HURRICANE; ISLAND BIOGEOGRAPHY; LIZARD; PHYSICAL DISTURBANCE; POPULATION SIZE; SPIDER;

ARTICLE; BAHAMAS; CONTROLLED STUDY; DISASTER; LIZARD; NONHUMAN; POPULATION; PRIORITY JOURNAL; SPIDER; SURVIVAL;

EID: 0032584716     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.281.5377.695     Document Type: Article

References (35)

1. J. H. Connell, Science 199, 1302 (1978); W. P. Sousa, Annu. Rev. Ecol. Syst. 15, 353 (1984); S. T. A. Pickett and P. S. White, The Ecology of Natural Disturbance and Patch Dynamics (Academic Press, New York, 1985); M. Mangel and C. Tier, Ecology 75, 607 (1994).
2. J. H. Connell, Science 199, 1302 (1978); W. P. Sousa, Annu. Rev. Ecol. Syst. 15, 353 (1984); S. T. A. Pickett and P. S. White, The Ecology of Natural Disturbance and Patch Dynamics (Academic Press, New York, 1985); M. Mangel and C. Tier, Ecology 75, 607 (1994).
3. J. H. Connell, Science 199, 1302 (1978); W. P. Sousa, Annu. Rev. Ecol. Syst. 15, 353 (1984); S. T. A. Pickett and P. S. White, The Ecology of Natural Disturbance and Patch Dynamics (Academic Press, New York, 1985); M. Mangel and C. Tier, Ecology 75, 607 (1994).
4. J. H. Connell, Science 199, 1302 (1978); W. P. Sousa, Annu. Rev. Ecol. Syst. 15, 353 (1984); S. T. A. Pickett and P. S. White, The Ecology of Natural Disturbance and Patch Dynamics (Academic Press, New York, 1985); M. Mangel and C. Tier, Ecology 75, 607 (1994).
5. I. Thornton, Krakatoa (Harvard Univ. Press, Cambridge, MA, 1996).
6. 2. Lizard population sizes were usually estimated by means of the multiple-mark-recapture method [S. H. Fienberg, Biometrika 59, 591 (1972); D. C. Heckel and J. Roughgarden, Ecology 60, 966 (1979)]; lizards were marked with different colors of nontoxic paint on each of 3 days. On a few occasions, lizards were marked on only 2 days, and the Lincoln index was used to estimate population sizes. We searched the entire island for web spiders, recording the species identity of all observed individuals on each of the lizard-introduction islands and on four islands without lizards.
7. 2. Lizard population sizes were usually estimated by means of the multiple-mark-recapture method [S. H. Fienberg, Biometrika 59, 591 (1972); D. C. Heckel and J. Roughgarden, Ecology 60, 966 (1979)]; lizards were marked with different colors of nontoxic paint on each of 3 days. On a few occasions, lizards were marked on only 2 days, and the Lincoln index was used to estimate population sizes. We searched the entire island for web spiders, recording the species identity of all observed individuals on each of the lizard-introduction islands and on four islands without lizards.
8. J. B. Losos and D. A. Spiller, Ecology, in press.
9. Vegetation volume was estimated before (October 1994) and after (December 1996) the hurricane on each island as follows. Each island was approximated as an ellipse. A measuring tape was placed along the major axis of the island, from the beginning to the end of the vegetation. Perpendicular transects were placed at 4-m intervals on larger islands and at 3-m intervals on smaller islands. The maximum height of the vegetation within a 0.5-m radius of a given point was measured along each transect, at 3-m intervals on larger islands and at 2-m intervals on smaller islands. The vegetated area was estimated by connecting the outer points of transects and measuring the enclosed area. Volume was estimated by multiplying mean maximum vegetation height by vegetated area.
10. See "Atlantic hurricane tracking data by year," available at http://wxp.atms.purdue.edu/hur_atlantic/
11. M. B. Lawrence, Preliminary Report: Hurricane Lili (National Hurricane Center, Miami, FL, 1996), available at www.nhc.noaa.gov/1996lili.html
12. J. H. Connell, in Ecology and Evolution of Communities, M. L. Cody and J. M. Diamond, Eds. (Belknap, Cambridge, MA, 1975), pp. 460-490.
13. S. L. Pimm, The Balance of Nature? (Univ. of Chicago Press, Chicago, IL, 1991).
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15. R. D. Holt, in Species Diversity in Ecological Communities, R. E. Ricklefs and D. Schluter, Eds. (Univ. of Chicago Press, Chicago, IL, 1993), pp. 77-89; R. J. Whittaker, Trends. Ecol. Evol. 10, 421 (1995).
16. R. D. Holt, in Species Diversity in Ecological Communities, R. E. Ricklefs and D. Schluter, Eds. (Univ. of Chicago Press, Chicago, IL, 1993), pp. 77-89; R. J. Whittaker, Trends. Ecol. Evol. 10, 421 (1995).
17. The proportional changes in numbers of lizards and spiders between two censuses on each island were shown to be statistically greater than zero by performance of a paired t test on log-transformed numbers. The P values are one-tailed because numbers were expected to decrease from immediately before to immediately after the hurricane. The difference between lizards and spiders in the proportional change was analyzed with a t test; the P value is one-tailed because the numbers of spiders were expected to decrease more than the numbers of lizards. The P values for changes from immediately after versus 1 year after the hurricane are two-tailed.
