Frogs and toads of the Pedra Azul – Forno Grande Biodiversity Corridor , southeastern Brazil

Corredor Ecológico Pedra Azul–Forno Grande (Pedra Azul– Forno Grande Biodiversity Corridor [from now on PA-FG], Figure 1). The entire region of PA-FG is part of the Atlantic Rainforest biome. The area is located in the mountain region of Espírito Santo, across the municipalities of Alfredo Chaves, Castelo, Domingos Martins, and Vargem Alta, and comprises the protected areas Parque Estadual de Pedra Azul (PEPAZ; Figure 2A) and Parque Estadual do Forno Grande (PEFG; Figure 2B), and several patches of forest with distinct degrees of preservation, but not inserted in any protected area. PEPAZ is located in the Introduction Despite intensive alteration of its habitats, due to logging, urbanization, intensive farming and other uses, the Atlantic Rainforest still harbors a significant fraction of the World’s biological diversity (Morellato and Haddad 2000). The biome is also house to a great number of endemic species; around 6000 vascular plants and 550 terrestrial vertebrates (Myers et al. 2000). At least 80 of the over 400 frog species found in the Atlantic Rainforest are endemic to the biome (Silvano and Pimenta 2003; Haddad et al. 2008). The state of Espírito Santo, Brazil, was totally covered by Atlantic Rainforest prior to European colonization. Although there is a considerable portion of the habitat already destroyed in the state, it still comprises a great realm for biodiversity. Species diversity is astonishing and a large number of endemic taxa are present, including vertebrates, invertebrates and plants (Almeida et al. 2011, Simon et al. 2005; Moreira et al. 2008, Brown and Freitas 2000, Thomaz and Monteiro 1997). Furthermore, of the 133 species of amphibians listed for Espírito Santo, sixteen are endemic to the state, six of which only known from their type-localities (Almeida et al. 2011). Here we provide a species list for the frog and toad species (Anura) in the biodiversity corridor Pedra Azul–Forno Grande, a highly fragmented Atlantic Rainforest remnant in the mountain region Espírito Santo. We also briefly discuss amphibian diversity in the state, comparing our results to those from published lists.


Introduction
Despite intensive alteration of its habitats, due to logging, urbanization, intensive farming and other uses, the Atlantic Rainforest still harbors a significant fraction of the World's biological diversity (Morellato and Haddad 2000).The biome is also house to a great number of endemic species; around 6000 vascular plants and 550 terrestrial vertebrates (Myers et al. 2000).At least 80 of the over 400 frog species found in the Atlantic Rainforest are endemic to the biome (Silvano and Pimenta 2003;Haddad et al. 2008).
The state of Espírito Santo, Brazil, was totally covered by Atlantic Rainforest prior to European colonization.Although there is a considerable portion of the habitat already destroyed in the state, it still comprises a great realm for biodiversity.Species diversity is astonishing and a large number of endemic taxa are present, including vertebrates, invertebrates and plants (Almeida et al. 2011, Simon et al. 2005;Moreira et al. 2008, Brown and Freitas 2000, Thomaz and Monteiro 1997).Furthermore, of the 133 species of amphibians listed for Espírito Santo, sixteen are endemic to the state, six of which only known from their type-localities (Almeida et al. 2011).Here we provide a species list for the frog and toad species (Anura) in the biodiversity corridor Pedra Azul-Forno Grande, a highly fragmented Atlantic Rainforest remnant in the mountain region Espírito Santo.We also briefly discuss amphibian diversity in the state, comparing our results to those from published lists.
Municipality of Domingos Martins (~ 20°24' S, 41°01' W; 1240 ha) and PEFG is located in the Municipality of Castelo (~ 20°31' S, 41°07' W; 730 ha).Coldest months are from May to September (driest months from April to September), with the raining season extending from November to January.The altitudinal range inside PEPAZ is 960-1910m and PEFG is 1200-2039m.Vegetation in the region is composed predominantly by Tropical rain forest but several areas have been heavily logged, or even completely cut for the opening of pastures or agriculture (evident in Figures 2A, B, E).A plethora of breeding sites for amphibians are available, including several small streams and natural temporary ponds (Figure 2C, D).Human made, temporary and permanent, ponds are also common in the region (Figure 2E) and serve as breeding and foraging sites for many species.Within both protected areas (PEPAZ and PEFG) large rock outcrops are present (Figures 2A, B), and herbaceous to shrubby vegetation is common.Many large bromeliads (e.g.Alcantharea) are found over the rocks (Figure 2F), but epiphytic species are also found inside forests (the latter have been largely harvested; our personal observation).Several species were found within bromeliads, using them either as breeding sites or for shelter and foraging.

Sampling
We surveyed PA-FG from September 2004 to October 2009, using visual and audio surveys, as described in Heyer et al. (1994).Sampling was more intense inside the protected areas and its immediate vicinities, but we also collected in several sites along the forest remnants that link the two parks.The list was compiled from several distinct projects we held on the region along the years, and sampling effort was not equal among regions and therefore cannot be exactly quantified, except from a few time intervals.Photographs of at least one individual of every species were taken in the field, during this study, unless noted otherwise.Species not photographed in PA- To complement the list, we surveyed zoological collections with large holdings of specimens from Espírito Santo.Voucher specimens are deposited in the following institutions: Coleção de Anfíbios Célio F. B.

