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Distribution and abundance of frogs in a central Amazonian forest

This study is the first comprehensive survey of a frog assemblage in the central Amazon. Forty-three species of frog were found in a 2,000 hectare tract of primary forest near Manaus, Brazil. Breeding habitat affiliation, breeding phenology, spatial distribution, and relative abundance were determined for most species principally by counting calling males along variable-width strip transects. Frogs were also censused with visual detection methods and in litter plots. However, these techniques were not as powerful as audio transects for assessing species composition, habitat occupancy, and abundances throughout a large area. Anuran species and generic richnesses are similar throughout the Amazon except for Eleutherodactylus which is depauperate in the central and lower Amazon. As many species were abundant in the study area as were rare. The distribution of breeding habitat abundance parallels the distribution of species-abundance and so breeding habitat availability seems the best candidate to explain the relative abundances of species in the study area. / There is pervasive correlation between life history variables, particularly reproductive mode and habitat affiliation, and phylogeny in tropical forest anurans. This association supports a hypothesis that, at a regional scale, the history of an area's colonization and speciation rates of the colonists influenced the distribution of habitat use by frogs in forest assemblages more than selection. / Litter plot sampling was biased in favour of conspicuously behaving litter species. Since the proportion of the litter fauna that is conspicuously behaving is much lower in southeast Asia than the Neotropics, there is no evidence that litter frogs per se are more abundant in the Neotropics. However, abundances of conspicuously behaving species are higher in the Neotropics. Practically all abundant species at Manaus undergo terrestrial development. It appears that terrestrial reproduction releases frog populations from dependence on limited aquatic habitat. Since two prominent Neotropical families of litter frog reproduce terrestrially whereas terrestrial development is not associated with any southeast Asian taxon, the historical colonization of these regions by different lineages explains inter-regional abundance differences most parsimoniously. / Source: Dissertation Abstracts International, Volume: 52-04, Section: B, page: 1904. / Major Professor: Daniel Simberloff. / Thesis (Ph.D.)--The Florida State University, 1991.

Identiferoai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76396
ContributorsZimmerman, Barbara L., Florida State University
Source SetsFlorida State University
LanguageEnglish
Detected LanguageEnglish
TypeText
Format311 p.
RightsOn campus use only.
RelationDissertation Abstracts International

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