Restinga De Jurubatiba Research Articles

Evolução Paleoambiental de Lagunas da Restinga de Jurubatiba, Estado do Rio de Janeiro

This work analysed assemblages of benthic foraminifera in core samples in lagoons from the Restinga de Jurubatiba Rio de Janeiro State, to observe paleoenvironmental changes and sedimentary deposition processes. Six cores were drilled (vibra-cores) until a depth of 1,56cm, in the Garcas, Maria Menina, Robalo, Visgueiro, Catingosa and Pires lagoons. It was found that cores with sandy sediments presented lower abundance and richness of foraminifera species than fine sediment cores. Through the foraminiferal assemblages, four biofacies were characterized that reflected episodes of distinct evolutionary conditions for each lagoon. For the sandy lagoons, it was recorded the biofacies Ammonia/ Elphidium representing moderate marine influence, and the biofacies Aglutinated/Trochammina inflata representing the lagoon confinement. At the muddy lagoons, occurred the biofacies Ammonia spp./Elphidium spp./Haynesina germanica which represents paleoenvironments with high marine influence and the biofacies A. tepida/ A. parkinsoniana with low marine influence that favor conditions to opportunistic species. Radiocarbon dating allowed to record, in the sedimentary deposition process of the lagoons, Holocene submergence phases related to the marine transgressions.

Plants of Brazilian restingas with tripanocide activity against Trypanosoma cruzi strains.

Chagas disease is caused by the Trypanosoma cruzi affecting millions of people, and widespread throughout Latin America. This disease exhibits a problematic chemotherapy. Benznidazole, which is the drug currently used as standard treatment, lamentably evokes several adverse reactions. Among other options, natural products have been tested to discover a novel therapeutic drug for this disease. A lot of plants from the Brazilian flora did not contain studies about their biological effects. Restinga de Jurubatiba from Brazil is a sandbank ecosystem poorly studied in relation to plant biological activity. Thus, three plant species from Restinga de Jurubatiba were tested against in vitro antiprotozoal activity. Among six extracts obtained from leaves and stem parts and 2 essential oils derived from leave parts, only 3 extracts inhibited epimastigote proliferation. Substances present in the extracts with activity were isolated (quercetin, myricetin, and ursolic acid), and evaluated in relation to antiprotozoal activity against epimastigote Y and Dm28 Trypanosoma cruzi strains. All isolated substances were effective to reduce protozoal proliferation. Essentially, quercetin and myricetin did not cause mammalian cell toxicity. In summary, myricetin and quercetin molecule can be used as a scaffold to develop new effective drugs against Chagas's disease.

Lizard assemblage from a sand dune habitat from southeastern Brazil: a niche overlap analysis.

Communities are structured by interactions of historical and ecological factors, which influence the use of different resources in time and space. We acquired data on time of activity, microhabitat use and diet of a lizard assemblage from a sand dune habitat in a coastal area, southeastern Brazil (Restinga de Jurubatiba). We analyzed the data of niche overlap among species in these three axes (temporal, spatial and trophic) using null models. We found a significant overlap within the trophic niche, whereas the overlap for the other axes did not differ from the expected. Based on this result, we discuss the factors acting on the structure of the local lizard community.

Heterogeneity of bird communities in a mosaic of habitats on a restinga ecosystem in southeast Brazil

Restinga occurs as a narrow band of coastal habitats throughout the Atlantic Forest, although it presents considerable variation in vegetation structure, which likely contributes to heterogeneity in species inhabiting this endangered ecosystem. The goal of this study is to examine how variation in vegetation and abiotic conditions in the restinga ecosystem may contribute to heterogeneity of bird communities in Restinga de Jurubatiba, Brazil. Temperature, relative humidity, and vegetation structure were sampled to characterize four sites (dry forest, flooded forest, open scrub and closed scrub). Birds were sampled using observations, mist-netting and voice recordings. Results indicate that major differences of all variables occur between forest and scrub in both vegetation and birds. In addition, differences also exist within forests and within scrub, resulting in considerable heterogeneity among sampled areas. Scrub sites were richer in bird species (n = 58) than forest sites (n = 41), while closed scrub had the most species (n = 49). Also, 64% (47 of 73) of bird species were exclusive to forest or scrub habitats. Scrub habitats were more similar to each other than forest habitats. Normalized Difference Vegetation Index (NDVI) calculated from satellite images distinguished scrub sites and may be useful to monitor changes in vegetation patches through time. The restinga ecosystem is quite heterogeneous with considerable turnover in bird species composition and differences in vegetation structure. Forest strips may serve as connectors on the landscape and to help maintain species diversity and conservation of forest species. Also, this highly dynamic ecosystem, which includes a mosaic of habitat types, likely promotes resilience of bird populations under changing conditions.

