Abstract
The Bahian giant tree rat Phyllomys unicolor (Wagner) was described from a single specimen collected in the early nineteeth century, and it has not been recorded since. It was included on the Brazilian endangered species list, and considered extinct by some. Here we report the rediscovery of P. unicolor around the type locality in the Atlantic forest of southeastern Bahia, eastern Brazil. We trapped only one young individual during seven expeditions to ten localities in the area. The phylogenetic distinctiveness of this taxon based on the mitochondrial cytochrome b gene is clear, in spite of uncertainties regarding clade support. The evolutionary uniqueness of P. unicolor was confirmed by a high level of sequence divergence from congeneric species. We propose that the Bahian giant tree rat should be globally listed as Critically Endangered by the World Conservation Union. Phyllomys unicolor seems to be restricted to swamp forests and it does not occur in any protected area. Intensive field studies should be carried out in the region to locate populations and to study ecological attributes of this species. The rediscovery of P. unicolor draws attention to the biological importance and the lack of protected areas in this region of the Atlantic forest.References
Bonvicino, C.R., Oliveira, J.A., D`Andrea, P.S. & Carvalho, R.W. (2001) Rediscovery of the endemic Atlantic forest rodent Phaenomys ferrugineus (Sigmodontinae): new data on its morphology and karyology. Boletim do Museu Nacional, nova série, Zoologia, 467, 1–12.
Costa, L.P., Leite, Y.L.R., Mendes, S.L. & Ditchfield, A.D. (2005) Mammal conservation in Brazil. Conservation Biology, 19(3), 672–679.
Contreras, L. (1996) Echimys unicolor. In: 2006 IUCN Red List of Threatened Species. Available from http://www.iucnredlist.org (accessed May 2007).
Correa, L.S. (2005) O resgate de um esquecimento – a Colônia de Leopoldina. Geographica, 13, 87–111.
Emmons, L.H., Leite, Y.L.R., Kock, D. & Costa, L.P. (2002) A review of the named forms of Phyllomys (Rodentia: Echimyidae) with the description of a new species from coastal Brazil. American Museum Novitates, 3380, 1–40.
Fonseca, G.A.B. (1985) The vanishing Brazilian Atlantic Forest. Biological Conservation, 34, 17–34.
Galewski, T., Mauffrey, J.-F., Leite, Y.L.R., Patton, J.L. & Douzery, E.J.P. (2005) Ecomorphological diversification among South American spiny rats (Rodentia; Echimyidae): a phylogenetic and chronological approach. Molecular Phylogenetics and Evolution, 34, 601–615.
IUCN (World Conservation Union) (1994) IUCN Red List Categories and Criteria, version 2.3. IUCN Species Survival Commission, Gland. Available from http://www.iucnredlist.org/info/categories_criteria1994#categories (accessed May 2007).
IUCN (World Conservation Union) (2001) IUCN Red List Categories and Criteria, version 3.1. IUCN Species Survival Commission, Gland. Available from http://www.iucnredlist.org/info/categories_criteria2001 (accessed May 2007).
IUCN (World Conservation Union) (2004) Guidelines for Using the IUCN Red List Categories and Criteria. IUCN Species Survival Commission, Gland.
Kimura, M. (1980) A single method for estimating evolutionary rate of base substitutions through comparative studies of nucleotide sequences. Journal of Molecular Evolution, 16, 111–120.
Leite, Y.L.R. (2003) Evolution and systematics of the Atlantic tree rats, genus Phyllomys (Rodentia, Echimyidae), with description of two new species. University of California Publications in Zoology 132, 1–118. University of California Press, Berkeley. Available from http://repositories.cdlib.org/ucpress/ucpz/vol_132 (accessed August 2007).
Mittermeier, R.A., Gil, P.R., Hoffman, M., Pilgrim, J., Brooks, T., Mittermeier, C.G., Lamoreux, J. & Fonseca, G.A.B. (2005) Hotspots Revisited: Earth's Biologically Richest and Most Endangered Terrestrial Ecoregions. CEMEX and Conservation International, Washington, D.C.
Myers, N., Mittermeier, R.A., Mittermeier, C.G., Fonseca, G.A.B. & Kent, J. (2000) Biodiversity hotspots for conservation priorities. Nature, 403, 853–858.
Oliver, W.L.R. & Santos, I.B. (1991) Threatened endemic mammals of the Atlantic forest region of south-east Brazil. Jersey Wildlife Preservation Trust, Special Scientific Report, 4, 1–126.
Percequillo, A.R., Gonçalves, P.E. & Oliveira, J.A. (2004) The rediscovery of Rhagomys rufescens (Thomas, 1886), with a morphological redescription and comments on its systematic relationships based on morphological and molecular (cytochrome b) characters. Mammalian Biology, 69, 238–257.
Rodrigues, A.S.L., Andelman, S.J., Bakarr, M.I., Boitani, L., Brooks, T.M., Cowling, R.M., Fishpool, L.D.C., da Fonseca, G.A.B., Gaston, K.J., Hoffmann, M., Long, J.S., Marquet, P.A., Pilgrim, J.D., Pressey, R.L., Schipper, J., Sechrest, W., Stuart, S.N., Underhill, L.G., Waller, R.W., Watts, M.E.J. & Yan, X. (2004) Effectiveness of the global protected area network in representing species diversity. Nature, 428, 640–643.
Scarano, F.R. (2002) Structure, function and floristic relationships of plant communities in stressful habitats marginal to the Brazilian Atlantic rainforest. Annals of Botany, 90, 517–524.
Soltis, P.S. & Gitzendanner, M.A. (1999) Molecular systematics and the conservation of rare species. Conservation Biology, 13(3), 471–483.
Swofford, D.L. (2003) PAUP*: Phylogenetic Analysis Using Parsimony (*and Other Methods). Version 4. Sinauer Associates, Sunderland.
Wagner, A. (1842) Diagnosen neuer Arten brasilischer Säugthiere. Archiv für Naturgeschichte, 1, 356–362.