Predação de ninhos de Trachemys dorbigni (Duméril &amp; Bibron) (Testudines, Emydidae) no extremo sul do Brasil

Gonçalves, Fernanda A.; Cechin, Sônia Zanini; Bager, Alex

doi:10.1590/s0101-81752007000400025

Cited by 12 publications

(16 citation statements)

References 28 publications

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“…Skunks also take advantage of some temporarily available resources, such as eggs of freshwater turtles and ground-nesting birds. We found no evidence of consumption of eggs, but they probably represent an important energy source in some regions, such as the coastal regions of southern Brazil and Uruguay, where Gonçalves et al (2007) reported the predation of 98% of turtle nests, 31% of them by Conepatus chinga. In a study of the spatial ecology of C. chinga, Kasper et al (2012b) recorded several instances of skunks preying on turtle and bird nests to eat eggs, mainly in summer.…”

Section: Discussioncontrasting

confidence: 60%

Trophic relationships of sympatric small carnivores in fragmented landscapes of southern Brazil: niche overlap and potential for competition

et al. 2016

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Between 2000 and 2010, digestive tracts collected from carnivore carcasses found in southern Brazil were analyzed to determine the frequency and proportion of items constituting the diets of each species. Material was collected and analyzed from 194 animals of 10 species: Cerdocyon thous, Lycalopex gymnocercus (Canidae), Procyon cancrivorus (Procyonidae), Galictis cuja (Mustelidae), Conepatus chinga (Mephitidae), Leopardus colocolo, Leopardus geoffroyi, Leopardus guttulus, Leopardus wiedii, and Puma yagouaroundi (Felidae). Most of these species are sympatric, which makes them potential competitors when sharing, to a greater or lesser degree, the same resources. The food niche breadth was relatively narrow, demonstrating that even generalist species, such as the crab-eating raccoon, used food resources rather unequally. An extensive overlap ( > 90%) in food niches was found among the cat species, the grison, and the Pampas fox, which had diets based on rodents. Crab-eating raccoons occupied a different food niche, based on aquatic or semiaquatic prey and fruits. Conepatus chinga was unique in exploiting arthropods and insect larvae as basic dietary items.

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Section: Discussioncontrasting

confidence: 60%

Trophic relationships of sympatric small carnivores in fragmented landscapes of southern Brazil: niche overlap and potential for competition

et al. 2016

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“…Uruguai e nordeste da Argentina (VANZOLINI, 1997). No Brasil, ocorre no Rio Grande do Sul (ERNST, 1990;BAGER et al, 2007b;FAGUNDES, 2007;GONÇALVES et al, 2007;BUJES, 2008) Hábitat e ecologia. Ocupa ambientes aquáticos como lagunas, rios, banhados, lagos e açudes com abundância de vegetação (BUJES, 2008), como a lagoa Mangueira e Estação Ecológica do Taim; banhados formados pelas águas do rio Santa Bárbara, em Pelotas; banhados, arroios e meandros formadores do Delta do rio Jacuí e Reserva Biológica do Lami, em Porto Alegre (C. S. Bujes, obs.…”

Section: Família Emydidaeunclassified

“…Estes ninhos apresentaram tamanho da abertura entre 42 e 49 mm, tamanho da câmara de incubação entre 85 e 100 mm e profundidade média do ninho 116,92 mm. Indivíduos constroem ninhos de maneira solitária (GONÇALVES et al, 2007;FAGUNDES, 2007;BUJES, 2008), porém, dependendo da disponibilidade de locais para a nidificação, pode ocorrer destruição dos mesmos em virtude da atividade de outras fêmeas sobre ninhos já finalizados, o que foi observado, por duas ocasiões, em um sítio de desova reduzido na Ilha da Pintada, Porto Alegre (C. S. Bujes, obs. pess.).…”

Section: Família Emydidaeunclassified

“…FAGUNDES (2007) e BAGER et al (2007b relataram oviposição anual em 35,3% da população de fêmeas do arroio Santa Bárbara, Pelotas, e em 31% da população da Estação Ecológica do Taim, respectivamente. Os ninhos foram construídos a uma distância que variou de 0,4 a 160,5 m em relação ao curso d'água mais próximo, depositados isoladamente, porém com disposição agregada (GONÇALVES et al, 2007;FAGUNDES, 2007). …”

Section: Família Emydidaeunclassified

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Os Testudines continentais do Rio Grande do Sul, Brasil: taxonomia, história natural e conservação

Bujes

2010

Iheringia, Sér. Zool.