Record of insects in two fern species of the genus Microgramma (Polypodiaceae) in the Atlantic Rain Forest, Rio de Janeiro state, Brazil.

species, Microgramma vacciniifolia (Langsd. et Fisch.) Copel. and Microgramma geminata (Schrad.) R.M.Tryon et A.F.Tryon.M. vacciniifolia is a fern epiphyte with Neotropical geographic range. It occurs in many types of vegetation and also in urban trees. In field work in the restinga (sandy coastal plains) of the Marica Environmental Protection Area, Rio de Janeiro State, Brazil, two morphological types of galls, ellipsoid and ovoid ( Figure 1a, b), were reported. Both galls were collected in a Myrtaceae “thicket” community from June 2008 to August 2009 and transported to the laboratory. Part of the sample was packed in transparent plastic bags with moist cotton and checked daily for adult emergence. The botanical dried specimens were deposited in the herbarium of the Faculdade de Formacao de Professores, UERJ (RFFP) and the zoological material were incorporated into the holdings of the Museu Nacional (MNRJ), Rio de Janeiro, Brazil (Cecidomyiidae), Agencia Paulista de Tecnologia dos Agronegocios (APTA), Ribeirao Preto (wasps) and Instituto Uiracu, Bahia (micromoths).The ellipsoid galls are induced by a micromoth (Microlepidoptera), Tortrimosaica polypodivora (Brown et Baixeras, 2004) (Figure 1a). One parasitoid wasp - Cheloninae (Braconidae) - and one inquiline species - Dasineura sp. (Cecidomyiidae) - are also found in the galls and this is the first record of both being connected to M. vacciniifolia. T. polypodivora also induces galls in another fern, Microgramma squamulosa (Kaulf.) de la Sota (Brown et al., 2004). Maia and Santos (2011) described Primadiplosis microgrammae (Maia, 2011) (Cecidomyiidae, Diptera) ( Figure 1b) as producing the ovoid galls found in M. vacciniifolia. In the present note, we record the occurrence of two parasitoids Torymidae and Tetrastichinae (Eulophidae). Hymenoptera is also recorded in these galls for the first time.Although these new records of wasps are presented at family or subfamily levels, they represent an important contribution due to the scarceness of data on insect-fern interactions in the neotropics. The new data indicate that these interactions are much more complex than our previous knowledge indicated.A compilation of gall midges and host plant species of the neotropical region revealed that 92% of these species were monophagous (inducing galls on a single host plant species) and only 5.6% were oligophagous (Carneiro et al., 2009). There is currently no data available for micromoths.The galls induced by micromoths (ellipsoid) are more frequent than those induced by midges (ovoid). The first galls can be found in M. vacciniifolia occurring in natural areas and urban trees, while the second galls are rare even in natural areas. This fern is cyanogenic. The cyanogenesis always occurs in the leaves and there is variation in the stem ( Santos et al., 2005 ). Studies suggest that insect oviposition is stimulated by cyanoglucosides and these compounds could play an important role in host selection (Honda et al., 1997). In field work in a Clusia “scrub” community, in the Restinga de Jurubatiba National Park (Carapebus municipality, Rio de Janeiro state) another micromoth (not identified) in the pupal stage was found to use the stem of

Barn Owl pellets (Aves: Tyto furcata) reveal a higher mammalian richness in the Restinga de Jurubatiba National Park, Southeastern Brazil

The northern coast of the state of Rio de Janeiro harbors the largest coastal sandy plains (restingas) of southeastern Brazil, severely threatened due to recent human occupation. In this context, mammal inventories becomes urgent to support biodiversity conservation and management policies. This paper aims to update the knowledge on the mammalian species richness of Restinga de Jurubatiba National Park by analyzing pellets of the Barn owl Tyto furcata. The analyses of 4745 mammalian bone fragments (1739 individuals) revealed the occurrence of 17 species belonging to the orders Rodentia (9 spp.), Didelphimorphia (2 spp.) and Chiroptera (6 spp.). The rodents Mus musculus and Cerradomys goytaca accounted for 77.2% of the total individuals preyed, suggesting that the Barn owl hunts in both disturbed and natural open shrub formations. A compilation of previous records, together with those provided in the present study, indicates the occurrence of 44 species of mammals in the Restinga de Jurubatiba National Park, of which six (13.6%) were exclusively detected in pellets. These new records include species adapted to open formations of the interior of Brazil that were not previously reported in restingas on the basis of voucher-specimens, such as the rodents Necromys lasiurus and Calomys tener, the latter being recorded for the first time in the littoral of Rio de Janeiro state. This study underscores the importance of owl pellet analysis as a complementary and indispensable method for inventorying mammals. The results highlight the Restinga de Jurubatiba National Park as one of the restingas in Southeastern Brazil with the highest number of mammal species.

