Supplemental material, sj-pdf-1-trc-10.1177_19400829211017366 for Species-Area Relationships Induced by Forest Habitat Fragmentation Apply Even to Rarely Detected Organisms by Ana Filipa Palmeirim, Rafael de Fraga, Marcus V. Vieira and... more
Supplemental material, sj-pdf-1-trc-10.1177_19400829211017366 for Species-Area Relationships Induced by Forest Habitat Fragmentation Apply Even to Rarely Detected Organisms by Ana Filipa Palmeirim, Rafael de Fraga, Marcus V. Vieira and Carlos A. Peres in Tropical Conservation Science
Natural environments disturbed by human activities can suffer from species extinctions, but some can still harbor high taxonomic diversity. However, disturbances may have impacts beyond the species level, if the species lost represent... more
Natural environments disturbed by human activities can suffer from species extinctions, but some can still harbor high taxonomic diversity. However, disturbances may have impacts beyond the species level, if the species lost represent unique functions in the ecosystem. In this study, we evaluated to what extent the amount of habitat can determine the functional diversity and nestedness of amphibian communities in an Atlantic Forest fragmented landscape in Brazil, and if there is a threshold of habitat amount beyond which there is severe loss of functional diversity. As species responses may depend on their habitat type, we performed the analyses for three different sets of species: all species, forest‐dependent species, and generalist species. We also evaluated the relative importance of turnover and nestedness components to total functional dissimilarity among sites. Habitat amount affected functional diversity of frogs, especially for forest‐dependent species where a linear reduction was detected. The functional dissimilarity among sites was mostly explained by the nestedness component. The reduction of functional diversity was mediated by an ordered loss of traits, leading to a functionally nested metacommunity. These sensitive traits were closely related to habits and reproductive modes that depend on rivers and streams. The maintenance of functional diversity of frogs in fragmented landscapes must rely on the conservation of both terrestrial and aquatic environments, as some species and their traits can disappear from remnants of native vegetation lacking some specific habitats (e.g. streams)
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MATHEMATICAL MODELS IN ECOLOGICAL THEORY: A REVIEW BY BRAZILIAN RESEARCHERS ON ITS CURRENT STATUS AND PERSPECTIVES
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Neotropical snakes have extremely low detection rates, hampering our understanding of their responses to habitat loss and fragmentation. We addressed this gap using a limited sample (50 individuals, 16 species) across 25 variable-size... more
Neotropical snakes have extremely low detection rates, hampering our understanding of their responses to habitat loss and fragmentation. We addressed this gap using a limited sample (50 individuals, 16 species) across 25 variable-size insular forest fragments within a hydroelectric lake and four adjacent mainland continuous forest sites, in Central Brazilian Amazonia. The number of species recorded on forest islands (1.55 [Formula: see text] 0.78) was much lower than that at continuous forest sites (5.0 [Formula: see text] 3.1), with no snakes being recorded at twelve islands smaller than 30 ha. As such, snake assemblages were positively affected by forest area, explaining 48% of the number of species, and negatively affected by island isolation. The markedly higher number of species recorded across continuous forest sites likely results from the availability of riparian habitats, which have virtually disappeared from the archipelagic landscape given the widespread inundation of low...
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We report the first record of homing behavior of a Neotropical marsupial, the opossum Philander frenatus. The individual studied returned to the home forest fragment where it was captured (1050 m away) crossing a hostile matrix, instead... more
We report the first record of homing behavior of a Neotropical marsupial, the opossum Philander frenatus. The individual studied returned to the home forest fragment where it was captured (1050 m away) crossing a hostile matrix, instead moving to a much closer fragment (50 m distant). Movements did not follow wind or the direction of the closest fragment, but they were significantly oriented towards the home fragment. The individual probably had previous experience with the release site. This unique observation suggests that the ability of P. frenatus to overcome the effects of habitat fragmentation may be higher than considered previously. RESUMO: Comportamento de “homing” de Philander frenatus (Didelphimorphia, Didelphidae) em uma paisagem fragmentada da Mata Atlântica do Brasil. Relatamos o primeiro registro de comportamento de “homing” de um marsupial neotropical, Philander frenatus. O indivíduo estudado retornou para o fragmento onde foi capturado (distante 1050 m) atravessando...
