23 results on '"niche overlap"'
Search Results
2. Comparative phylogeography shows congruent co‐divergence in Neotropical seasonally dry forest and savanna tree species.
- Author
-
Vitorino, Luciana Cristina, Reis, Mateus Neri Oliveira, Melo, Warita Alves, and Collevatti, Rosane G.
- Subjects
- *
PHYLOGEOGRAPHY , *TROPICAL dry forests , *LAST Glacial Maximum , *SAVANNAS , *CERRADOS , *GENETIC variation - Abstract
Aim: The response of South American seasonally dry tropical forest (SDTF) and savanna species to the Quaternary climate changes is still poorly understood. Here we use multi‐model inference approach to compare the phylogeography and demographic history of five trumpet tree species (also known as pau‐d'arco) and draw general biogeographical patterns: Handroanthus impetiginosus, H. ochraceus, H. serratifolius, Tabebuia aurea and T. roseoalba. Location: Amazonia, Atlantic Forest, Cerrado and Caatinga ecoregions, South America and Brazil. Taxa: Bignoniaceae, Tabebuia Alliance, trees. Methods: We compiled genetic data, occurrence records and ecological niche modelling (ENM) from published articles. We used coalescent modelling to test patterns of co‐divergence, and analysed niche breadth and overlap and spatial patterns in genetic diversity using quantile regressions. Results: Species showed concordant lineage divergence times in the Pleistocene. Lineage diversification and phylogeographical patterns are more related to species niche breadth than to biome (savanna or SDTF). Differences in genetic diversity among species matches the expected for the demographic scenarios obtained with coalescent simulations and ENMs: species with wider range expansion during the Last Glacial Maximum had higher diversity than species with range retraction or multiple refugia. Main Conclusions: Diversification burst in the Pliocene, and major diversification of lineages during the Pleistocene seems to be a general pattern in SDTF and savannas in the South America. The high number of haplotypes at the Central Brazil, corresponding to the Cerrado ecoregion, highlights the importance of Protected Areas for SDTFs and savannas, highly threatened biomes in Brazil. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Diet composition and coexistence of Boana geographica and Boana raniceps (Anura: Hylidae) from Central Amazonia, Brazil.
- Author
-
SANT'ANNA, Bruno Sampaio, FONSECA, Aldeiza Marques, and FERREIRA, Rafaela Fernanda Batista
- Subjects
HYLIDAE ,COEXISTENCE of species ,DIET ,ANURA ,ORTHOPTERA ,TADPOLES ,SPECIES - Abstract
Investigating feeding patterns among species is essential to understanding and preserving populations, especially in habitats like the Amazon. This study analyzed the patterns of food resource use of two coexisting species of Hylidae, Boana geographica and B. raniceps, in Central Amazonia, Brazil. High trophic niche overlap (0.74) and differences in the most important food items were observed between the two species. For B. geographica, anuran tadpoles were the prey with the greatest volume (63.73%) and frequency (30%). For B. raniceps, the items with the highest volume were Orthoptera (53.14%) and Araneae (30.39%), and the most frequent item was Coleoptera (18.75%). The most important food items for B. geographica were tadpoles (Ix = 39.41) and for B. raniceps were Orthoptera (Ix = 25.05) and Coleoptera (Ix = 16.85). For both species, no correlation was found between predator size and mouth width in relation to the size and volume of the prey. Boana raniceps was considered a passive, generalist forager with a sit-and-wait feeding strategy like most Hylidae. On the other hand, B. geographica may be regarded as an active generalist forager due to the high consumption of tadpoles. Despite the high overlap in their diet composition, the differences in prey categories with greater dietary importance likely seem to enable these species' coexistence. [ABSTRACT FROM AUTHOR]
- Published
- 2022
4. Diet composition and tropic niche overlap of Ameivula ocellifera Spix 1825 (Squamata: Teiidae) and Tropidurus cocorobensis Rodrigues 1987 (Squamata: Tropiduridae), sympatric species with different foraging modes, in Caatinga.
- Author
-
Marques do A. Oliveira, Patricia, Navas, Carlos A., and Sales Nunes, Pedro M.
