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A useful approach to deepen our knowledge about the origin and evolution of venom systems in Reptilia has been exploring the vast biodiversity of this clade of vertebrates in search of orally produced proteins with toxic actions, as well as their corresponding delivery systems. The occurrence of toxins in anguimorph lizards has been demonstrated experimentally or inferred from reports of the toxic effects of the oral secretions of taxa within the Varanidae and Helodermatidae families. In the present study, we have focused on two alligator lizards of the Anguidae family, the Mexican alligator lizard, Abronia graminea, and the red-lipped arboreal alligator lizard, A. lythrochila. In addition, the fine morphology of teeth of the latter species is described. The presence of a conserved set of proteins, including B-type natriuretic peptides, cysteine-rich secretory proteins, group III phospholipase A2, and kallikrein, in submandibular gland extracts was demonstrated for both Abronia species. These proteins belong to toxin families found in oral gland secretions of venomous reptile species. This finding, along with previous demonstration of toxin-producing taxa in both paleo- and neoanguimorpha clades, provides further support for the existence of a handful of conserved toxin families in oral secretions across the 100+ million years of Anguimorpha cladogenesis.

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We present the first description of a diurnal live birth of a wild black howler monkey (Alouatta pigra). The mother formed part of a group of five individuals inhabiting an anthropogenic setting in the tropical lowlands of southeast Mexico. A total of 7 h and 50 min passed from the rupture of the amniotic sac early in the day to the crowning of the infant from the birth canal. The delivery of the infant lasted ~ 3 min. We describe the event while referencing images and time points in a supplementary video recording. We place our findings in the context of the available reports of live births in the Alouatta genus, time of day, birth duration, and group activity budget on the day of the birth. While primates tend to give birth at night to reduce complications from group interactions, the observed birth took place during the day, which may have been possible due to an alteration in group time allocation. Our report provides in-depth details of the events of a birth and important information regarding the natural history of the black howler monkey.

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Research on food finding by pest termites can be used to inform the development of techniques to control their population; however, there is a paucity of information available on the foraging behavior of Nasutitermes corniger, an urban pest in South America. In the present study, we analyzed the effect of the distance between the nest and food on the exploration and recruitment of N. corniger during foraging behavior under laboratory conditions. Nests containing mature colonies were collected in the field and placed in a glass cube connected to a test arena (50.0 × 40.0 cm) in which Eucalyptus grandis blocks were supplied at three different distances: 10, 20 and 30 cm. In each test, the occurrence of the following events were recorded: initial exploitation, initial recruitment, and mass worker recruitment. Individuals in the blocks were counted at the end of each test and divided into the total number of recruited termites, recruited workers, consuming workers and recruited soldiers. Each test lasted 60 minutes and was repeated with 20 colonies. Nasutitermes corniger foragers showed the three behavioral events of interest at all three distances. The occurrences of initial exploitation and initial recruitment, the latency of the three events and the number of foragers were not affected by the distance between the nest and food. The occurrence of mass worker recruitment was the only event affected by this distance, with higher recruitment at shorter distances.

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Tityus obscurus has caused mild, moderate and severe accidents of medical relevance in the eastern Brazilian Amazon and French Guiana. Tityus obscurus has sexual dimorphism although males and females have uniform black coloration. In the Amazon, one of the habitats of this scorpion is seasonally flooded forests (igapós and várzeas). However, most stings occur in terra firme forest areas (non-flooded region), where most rural communities are located. Adults and children stung by T. obscurus may experience an “electric shock” sensation for more than 30 h after the sting. Our data shows that people inhabiting remote forest areas, including rubber tappers, fishermen and indigenous people, with no access to anti-scorpion serum, use parts of native plants, such as seeds and leaves, against pain and vomiting caused by scorpion stings. Although there is a technical effort to produce and distribute antivenoms in the Amazon, many cases of scorpion stings are geographically unpredictable in this region, due to the lack of detailed knowledge of the natural distribution of these animals. In this manuscript, we compile information on the natural history of T. obscurus and the impact of its envenoming on human health. We identify the natural sites that host this scorpion in the Amazon, in order to warn about the risk of human envenoming. The use of specific antivenom serum is the recommended treatment for accidents involving venomous animals. However, atypical symptoms not neutralized by the available commercial antivenom are reported in the Amazon region. Facing this scenario, we present some challenges to the study of venomous animals in the Amazon rainforest and possible experimental bottlenecks and perspectives for establishing a method aimed at producing an efficient antivenom.

