Erica M. Sampaio

A Biodiversity Assessment of Bats (Chiroptera) in a Tropical Lowland Rainforest of Central Amazonia, Including Methodological and Conservation Considerations

In our study of bat diversity in the Amazon Basin, we captured bats in undisturbed continuous forest and in forest fragments at the Biological Dynamics of Forest Fragments Project (BDFFP) near Manaus, Brazil, from January 1996 until July 1999. We recorded 72 species of bats in a sample of more than 7700 individuals caught during 29,900 mistnet hours in terra-firme forest. Species accumulation curves and mathematical estimates of species numbers based on the number of species captured with standardized methodology suggest that we sampled about 95% of the entire expected bat fauna of the area, including aerial insectivorous bats. Our results are similar to those of other mistnetting inventories of Amazonian bat assemblages in terms of species composition and number of species per bat family. Some species considered widespread in Central Amazonia and expected at our study site were not recorded. We interpret their absence as effects of sampling bias and of local ecological conditions. We know from acoustic monitoring (i.e., identification of bats by their echolocation calls) that our mistnet data are incomplete for aerial insectivorous species. We conclude that the development of comprehensive inventories of key vertebrate taxa such as bats derived from a combination of several standardized sampling procedures is essential to develop meaningful, conservation-oriented plans for land-use and management of protected areas. Resumo Em nosso estudo sobre diversidade de morcegos na Bacia Amazônica, nós capturamos morcegos em floresta contínua não perturbada e em fragmentos florestais no Projeto Dinâmica Biológica de Fragmentos Florestais (PDBFF), próximo à Manaus, Brazil, de Janeiro de 1996 até Julho de 1999. Nós registramos 72 espécies de morcegos capturando cerca de 7700 indivíduos em 29,900 horas de captura em áreas de terra-firme. As curvas de acumulação e modelos matemáticos baseados no número de espécies capturadas com metodologia estandartizada indicam que nós registramos cerca de 95% da fauna esperada para a área, incluindo as capturas de espécies de morcegos aéreos insetívoros. Nossos resultados são equivalentes a outros inventários baseados em redes de captura de morcegos na Amazônia, em termos de composição de espécies e em número de espécies para cada família de morcegos. Algumas espécies consideradas como uniformemente distribuídas na região Amazônica e que deveriam também ocorrer na nossa área de estudo não foram coletadas. Nós interpretamos a ausência de espécies esperadas como um efeito de limitações na metodologia e devido a condições ecológicas locais. Sabemos por monitoramento acústico (identificação de morcegos através dos sinais de ecolocação), que nossos dados de redes de captura estão incompletos para morcegos insetívoros aéreos. Nós concluímos que o desenvolvimento de inventários de grupos chave, como morcegos, com a combinação de vários métodos de amostragem estandardizados é essencial para o desenvolvimento de planos conservationistas significativos no uso da terra e no controle de áreas protegidas.

Bats of Jaú National Park, central Amazônia, Brazil

ABSTRACT Although recognized as highly diverse, the bat fauna of the Amazon basin has been only patchily sampled. This paper combines data from five short surveys conducted between 1998 and 2001 in Jaú National Park, 220 km east of Manaus, central Amazônia. We used mistnets, recordings of echolocation calls and roost visits to provide the first bat inventory for this area. A total of 53 bat species in 33 genera and five families were documented, including several species that are regarded as rare, in particular Saccopteryx gymnura, Vampyriscus brocki, Molossops neglectus, and Promops centralis. The Chao 1 index indicates that sampling is about 72% complete, suggesting that around 73 bat species might co-exist in Jaú. We compare the composition of Jaús bat fauna to those of other sites in Amazônia and interpret the resulting patterns of diversity. Data on reproduction are given for 14 species.

Secondary forest regeneration benefits old-growth specialist bats in a fragmented tropical landscape

Tropical forest loss and fragmentation are due to increase in coming decades. Understanding how matrix dynamics, especially secondary forest regrowth, can lessen fragmentation impacts is key to understanding species persistence in modified landscapes. Here, we use a whole-ecosystem fragmentation experiment to investigate how bat assemblages are influenced by the regeneration of the secondary forest matrix. We surveyed bats in continuous forest, forest fragments and secondary forest matrix habitats, ~15 and ~30 years after forest clearance, to investigate temporal changes in the occupancy and abundance of old-growth specialist and habitat generalist species. The regeneration of the second growth matrix had overall positive effects on the occupancy and abundance of specialists across all sampled habitats. Conversely, effects on generalist species were negligible for forest fragments and negative for secondary forest. Our results show that the conservation potential of secondary forests for reverting faunal declines in fragmented tropical landscapes increases with secondary forest age and that old-growth specialists, which are often of most conservation concern, are the greatest beneficiaries of secondary forest maturation. Our findings emphasize that the transposition of patterns of biodiversity persistence in island ecosystems to fragmented terrestrial settings can be hampered by the dynamic nature of human-dominated landscapes.

The Road to Functional Recovery: Temporal Effects of Matrix Regeneration on Amazonian Bats:

Across the tropics, vast deforested areas are undergoing forest regeneration due to land abandonment. Although secondary forest is an expanding type of landscape matrix that has been shown to buffer some of the negative consequences of forest loss and fragmentation on taxonomic diversity, little is known in this regard about the functional dimension of biodiversity. We took advantage of an ecosystem-wide fragmentation experiment to investigate longer term changes in functional diversity of a mega-diverse Amazonian bat assemblage associated with regrowth development in the matrix. We found that matrix regeneration affected several facets of bat functional diversity in secondary forest over time, increasing functional α diversity, species- and community-level functional uniqueness, altering functional trait composition, and resulting in functional β-diversity changes via trait gains. However, approximately 30 years of matrix regeneration were insufficient for functional diversity to recover to the same levels as in continuous forest. Our results suggest that a combination of natural, human-assisted, and active restoration is likely to be the most successful strategy for restoring functional biodiversity of bats in human-modified tropical landscapes, a finding that most likely also applies to many other taxa.