- Subjects
- *
LAVA lizards , *CAATINGA reptiles , *FOOD consumption , *DIETARY supplements - Abstract
Lizard diets can be influenced by several factors, such as age, physiological aspects, food availability, behaviour and foraging mode. The latter can be an important predictor of the type of prey consumed. This study analysed Ameivula ocellifera and Tropidurus cocorobensis diets, both of which are psammophiles and coexist in an area of Caatinga in north-eastern Brazil, but use different foraging modes. Lizard stomachs were examined, and prey categories were quantified by frequency of occurrence, number, volume and relative importance index. We used PERMANOVA and SIMPER analyses to understand the dissimilarities among diets. Additionally, we estimated the degree of trophic niche overlap between species using the Pianka index. The most frequently consumed food item by A. ocellifera was Isoptera and Formicidae (Hymenoptera) for T. cocorobensis. The trophic niche overlap between the species was approximately 0.24 and, although there were many consumed prey categories in common, the proportion at which these prey categories were consumed was quite divergent. For example, the consumption of plant material, which was present in the diet of both species, was much more important for T. cocorobensis compared to the active forager A. ocellifera. Our results indicate that despite sharing the same space and consuming the same prey types, these species have significant differences in their diets. Furthermore, these divergences can be explained by several factors in the environment and even by the evolutionary history of each species, which are included in different families and are not evolutionarily close to each other. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Navigating in harmony: Investigating spatial correlations between cetacean distribution and marine traffic in the Santos Basin, Brazil.
- Author
-
Pratezi, Murilo Rainha and Rollo, Mario Manoel
- Subjects
CETACEA ,MARINE parks & reserves ,BIODIVERSITY ,MARINE biodiversity - Abstract
Cetaceans inhabit oceans worldwide, coexisting amidst the growing intensity of human activities in the aquatic environment, particularly motorized vessel traffic. Understanding spatial correlations is essential for devising appropriate responses to these impacts. Hence, this project delved into the spatial relationship between cetacean distribution and marine traffic activities in the Santos Basin, Brazil. Data from two different databases were collected: one detailing cetacean distribution and the other to documenting various types of marine traffic in general. A total of 2352 cetacean records and 718777 vessel records were obtained. Subsequently, Structural Similarity analyses were carried out to identify niche overlap, yielding a result of 0.88. Addition, analysis utilizing the Nearest Neighbor method and Kernel density were employed, to pinpoint overlapping records of marine traffic with cetaceans, generating heat maps. These findings facilitated the identification of the areas where marine traffic intersects with cetacean habitats, leading to the proposal of both mandatory and voluntary conservation strategies. Key recommendations include speed reduction and voluntary exclusion zones. It is anticipated that the implementation of these strategies in the study area will aid in the conservation of cetaceans and the broader biodiversity of Brazilian Marine Protected Areas. • P. blainvillei , M. novaeangliae , and T. truncatus showed high correlation with vessel distribution in the Santos Basin • Marine Protected Areas can use Management Plans to support cetacean conservation amid vessel conflicts. • Reducing vessel speed and adopting Voluntary Exclusion Zones (VEZs) are key strategies for cetacean conservation. • Conservation strategies should be discussed in the context of legal and penal considerations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Trophic niche of Pseudopaludicola boliviana (Anura: Leptodactylidae) from northern Brazil.
