Birds, Ilha Grande, state of Rio de Janeiro, Southeastern Brazil

We provide a list of bird species from our primary surveys and secondary data for an island (Ilha Grande) in southeastern Brazil. The information derives mainly from primary data collected since 1995, particularly in the oceanic side of the island. The methodologies included capture-mark-recapture studies using mist nets, transects (visual and vocal records) and supplementary observations. Our total species list from primary data is 175 species (127 captured) and 47 species were added from secondary data. This represents 222 species from 58 families. Of this total, 44 are endemic to Atlantic forest and nine are threatened with extinction. Our results are discussed comparing our study area with another large island included in the Serra do Mar corridor (Ilha de São Sebastião), and also a nearby continental area (Paraty). The results indicate the importance of Ilha Grande as a reservoir of bird species of Atlantic forest. Introduction The Atlantic forest is a top global priority for conservation (Myers et al. 2000). However, some habitats of the Atlantic forest are poorly known, such as the montane coastal forests of Ilha Grande, state of Rio de Janeiro, which holds several endemics of this bioma, including endangered species (Alves et al. 2000a; Alves 2001). Although Ilha Grande is part of one of the largest continous remnants of the Atlantic forest in the state of Rio de Janeiro, there are few publications on its bird fauna. The great majority of published studies about birds from Ilha Grande is related to aspects of population ecology, such as interactions, autoecology or breeding (Alves et al. 2001). Here, we provide a list of species found during our primary surveys of the forests of Ilha Grande, particularly around Vila Dois Rios, the oceanic part of the island, as well as secondary data. Study Site and Methods Ilha Grande is a 19,300 ha continental island located in the municipality of Angra dos Reis (23o15' S, 44o15' W), on the southern coast of the state of Rio de Janeiro. The field surveys for the present study were carried out in a protected area, Parque Estadual da Ilha Grande, which comprises more than a half of the island. Ilha Grande forms part of one of the largest continuous remnants of Atlantic forest in the state (Figure 1). Annual rainfall in the area is around 1,700 mm, and mean annual temperature is about 23°C (Alho et al. 2002). The vegetation of Ilha Grande is represented by the Atlantic forest formation “Floresta Ombrófila Densa” and areas of restinga and mangroves, particularly in the oceanic side (Alho et al. 2002; Rocha et al. 2003). The island vegetation is in distinct stages of regeneration due to anthropogenic disturbance, in particular past agricultural practices involving the growth of crops such as sugar cane, coffee and corn (Alho et al. 2002). Cultivations were finished when the State Park was established in the area (Araújo and Oliveira 1988). The least disturbed areas of forest are located in the most inaccessible parts of the island. Field surveys We gathered information on bird species mainly from primary data. Since 1995, surveys carried out by the authors and members of the Bird Ecology Laboratory of the Universidade do Estado do Rio de Janeiro (UERJ) have resulted in the accumulation of bird records for Ilha Grande. Methods used included capture-mark-recapture using mist nets, transects (including visual and vocal records) and supplementary observations. To catch birds we used 10 mist nets (12 x 2.5 m, 36 mm mesh) per month, set for 7 h, from the early morning, over two consecutive days. Nets Check List 5(2): 300–313, 2009. ISSN: 1809-127X


Introduction
The Atlantic forest is a top global priority for conservation (Myers et al. 2000).However, some habitats of the Atlantic forest are poorly known, such as the montane coastal forests of Ilha Grande, state of Rio de Janeiro, which holds several endemics of this bioma, including endangered species (Alves et al. 2000a;Alves 2001).Although Ilha Grande is part of one of the largest continous remnants of the Atlantic forest in the state of Rio de Janeiro, there are few publications on its bird fauna.The great majority of published studies about birds from Ilha Grande is related to aspects of population ecology, such as interactions, autoecology or breeding (Alves et al. 2001).Here, we provide a list of species found during our primary surveys of the forests of Ilha Grande, particularly around Vila Dois Rios, the oceanic part of the island, as well as secondary data.

