Differences among avian frugivores in seed dispersal to degraded habitats |
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| Authors: | Evan M. Rehm Janelle Chojnacki Haldre S. Rogers Julie A. Savidge |
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| Affiliation: | 1. Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO 80523, U.S.A.Present address: Department of Ecology, Evolution and Marine Biology, University of California at Santa Barbara, Santa Barbara, CA 93106, U.S.A.;2. Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO 80523, U.S.A.;3. Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, U.S.A. |
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| Abstract: | Vertebrate frugivores enhance tropical forest regeneration by dispersing seeds into degraded areas. However, the importance of individual species as dispersers may vary within a community. Management and restoration would benefit from understanding which species are critical in moving native seeds into degraded habitats. We compared habitat composition of bird start and end locations for movement intervals based on mean gut passage times for the avian frugivore community on the island of Saipan. The proportion of movement intervals that began in intact, native forest varied among species, with Golden White‐eyes having the highest proportion. However, this species tended to remain in intact forest and only rarely crossed into degraded habitats. Bridled White‐eyes and Mariana Fruit Doves exhibited slightly higher rates of crossing from intact forest to degraded habitats, suggesting an ability to disperse native seeds to degraded areas. White‐throated Ground Doves were never recorded crossing from intact forest to degraded habitats. Despite having a low proportion of movement intervals beginning in intact forest, Micronesian Starlings showed a higher proportion and absolute number of movements from intact forest to degraded habitats, due to their propensity to move frequently, across long distances, and across habitat types. In this species‐poor frugivore network, seed dispersal into degraded habitats appears highly dependent on one species within the community. Regeneration of degraded lands may be severely hindered if this key disperser is lost. |
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| Keywords: | avian community deforestation dispersal network ecotone Guam network disruption |
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