- Author
-
PEDROSO-SANTOS, Fillipe, SANCHES, Patrick R., and COSTA-CAMPOS, Carlos Eduardo
- Subjects
LEPTODACTYLIDAE ,ANURA ,FROGS ,HYMENOPTERA ,BODY weight ,FLOODPLAINS ,DIPTERA - Abstract
In this work, we studied the diet of Pseudopaludicola boliviana from a floodplain area in southern Amapá, Brazil. A total of 141 frogs were collected by hand from March 2017 to March 2018, with 87 individuals collected during the rainy season (January-July) and 54 collected during the dry season (August-December). Of these, 86 stomachs (58 in the rainy season and 28 in the dry season) revealed 284 prey items. Acari (rainy season 35.56%, dry season 20.39%), Coleoptera (23.24%, 49.12%) and Diptera (20.42%, 20.53%) were the most abundant and important prey items. The most frequent items were Coleoptera (65.51%), Diptera (48.27%) and Hymenoptera (37.93%) for the males, and Diptera (57.14%), Acari (42.85%) and Coleoptera (39.28%) for the females. Frog morphometrics (snout-vent length, jaw width, and body weight) did not determine differences in dietary composition. The rarefaction curve did not reach the asymptote and indicated higher taxonomic richness in the diet of males, who also consumed a greater amount of prey than females. Niche breadth varied seasonally, with a wider niche breadth during the rainy season (Bsta = 0.453) compared to the dry season (Bsta = 0.238). The high trophic niche overlap (rainy season: Ojk = 0.866; dry season: Ojk = 0.708) between males and females in both seasons indicated similarity in diet during the entire year. During the entire year, P. boliviana consumed prey of similar volumetric size but seemed to consume more prey items during the rainy season. We conclude that P. boliviana has a generalist diet, marked by high dietary plasticity. [ABSTRACT FROM AUTHOR]
- Published
- 2022
7. Trophic structure of frog assemblages in coastal habitats in southern Brazil.
- Author
-
Huckembeck, Sônia, Winemiller, Kirk O., Loebmann, Daniel, and Garcia, Alexandre M.
- Subjects
- *
SAND dunes , *STABLE isotope analysis , *COASTAL wetlands , *FROGS , *GASTROINTESTINAL contents - Abstract
We evaluated the hypothesis that contrasting environmental conditions in a coastal wetland and nearby sand dunes results in frog assemblages with divergent trophic structures. We predicted that the more productive habitat (wetland) would have higher diversity of primary producers and frogs with larger trophic niches and greater interspecific dietary overlap when compared to the less‐productive dune habitat. Stomach content analysis (SCA) and stable isotope analysis (SIA) were used to compare frog trophic ecology in the two habitats. We compared trophic niche size (Shannon's index) and overlap (Pianka's index; isotopic ellipse area, SEAc). Bayesian isotope mixing models were used to estimate relative contributions of basal production sources to frog biomass in each habitat. Estimates indicated that wetland frogs assimilated material from diverse basal sources (suspended particulate organic matter (POM), C3 plants, periphyton), whereas frogs inhabiting dunes assimilated material mostly originating from C3 plants. Both SCA and SIA revealed less trophic overlap among frogs from the sand dunes compared with those from the wetland. Dietary overlap was greater than expected at random for frogs in both the wetland and dunes. Mean overlap among isotopic ellipses (SEAc) of all frogs at each habitat was higher in the wetland (0.14‰) than in the dunes (0.04‰). These findings corroborate our prediction that trophic structure in the wetland is more complex than in the sand dunes. Also, as expected, we observed greater isotopic niche segregation among frogs in the sand dunes, a potential mechanism that reduces competition for limited food resources. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
8. Niche breadth of invertebrate shredders in tropical forest streams: which taxa have restricted habitat preferences?
- Author
-
Serpa, Karoline Victor, Kiffer, Walace Pandolpho, Borelli, Miliane Fardim, Ferraz, Marcos Antônio, and Moretti, Marcelo S.
- Subjects
- *
HABITAT selection , *RIVERS , *AQUATIC invertebrates , *INVERTEBRATES , *STONEFLIES , *CADDISFLIES , *MACROBRACHIUM - Abstract
Despite the importance of shredders in organic matter processing in streams, information about the habitat specificities of different taxa is scarce. Herein, we evaluated the habitat preferences of invertebrate shredders in tropical forest streams. A total of 72 leaf patches were sampled in three Atlantic Forest streams (SE Brazil). For each sample, 20 environmental variables were measured, including water properties and characteristics of the leaf patch. We used an Outlying Mean Index analysis to evaluate the niche breadth and overlap of each taxon found as well as habitat preferences. In total, we found 14 shredder taxa in 68 leaf patches, and the gradient of environmental conditions influenced the distribution of most taxa. Considering taxa that occurred in atypical habitats in the study sites, Blaberidae (semiaquatic cockroaches) and Trichodactylus fluviatilis (Decapoda) showed niche segregation, while Macrobrachium potiuna (Decapoda), Tupiperla (Plecoptera), and Nectopsyche (Trichoptera) showed niche overlap. On the other hand, Heterelmis (Coleoptera), Stenochironomus (Diptera), Phylloicus major, and Triplectides gracilis (Trichoptera) occurred in typical habitats. These results showed that shredder taxa had different habitat preferences. The observed differences in niche breadths and habitat specificities among taxa probably result in different leaf processing rates across leaf patches in Atlantic Forest streams. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
9. Nightly patterns of calling activity in anuran assemblages of the Cerrado, Brazil.
- Author
-
Guerra, Vinicius, de Queiroz Costa, Nathane, Llusia, Diego, Márquez, Rafael, and Bastos, Rogério P.
