Adriano G. Chiarello

Is camera-trapping an efficient method for surveying mammals in Neotropical forests? A case study in south-eastern Brazil

Although highly diverse (Fonseca et al . 1996), the Atlantic forest mammal fauna is still poorly known, with very few sites exhaustively inventoried or subjected to long-term studies (Passamani et al . 2000). Although the first surveys using camera traps were carried out in the 1920s (e.g. Chapman 1927), most studies are rather recent (Karanth & Nichols 1998). This is not different in Brazil, where few studies have been published (Marques & Ramos 2001, Santos-Filho & Silva 2002, Silveira et al . 2003, Trolle 2003, Trolle & Kery 2003). Given this, the objective of this paper is to assess the efficiency of camera trapping as an inventory technique for Neotropical forests in general and Atlantic forest in particular. The study was conducted at the Santa Lucia Biological Station (SLBS), a biologically rich Atlantic Forest preserve located in south-eastern Brazil (Mendes & Padovan 2000) where mammals have been intensively live-trapped, observed from line-transects or had indirect evidence of their presence (faeces, footprints, scratches, etc.) recorded in earlier years (Passamani et al . 2000).

Slow death of Atlantic forest trees in cocoa agroforestry in southeastern Brazil

Cocoa (Theobroma cacao) is cultivated in the states of Bahia and Espírito Santo in eastern Brazil under the so-called ‘cabruca system’, where the understorey of native Atlantic forest is cleared and the canopy is thinned out to provide adequate shading for the cocoa trees. Apart from its economic and social role, the cabruca system is said to be important for the conservation of Atlantic forest biodiversity. In this paper we studied tree species richness and forest structure of cabrucas to examine the demographic health of these forests and discuss their long-term survival. Data were collected in 20 farms located alongside a 30 km track of the northern margin of the Rio Doce, in northern Espírito Santo. All trees ≥5 cm DBH were identified and their diameter was measured in 80 plots (600 m2), totalling 4.8 ha of sampled area. Recorded trees were also allocated to four different regeneration phases (pioneers, early secondary, late secondary and climax). The inventory resulted in 507 trees belonging to 105 species in 39 families. This species richness is much lower than in less disturbed forests located in the region. Pioneers and early secondary species dominate the cabruca forest in terms of number of species (56.2%), density (71.0%) and basal area (72.3%). The distribution of diameter frequency showed an imbalance in tree regeneration. Most trees in the range of 5–30 cm DBH were pioneers (40.7%), or early secondary species (32.6%), while late secondary and climax trees were less frequent (10.2 and 16.5% of the sampled trees, respectively). The dominance of species of early regeneration phases was also observed for trees >30 cm DBH (69.0% of pioneers or early secondary and 31.0% of late secondary or climax species). The results indicated that the cabruca forests are not only less diverse and less dense than secondary or primary forests of the region, but also, and more importantly, their natural succession and gap dynamics are being severely impaired. As a consequence, cabrucas present a structure where tree species of late successional phases are becoming increasingly rare while pioneers and early secondary species are becoming dominant. If current management practices of thinning and clearing of native trees are not improved, the long-term survival of these forests is questionable and their role in maintaining biodiversity in the long run is limited.

Primates of the Brazilian Atlantic Forest: The Influence of Forest Fragmentation on Survival

The Atlantic forest has been cleared and disturbed since the arrival of the first Europeans in the early 1500s (Dean, 1995). More than 70% of the Brazilian population is concentrated in this region, and it is estimated that less than 8% of the original forest remains as isolated forest (SOS Mata Atlântica et al., 1998). Nevertheless, this forest still harbors an extremely rich biological diversity, second only to the Amazon region, with about 261 mammal species already recorded, 73 (28%) of which are endemics (da Fonseca et al., 1999; Myers et al., 2000). Until the present, 15 species and 24 subspecies of primates have been recognized for the Atlantic forest (Rylands et al., 1996, 2000), including two endemic genera, Brachyteles and Leontopithecus. The overall biological richness and the high degree of threat make the Atlantic forest one of the top biodiversity “hotspots” in the world (Myers et al., 2000).