Secondary Metabolites from Leaves of Manilkara subsericea (Mart.) Dubard.

Background:Manilkara subsericea (Sapotaceae) is a species widely spread in the sandbanks of Restinga de Jurubatiba National Park (Rio de Janeiro, Brazil). It is commonly known as “maçaranduba”, “maçarandubinha” and “guracica”, being used in this locality as food, and timber. However, M. subsericea remains almost unexplored regarding its chemical constituents, including secondary metabolites from the leaves.Objective:Identify the chemical constituents from the leaves of M. subsericea.Materials and Methods:Leaves were macerated with ethanol (96% v/v), and dried crude ethanolic extract was sequentially washed with the organic solvents in order to obtain an ethyl acetate fraction. Substances from this fraction were identified by different techniques, such as negative-ion electrospray ionization Fourier and 1H and 13C nuclear magnetic resonance (NMR). Fresh leaves from M. subsericea were also submitted to hydrodistillation in order to obtain volatile substances, which were identified by gas chromatograph coupled to mass spectrometer.Results:NMR1H and 13C spectra allowed for the identification of the compounds myricetin, quercetin, and kaempferol from the ethyl acetate fraction. The negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry mass spectrum also revealed the presence in this fraction of a polyhydroxytriterpene acid (pomolic acid), and some flavonoids, such as quercitrin, and myricitrin. In all 34 volatile compounds were identified by gas chromatography-mass spectrometry, including monoterpenes, sesquiterpenes, and long chain hydrocarbons.Conclusion:This study describes the first reports concerning the phytochemical information about leaves from M. subsericea.SUMMARY Manilkara subsericea fruits proved to be a rich source of triterpenes. However, no phytochemical studies were carried out with leaves. Thus, we described identification of volatile substances from its essential oils, in addition to non-reported triterpene and flavonoids from this species.

Enzymes produced by halotolerant spore-forming gram-positive bacterial strains isolated from a resting habitat (Restinga de Jurubatiba) in Rio de Janeiro, Brazil: focus on proteases.

The screening for hydrolases-producing, halotolerant, and spore-forming gram-positive bacteria from the root, rhizosphere, and non-rhizosphere soil of Blutaparon portulacoides, a plant found in the Restinga de Jurubatiba located at the northern region of Rio de Janeiro State, Brazil, resulted in the isolation of 22 strains. These strains were identified as Halobacillus blutaparonensis (n = 2), Oceanobacillus picturae (n = 5), and Oceanobacillus iheyensis (n = 15), and all showed the ability to produce different extracellular enzymes. A total of 20 isolates (90.9 %) showed activity for protease, 5 (22.7 %) for phytase, 3 (13.6 %) for cellulase, and 2 (9.1 %) for amylase. Some bacterial strains were capable of producing three (13.6 %) or two (9.1 %) distinct hydrolytic enzymes. However, no bacterial strain with ability to produce esterase and DNase was observed. The isolate designated M9, belonging to the species H. blutaparonensis, was the best producer of protease and also yielded amylase and phytase. This strain was chosen for further studies regarding its protease activity. The M9 strain produced similar amounts of protease when grown either without or with different NaCl concentrations (from 0.5 to 10 %). A simple inspection of the cell-free culture supernatant by gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of three major alkaline proteases of 40, 50, and 70 kDa, which were fully inhibited by phenylmethylsulfonyl fluoride (PMSF) and tosyl-L-phenylalanine chloromethyl ketone (TPCK) (two classical serine protease inhibitors). The secreted proteases were detected in a wide range of temperature (from 4 to 45 °C) and their hydrolytic activities were stimulated by NaCl (up to 10 %). The serine proteases produced by the M9 strain cleaved gelatin, casein, albumin, and hemoglobin, however, in different extensions. Collectively, these results suggest the potential use of the M9 strain in biotechnological and/or industrial processes.