- Subjects
SPECIES diversity ,HUMIDITY ,ATMOSPHERIC temperature ,PLANT phenology ,TEMPERATURE effect - Abstract
Anurans living in species-rich assemblages may experience acoustic niche overlap. To deal with potential masking interference during reproductive activity, species can present acoustic partitioning based on differences in calling period. Studies addressing this question in tropical assemblages have mainly focused on the seasonal scale, and little is known about nightly variation in calling. Here, we reported on phenology and abundance of five tropical anuran assemblages at both seasonal and daily scale and tested the effects of temperature and relative humidity on calling activity patterns of 19 species. Based on 420 hourly acoustic surveys, an overall peak of calling activity in between the first and fourth hour after sunset was identified by Rayleigh's circular test, with a gradual decrease until sunrise. This nightly pattern was followed by most of the species in the assemblages and similarly observed for species presence and abundance of calling males. The acoustic niche overlap was greater than expected by chance within the assemblages, while no pattern of coincidence or segregation was found for the syntopic congeneric species (Dendropsophus, Boana and Leptodactylus). Moreover, the calling activity of the assemblages, measured as richness and diversity of calling species, was negatively influenced by air and water temperature and positively by relative humidity. Thus, climatic variables act as driver factors to determine calling activity and reproduction of anurans at daily scale. The absence of a segregation pattern at the assembly or genus levels in the calling activity over time indicates that the use of the acoustic temporal niche is not a limiting resource for Cerrado anurans. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
10. Resource competition among the Anostraca Dendrocephalus brasiliensis and three Neotropical cladocerans: implications on population dynamics and secondary production.
- Author
-
Gebara, Renan Castelhano, Rocha, Giseli Swerts, Sarmento, Hugo, and Melão, Maria da Graça Gama
- Subjects
- *
COMPETITION (Biology) , *POPULATION dynamics , *BIOTIC communities , *INTRODUCED species , *BODY size - Abstract
Invasive species may affect the equilibrium of natural communities, competing for resources and occupying niches of the native biota. Dendrocephalus brasiliensis (DEN) has potential to aquaculture, although its use is concerning, since DEN is allochthone in some regions of Brazil. Here, we aimed to study the possible effects of DEN on three cladocerans Moina micrura (MOI), Macrothrix flabelligera (MAC) and Daphnia laevis (DAPH). We performed microcosm experiments combining different cladoceran species in mono- and polycultures in the presence and absence of DEN by evaluating density, biomass, production, stages of development and turnover. MOI was competitive excluded when in 2-species polycultures with MAC and DAPH, and in 4-species polycultures with MAC, DAPH and DEN together. Since MOI survived when cultured with MAC and DAPH in 3-species polycultures, DEN possibly played a role on MOI suppression. Regarding density, DAPH had a slightly suppression when exposed separately with MOI, although MAC had higher production in the presence of MOI. Development stages with similar body size apparently competed more intensely for resources. Our results indicate that DEN has potential to invade ecosystems, destabilizing native zooplankton communities, since it affected MAC and DAPH, thus altering their competitive advantage, besides contributing to MOI exclusion. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. Structure of a Lizard Assemblage in a Semiarid Habitat of the Brazilian Caatinga.
