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and most threatened species are limited to a few disconnected subpopulations, theories
<br />of metapopulation dynamics seem promising. Metapopulation models can be further
<br />refined within a source/sink structure by determining how individuals are exchanged
<br />between subpopulations. Our experimental work with small mammals in fragmented
<br />populations lends support to these new theoretical approaches, and that source/sink
<br />components incorporated in metapopulation dynamics should be particularly fruitful.
<br />As the need for informed conservation management decisions increases, our under-
<br />standing of the ecology of threatened populations continues to grow.
<br />Acknowledgments
<br />We are grateful to Andrea J. Freedman, Michael L. Johnson, John L. Koprowski,
<br />Lee McClenaghan, Robert Tamarin, John Wiens, and Frank Wray for their comments
<br />on the manuscript. Our work on small mammals was supported by National Science
<br />Foundation grant number BSR-8718088.
<br />References
<br />Belovsky, G. E. 1987. Extinction models and mammalian persistence. Pages 35-58 in M. E. Soule,
<br />ed., Viable Populations for Conservation. Cambridge Univ. Press. Cambridge, MA. 189 pp.
<br />Bennett, A. F. 1991. Habitat corridors and the conservation of small mammals in a fragmented
<br />forest environment. Landscape Ecology 4:109-122.
<br />Berger, J. 1990. Persistence of different-sized populations: An empirical assessment of rapid ex-
<br />tinctions in bighorn sheep. Conservation Biology 4:91-98.
<br />Birkenholz, D. E. 1967. The harvest mouse (Reirhrodontomvs megalotis) in central Illinois. Trans.
<br />Illinois St. Acad. Sciences 60:49-53.
<br />Duran, L. R. 1989. Variation and persistence of the middle rocky intertidal community of central
<br />Chile, with and without human harvesting. Marine Biology 103:555-562.
<br />Fitch, H. S., V. R. Fitch, and W. D. Kettle. 1984. Reproduction, population changes and inter-
<br />actions of small mammals on a natural area in northeastern Kansas. Occa. Papers of the Mus.
<br />Nat. Hist. Univ. Kansas. No. 109.
<br />Foster, J. and M. S. Gaines. 1991. The effects of a successional habitat mosaic on a small mammal
<br />community. Ecology 72:1358-1373.
<br />Gaines, M. S., G. R. Robinson, J. E. Diffendorfer, R. D. Holt, and M. L. Johnson. 1992. The
<br />effects of habitat fragmentation on small mammal populations. In D. R. McCullough and R. H.
<br />Barret, eds., Wildlife 2001: Populations. In press.
<br />Gilbert, L. E. 1980. Food web organization and the conservation of neotropical diversity. Pages
<br />11-33 in Soule, M. E. and Wilcox, B. A., eds., Conservation Biology: An Evolutionary-
<br />Ecological perspective. Sinauer. Sunderland, MA.
<br />Gilpin, M. E. and M. E. Soule. 1986. Minimum viable populations: Processes of species extinction.
<br />Pages t9-34 in M. E. Soule, ed., Conservation Biology, Sinauer, Sunderland, MA. 584 pp.
<br />Goodman, D. 1987. The demography of chance extinction. Pages 1 1-34 in M. E. Soule, ed., Viable
<br />Populations for Conservation, Cambridge Univ. Press, Cambridge, MA. 189 pp.
<br />Grabherr, G. 1989. On community structure in high alpine grasslands. Vegetatio 83:223-227.
<br />Hanski, I. 1989. Metapopulation dynamics: Does it help to have more of the same? Trends in
<br />Ecology and Evolution 4:113-114.
<br />Hanski, I. and M. Gilpin. 1991. Metapopulation dynamics: Brief history and conceptual domain.
<br />Biological J. Linnean Soc. 42:73-88.
<br />Harrison, S. and Quinn, J. F. 1989. Correlated environments and the persistence of metapopulations.
<br />Oikos 56:293-298.
<br />Holt, R. D. 1985. Population dynamics in two-patch environments: Some anomalous consequences
<br />of an optimal habitat distribution. Theoretical Population Biology 28:181-208.
<br />Ims, R. A. 1990. The effect of habitat fragmentation on social systems: Small rodents as an empirical
<br />mode! system. Abstract, V International Congress of Ecology meetings.
<br />Population Processes ? 261
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