Laboratory evaluation of the effects of essential oil of Myrciaria floribunda leaves on the development of Dysdercus peruvianus and Oncopeltus fasciatus

Myrciaria floribunda (H. West ex Willd.) O. Berg, Myrtaceae, is popularly known as “camboim-amarelo” and was collected at Restinga de Jurubatiba (RJ, Brazil). Leaves from this species were submitted to hydrodistillation to extract its essential oil. Monoterpenes were the main compounds found (53.9%), and 1,8-cineole was the major constituent (38.4%). Studies were carried out to evaluate the effects of this essential oil on the development of two species of agricultural pests (Oncopeltus fasciatus and Dysdercus peruvianus). The essential oil was considered effective against D. peruvianus and O. fasciatus, causing mortality in both insects. The LD50 values (μg/insect) observed were 112.44μg/insect (O. fasciatus) and 309.64μg/insect (D. peruvianus) after one day of treatment, and 72.18μg/insect (O. fasciatus) and 94.42μg/insect (D. peruvianus) after 22 days of treatment. The present study reports for the first time the bioinsecticidal activity of essential oil of Myrciaria floribunda leaves, and provides important data regarding the use of essential oils in complementary programs for pest control.

Structure and phytogeographic relationships of swamp forests of Southeast Brazil

Swamp forests are associated with soils that are saturated or inundated because of a high water table. In Brazil, little is known about the plant ecology of such forests. In this paper, we aimed to describe the phytosociological structure of the tree layer of swamp forests in Restinga de Jurubatiba National Park, in the northern part of the state of Rio de Janeiro, and to evaluate the floristic similarities between these forests and some other possibly related types of vegetation formations in Brazil. The sampling included 84 species, within 62 genera and 34 families. The Shannon diversity index was 3.42, and the Shannon evenness index was 0.77. The forests studied showed an oligarchic structure; Tapirira guianensis, Calophyllum brasiliense and Protium icicariba were the most important species. Oligarchy, or monodominance, and relatively low species richness are the norm in the swamp forests of southeastern Brazil and result from the strong selective character of the saturated/inundated soils. In comparison with local areas of restinga (coastal woodland), Atlantic Forest sensu stricto, other swamp forests and flooded riparian forests, the similarity was low (Jaccard similarity coefficient < 0.25). In addition to the similar ecological conditions, geographic proximity was a key factor determining the patterns of similarity found. Our results indicate that the swamp forests of southeastern Brazil do not represent a distinguishable floristic unit, due to sources of local variation, notably migration and the establishment of adaptive species from neighboring vegetation formations (some 70% of the species surveyed).

Vegetation cover and land use of a protected coastal area and its surroundings, southeast Brazil

We applied remote sensing techniques on a TM Landsat 5 image (1:50,000) to map land use and vegetation cover of the Restinga de Jurubatiba National Park and surroundings. The thematic map generated from the digital classification of the image allowed us to spatially characterize and quantify the different land uses and soil covers of the area. Thirteen classes were identified. The most representative classes in the park were the Clusia (31.99%) and Ericaceae formations (29.14%). More than 90% of the park is occupied by native vegetation and coastal lagoons. The surroundings are very much altered by human activities (e.g. 70.64% is used for agriculture and/or cattle raising). Two hundred and three forest fragments (0.3 to 235 ha) were identified, of which 45.3% are less than 5 ha. Most fragments (56.7%) have a very elongated shape, and are thus submitted to an intense edge effect. The intense fragmentation of the surroundings and the isolation of this protected area can imply, in the long run, the loss of genetic diversity.

An update on the fish composition (Teleostei) of the coastal lagoons of the Restinga de Jurubatiba National Park and the Imboassica Lagoon, northern Rio de Janeiro State