- Author
-
Gonçalves-Sousa, José Guilherme, Mesquita, Daniel Oliveira, and Ávila, Robson Waldemar
- Subjects
- *
ECOLOGICAL niche , *LIZARDS , *PRINCIPAL components analysis , *PITFALL traps , *HABITATS , *HEMIDACTYLUS - Abstract
We investigated the importance of ecological and historical effects in structuring a lizard assemblage in a semiarid area of Caatinga habitat. We collected lizards using pitfall traps and active searching; we also collected data concerning microhabitat and diet composition for the lizard species examined. We used null models to test whether or not the community was structured following microhabitat or trophic niches. We also tested whether or not such structure had a historical or ecological origin using canonical phylogenetic ordination and phylogenetic principal component analysis. Gymnodactylus geckoides and Tropidurus hispidus were most generalized in their microhabitat use. Hemidactylus brasilianus and Phyllopezus pollicaris had the greatest numeric niche breadth, whereas P. pollicaris and T. hispidus had the greatest volumetric niche breadth. In contrast, Brasiliscincus heathi and Ameiva ameiva had the smallest numeric and volumetric niche breadths, respectively. The lizard assemblage examined had structure in both microhabitat and trophic niches. We detected phylogenetic conservatism on the basis of spatial niches in the clades Teoidea, Teiidae, and Tropiduridae. In contrast to the predictions of the niche complementarity hypothesis, we found high trophic overlap coupled with low microhabitat overlap for tropidurids. Moreover, spatial niche structure was mainly attributable to historical factors (phylogenetic), whereas ecological factors were more important determinants of trophic niche structure. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
12. Spatial overlap between domestic cats and wild felines in an insular Atlantic Forest remnant.
- Author
-
Ferreira, Giovanne A., Nakano-Oliveira, Eduardo, Andriolo, Artur, and Genaro, Gelson
- Subjects
- *
CATS , *FELIDAE , *FOREST reserves , *NATURE reserves - Abstract
Anthropogenic changes are a major threat to biodiversity. One of these possible changes that affect biodiversity is the introduction of domestic species in the environment, which might represent a threat to wild species. The domestic cat, in particular, has biological and behavioral characteristics that allow a great adaptability to natural areas, thus representing a potential risk to the native species, mainly to the other members of the Felidae family. In this study, the spatial overlap between four species of Neotropical wildcats and domestic cats living in an Atlantic Forest Protected Area in one of the most important forest remnants of this ecosystem was verified. The results indicate the need to adopt mitigation measures against the potential risks of this interaction with the goal of preserving the native species. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
13. Climate change is likely to affect the distribution but not parapatry of the Brazilian marmoset monkeys (Callithrix spp.).
- Author
-
Braz, Alan Gerhardt, Lorini, Maria Lucia, Vale, Mariana Moncassim, and Wiersma, Yolanda
- Subjects
- *
CLIMATE change , *MARMOSETS , *CALLITHRIX jacchus , *MONKEYS , *SHRUBLANDS ,POTENTIAL distribution - Abstract
Aim: Parapatric distributional patterns can arise from abiotic or biotic factors, or from dispersal barriers. Climate change can potentially affect parapatry by changing species' potential geographic distribution, and thereby widening or shrinking contact zones. Here, we study the effects of climate change on all six species in the genus Callithrix, a group of small‐sized Neotropical primates that is distributed parapatrically in eastern Brazil, allegedly due to biotic interactions. Location: Atlantic Forest, savanna and xeric shrublands from Brazil. Methods: We explore a method to investigate potential effects of climate change on the distribution of parapatric species by (a) determining whether the parapatric pattern is explained by abiotic (climate) or biotic (species' interactions) factors using niche equivalency and niche similarity tests; (b) estimating each species' potential distribution under current and future climatic conditions, using ecological niche models; and (c) performing a pixel‐by‐pixel analysis in order to constrain distribution overlap between species pairs in which parapatry is maintained by biotic factors. Results: We found that parapatry in Callithrix is maintained mostly by abiotic factors, except for two species pairs (Callithrix aurita vs. C. flaviceps and C. geoffroyi vs. C. penicillata) in which biotic factors are more likely to be acting. Our proposed method is able to produce better models than conventional ecological niche modelling, predicting net reductions in distribution area for some species and increases for others; however, reductions generally exceeded expansions. The reduction in potential distribution areas would maintain Callithrix flaviceps as Endangered under IUCN criteria. Main conclusions: Despite range contractions and the loss of area of sympatry, climate change is unlikely to affect the parapatric distribution patterns in Callithrix, nor intensify interspecific interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