Results and Discussion
We registered 43 species, representing nine families, in the PA-FG (Table 1, Figures 3-10 Recent data on the diversity of amphibians in the state of Espírito Santo, together with recent findings of new species of frogs in the state (e.g.Pombal et al. 2003;Caramaschi et al. 2004, Napoli 2005, Pombal and Gasparini 2006, Caramaschi et al. 2009, Faivovich et al. 2010, Canedo and Pimenta 2010) reinforces the importance of additional biodiversity surveys in the state, even in previously studied areas, as is the case of Pedra Azul, studied by many herpetologists for many decades (our personal observation), but for which no published species list is available.
The species list of PA-FG will probably grow when additional techniques are used.The use of pitfall traps  (Prado and Pombal 2005).Several of the additional records found by Tonini et al. (2010) were representatives of terrestrial secretive species, most likely only sampled because of the use of traps.Even without additional techniques (e.g.pitfall traps), our inventory attained a considerable number of species.
Conservation of biodiversity corridors is crucial for maintaining genetic diversity of populations present in fragments.Dixo et al. (2009) evaluated the reduction of genetic diversity in populations of Rhinella ornata and connectivity among fragmented habitats, comparing medium and small forest fragments, connected or not to forest areas through corridors.Their work shows that the fragment size is positively correlated with genetic diversity, posing a problem for smaller populations, where genetic variability is smaller (Dixo et al. 2009).Biodiversity corridors should then be preserved and protected, and new ones must be implemented in the Atlantic Rainforest, to make up for its fragmented landscape.The presence of unique species in the forest fragments (nine species, see Table 1) that connect PEPAZ and PEFG and the occurrence of threatened species in this region reinforce the importance of conservation of this biodiversity corridor.

Figure 2 .
Figure 2. Localities and habitats surveyed for amphibians in Pedra Azul.(A) General view of the Pedra Azul region, with the actual Pedra Azul rock at the back.(B) General view of the Forno Grande region.(C) Small stream and a temporary pond inside the forest in Pedra Azul.(D) Temporary pond formed in an open area on the forest edge.(E) Permanent pond in an anthropic clearing.(F) Bromeliads attached to rocky outcrops in Forno Grande.
, Appendix 1).The list of amphibians threatened with extinction in the state of Espírito Santo includes 10 species(Gasparini et al. 2007), two of which we found in our study area: Dendropsophus ruschii and Megaelosia apuana.Both species have, however, been found in streams inside forest or on forest edges in other regions(Cassini et al. 2007, Almeida et al. 2011;Santos et al. 2011).In PA-FG we have found apparently healthy populations of both D. ruschii and M. apuana.Several calling males, amplectant pairs, egg clutches, tadpoles and juveniles of D. ruschii (Figure3A-B) were found in consecutive years since the discovery of the population in 2005(Peloso and Gasparini 2006).We did not observe reproductive behavior of M. apuana, but the finding of large tadpoles and recently metamorphosed juveniles (Figure3C) evidences that reproduction is taking place.Furthermore, Scinax belloni (Figure8B) -considered as Endangered in the IUCN Red List of Threatened Species (IUCN 2011) -was recorded both in PEFG and in the fragments between PEPAZ and PEFG.Published amphibian inventories for the Espírito Santo are scant and generally based on rapid inventories (but seeTonini et al. 2010).In a recent workAlmeida et al. (2011) recorded 133 amphibian species occurring in the state.Species diversity found in PA-FG is similar to other mountain regions in the state of Espírito Santo.Ramos and Gasparini (2004) found 41 species in the Goiapaba-Açu region, municipality of Fundão, andTonini et al. (2010) found 52 species in the Reserva Biológica de Duas Bocas, municipality of Cariacica.Rödder et al. (2007) briefly commented on anuran diversity in scattered locations in the municipality of Santa Teresa and adjacent localities.The authors listed 54 species for Estação Biológica de Santa Lúcia, 21 for Pousada Paradiso, 30 for Reserva Biológica de Nova Lombardia, and 23 for Vargem Alta.

Figure 3 .
Figure 3. Species found during this study that are included in the list of threatened species of Espírito Santo: Dendropsophus ruschii: (A) egg clutch deposited on a pending leaf above water and (B) juvenile.Megaelosia apuana: (C) juvenile.

Figure 9 .
Figure 9.Some of the frog species from Pedra Azul-Forno Grande: (A) Physalaemus crombiei; (B) Physalaemus cuvieri; (C) Leptodactylus fuscus, specimen from Santa Teresa, ES; (D) Leptodactylus latrans.Table1.List of species found in the Pedra Azul-Forno Grande Biodiversity Corridor, state of Espírito Santo, Brazil.The sampling method can be Species marked with an asterisk were found exclusively during examination of collections material and were not collected during our study.Sampling Methods; A = adult, T = tadpole, V = vocalizations, PA = Parque Estadual da Pedra Azul, FG = Parque Estadual do Forno Grande, Fr = Forest fragments: any specimen collected outside the parks but within the biodiversity corridor PA-FG.