PARENT SESSION
Symposium #4: Long-distance dispersal.
Sponsored by ESA Plant Population and Theoretical Ecology Sections
Organized by: R. Nathan, M. Cain, S. Levin.
Monday, August 6, 2001. 1:00 PM to 5:00 PM. Lecture Hall

Are long-distance dispersal events usually caused by nonstandard means of dispersal?

HIGGINS, STEVEN¹, NATHAN, RAN², CAIN, MICHAEL³, ^{1 2 3}

ABSTRACT- An emerging undertone in the literature on long-distance dispersal and migration modeling is that nonstandard mechanisms of dispersal are often responsible for the rare long-distance events that drive migration. For example plant seeds, which appear to be adapted for wind dispersal may occasionally be dispersed long distances by birds. Here we review several of these nonstandard mechanisms of dispersal and thereby show that these dispersal mechanisms may account for rare long-distance dispersal. The plethora of nonstandard mechanisms of dispersal suggests that a species that lacks classical dispersal adaptations may nevertheless have a nonstandard, but cryptic, dispersal mechanism that allows rapid migration; this is a view that can lead to complacency with respect to the ability of communities to response to global change. We explore whether existing data on dispersal distances, colonization rates and migration rates support the idea a single dispersal process is responsible for the observed data. We conclude that it is (1) important to look beyond classical dispersal mechanisms when trying to predict migration and colonization rates, (2) difficult to exclude the possibility that many species have additional dispersal mechanisms that enable long-distance dispersal and rapid migration.

KEY WORDS: DISPERSAL, MIGRATION, LONG-DISTANCE