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1.
An Acad Bras Cienc ; 95(1): e20201869, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37162080

RESUMO

The Cerrado domain and its biodiversity has suffered several anthropogenic influences. Our objective was to evaluate the influence of biotic and anthropic variables on the mammal community in a protected area in the Cerrado-Caatinga ecotone. For this we sampled the mammals using camera traps (4,072 days/trap) for 16 months. We used generalized mixed linear models (GLMM) with model selection via Akaike's Information Criteria corrected for small sample size (AICc) to assess the influence of variables on richness, abundance and functional groups of mammals. We made a total of 663 photographic records of 16 species of medium and large mammals. The richness and number of mammals was negatively influenced by the distance to human settlements while carnivores were not affected by any of the variables evaluated, herbivores and generalists were more common in areas closer from human habitation. Despite the presence of large areas of native vegetation, our results show that there is a dominance of common and generalist species. The protected area is vulnerable to different sources of human pressure and the design and implementation of a management plan can be a key tool for protecting biodiversity and regulating the use of natural resources by local communities.


Assuntos
Biodiversidade , Mamíferos , Animais , Humanos , Brasil , Herbivoria , Modelos Lineares
2.
Am J Primatol ; 84(6): e23341, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34662461

RESUMO

Primates are affected by fluctuations in ambient temperatures, mostly through thermoregulatory costs and changes in the availability of food. In the present study, we investigate whether the ambient temperature and proxies of food availability affect the activity period of marmosets (Callithrix spp.). We predicted that: (i) at colder sites, marmosets would spend more time at sleeping sites; (ii) midday resting bouts would be longer at hotter sites; (iii) the onset/cessation of activity and resting behavior at midday would be more closely related to temperature than food availability, and (iv) highly exudativorous groups would have higher total levels of resting. We compiled data on the onset and cessation of activity and the time spent resting at midday from seven marmoset studies from sites with a wide range of temperatures. We used generalized linear mixed models to verify the relationship between the dependent variables (lag between dawn and the onset of activities, lag between cessation of activities and dusk, and proportion of resting during midday) and the minimum and maximum temperatures at the respective study sites, together with proxies of food availability (exudativory rates, the amount of habitat available per individual, and net primary productivity) using each sample month as a sampling unit and the identity of the study as a categorical random factor. At colder sites and during colder months, the marmosets left sleeping trees later in the morning and ceased their activities earlier, while at hotter sites and during hotter months, they spent more time resting during midday. More exudativorous groups become active later in the morning, but also ceased their activities later. The abundance of food did not affect the timing of activities. We provide evidence that both low and high temperatures affect marmosets' activities, and that their activity period appears to be more influenced by the thermal environment than food availability.


Assuntos
Callithrix , Ecossistema , Animais , Temperatura , Árvores
3.
Oecologia ; 197(1): 243-257, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34370096

RESUMO

The diversity of endotherms and ectotherms may be differently affected by ambient temperature and net primary productivity (NPP). Additionally, little is known about how these drivers affect the diversity of guilds of different trophic levels. We assessed the relative role of temperature and NPP in multitrophic guilds of ectothermic (arthropods: ants, ground beetles, spiders, and harvestmen) and endothermic (large mammals) animals along a tropical elevational gradient. We sampled arthropods at eight elevation belts and large mammals at 14 elevation belts in Atlantic rainforest (ranging from 600 to 2450 m.a.s.l.) of Itatiaia National Park, Southeast Brazil. Overall arthropod species richness was more associated with temperature than overall large-mammal species richness, while the latter was more associated with NPP. When separated into trophic guilds, we found that the species richness associated with NPP increased across arthropod trophic levels from herbivores to predators. Conversely, although NPP influenced large-mammal herbivore species richness, its effects did not seem to accumulate across large-mammal trophic levels since the species richness of large-mammal omnivores was more associated with temperature and none of the variables we studied influenced large-mammal predators. We suggest that thermal physiological differences between ectotherms and endotherms are responsible for the way in which arthropods and large mammals interact with or are constrained by the environment. Furthermore, the inconsistency regarding the role of temperature and NPP on species richness across multitrophic guilds of ectotherms and endotherms could indicate that thermal physiological differences might also interfere with energy use and flux in the food web.