Study Site and Methods
Ilha Grande is a 19,300 ha continental island located in the municipality of Angra dos Reis (23º15' S, 44º15' W), on the southern coast of the state of Rio de Janeiro.The field surveys for the present study were carried out in a protected area, Parque Estadual da Ilha Grande, which comprises more than a half of the island.
Ilha Grande forms part of one of the largest continuous remnants of Atlantic forest in the state (Figure 1).Annual rainfall in the area is around 1,700 mm, and mean annual temperature is about 23°C (Alho et al. 2002).The vegetation of Ilha Grande is represented by the Atlantic forest formation "Floresta Ombrófila Densa" and areas of restinga and mangroves, particularly in the oceanic side (Alho et al. 2002;Rocha et al. 2003).
The island vegetation is in distinct stages of regeneration due to anthropogenic disturbance, in particular past agricultural practices involving the growth of crops such as sugar cane, coffee and corn (Alho et al. 2002).Cultivations were finished when the State Park was established in the area (Araújo and Oliveira 1988).The least disturbed areas of forest are located in the most inaccessible parts of the island.

Field surveys
We gathered information on bird species mainly from primary data.Since 1995, surveys carried out by the authors and members of the Bird Ecology Laboratory of the Universidade do Estado do Rio de Janeiro (UERJ) have resulted in the accumulation of bird records for Ilha Grande.Methods used included capture-mark-recapture using mist nets, transects (including visual and vocal records) and supplementary observations.To catch birds we used 10 mist nets (12 x 2.5 m, 36 mm mesh) per month, set for 7 h, from the early morning, over two consecutive days.Nets were set in areas of least disturbed forest, mainly near the university research station [Centro de Estudos Ambientais e Desenvolvimento Sustentável -CEADS/UERJ -at Vila Dois Rios (Figure 1)].Captured birds were individually marked with metal rings and released.
Besides the primary data, the list of birds presented in this paper (Table 1) also includes information on the birds of Ilha Grande from other researchers (Maciel et al. 1984;Coelho et al. 1991;Maciel and Pacheco 1995;Pacheco et al. 1997;Buzzetti 2000;Raposo et al. unpublished data; Maciel unpublished data), following taxonomy from CBRO (2008).Figure 1.Geographic location of Ilha Grande Island at Ilha Grande Bay, in the state of Rio de Janeiro, Brazil.Source: Alves et al. 2000b.

Results and Discussion
A total of 175 bird species were encountered at Ilha Grande during the primary surveys.An additional 47 species were obtained from secondary data from other authors (Maciel et al. 1984;Maciel and Pacheco 1995;Coelho et al. 1991;Pacheco et al. 1997;Buzzetti 2000;Raposo et al. unpublished data;Maciel unpublished data), including data from other locations at Ilha Grande besides the ones we sampled (Table 1).This represents 222 bird species from 58 families.