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As florestas semidecíduas do interior do Estado de São Paulo são isoladas e pequenas devido às atividades agrícolas, expansão urbana e industrial. Os remanescentes dos fragmentos florestais são importantes para a persistência de diversas... more
As florestas semidecíduas do interior do Estado de São Paulo são isoladas e pequenas devido às atividades agrícolas, expansão urbana e industrial. Os remanescentes dos fragmentos florestais são importantes para a persistência de diversas espécies de mamíferos. Neste estudo foi feito um inventário da mastofauna de um fragmento de mata mesófila semidecídua no interior do Estado (Fazenda São José) nos municípios de Rio Claro e Araras. Nos três períodos amostrados, entre maio de 1997 e março de 1999, o levantamento da mastofauna foi feito por meio de armadilhas para pequenos mamíferos, bem como de observação direta e identificação de rastros dos animais. Registrou-se a ocorrência de três espécies de marsupiais (Didelphidae), duas de tatus (Dasipodidae), três de primatas (Callithrichidae e Cebidae), cinco de carnívoros (Canidae, Procyonidae e Mustelidae), uma de veado (Cervidae), sete de roedores (Sciuridae e Muridae) e uma de coelho (Leporidae). Didelphis albiventris (Didelphidae), Nect...
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Medidas de desempenho utilizadas podem fornecer uma medida do nicho fundamental, permitindo prever uso do habitat ou recursos na ausência de interações entre espécies. Propomos um conjunto padrão de testes de desempenho locomotor para... more
Medidas de desempenho utilizadas podem fornecer uma medida do nicho fundamental, permitindo prever uso do habitat ou recursos na ausência de interações entre espécies. Propomos um conjunto padrão de testes de desempenho locomotor para vertebrados arborícolas, e um método para desenvolver modelos ecomorfológicos baseados em testes de desempenho e análise de caminhos. Os testes propostos simulam características do habitat como diâmetro e orientação de suportes. Modelos de relações entre variáveis podem ser formulados e comparados através da análise de caminhos, permitindo escolher o modelo de melhor ajuste aos dados. Este procedimento foi aplicado ao marsupial Philander frenata, comparando-se o efeito da forma corporal sobre o comprimento e freqüência de passadas no andar arborícola. O modelo incluindo caminhos tanto para freqüência como para comprimento de passadas teve um ajuste significativamente melhor que o modelo com caminhos apenas para o comprimento das passadas. Um modelo ger...
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Fragment size, isolation, and matrix properties have received considerable attention as predictors of species richness, abundance, and composition in habitat patches. However, measurements of habitat attributes or habitat quality are more... more
Fragment size, isolation, and matrix properties have received considerable attention as predictors of species richness, abundance, and composition in habitat patches. However, measurements of habitat attributes or habitat quality are more directly related to the proximate effects of habitat fragmentation and may be more determinant of assemblages than traditional explanatory variables at local scales. We determine how habitat structure in fragments—a measure of habitat quality—compares to fragment size, isolation, and matrix properties as determinants of richness, abundance, and composition of non-volant small mammals in a fragmented landscape of Atlantic Forest. Small mammals were surveyed once in 25 fragments in the Macacu River watershed, Rio de Janeiro, Brazil, from 1999 to 2001 and 2005 to 2009. A total of 83 candidate models were formulated and compared by Akaike Information Criteria. Habitat structure was one of the main determinants of small mammal assemblages in fragments, ...
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Population fluctuations are the result of the combined action of endogenous (feedback structure) and exogenous factors (large- and local-scale climate variables). In this paper, we used a 13-year time series to identify the feedback... more
Population fluctuations are the result of the combined action of endogenous (feedback structure) and exogenous factors (large- and local-scale climate variables). In this paper, we used a 13-year time series to identify the feedback structure in a population of the brown 4-eyed opossum Metachirus nudicaudatus and to test a hypothesis on the effects of El Niño Southern Oscillation and rainfall using Royama’s theoretical framework. Metachirus nudicaudatus was regulated by a strong 1st-order negative feedback, with intraspecific competition for food resources as the probable factor governing the endogenous system. Contrary to our expectations, El Niño did not explain the marsupial dynamics better than 1-year lagged rainfall, that may operate in 2 different manners: as a nonlinear perturbation effect influencing the strength of density dependence (intraspecific competition and intraguild predation) or as a lateral perturbation effect influencing the carrying capacity of the environment....