AIM: We present an update on the composition of the fish species of the Restinga de Jurubatiba National Park and the Imboassica Lagoon, in the northern portion of Rio de Janeiro State, based on collecting efforts of almost two decades, historical museum records, and a review of the literature. METHODS: Specimens were collected using a variety of techniques, mostly between 1994 and 2012, and were fixed with the use of a 10% solution of formalin and subsequently stored in 70% alcohol solution. All specimens examined are deposited in the fish collections of the Nucleo em Ecologia e Desenvolvimento Socioambiental de Macae, Universidade Federal do Rio de Janeiro (NPM), and Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ). Continental (freshwater) fishes and some marine or estuarine species frequently collected were regarded as Resident, whereas marine species collected only sporadically were regarded as Occasional. Possible associations between the orientation of the lagoons and the composition of Resident fishes were explored through a Correspondence Analysis (CA). RESULTS: A total of 100 species, belonging to 19 orders and 41 families of the Teleostei were recorded. When both Resident and Occasional species are considered, families Carangidae and Engraulidae, with nine and eight species respectively, are the most representative. When only Resident species are considered, the Gerreidae and Gobiidae, both with seven species, are the most representative families. The Imboassica Lagoon, with 76 species, has the highest species richness among lagoons included in this study. A total of 81 species were recorded in the Restinga de Jurubatiba National Park, a number two times higher than reported on previous studies. An identification key, including 57 Resident species, is also presented. CONCLUSIONS: Parallel lagoons were characterized by a small group of continental species presumably of marine ancestry (Secondary Division), while marine species were more representative in Orthogonal lagoons. The higher frequency of marine species in Orthogonal lagoons is possibly associated with sandbar openings. Temporary and sporadic connections between Parallel lagoons during periods of higher rainfall may promote a higher similarity in terms of species composition.

Essential Oils from Fruits with Different Colors and Leaves ofNeomitranthes obscura(DC.) N. Silveira: An Endemic Species from Brazilian Atlantic Forest

Neomitranthes obscura (DC.) N. Silveira is an endemic plant of Brazilian Atlantic Forest and widely spread in the sandbanks of “Restinga de Jurubatiba” National Park. It is popularly known by local population as “camboim-de-cachorro” or “cambuí-preto” and recognized by its black ripe fruits. However, specimens with yellow ripe fruits were localized in the “Restinga de Jurubatiba” National Park. The aim of the present study was to evaluate chemical composition of essential oils obtained from leaves and fruits of N. obscura specimens with different fruit color (black and yellow) by GC and GC-MS. Essential oils from leaves of specimens with black and yellow fruits indicated a predominance of sesquiterpenes (81.1% and 84.8%, resp.). Meanwhile, essential oil from black fruits presented a predominance of monoterpenes (50.5%), while essential oil from yellow fruits had sesquiterpenes (39.9%) as major substances. Despite previous studies about this species, including essential oil extraction, to our knowledge this is the first report on N. obscura fruits with different colors. Our results suggest the occurrence of unless two different varieties for this species.

A remarkable leaf mine induced by Tachygonus sp.n. (Coleoptera: Curculionidae: Curculioninae: Rhamphini) on Erythroxylum subsessile (Erythroxylaceae) with a description of the new species

In this study, we describe and present original data on the bionomics and ecology of Tachygonus erythroxyli Hespenheide, New Species, on Erythroxylum subsessile (Mart.). Thirty individuals of E. subsessile were analysed every two months, from October, 2006 to October, 2007 at the National Park of Restinga de Jurubatiba (PNRJ) Carapebus, Rio de Janeiro, Brazil. Females of T. erythroxyli lay their eggs singly on the upper surface of the host's leaves. The mine of T. erythroxyli is expanded with three bubbles, each one representing one larval instar. These mines occur throughout the year in at least half of the host plants and are markedly more abundant in summer. We obtained three parasitoid species, making a total of 53% of the rate of parasitism. Cirrospilus sp. (Eulophidae) was the most prevalent and represented 88% of the parasitoids. The great abundance of Tachygonus mines, their high frequency in their host plant, and local monophagy of this leaf miner weevil suggest a close association between T. erythroxyli and Erythroxylum subsessile.

Morcegos (Chiroptera) capturados em lagoas do Parque Nacional da Restinga de Jurubatiba, Rio de Janeiro, Brasil

O objetivo deste trabalho foi elaborar uma lista das espécies de quirópteros capturados em seis lagoas no Parque Nacional da Restinga de Jurubatiba, Estado do Rio de Janeiro, Brasil. O Parque está localizado a cerca de 180 km a leste da cidade do Rio de Janeiro e abrange os municípios de Macaé, Carapebus e Quissamã. A região é dominada por dunas e cordões arenosos formados no Quaternário. Foram capturados 149 morcegos, pertencentes a três famílias e 14 espécies. A maior parte das espécies capturadas na restinga de Jurubatiba foi de frugívoros, em parte devido à técnica empregada, com redes de neblina, que favorece a captura de indivíduos da família Phyllostomidae. Foram capturadas cinco espécies pouco frequentes em inventários de morcegos (Uroderma magnirostrum, Lasiurus cinereus, Lophostoma brasiliense, Chiroderma villosum e Diaemus youngi). As espécies capturadas variaram entre as lagoas, o que mostra a importância desses ambientes para a manutenção da diversidade de morcegos.