Assuntos
Artrópodes , Biodiversidade , Animais , Ecossistema , Herbivoria , Temperatura
4.
Proc Natl Acad Sci U S A ; 113(4): 1008-13, 2016 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-26755597

RESUMO

The forest refuge hypothesis (FRH) has long been a paradigm for explaining the extreme biological diversity of tropical forests. According to this hypothesis, forest retraction and fragmentation during glacial periods would have promoted reproductive isolation and consequently speciation in forest patches (ecological refuges) surrounded by open habitats. The recent use of paleoclimatic models of species and habitat distributions revitalized the FRH, not by considering refuges as the main drivers of allopatric speciation, but instead by suggesting that high contemporary diversity is associated with historically stable forest areas. However, the role of the emerged continental shelf on the Atlantic Forest biodiversity hotspot of eastern South America during glacial periods has been ignored in the literature. Here, we combined results of species distribution models with coalescent simulations based on DNA sequences to explore the congruence between scenarios of forest dynamics through time and the genetic structure of mammal species cooccurring in the central region of the Atlantic Forest. Contrary to the FRH predictions, we found more fragmentation of suitable habitats during the last interglacial (LIG) and the present than in the last glacial maximum (LGM), probably due to topography. We also detected expansion of suitable climatic conditions onto the emerged continental shelf during the LGM, which would have allowed forests and forest-adapted species to expand. The interplay of sea level and land distribution must have been crucial in the biogeographic history of the Atlantic Forest, and forest refuges played only a minor role, if any, in this biodiversity hotspot during glacial periods.


Assuntos
Biodiversidade , Florestas , Clima , Ecossistema , Evolução Molecular , Filogeografia
5.
J Anim Ecol ; 86(5): 1214-1223, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28656732

RESUMO

Niche conservatism, i.e. the retention of a species' fundamental niche through evolutionary time, is cornerstone for biological invasion assessments. The fact that species tend to maintain their original climate niche allows predictive maps of invasion risk to anticipate potential invadable areas. Unravelling the mechanisms driving niche shifts can shed light on the management of invasive species. Here, we assessed niche shifts in one of the world's worst invasive species: the wild boar Sus scrofa. We also predicted potential invadable areas based on an ensemble of three ecological niche modelling methods, and evaluated the performance of models calibrated with native vs. pooled (native plus invaded) species records. By disentangling the drivers of change on the exotic wild boar population's niches, we found strong evidence for niche conservatism during biological invasion. Ecological niche models calibrated with both native and pooled range records predicted convergent areas. Also, observed niche shifts are mostly explained by niche unfilling, i.e. there are unoccupied areas in the exotic range where climate is analogous to the native range. Niche unfilling is expected as result of recent colonization and ongoing dispersal, and was potentially stronger for the Neotropics, where a recent wave of introductions for pig-farming and game-hunting has led to high wild boar population growth rates. The invasive potential of wild boar in the Neotropics is probably higher than in other regions, which has profound management implications if we are to prevent their invasion into species-rich areas, such as Amazonia, coupled with expansion of African swine fever and possibly great economic losses. Although the originally Eurasian-wide distribution suggests a pre-adaptation to a wide array of climates, the wild boar world-wide invasion does not exhibit evidence of niche evolution. The invasive potential of the wild boar therefore probably lies on the reproductive, dietary and morphological characteristics of this species, coupled with behavioural thermoregulation.


Assuntos
Distribuição Animal , Regulação da Temperatura Corporal , Clima , Espécies Introduzidas , Sus scrofa , Animais , Mudança Climática , Dieta , Ecossistema , Reprodução , Suínos
6.
BMC Vet Res ; 12: 21, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26822375