18. This surprising observation suggests that the hurricane transported the species beyond its normal range of dispersal. Although these spiders might have come from Great Exuma, M. bahama was previously recorded on only Andros and Bimini, located > 100 km from the study islands [H. W. Levi, Bull. Mus. Comp. Zool. 154, 81 (1995); H. Levi, personal communication]. One year after the hurricane, M. bahama was absent on all islands, as it was in each of our four annual censuses before the hurricane.
19. This surprising observation suggests that the hurricane transported the species beyond its normal range of dispersal. Although these spiders might have come from Great Exuma, M. bahama was previously recorded on only Andros and Bimini, located > 100 km from the study islands [H. W. Levi, Bull. Mus. Comp. Zool. 154, 81 (1995); H. Levi, personal communication]. One year after the hurricane, M. bahama was absent on all islands, as it was in each of our four annual censuses before the hurricane.
20. The results from the protected islands are consistent with previous studies of small islands in the Central Exumas, located approximately 100 km north of the present study site [T. W. Schoener, in Community Ecology, J. Diamond and T. J. Case, Eds. (Harper and Row, New York, 1986), pp. 556-586; T. W. Schoener and D. A. Spiller, Nature 330, 474 (1987); Am. Nat. 139, 1176, (1992)]: The extinction rate was higher for web spiders than for lizards, and the extinction rate of spiders increased with decreasing population size. No hurricane occurred during those studies.
21. The results from the protected islands are consistent with previous studies of small islands in the Central Exumas, located approximately 100 km north of the present study site [T. W. Schoener, in Community Ecology, J. Diamond and T. J. Case, Eds. (Harper and Row, New York, 1986), pp. 556-586; T. W. Schoener and D. A. Spiller, Nature 330, 474 (1987); Am. Nat. 139, 1176, (1992)]: The extinction rate was higher for web spiders than for lizards, and the extinction rate of spiders increased with decreasing population size. No hurricane occurred during those studies.
22. The results from the protected islands are consistent with previous studies of small islands in the Central Exumas, located approximately 100 km north of the present study site [T. W. Schoener, in Community Ecology, J. Diamond and T. J. Case, Eds. (Harper and Row, New York, 1986), pp. 556-586; T. W. Schoener and D. A. Spiller, Nature 330, 474 (1987); Am. Nat. 139, 1176, (1992)]: The extinction rate was higher for web spiders than for lizards, and the extinction rate of spiders increased with decreasing population size. No hurricane occurred during those studies.
23. J. H. Connell, T. P. Hughes, C. C. Wallace, Ecol. Monogr. 67, 489 (1997).
24. D. P. Reagan, Biotropica 23, 468 (1991).
25. J. M. Wunderle Jr., D. J. Lodge, R. B. Waide, Auk 109, 148 (1992).
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27. D. S. Simberloff and E. O. Wilson, Ecology 50, 278 (1969); J. R. Rey, Ecol. Monogr. 51, 237 (1981).
28. D. S. Simberloff and E. O. Wilson, Ecology 50, 278 (1969); J. R. Rey, Ecol. Monogr. 51, 237 (1981).
29. T. W. Schoener and C. A. Toft, Science 219, 1353 (1983); T. W. Schoener and D. A. Spiller, ibid. 267, 1811 (1995).
30. T. W. Schoener and C. A. Toft, Science 219, 1353 (1983); T. W. Schoener and D. A. Spiller, ibid. 267, 1811 (1995).
31. No lizard species recolonized any of the 11 exposed islands having introduced lizard populations. One small exposed island having a natural lizard population before the hurricane was apparently recolonized; no lizard was found immediately after the hurricane but a few were found the next year. This island was very close (<30 m) to a much larger island and was the nearest to Great Exuma of all the islands surveyed. On the four other small exposed islands surveyed that had natural lizard populations before the hurricane, no lizard was found immediately after nor 1 year after the hurricane.
32. T. W. Schoener and A. Schoener, Nature 302, 332 (1983).
33. T. W. Schoener and D. A. Spiller, ibid. 381, 691 (1996).
34. J. L. Carew and J. E. Mylroie, in Terrestrial and Shallow Marine Geology of the Bahamas and Bermuda, H. A. Curran and B. White, Eds. (Geological Society of America, Boulder, CO, 1995), pp. 5-32.
35. We thank R. Mayfield for field assistance, H. Levi for spider identifications, and NSF for support.