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Families with higher number of species were Tyrannidae and Thraupidae with 35 and 16 species, respectively.A total of 44 species are endemic of Atlantic forest and nine are threatened with extinction at regional, national or global levels (Table 1).Elaenia obscura (d'Orbigny & Lafresnaye, 1837) was recorded by Helmut Sick in 1944 and it was quoted by Pacheco et al. (1997).
Although Megascops atricapilla (Temminck, 1822) was cited by Pacheco et al. (1997) and Buzzetti (2000), we have referred to Megascops sp. in the present study, as we recorded only one species of this genus, which we considered as Megascops cf.choliba.Therefore, we recommend a more detailed study of this taxon.
Of the 222 species recorded for Ilha Grande (Table 1), 44 (20.7 %) are endemic to Atlantic forest (according to Bencke et al. 2006).This total of endemics is about three times more than that recorded by Alho et al. (2002) for the study area, using the database included in the Plano Diretor do Parque Estadual da Ilha Grande.
Nine of the species recorded are threatened with extinction at global (IUCN 2008), national (Machado et al. 2008) and regional (Alves et al. 2000a)  Atlantic forest remnants at Ilha Grande, as well as Itatiaia (states of Rio de Janeiro and Minas Gerais), can be two remarkable Atlantic forest remnants for Pyroderus scutatus, whose populations are much reduced in Southeast Brazil (Sick 1997).----------Of the 175 species recorded during our primary surveys, 127 were captured using mist nets.Turdus albicollis Vieillot, 1818 was the species most frequently captured in the understory of the least disturbed forest during these systematic long-term studies (Alves 2001;Alves 2007).This kind of data allows evaluations of the population numbers over the years and between years (Alves 2007).Other species frequently captured and recorded based on sightings or vocalizations were Chiroxiphia caudata (Shaw & Nodder, 1793) and Trichothraupis melanops (Vieillot, 1818).One example of a species not regularly recorded is Haplospiza unicolor Cabanis, 1851, captured only six years after starting our mist netting study (Alves 2007).This last species is endemic of Atlantic forest, feeds on bamboo seeds, and is usually detected during the flowering and fructification of these plants (Olmos 1996b).Species eventually captured but with no visual or vocal record were Pionopsitta pileata (Scopoli, 1769), Elaenia mesoleuca (Deppe, 1830) and Phyllomyias fasciatus (Thunberg, 1822).We did not recorded any species based only on vocal record, except Grallaria varia (Boddaert, 1783), and Nyctibius griseus (Gmelin, 1789), which we have no doubt in terms of vocal identification.----------In contrast to generalist species such as Pitangus sulphuratus (Linnaeus, 1766), the frugivores Lipaugus lanioides (Figure 3), Procnias nudicollis, Pyroderus scutatus and Selenidera maculirostris (Lichtenstein, 1823) (Figure 4) are restricted in their use of the habitat, and endemic of Atlantic forest (Bencke et al. 2006).The three Cotingidae species, which occur in the superior forest stratum (M.B. Vecchi, unpublished data), are highly sensitive to human disturbance, and good indicators of environmental quality (Parker et al. 1996).Another highly sensitive species according to Parker et al. (1996) is Leucopternis lacernulatus (Figure 5), a globally threatened top predator (Table 1).The presence of these species at Ilha Grande reinforces the importance of this area for the conservation of birds of the Atlantic forest biome.Another analysis of the sensitivity of bird species to habitat disturbance indicated a stable conservation status at Ilha Grande, which means that the islands' forests have a satisfactory level of conservation for this group (Alho et al. 2002).
There are few studied islands with Atlantic forest cover to compare with our results.However, our data can be compared with São Sebastião, which together with Ilha Grande is one of the largest islands of the Serra do Mar corridor, and is also located relatively close to the continent.During a study at Ilha de São Sebastião, Olmos (1996a) recorded 207 bird species associated with forest habitats only.Selecting only this group of birds, we recorded 194 species at Ilha Grande, representing approximately 94 % of the total recorded for Ilha de São Sebastião.Considering that Ilha Grande is 57 % of the size of Ilha de São Sebastião, and twice farthest from the continent (3.5 km compared with 1.76 km), Ilha Grande stands out in terms of species richness.However, the number of endemics species of Atlantic forest was slightly higher for Ilha de São Sebastião (58 species, 28 % of the total) than for Ilha Grande (44 species, 23.4 % of the total).In terms of the terrestrial birds, 140 species occurred in both islands, 54 species were exclusive to Ilha Grande and 67 to Ilha de São Sebastião.This similarity is likely to be a consequence of the close proximity and similar environment of both islands, separated by 110 km.Among nationally and/or globally threatened Atlantic forest endemics, only two species were common in both islands (Procnias nudicollis and Sporophila frontalis), two were exclusive to Ilha Grande (Leucopternis lacernulatus and Amazona   The list of species we have compiled for Ilha Grande includes about 30% of the 730 bird species occurring in the state of Rio de Janeiro (Gagliardi 2008).In this context, it is important to note that, although our team has worked at Ilha Grande for approximately 12 years, our systematic long-term study is restricted to a small portion of Ilha Grande, so our surveys have probably underestimated the bird species richness.
The presence at Ilha Grande of a representative portion of the avifauna of the state of Rio de Janeiro, together with a high number of endemic species of Atlantic forest and nine threatened species, indicates the importance of this island as a bird species reservoir of Atlantic forest.

Figure 2 .
Figure 2. Thraupis cyanoptera is an endemic species of Atlantic forest occurring at Ilha Grande, state of Rio de Janeiro, Brazil.Photo by M. B. Vecchi.

Figure 3 .
Figure 3. Lipaugus lanioides is an endemic species of Atlantic forest occurring at Ilha Grande, state of Rio de Janeiro, Brazil.Photo by M. B. Vecchi.

Figure 5 .
Figure 5. Leucopternis lacernulatus is a threatened and endemic bird of Atlantic forest at Ilha Grande, state of Rio de Janeiro, Brazil.Photo by M. S. Zanon.
Browne (2005)compiled a considerable volume of information about birds for continental areas west of Ilha Grande for the municipality of Paraty.Including primary and secondary data, this author listed 379 species for Paraty in localities 20 to 50 km from Ilha Grande.Despite the high species richness for birds and the proximity between Paraty and Ilha Grande Bay, the list we compiled for Ilha Grande in the present study includes 32 species not cited by Browne, which corresponds to 14.4 % of our records.Examples of these species are Accipiter bicolor (Vieillot, 1817),