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This study evaluated the nutritive value of signalgrass (Urochloa decumbens Stapf R. D. Webster) and sabiá (Mimosa caesalpiniifolia Benth.), and animal performance in grass monoculture pastures and in silvopastoral system (SPS) in the early development stage, in the Agreste of Pernambuco. Four treatments were evaluated in a randomized block design with three replications: signalgrass + Eucalyptus spp.; signalgrass + sabiá; signalgrass monoculture and sabiá monoculture. Holstein × Zebu crossbred calves (170 ± 15 kg BW) were managed under continuous stocking with variable stocking rate (SR). The dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), and in vitro dry matter digestibility (IVDMD) of signalgrass and sabiá were assessed, as well as forage allowance (FA), stocking rate (SR), average daily weight gain (ADG) and weight gain per area (WGA) over eleven evaluation cycles (March 2019 to January 2020). Signalgrass had the highest DM contents in March 2019 and January 2020 (456 and 507 g kg-1, respectively), while for IVDMD the highest values ranged from 436 to 547 g kg-1 (April to August 2019). Sabiá presented the highest's IVDMD (311 and 381 g kg-1 DM) and DM content (385 and 416 g kg-1) and lowest CP (110 and 82 g kg-1 DM) and NDF (568 and 500 g kg-1 DM) in November 2019 and January 2020, respectively. FA and SR decreased throughout the evaluation cycles. ADG (0.38 kg animal-1 day-1) and WGA (17.89 kg ha-1 28 days-1) did not differ among treatments, with weight loss in the period of low water availability. In the early development stage of the trees, SPS does not affect the nutritive value of signalgrass, nor the animal performance.

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Scorpionism is a relevant medical condition in Brazil. It is responsible for most accidents involving venomous animals in the country, which leads to severe symptoms that can evolve to death. In recent years, an increase of almost 50% in the incidence of scorpionism has been observed in the Northern Region, where the highest severity of envenoming has been notified since the beginning of the 21st century. This review aims to provide an in-depth assessment of public data and reports on symptoms and epidemiology of envenoming, ecological aspects of scorpions, and characterization of venoms and toxins to access the gaps that need to be filled in the knowledge of the scorpion species of medical importance from the Brazilian Amazon. A systematic search using the string words "Amazon" and "scorpion" was performed on 11 databases. No restriction on date, language or status of the publication was applied. Reports not related to the Brazilian Amazon were excluded. Therefore, 88 studies remained. It is shown that populations of scorpions of medical importance, even of the same species, may present significant toxic variations peculiar to some regions in the Brazilian Amazon, and commercial scorpion antivenoms were not able to shorten the intensity and duration of neurological manifestations in patients stung by T. silvestris, T. apiacas or T. obscurus. It is also highlighted that the toxins responsible for triggering these alterations have not been elucidated yet and this is a fruitful field for the development of more efficient antivenoms. Furthermore, the geographic distribution of scorpions of the genus Tityus in the Brazilian Amazon was revised and updated. The cumulative and detailed information provided in this review may help physicians and scientists interested in scorpionism in the Brazilian Amazon.

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Wood-boring beetle larvae act as ecosystem engineers by creating stem cavities that are used secondarily as nests by many arboreal ant species. Understanding the heterogeneity and distribution of available cavities and their use by ants is therefore key to understanding arboreal ant community assembly and diversity. Our goals were to quantify the abundance and diversity of beetle-produced cavity resources in a tropical canopy, reveal how ants use these resources, and determine which characteristics of the cavity resource contribute to ant use. We dissected branches from six common tree species in the Brazilian Cerrado savanna, measuring cavity characteristics and identifying the occupants. We sampled 2310 individual cavities, 576 of which were used as nests by 25 arboreal ant species. We found significant differences among tree species in the proportion of stem length bored by beetles, the number of cavities per stem length, average entrance-hole size, and the distribution of cavity volumes. The likelihood that a cavity was occupied was greater for cavities with larger entrance-hole sizes and larger volumes. In particular, there was a strong positive correlation between mean head diameters of ant species and the mean entrance-hole diameter of the cavities occupied by those ant species. Wood-boring beetles contribute to the structuring of the Cerrado ant community by differentially attacking the available tree species. In so doing, the beetles provide a wide range of entrance-hole sizes which ant species partition based on their body size, and large volume cavities that ants appear to prefer.