RESUMO

BACKGROUND: Despite the crucial role of domestic dogs as reservoirs for zoonosis and some of the most threatening diseases for wild carnivores such as distemper and parvovirosis, little is known about the epidemiological features and the risk factors involved in pathogen exposure of dogs that live in human/wildlife interfaces and actually contacts wildlife. Through a cross-sectional serological approach and questionnaire survey, we assessed the prevalence along with individual and environment-associated risk factors for four important viral diseases of rural dogs living in households around six Atlantic Forest fragments in southeast Brazil. RESULTS: Widespread exposure to canine parvovirus (97%), canine distemper virus (15%) and canine adenovirus (27%) was detected, but none for canine coronavirus. Dogs from small private reserves were more exposed to parvovirus and canine distemper virus than those from larger state parks. Exposure was associated with dog sex and age, lack of health care and the number of people in the households. Remarkably, factors linked to free-ranging behaviour of dogs were associated with the exposure for all pathogens detected. CONCLUSIONS: According to identified associations, reducing viral pathogen exposure in dogs will require inhibiting dog's movements and access to nearby forests and villages and improving veterinary assistance. Promoting dog vaccination and population control through sterilization around protected areas is also necessary. The study provides support for preventive management actions aimed to protect the health of rural dogs, and consequently of Atlantic Forest's wild carnivores.


Assuntos
Doenças do Cão/epidemiologia , Doenças do Cão/virologia , Viroses/veterinária , Adenovirus Caninos , Criação de Animais Domésticos , Animais , Brasil/epidemiologia , Vírus da Cinomose Canina , Cães , Feminino , Florestas , Humanos , Masculino , Parvovirus Canino , Animais de Estimação/virologia , Prevalência , Fatores de Risco , Viroses/epidemiologia , Viroses/prevenção & controle
8.
Rev Biol Trop ; 60(3): 1335-43, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23025102

RESUMO

Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a context, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors) using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS) ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments).


Assuntos
Ecossistema , Mamíferos/classificação , Árvores , Animais , Brasil , Densidade Demográfica , Dinâmica Populacional
9.
Anat Histol Embryol ; 48(3): 256-263, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30730072

RESUMO

The name of the species tetradactyla means "four digits." In the literature, the hand of the lesser anteater (Tamandua tetradactyla) is described as having four digits (I, II, III and IV) with the absence of a fifth digit. The purpose of this study was to carry out an update adequately proposing an anatomical description of the T. tetradactyla hand. The present findings were analysed on the validation of Morse's law for this species. In total, seven male cadavers were radiographed and dissected. We observed that the hand of the T. tetradactyla was formed by a carpus containing four bones in the proximal row, which in the medium lateral direction was the radial, intermediate, ulnar and accessory bones of the carpus, and the distal row was formed by carpal bones I, II, III and IV. There were five metacarpal bones (I, II, III, IV and V). The presence of five digits was verified but not confirmed with the literature. Digit I had two phalanges, the proximal and distal; digits II, III and IV had three phalanges: proximal, middle and distal. Digit five had only one phalanx, the proximal, but it was not externally visible. According to the findings of this study, the presence of the fifth digit raises the question of whether the term tetradactyla is the most appropriate to describe this species. This rudimentary fifth digit and the presence of a functional first digit show that the Morse's law does not applies for the T. tetradactyla species.


Assuntos
Carpo Animal/anatomia & histologia , Xenarthra/anatomia & histologia , Animais , Cadáver , Ossos do Carpo/anatomia & histologia , Ossos do Carpo/diagnóstico por imagem , Carpo Animal/diagnóstico por imagem , Espécies em Perigo de Extinção , Masculino , Ossos Metacarpais/anatomia & histologia , Ossos Metacarpais/diagnóstico por imagem , Radiografia/veterinária , Falanges dos Dedos do Pé/anatomia & histologia , Falanges dos Dedos do Pé/diagnóstico por imagem , Xenarthra/fisiologia
10.
Biota Neotrop. (Online, Ed. ingl.) ; 22(2): e20211307, Mar 31, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1374522

RESUMO

Abstract: Among the ecoregions that comprise the high-Andean zone of the Tropical Andes, the Puna and the Yungas stand out for covering a large part of the Peruvian Eastern Andes. Located in the ecotone of these two ecoregions, the Pampa Hermosa National Sanctuary (PHNS) houses one of the priority areas for conservation in Peru. However, the biodiversity of the high-Andean zone of the sanctuary and its surroundings remains poorly studied. Thus, through camera traps and transects, we sought to inventory for the first time the medium and large mammals from the high-Andean region of the PHNS and its buffer zone. We recorded 11 native and three domestic species of medium and large mammals. The richness of native mammals sampled reached 91.7% of the estimated richness (S est.= 11.99 ± 1.85). Among the native species Odocoileus virginianus had the highest relative frequency (56%). We recorded three endemic mammals from the Tropical Andes, Cuniculus taczanowskii, Tremarctos ornatus, and Pudu mephistopheles. The observed richness was higher than most surveys of medium and large mammals carried out in the Puna-forest ecotone in Peru, where the reported richness ranged from 4 to 13 species. In addition, our records of Leopardus pardalis and Eira barbara are the highest for all distribution of these two carnivores. Our results showed that more than 90% of the species recorded were found in it, demonstrating that the entire high-Andean region of the PHNS and its surroundings has an important value for the local mammal community.