14. Interindividual patterns of resource use in three subtropical Atlantic Forest frogs.
- Author
-
Carvalho‐Rocha, Vítor, Lopes, Benedito Cortês, and Neckel‐Oliveira, Selvino
- Subjects
- *
FROGS , *ANURA , *COMPETITION (Biology) , *FORESTS & forestry , *ECOLOGY - Abstract
Abstract: Studies with disparate taxa suggest that generalist populations are composed of relatively specialist individuals that use a narrow part of a population's resource pool. Models based on optimum diet theory (ODT) can be used to predict different patterns of variation in resource use among individuals. In this work, we investigated the diet and measured the degree of individual specialization of three anuran species,
Hypsiboas leptolineatus ,Pseudis cardosoi andScinax granulatus , from the Atlantic Forest of southern Brazil. The study is based on gut content obtained using a stomach‐flushing technique. Additionally, we tested for a correlation between the individuals’ diet and morphological variation. Furthermore, we applied methods based on network theory to investigate patterns of resource use among individuals of each species. All three study species showed generalized diets and significant values of individual specialization. However, we did not find any correlation between diet and morphology, indicating that diet variation is not a consequence of morphological trade‐offs. The individual‐resource networks ofH. leptolineatus andS. granulatus showed a nested pattern. This result indicates the presence of individuals with more diverse diets than others, and the diets of the more specialist individuals are a predictable subset of the diets of the more generalist ones. The individual‐resource network ofP. cardosoi did not show a distinct pattern, diverging from what was predicted by optimal diet theory‐based models. Although nested or modular patterns are commonly found in individual‐resource networks, our results indicate that they are not ubiquitous and that random patterns can also be found. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
15. Testing the Coexistence of Artibeus lituratus and A. planirostris in a Neotropical Savanna.
- Author
-
Amaral, Thales Simioni, Macário, Lucas Mousinho, and Souzaaguiar, Ludmilla Moura De
- Subjects
BAT reproduction ,COEXISTENCE of species ,BATS -- Food ,BAT physiology ,CERRADOS - Abstract
Dissimilarity of relevant ecomorphological traits between species is expected to promote coexistence within a community. In this study, we tested hypotheses concerning differences in occurrence, in periods of activity and reproduction, in morphology and diet between two sympatric and phylogenetically related bat species ( Artibeus lituratus and A. planirostris) in the Cerrado region of Central Brazil. No differences were found in the occurrence, activity patterns, or breeding season between species. In contrast, the species presented dissimilar morphological traits and diets (28% of overlap in diet). Our analysis suggests that A. lituratus and A. planirostris do not compete strongly with each other. This lack of competition between species facilitates coexistence on a local scale in the studied Neotropical savanna. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
16. Diet composition for three sciaenids caught off northeastern Brazil.
- Author
-
Santos, Marcella N., Rocha, Gecely R. A., and Freire, Kátia M. F.
- Subjects
SCIAENIDAE fisheries ,ONTOGENY ,CLIMATE change ,ECOLOGICAL niche - Abstract
Copyright of Revista de Biologia Marina y Oceanografía (RBMO) is the property of Universidad de Valparaiso, Facultad de Ciencias del Mar and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2016
17. Consumo de pequenos mamíferos por canídeos simpátricos do sul do Brasil: sobreposição de nichos e seleção de presas.
- Author
-
Lobato Abreu, Maury Sayão, da Rosa Wieliczko, Andressa, Mesquita, Alex, and Vieira, Emerson M.
- Subjects
FOXES ,CERDOCYON thous ,DUSICYON ,ANIMAL species ,PSEUDALOPEX - Abstract
Copyright of Neotropical Biology & Conservation is the property of Pensoft Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2010
- Full Text
- View/download PDF
18. Activity, habitat use, density, and reproductive biology of the crab-eating fox (Cerdocyon thous) and comparison with the pampas fox (Lycalopex gymnocercus) in a Restinga area in the southern Brazilian Atlantic Forest
- Author
-
Faria-Corrêa, Mariana, Balbueno, Rodrigo A., Vieira, Emerson M., and de Freitas, Thales R.O.