Research Interests: Biology, Ecology, Mammalogy, Population Dynamics, Population ecology, and 13 moreMarsupials, Mammals, Biological Sciences, Small Mammals, Environmental Sciences, Population, ENSO, Population Regulation, El Nino-Southern Oscillation, Small mammal, South American Marsupials, Intraspecific Competition, and Ecology of Small Mammals
We compared the trappability of marked and unmarked individuals in species of marsupials and rodents of three tropical assemblages of small mammals in Brazil. Two studies used trapping grids, one in cerrado and the other in an Atlantic... more
We compared the trappability of marked and unmarked individuals in species of marsupials and rodents of three tropical assemblages of small mammals in Brazil. Two studies used trapping grids, one in cerrado and the other in an Atlantic forest reserve, whereas the study in a rural area used transects. In the two studies using trapping grids, marked animals were frequently more trappable than unmarked ones, but in some species this difference was not significant. In the rural area, marked and unmarked animals did not differ significantly. The number of recaptures per resident animal was higher in the two studies using trapping grids than in the rural area where transects were used. Differences in trappability between the three studies might have been caused by differences not only in trapping design (grids vs. transects), but also in the type of trap used, bait, and habitat. Although differential trappability tends to be considered the rule in small mammals, these results suggest that...
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Studies quantifying habitat structure generally use several instruments. This paper aims to propose a new and efficient device to characterize microhabitat structure of small mammals. Seven measurements were taken: plant cover, litter... more
Studies quantifying habitat structure generally use several instruments. This paper aims to propose a new and efficient device to characterize microhabitat structure of small mammals. Seven measurements were taken: plant cover, litter cover, rock cover, canopy cover, and vegetative obstruction at three heights. The device is a 0.25 m² square wooden frame (0.50 m x 0.50 m) divided in to 100 open squares by wire mesh. Average time spent to measure each trapping station was six minutes. This new device is efficient, i.e., quick, practical, simple, and reliable. It can be used in any kind of forest. We propose this method as a standard method to describe habitat structure.
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Because extinctions are not random across taxa, it is important for conservation biologists to identify the traits that make some species more vulnerable. Factors associated with vulnerability include small geographical ranges, low... more
Because extinctions are not random across taxa, it is important for conservation biologists to identify the traits that make some species more vulnerable. Factors associated with vulnerability include small geographical ranges, low densities, high trophic level, "slow" life histories, body size, and tolerance to altered habitats. In this study we examined the relationship of body size, reproductive output, longevity, and extinction risk for carnivores occurring in Brazil. We used generalized linear models analyses on phylogenetically independent contrasts to test the effect of body size alone, and the combined effect of body size, litter size and longevity on extinction risk. Body size appeared in the two best models according to the selection criteria (AIC), and it was the most plausible bionomic variable associated with extinction risk. Litter size and longevity, bionomic traits previously associated with threat risk of Brazilian carnivores, were implausible. The higher ...
Research Interests: Geography, Biology, Ecology, Longevity, Carnivores, and 3 moreExtinction Risk, Body Size, and South America
We propose a simple, accurate, and inexpensive timing device to record the activity patterns of small mammals in the field using live traps. The present timing device can be used in cage-type live traps. It is built from commercially... more
We propose a simple, accurate, and inexpensive timing device to record the activity patterns of small mammals in the field using live traps. The present timing device can be used in cage-type live traps. It is built from commercially available components and does not require special skills to construct. The device is set outside the trap and does not need to be permanently affixed or require drill perforations, as others devices do. This device is easily incorporated into long-term monitoring studies to provide temporal information about small mammal populations without affecting their behavior.
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A population of the black-eared opossum, Didelphis aurita Wied-Neuwied 1826, was studied during 1997-2006 by capture-mark-recapture in the Atlantic Forest in the state of Rio de Janeiro. Cohorts were established with females marked still... more
A population of the black-eared opossum, Didelphis aurita Wied-Neuwied 1826, was studied during 1997-2006 by capture-mark-recapture in the Atlantic Forest in the state of Rio de Janeiro. Cohorts were established with females marked still in the pouch, classified into five age classes. Population parameters were estimated using life tables. Survival was type III and mortality was greatest in age classes I and II, just after weaning. Fecundity was inversely correlated with survival, reproductive value was inversely correlated with mortality and residual reproductive value was inversely correlated with fecundity. The intrinsic rate of increase was always close to zero and tended to be slightly negative. The black-eared opossum can be considered a good model species for this type of study.