Resumo: Dentre as ecorregiões que compreendem a zona alto-andina dos Andes Tropicais, a Puna e as Yungas se destacam por abranger grande parte dos Andes Orientais peruanos. Localizado no ecótono entre estas duas ecorregiões, o Santuário Nacional Pampa Hermosa (SNPH) abriga uma das áreas prioritárias para conservação no Peru. No entanto, a biodiversidade da zona alto-andina do santuário e seu entorno permanece pouco estudada. Dessa forma, através de armadilhas fotográficas e transectos, buscamos inventariar pela primeira vez os mamíferos de médio e grande porte da região alto-andina do SNPH e de sua zona de amortecimento. Nós registramos 11 espécies nativas e três espécies domésticas de mamíferos de médio e grande porte. A riqueza observada dos mamíferos nativos atingiu 91,7% da riqueza estimada (S est.= 11,99 ± 1,85). Dentre as espécies nativas, Odocoileus virginianus foi a que apresentou a maior frequência relativa (56%). Registramos três mamíferos endêmicoss dos Andes Tropicais, Cuniculus taczanowskii, Tremarctos ornatus, e Pudu mephistopheles. A riqueza observada foi superior que a maioria dos levantamentos de mamíferos de médio e grande porte feitos em ecótono Puna-bosque no Peru, onde a riqueza reportada variou de 4 a 13 espécies. Além disso, os registros de Leopardus pardalis e Eira barbara são os mais elevados para toda distribuição destes dois carnívoros. Nossos resultados demonstraram que mais de 90% das espécies registradas foram encontradas nela, demonstrando que toda região alto-andina do SNPH e seu entorno tem um importante valor para a fauna de mamíferos local.

11.
PLoS One ; 9(8): e104003, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25089629

RESUMO

Canine visceral leishmaniasis is an important zoonosis in Brazil. However, infection patterns are unknown in some scenarios such as rural settlements around Atlantic Forest fragments. Additionally, controversy remains over risk factors, and most identified patterns of infection in dogs have been found in urban areas. We conducted a cross-sectional epidemiological survey to assess the prevalence of leishmaniasis in dogs through three different serological tests, and interviews with owners to assess features of dogs and households around five Atlantic Forest remnants in southeastern Brazil. We used Generalized Linear Mixed Models and Chi-square tests to detect associations between prevalence and variables that might influence Leishmania infection, and a nearest neighbor dispersion analysis to assess clustering in the spatial distribution of seropositive dogs. Our findings showed an average prevalence of 20% (ranging from 10 to 32%) in dogs. Nearly 40% (ranging from 22 to 55%) of households had at least one seropositive dog. Some individual traits of dogs (height, sterilization, long fur, age class) were found to positively influence the prevalence, while some had negative influence (weight, body score, presence of ectoparasites). Environmental and management features (number of cats in the households, dogs with free-ranging behavior) also entered models as negative associations with seropositivity. Strong and consistent negative (protective) influences of the presence of chickens and pigs in dog seropositivity were detected. Spatial clustering of cases was detected in only one of the five study sites. The results showed that different risk factors than those found in urban areas may drive the prevalence of canine leishmaniasis in farm/forest interfaces, and that humans and wildlife risk infection in these areas. Domestic dog population limitation by gonadectomy, legal restriction of dog numbers per household and owner education are of the greatest importance for the control of visceral leishmaniasis in rural zones near forest fragments.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/epidemiologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Animais , Brasil/epidemiologia , Gatos , Galinhas , Estudos Transversais , Doenças do Cão/parasitologia , Doenças do Cão/transmissão , Cães , Monitoramento Epidemiológico , Características da Família , Feminino , Florestas , Humanos , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/transmissão , Modelos Lineares , Masculino , Prevalência , Fatores de Risco , População Rural , Estudos Soroepidemiológicos , Suínos
12.
PLoS One ; 6(8): e23312, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21912591