- Subjects
- *
HABITATS , *POPULATION density , *FOXES , *DUSICYON , *PSEUDALOPEX , *REPRODUCTION - Abstract
Abstract: The ecology and reproductive biology of the crab-eating fox (Cerdocyon thous) and the pampas fox (Lycalopex gymnocercus) were studied in Itapuã State Park, an Atlantic Forest fragment. In this study we describe their activity patterns (diel, lunar, and seasonal), reproductive period, density, spatial distribution, and habitat overlap. The crab-eating fox was more abundant than the pampas fox, occurring in all types of habitats and overlapping with the pampas fox only in the southern portion of the study area, covered by open vegetation. Both canid species presented nocturnal habits and C. thous showed no significant differences in activity among lunar phases or else year season. The density of C. thous was estimated to be 0.78ind/km2. The crab-eating fox reproduced once a year, generating pups during spring (October to December). In comparison with C. thous populations from lower-latitude regions the relatively low density and one reproductive event per year that we observed are probably related to a colder climate, shorter photoperiod, and shortage of food resources in the winter, characteristic of southern Brazil. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
19. Trophic structure of a fish community along environmental gradients of a subtropical river (Paraitinga River, Upper Tietê River Basin, Brazil).
- Author
-
Esteves, Katharina, Lobo, Ana, and Faria, Marcos
- Subjects
- *
FISH communities , *FISH feeds , *HABITATS , *ELECTRIC fishing , *POPULATION biology , *BIODIVERSITY , *RIPARIAN plants - Abstract
This research characterized the feeding ecology of the fish community of the upper-middle course of Paraitinga River, located within the Upper Tietê River Basin, a peculiar Atlantic Forest area, regarded as a hotspot for fish conservation. Considering the several anthropogenic modifications, knowledge of the trophic structure might contribute to a better understanding of the factors that maintain the present fish community. Fish were collected with electrofishing equipment at 16 sites with different riparian vegetation, including native forest, secondary forest, pasture, and Eucalyptus, during the dry and rainy season of 2004/2005. Results obtained for 15 species indicated a predominance of insectivores and herbivore-detritivores along the course and an increase of total biomass, specifically of the herbivores-detritivores at the pasture sites, which seemed to be mediated by specific habitat features, which included open canopy, high water speed, and deeper areas. Strategies of resource use indicated that 47% of total combination pairs showed high overlap, but competition seemed to be minimized through low co-occurrence, spatial segregation, and abundance of food resources. Niche width was broad for all species, with no significant differences occurring among sites, seasons, and upper and lower course. With regard to the ongoing modifications in riparian zone conditions in this area, the implications of these findings for regional biodiversity conservation are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
20. ECOLOGY OF THE ARMADILLOS CABASSOUS UNICINCTUS AND EUPHRACTUS SEXCINCTUS (CINGULATA: DASYPODIDAE) IN A BRAZILIAN CERRADO.
- Author
-
Bonato, Vinícius, Martins, Eduardo G., Machado, Glauco, Da-Silva, Cibele Q., and Dos Reis, Sé F.
- Subjects
- *
ARMADILLOS , *CERRADO ecology , *HABITATS , *NOCTURNAL animals , *FORESTS & forestry - Abstract
We report on aspects of the ecology and natural history of 2 species of armadillos commonly found in a cerrado remnant in southeastern Brazil--the naked-tailed armadillo (Cabassous unicinctus) and the 6-banded armadillo (Euphractus sexcinctus). Armadillos were captured in pitfall traps or by hand, double-marked, and the habitat (campo sujo, campo cerrado, and gallery forests), season, and time of capture were recorded. We also recorded the sex and age of all armadillos, and reproductive condition of females. Population densities were estimated as 0.27 and 0.14 individuals/ha for C. unicinctus and E. sexcinctus, respectively. E. sexcinctus did not preferentially use any of the habitats included in the study area, whereas C. unicinctus preferentially used habitats with a more complex vegetation structure, such as gallery forests. C. unicinctus was diurnal and E. sexcinctus was mainly nocturnal. Neither species changed its activity pattern with season, but C. unicinctus was more active in months with decreased abundance of arthropods--the main food resource consumed by this species. Both species of armadillos appeared to reproduce year-round. Differences in habitat use and daily activity between C. unicinctus and E. sexcinctus suggest spatial and temporal displacement between these species. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
21. Niche differences between two sympatric whiptail lizards (Cnemidophorus abaetensis and C. ocellifer, Teiidae) in the restinga habitat of northeastern Brazil.