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Research Interests: Biology, Ecology, Population Dynamics, Population ecology, Animal Ecology, and 15 moreMortality, Medicine, Mammals, Biological Sciences, Environmental Sciences, Population, Predation, Animals, Animal migration, Herbivory, Population Size, Population Density, Feeding Behavior, Body Weight, and Food Chain
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ABSTRACT Litterfall was collected in a 0.64 ha area for three months, using 25 litter traps. Resampling methods were used to calculate the total litterfall mass grand mean and coefficient ofvariation (CV) for each month using different... more
ABSTRACT Litterfall was collected in a 0.64 ha area for three months, using 25 litter traps. Resampling methods were used to calculate the total litterfall mass grand mean and coefficient ofvariation (CV) for each month using different numbers of litter traps (225). ...
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Hydroelectric dams have induced widespread loss, fragmentation and degradation of terrestrial habitats in lowland tropical forests. Yet their ecological impacts have been widely neglected, particularly in developing countries, which are... more
Hydroelectric dams have induced widespread loss, fragmentation and degradation of terrestrial habitats in lowland tropical forests. Yet their ecological impacts have been widely neglected, particularly in developing countries, which are currently earmarked for exponential hydropower development. Here we assess small mammal assemblage responses to Amazonian forest habitat insularization induced by the 28-year-old Balbina Hydroelectric Dam. We sampled small mammals on 25 forest islands (0.83-1466 ha) and four continuous forest sites in the mainland to assess the overall community structure and species-specific responses to forest insularization. We classified all species according to their degree of forest-dependency using a multi-scale approach, considering landscape, patch and local habitat characteristics. Based on 65,520 trap-nights, we recorded 884 individuals of at least 22 small mammal species. Species richness was best predicted by island area and isolation, with small islands...
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The sets of species in animal and plant communities often comprise nested subsets of the species in broader communities. Although most mechanisms causing nested patterns are known and have been demonstrated for different environments and... more
The sets of species in animal and plant communities often comprise nested subsets of the species in broader communities. Although most mechanisms causing nested patterns are known and have been demonstrated for different environments and taxa, how amphibian communities are structured in ephemeral ponds in tropical disturbed landscapes remains unknown. We investigated if pond size, duration , presence of trees (local factors), and the proportion of forest cover surrounding ponds (landscape factor) affect anuran species richness and composition, and if pond assemblages showed a nested pattern. We sampled 11 ephemeral ponds in a pasture matrix near a large Atlantic Forest remnant in Brazil and measured local and landscape variables inside two buffer zones around each pond (100 and 500 m). We marked 1514 individuals from 23 anuran species, and found that richness in ponds ranged from 3–14 species. Both local and landscape factors explained frog species richness in the sampled ponds, and seemed to affect community composition. Frog communities occurred in a non-nested pattern, contrary to our expectations: species found in poor subsets were not found in larger, more complex ponds. Local and landscape characteristics create a variety of environments in ephemeral ponds, even in impoverished ones; these characteristics restrict pond occupancy for some species, and result in a non-nested pattern. Abstract in Portuguese is available with online material.
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The conditions that a population experiences during one season can affect the strength of density dependence in the following season. In the tropics, many populations face their biggest challenges in the dry season due to limited food and... more
The conditions that a population experiences during one season can affect the strength of density dependence in the following season. In the tropics, many populations face their biggest challenges in the dry season due to limited food and cold-dry conditions. Seasonal environmental changes can be especially problematic for small, short-lived, seasonally breeding endotherms. To investigate the effects of seasonality on population dynamics, we studied five marsupial species in the Brazilian Atlantic Forest, using a 16-year dataset. We tested if (1) compensatory density feedback is stronger in the dry season, due to the high population sizes and limited food; (2) lower temperatures and the overall abundance of small mammals negatively affect dry season population growth rates; and (3) rainfall, a proxy for food availability, is positively related to wet season population growth rates. Population growth rates were regressed against seasonal population sizes and exogenous variables, and analyzed with linear autoregressive models. Seasonal compensatory density feedback occurred in both seasons, with compensation processes in just one season being sufficient to allow population persistence. Rainfall and the overall abundance of small mammals had little influence on populations, while colder temperatures decreased population growth rate of smaller species in both seasons. Although the study marsupials share similar life histories and phylogeny, they varied with respect to the season when compensatory density feedback was strongest. Our results demonstrate that seasonality plays a key role in driving marsupial population dynamics, and highlight the need to account for seasonality in demographic studies even in tropical environments.