Evaluation of Groundwater Quality used in the Districts of Campos dos Goytacazes, RJ

The purpose of this study was to investigate the contamination of septic tanks in the supply wells of a population settled over a sandbank area, the Lagomar neighborhood, in the city of Macaé (RJ). The neighborhood is located in the macro areas of the northern border, adjacent and buffer zone of Restinga de Jurubatiba National Park, with great ecological relevance and scenic beauty, and shelter for numerous coastal lagoons and endemic species. The studied area has low-income population, and no systems of wastewater treatment and public water supply, thus increasing the risk of diseases related to poor environmental sanitation. The presence of fecal coliforms in all samples, including a sample of treated water, indicates health risks to the local population, as well as risks of ecosystem change in the National Park and its surroundings.

Avaliação da Qualidade da Água Subterrânea Utilizada nos Distritos de Campos dos Goytacazes-RJ

The purpose of this study was to investigate the contamination of septic tanks in the supply wells of a population settled over a sandbank area, the Lagomar neighborhood, in the city of Macae (RJ). The neighborhood is located in the macro areas of the northern border, adjacent and buffer zone of Restinga de Jurubatiba National Park, with great ecological relevance and scenic beauty, and shelter for numerous coastal lagoons and endemic species. The studied area has low-income population, and no systems of wastewater treatment and public water supply, thus increasing the risk of diseases related to poor environmental sanitation. The presence of fecal coliforms in all samples, including a sample of treated water, indicates health risks to the local population, as well as risks of ecosystem change in the National Park and its surroundings.

Recursos vegetais da Restinga de Carapebus, Rio de Janeiro, Brasil

The present paper aimed at identifying the plant resources used in the Restinga de Carapebus, Restinga de Jurubatiba National Park, Rio de Janeiro, Brazil. We carried out 13 one-week visits to the study area and the informants were&nbsp; nominated by the local population. For each species we present local name, category of use, local uses, and type of plant formation. We identified only one person in the Restinga de Carapebus who knows, uses, and indicates the plants of the coastal sand plains for several purposes. The informant indicated 119 species used, distributed in 100 genera and 49 families, and the most important families in number of species are Myrtaceae (10 species), Clusiaceae and Rubiaceae (both with 6 species). The plants used were classified into the following categories: food, medicine, ornamental, technology, hygiene, fragrance, construction, and firewood. The medicinal usage predominated, with 45 species, among which anti-diarrheic plants presented the highest number of species (10). Most useful species (67) occur in the open Clusia scrub formation. The results presented here are relevant to preserve the cultural use of plant resources in the Restinga de Carapebus.

Diet and seed dispersion of the crab-eaten fox, Cerdocyon thous (Linnaeus, 1766) in Restinga de Jurubatiba National Park, Rio de Janeiro State, Brazil

Diet and seed dispersion of the crab-eaten fox, Cerdocyon thous (Linnaeus, 1766) in Restinga de Jurubatiba National Park, Rio de Janeiro State, Brazil

Sex determination in Turdus amaurochalinus (Passeriformes: Muscicapidae): morphometrical analysis supported by CHD gene

Sex determination is important for conservation and population studies, particularly for reproduction programs of threatened species and behavioural ecology. Turdus amaurochalinus, Creamy-bellied Thrush, only exhibits sexual dimorphism during the breeding season, when males are considered to show intense yellow bills, and females and immature males show dark brown bills. The objectives of this study were: 1) to determine the sex of individuals using genetic techniques, and 2) to test the hypothesis that sex dimorphism can be detected by morphometry. This study was carried out at Parque Nacional da Restinga de Jurubatiba, a preserved area located on the North coast of Rio de Janeiro State. The birds were captured using ornithological nets, singly marked with metal rings, weighed, measured and had blood samples collected before being released. The sex of 42 T. amaurochalinus individuals was determined using the CHD gene marker. A total of 20 males and 22 females were identified from June to August, with peak capture frequency in June. Turdus amaurochalinus females and males differed significantly in morphometrical measures. The most important traits to distinguish males from females were wing length (Student t-test = 4.34, df = 40, p = 0.0001) and weight (Student t-test = 2.08, d f = 40, p = 0.044): females were heavier and had significantly shorter wing length than males. Females and males were correctly classified in 86% and 75% of cases, respectively, using Discriminant Analysis. The molecular analysis was the most secure method for sex determination in the studied species.