RESUMO

The objective of our work was to verify the value of the vegetation corridor in the conservation of small mammals in fragmented tropical landscapes, using a model system in the southeastern Minas Gerais. We evaluated and compared the composition and structure of small mammals in a vegetation corridor, forest fragments and a coffee matrix. A total of 15 species were recorded, and the highest species richness was observed in the vegetation corridor (13 species), followed by the forest fragments (10) and the coffee matrix (6). The absolute abundance was similar between the vegetation corridor and fragments (F = 22.94; p = 0.064), and the greatest differences occurred between the vegetation corridor and the matrix (F = 22.94; p = 0.001) and the forest fragments and the matrix (F = 22.94; p = 0.007). Six species showed significant habitat preference possibly related to the sensitivity of the species to the forest disturbance. Marmosops incanus was the species most sensitive to disturbance; Akodon montensis, Cerradomys subflavus, Gracilinanus microtarsus and Rhipidomys sp. displayed little sensitivity to disturbance, with a high relative abundance in the vegetation corridor. Calomys sp. was the species least affected by habitat disturbance, displaying a high relative abundance in the coffee matrix. Although the vegetation corridors are narrow (4 m width), our results support the hypothesis in which they work as a forest extension, share most species with the forest fragment and support species richness and abundance closer to forest fragments than to the coffee matrix. Our work highlights the importance and cost-effectiveness of these corridors to biodiversity management in the fragmented Atlantic Forest landscapes and at the regional level.


Assuntos
Coffea , Conservação dos Recursos Naturais , Mamíferos , Árvores , Animais , Oceano Atlântico , Biodiversidade , Brasil , Mamíferos/classificação
13.
Acta sci., Biol. sci ; 35(4): 499-503, out.-dez. 2013.
Artigo em Português | LILACS-Express | LILACS, VETINDEX | ID: biblio-1460767

RESUMO

Each kind of trap tends to be selective on species sampled, in a way that each one only reveals part of the abundance and species richness of the community sampled. In this way, in order to know the factors that affect the success of sampling methods is crucial for a better planning of experiments and data analysis. The aim of this study was to evaluate the factors that affect the success of pitfall traps in capturing small mammals, such as trap size, designs and use of bait. The study was carried out in two reserves inside the campus of the Universidade Federal de Lavras (UFLA), in South Minas Gerais State, Brazil. In total, 65 specimens belonging to 8 species were caught. Different types of trap design (Y-shaped and I-shaped) have not influenced the capture success of pitfalls. The same result was obtained for the different size of buckets, in exception for Oligoryzomys flavescens, in which larger buckets were more efficient. The use of baits was considered not necessary.

14.
Acta sci., Biol. sci ; 35(4): 499-503, out.-dez. 2013. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-849312

RESUMO

Each kind of trap tends to be selective on species sampled, in a way that each one only reveals part of the abundance and species richness of the community sampled. In this way, in order to know the factors that affect the success of sampling methods is crucial for a better planning of experiments and data analysis. The aim of this study was to evaluate the factors that affect the success of pitfall traps in capturing small mammals, such as trap size, designs and use of bait. The study was carried out in two reserves inside the campus of the Universidade Federal de Lavras (UFLA), in South Minas Gerais State, Brazil. In total, 65 specimens belonging to 8 species were caught. Different types of trap design (Y-shaped and I-shaped) have not influenced the capture success of pitfalls. The same result was obtained for the different size of buckets, in exception for Oligoryzomys flavescens, in which larger buckets were more efficient. The use of baits was considered not necessary.