Predation on the black capuchin monkey Cebus nigritus (Primates: Cebidae) by domestic dogs Canis lupus familiaris (Carnivora: Canidae), in the Parque Estadual Serra do Brigadeiro, Minas Gerais, Brazil

Predation on an adult male black capuchin monkey, Cebus nigritus (Goldfuss, 1809) by two domestic dogs was observed in the Parque Estadual Serra do Brigadeiro, in the Atlantic Forest of southeastern Minas Gerais. Predation occurred in an area of well preserved native forest 800 m from the nearest forest edge. This is the first confirmed record of predation by domestic dogs in this reserve, yet data from a study in the same area indicates that the domestic dog is the most frequently recorded mammal species, which suggests that it is common in the area. The few published reports indicate that this problem occurs in other conservation units in Brazil and should, therefore, be treated with more rigor by the environmental agencies.

Is the domestic dog becoming an abundant species in the Atlantic forest? A study case in southeastern Brazil.

Abstract The Brazilian Atlantic forest has been reduced to a small fraction of its original area, with most remaining fragments being small and surrounded by anthropogenic matrices. This degree of disturbance, together with the increasing sprawl of cities towards the rural zone, greatly facilitates the entrance of domestic animals into these remnants. We used camera traps to compare the abundances of the domestic dog with a similarly sized native carnivore, the ocelot, in a 957-ha reserve of the Brazilian Atlantic forest in a landscape largely composed by pastures and agriculture. The dog was the most recorded species among all 17 mammal species “captured” by the cameras. Dog abundance (32–38 dogs) and density (0.812–1.813 dogs/km2) were significantly higher than that of the ocelot (n=2 ocelots; density=0.158–0.347 ocelots/km2). Although our result is restricted to a single study site, it is supported by an increasing number of recent studies, which have detected dogs inside other Atlantic forest reserves. Our study suggests, therefore, that this invasion might be more widespread than generally thought. The presence of the domestic dog is a threat to native fauna and constitutes an important edge effect of human presence at the rural zone.

Life‐history traits and sexual dimorphism of the Atlantic forest maned sloth Bradypus torquatus (Xenarthra: Bradypodidae)

This work presents new data from 48 maned sloths Bradypus torquatus captured between November 2002 and November 2003 in three regions of the Atlantic forest where the largest remnant populations of this species are found. Data from another long-term study, carried out from 1994 to 1996 and from 1999 to the present (n=14), were also used, making a total sample of 62 sloths. Average adult body weight is 6594±236 g and average head-body length is 66.5±0.8 cm (n=35), indicating that Bradypus torquatus is the heaviest of all four Bradypus species. Individuals from lower-montane forests (600–1000 m a.s.l.) are significantly larger (head–body length; t-test; P=0.001) than individuals from the lowlands (<350 m a.s.l.), suggesting altitudinal differentiation between populations. Sexual dimorphism, here reported for the first time, was found in body length (females are significantly larger than males) and in other external characters, such as mane size and form (darker and larger in males), and size and shape of the external genitalia. Most differences between sexes are, however, only discernible in reproductively active individuals. Breeding is slightly seasonal; minimum observed interbirth interval was 1 year and litter size was always one. Infants stayed with their mothers until 8–11 months old; started feeding on solid food as early as 2 weeks old but continued suckling until c. 4 months of age. Age of sexual maturity was estimated at 2–3 years and the oldest captured maned sloth was a healthy male who was at least 12 years of age. Overall, results indicated that maned sloths are similar in these aspects to congeneric species. Information presented here significantly improves the current knowledge on this endangered sloth species and is useful for the proper planning and implementation of in situ conservation strategies such as translocations and reintroductions.