- Author
-
Dias, E. J. R. and Rocha, C. F. D.
- Subjects
ECOLOGICAL niche ,LIZARDS ,HABITATS ,ANIMAL feeding behavior - Abstract
Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2007
- Full Text
- View/download PDF
22. Trophic and Spatial Niches of two Large-sized Species of Leptodactylus (Anura) in Southeastern Brazil.
- Author
-
França, Leonardo F., Facure, Katia G., and Giaretta, Ariovaldo A.
- Subjects
- *
LEPTODACTYLUS , *FOOD habits , *FROGS , *LAKES , *NUTRITION - Abstract
Leptodactylus ocellatus ( LO ) and L . labyrinthicus ( LL ) are known to prey on other frogs. Here we compare their food habits based on the analysis of stomach contents and their spatial distribution when in sympatry. LO was found most frequently near stream banks, and LL on the margins of lakes and ponds. LO was found within 10 m of permanent water bodies; LL frequently used ponds far from lakes and rivers. Coleoptera, Formicidae, and Isoptera comprised 52% of the prey types identified in the LO sample, whereas Coleoptera and insect larvae represented 58% of the prey items of LL . Frogs were not frequent in the diet of either species but, in volume, represented the second most important category for LO and the first for LL . LO showed a larger trophic niche breadth than LL . The trophic niche overlap between the two species was 68.3% for percentage of prey items. The present work confirms the relative importance of frogs in the diet of both species. The greater capacity of LL in moving far away from permanent water bodies may generate better opportunities for prey selection and a narrower trophic niche breadth. The large range of prey used by these two species indicates they are generalist/opportunistic feeders. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
23. Mapping Brazilian spotted fever: Linking etiological agent, vectors, and hosts.
- Author
-
Donalisio, Maria Rita, Souza, Celso E., Angerami, Rodrigo N., and Samy, Abdallah M.
- Subjects
- *
FEVER , *AMBLYOMMA , *ECOLOGICAL niche , *NULL hypothesis , *ECOLOGICAL models - Abstract
• The results identified the environmental suitability of Brazilian spotted fever and recognized for the first time its potential to spread in Brazil. • The study predicted the potential distribution of two tick vectors associated with transmission of Brazilian spotted fever. • The study tested the niche similarities between Brazilian spotted fever, two tick vectors, and three host species. • The study assessed combination models for the vector-host pairs that better predict independent records of Brazilian spotted fever. Brazilian spotted fever (BSF) is a highly lethal disease in southeastern Brazil. BSF is caused by the bacterium Rickettsia rickettsii and is transmitted by the bites of the tick of the genus Amblyomma. The spatial distribution of BSF risk areas is not well known in the country given the complexity of the transmission cycle. This study used the ecological niche modeling (ENM) approach to anticipate the potential distribution of the etiological agent (Rickettsia rickettsii), vectors (Amblyomma sculptum and A. dubitatum), and hosts (Hydrochoerus hydrochaeris, Didelphis aurita , and D. marsupialis) of BSF in Brazil. We compiled occurrence records for all vectors, hosts, and BSF from our own field surveillance, online repositories, and literature. ENM identified BSF risk areas in southeastern and southern Brazil, and anticipated other dispersed suitable areas in the western, central, and northeastern coast regions of Brazil. Tick vectors and mammalian hosts were confined to these same areas; however, host species showed broader suitability in northern Brazil. All species ENMs performed significantly better than random expectations. We also tested the BSF prediction based on 253 additional independent cases identified in our surveillance; the model anticipated 251 out of 253 of these independent cases. Background similarity tests comparing the ENMs of R. rickettsii , tick vectors, and mammalian hosts were unable to reject null hypotheses of niche similarity. Finally, we observed close coincidence between independent BSF cases, and areas suitable for combinations of vectors and hosts, reflecting the ability of these model pairs to anticipate the distribution of BSF cases across Brazil. Image, graphical abstract [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.