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ABSTRACT. Freshwater turtles of Rio Grande do Sul, Brazil: taxonomy, natural history and conservation. Rio Grande do Sul is the southernmost state of Brazil with peculiar flora and fauna associated to the morfoclimatic characteristics of the region. The diversity of Testudines from Rio Grande do Sul is represented by six freshwater turtle species and five sea turtle species. This study reports on the freshwater turtle diversity of Rio Grande do Sul, based on a compilation of published and some new data on their biology and conservation status. KEYWORDS. Acanthochelys, Hydromedusa, Phrynops, Trachemys, freshwater turtles.RESUMO. O Rio Grande do Sul é o estado mais meridional do Brasil, apresentando fauna e flora peculiares associadas às características morfoclimáticas da região. A diversidade de Testudines do Rio Grande do Sul é representada por seis espécies continentais e cinco marinhas. Este estudo apresenta comentários sobre a diversidade de quelônios continentais do Rio Grande do Sul, através de uma compilação de dados publicados e alguns inéditos sobre sua biologia e estado de conservação.

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“…Several authors have suggested that predation risk should change over the nesting season due to shifts in predator activity related to nest availability or to predator learning (Stancyk, 1982;Nellis & Small, 1983;Leighton, Horrocks & Kramer, 2009), but seasonal changes in predation risk have only been documented in a few studies (Fowler, 1979;Talbert et al, 1980;Engeman et al, 2003). In addition, various studies have reported more frequent nest predation near the start (Stancyk, Nellis & Small, 1983;Goncalves, Cechin & Bager, 2007;Leighton et al, 2009) or the end (Fowler, 1979;Nellis & Small, 1983) of incubation, but the relationship between daily predation risk and nest age has not been rigorously explored.…”

Section: Introductionmentioning

confidence: 99%

Predicting nest survival in sea turtles: when and where are eggs most vulnerable to predation?

Leighton

Horrocks

Kramer

2010

Animal Conservation

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Nest predation is an important practical challenge for the conservation of egglaying reptiles, with the potential to reduce hatchling recruitment and slow the recovery of threatened populations. Accurately forecasting where and when predation will occur has the potential to optimize predation management. Survival analysis, a set of statistical techniques recently popularized in studies of avian nest success, provides a unique approach for modelling variation in egg mortality risk throughout development. We used Cox proportional hazards regression to model the survival of sea turtle eggs from predation by the small Asian mongoose Herpestes javanicus, a widely introduced and destructive sea turtle nest predator in the Caribbean. We evaluated the ability of models to predict egg survival using 7 years of nest predation data for critically endangered hawksbill sea turtles Eretmochelys imbracata in Barbados. Daily predation risk was the highest for freshly laid nests, decreasing rapidly with nest age but increasing again near the end of development. Predation risk was the highest in and near patches of beach vegetation, increased over the nesting season and increased with nest density on the open beach but not in vegetation. Survival models calibrated using data from 2004 to 2005 showed excellent discrimination and Z84% accuracy when predicting the fate of nests from previous years. Our study provides the first quantification of the daily variation in predation risk for incubating turtle eggs, revealing a narrow time window early in development during which the application of predation reduction measures is likely to have the greatest impact on nest survival. More generally, we demonstrate the utility of survival analysis for generating finescale predictions of spatiotemporal variation in turtle egg mortality, providing a flexible tool for the conservation of sea turtles and other egg-laying reptiles.

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Predação de ninhos de Trachemys dorbigni (Duméril & Bibron) (Testudines, Emydidae) no extremo sul do Brasil

Cited by 12 publications

References 28 publications

Trophic relationships of sympatric small carnivores in fragmented landscapes of southern Brazil: niche overlap and potential for competition

Trophic relationships of sympatric small carnivores in fragmented landscapes of southern Brazil: niche overlap and potential for competition

Os Testudines continentais do Rio Grande do Sul, Brasil: taxonomia, história natural e conservação

Predicting nest survival in sea turtles: when and where are eggs most vulnerable to predation?

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