Armadilhas fotográficas na amostragem de mamíferos: considerações metodológias e comparação de equipamentos

The use of camera traps is quite recent in Brazil. The high cost of equipments and constant expenses with supplies can, in some circumstances, limit the number of units to be deployed and sampling effort. The present study discusses methodological issues aiming at optimizing the use of these traps in mammalian inventories and also provides a comparison of two brands of equipments. The study was carried out in Santa Lucia Biological Station (SLBS) in Center-north Espirito Santo state between January 2002 and November 2003, using three Wildlife Pro Camera

A radio tracking study of home range and movements of the marsupial Micoureus demerarae (Thomas) (Mammalia, Didelphidae) in the Atlantic forest of south-eastern Brazil

From August 2001 to July 2002 the home range and movements of seven Micoureus demerarae (Thomas, 1905) (three males and four females) were investigated using radio tracking in the Uniao Biological Reserve, state of Rio de Janeiro, south-eastern Brazil. A total of 436 locations was obtained and home range estimated with fixed Kernel (95% of data points), and minimum convex polygon (MCP) methods, with 100 and 95% of data points. Male home ranges estimated by MCP (100%) ranged from 5.4-24.2 ha and females from 0.3-10.7 ha. Corresponding figures calculated with Kernel (95%) were 4-10.9 ha for males and 1.3-5.9 ha for females. Animals travelled on average 423 m/night, with males travelling significantly further (582.8 m/night) than females (335.1 m/night) (t test, t = 3.609, p = 0.001). We concluded that radio tracking produced much larger home ranges than those estimated with traditional live-trapping techniques, suggesting that the latter might underestimate ranging when the area covered with traps is relatively small (ca. 1 ha or less). Radio tracking also indicated that M. demerarae, although predominantly arboreal and weighting only ca. 130 g., has movements similar in magnitude to larger-sized terrestrial didelphimorph marsupials, such as Didelphis Linnaeus, 1758, Philander Linnaeus, 1758 and Metachirus (Desmarest, 1817).

Sleeping sites of woolly mouse opossum Micoureus demerarae (Thomas) (Didelphimorphia, Didelphidae) in the Atlantic Forest of south-eastern Brazil

Micoureus demerarae (Thomas, 1905) e um marsupial de tamanho medio, cerca de 130 g, de habito noturno e arboricola e dieta insetivora-onivora. No periodo de agosto de 2001 a julho de 2002, sete individuos, tres machos e quatro femeas, foram acompanhados, atraves de radio-telemetria, na Reserva Biologica Uniao, Rio de Janeiro, com o objetivo de investigar e descrever os abrigos utilizados por essa especie de marsupial. Foram localizados 58 abrigos, a maioria dos quais (70,7%) em palmeiras Iri Astrocaryum aculeatissimum (Schott) Burret e o restante em outras especies de arvores (29,3%), uma diferenca significativa (teste c2; p < 0,005). Esta preferencia por palmeiras nao foi significativamente diferente entre os sexos (teste c2; p = 0,920). Em 31 abrigos (53,4% do total) o local exato onde o animal se encontrava pode ser localizado: nas palmeiras os animais sempre estavam alojados no local de insercao dos peciolos junto ao tronco e a uma altura media de 4,66 ± 1,36 m, enquanto nas demais especies de arvores, sete animais estavam em emaranhados de cipos e dois em ocos, a uma altura media de 10,67 ± 2,75 m. Esta diferenca de altura entre abrigos em iris e nao iris foi significativa (teste Mann Whitney; p < 0,001). Os resultados indicam que as palmeiras iris sao um importante recurso para M. demerarae. A preferencia por A. aculeatissimum se deve provavelmente a maior protecao contra predadores exercida pelos numerosos espinhos presentes nesta especie.

The Red-Billed Curassow (Crax blumenbachii): Social Organization, and Daily Activity Patterns

Abstract We studied the Red-billed Currasow (Crax blumenbachii) in Vale Natural Reserve, Linhares, Espírito Santo State, Brazil, using camera traps. We found the Red-billed Curassow present in the entire area of the reserve (∼ 22,000 ha) during 40 months of camera trapping (2005–2008). Most records were of single individuals, especially males, but pairs and even groups of individuals were also recorded. Males were paired with one and two females, suggesting polygyny in the species. The species was recorded throughout the day with one peak from 0500 to 0600 hrs and another after 1600 hrs. The daily activity pattern was similar for males and females. The number and widespread nature of the records suggests the local population of this species may be higher than previously thought.