Cada tipo de armadilha exerce uma seleção quanto às espécies capturadas, de forma que cada uma revela uma fração da riqueza e abundância da comunidade amostrada. Conhecer os fatores que afetam no sucesso dos métodos de captura é de fundamental importância para o planejamento de experimentos e análise de dados. O objetivo deste estudo é avaliar fatores que podem afetar o sucesso de captura dos pitfalls (armadilhas de interceptação e queda), tais como forma da estação de captura, tamanho do balde e presença de isca. As coletas foram realizadas em duas Reservas Florestais localizados no campus da Universidade Federal de Lavras, UFLA, na cidade de Lavras, Estado de Minas Gerais. Ao todo foram capturados 65 indivíduos de oito espécies. A forma das estações (Y ou linha) não influenciou no sucesso de captura dos pitfalls. Os diferentes tamanhos de balde não apresentaram sucessos de captura diferentes significativamente, exceto para a espécie Oligoryzomys flavescens, em que os baldes maiores foram mais eficientes. O uso de isca se mostrou dispensável.


Assuntos
Animais , Pesquisa , Roedores , Estudos de Amostragem , Marsupiais
15.
Rev. biol. trop ; 60(3): 1335-1343, Sept. 2012. graf, mapas, tab
Artigo em Inglês | LILACS | ID: lil-659592

RESUMO

Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a text, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors) using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS) ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments).


La fragmentación del hábitat conduce al aislamiento y la reducción de los hábitats, además provoca una serie de efectos negativos sobre las poblaciones naturales, afectando la riqueza, abundancia y distribución de las especies de animales. Dentro de este contexto, los corredores biológicos sirven como una alternativa para la conectividad de los paisajes fragmentados, minimizando los efectos del aislamiento estructural de las áreas con diferentes hábitats. Este estudio evaluó la riqueza, la composición y la abundancia de las comunidades de mamíferos pequeños en fragmentos de bosque y en los corredores de vegetación relevantes que conectan estos fragmentos, localizados en el sur de Minas Gerais, sudeste de Brasil. Diez sitios fueron muestraeados (cinco fragamentos de bosque y cinco corredores biológicos ) usando el método de captura-marcaje-recaptura, desde abril de 2007-marzo de 2008. Un esfuerzo total de muestreo de 6 300 trampas nocturnas resultó en 656 capturas de 249 individuos. En los 10 sitios muestreados, se registraron 11 especies de mamíferos pequeños. Las ordenaciones del escalamiento Multidimensional (MDS) y el ANOSIM basados en la composición de las comunidades de mamíferos pequeños dentro de los corredores y los fragmentos revelan una diferencia cualitativa entre estos dos ambientes. En cuanto a la abundancia, no hubo una diferencia significativa entre los corredores y los fragmentos. Al comparar los valores promedio de abundancia por especie en cada ambiente, sólo Cerradomys subflavus mostró una diferencia significativa, siendo más abundante en el ambiente del corredor biológico. Los resultados sugieren que la presencia de varias especies de mamíferos pequeños en el entorno del corredor biológico, en abundancias relativamente altas, podría indicar el uso de los corredores como hábitat, aunque estos también podrían facilitar y/o permitir el movimiento de individuos que utilizan los diferentes parches de hábitat (fragmentos).


Assuntos
Animais , Ecossistema , Mamíferos/classificação , Árvores , Brasil , Densidade Demográfica , Dinâmica Populacional
16.
Primates ; 41(1): 27-38, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30545189

RESUMO

We report on the diet and feeding behaviour of a group of Geoffroy's marmosets (Callithrix geoffroyi) in an Atlantic forest fragment in south-eastern Brazil, studied during the period February 1993 to Januaray 1994. Major food categories were gums (68.6%) fruits (15%), and small animal prey (invertebrates 14.6% and vertebrates 0.8%). Dietary changes were observed between the wet and dry seasons, although they were not statistically significant. Insects and gums were consumed throughout the year but fruits were more prevalent in the diet in the wet season. Plant species exploited for their gums includedInga stipularis, followed byAcacia paniculata, Paulinia carpopodia, andBauhinia angulosa. Chemical analysis of the gum of the four species most used all presented high values for carbohydrates and crude proteins. Fruits of an unidentified species of Myrtaceae (sp. 2) were consumed the most. Animal prey consisted mainly of insects, arachnids, snails, and in three cases, lizards and frogs, with orthopterans being the most prevalent insect prey. This study demonstrates thatC. geoffroyi efficiently exploits resources typically available in secondary and disturbed forest habitat. The main threat to the species is forest destruction, degradation, and fragmentation, but the management of small forest fragments may be an effective corservation strategy.

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