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Ants have efficient and well-studied social immunity mechanisms, which prevent the colony contamination. Little is known about how workers keep their outside territory clear of diseases. We investigated the interactions between Azteca chartifex ants, their associated bacteria and bacteria on the phyllosphere of Byrsonima sericea trees, comparing plants patrolled and not by the ants. The hypothesis is that bacteria associated with the worker's exoskeleton may outcompete the leaf bacteria. Culturable bacteria were isolated from ants, from the main and satellite nests, and from phyllosphere of B. sericea taken from trees that had A. chartifex nests and from trees without nests. The isolates were grouped by Gram guilds and identified at the genus level. There was a higher percentage of Gram-negative isolates in the ants and on the leaves patrolled by them. There was a higher growth rate of ant bacteria from the main nest compared to those found in ants from the satellite nests. The most representative genus among ant isolates was Enterobacter, also found on leaves patrolled by ants. Under favourable in vitro conditions, A. chartifex Gram-negative bacteria outcompete leaf bacteria by overgrowth, showing a greater competition capacity over the Gram-positive bacteria from leaves with no previous interaction with ants in the field. It was demonstrated that ants carry bacteria capable of outcompeting exogenous bacteria associated with their outside territory. The leaf microbiota of a patrolled tree could be shaped by the ant microbiota, suggesting that large ant colonies may have a key role in structuring canopy plant-microbe interactions.

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Studies evaluating the health status and characteristics of free-ranging wildlife populations are scarce or absent for most species. Saurian health assessments are usually performed in species that have conservation issues or that are kept in captivity. The Berthold's bush anole (Polychrus guturossus) is one of eight species belonging to the genus Polychrus, the only representative of the family Polychrotidae. Only a handful of studies have been reported concerning these lizard's morphological variation, ecology, and natural history, probably because P. gutturosus is a canopy dweller and it can be difficult to locate individuals. It is believed that deforestation and habitat modification could pose a threat for this species, although to date no health assessment has been done. The aim of this study was to generate health baseline data on P. gutturosus. Forty Berthold's bush anoles (20 males and 20 females) were sampled at the Pacific versant in Costa Rica, where physical examination, skin and cloacal temperatures, and blood samples were obtained from individuals immediately after capture. Animals from the studied population were all healthy (body condition 2.5-3.0/5.0). No lesions or ectoparasites were detected, but hemoparasites were found in nine individuals. Hematological and biochemical values were obtained, and the morphology of leukocytes were found to be similar to other iguanians. A positive correlation was found between the tissue enzymes aspartate aminotransferase (AST) and creatinine kinase (CK) and a negative correlation was found between skin and cloacal temperatures and AST and CK. There were positive correlations between female weight and total protein, calcium, and the calcium and phosphorus ratio. No significant inter-sex differences were found in biochemical values, despite females being larger than males. This is the first health assessment performed on a free-ranging canopy dwelling lizard. These findings provide baseline data that may be useful for future monitoring if the species faces changes in health status due to anthropogenic causes or natural disturbances.

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Terrestriality in Platyrrhine primates is primarily associated with low arboreal resource availability, low predation risk when on the ground and increased contact time with human observers. To test the relationship between these variables and ground use frequency, we studied a group of endangered Coimbra-Filho's titi monkeys (Callicebus coimbrai) in a 14-ha forest fragment in north-eastern Brazil. Terrestriality data were collected on a monthly basis (33 months) using scan sampling procedures from July 2008 to July 2012. Overall, Coimbra-Filho's titi monkeys were recorded during 0.6% of observation time (113 out of 18,164 scans) on the ground. Most of the time on the ground was spent feeding on young leaves (71 records) and the least amount of time on fruits (14 records). Availability of arboreal foods, rainfall, and time of contact with human observers did not influence overall terrestrial behaviour (ground use). However, the timing and nature of the monkeys' terrestrial feeding was strongly related to the absence of arboreal fruit (ß-estimate = -3.078) and young leaf (ß-estimate = -3.515) food resources. We suggest that terrestrial feeding by Coimbra-Filho's titi monkeys could be an adaptation to low arboreal fruit availability and the exploitation of alternative food resources.

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Scorpionism is a relevant medical condition in Brazil. It is responsible for most accidents involving venomous animals in the country, which leads to severe symptoms that can evolve to death. In recent years, an increase of almost 50% in the incidence of scorpionism has been observed in the Northern Region, where the highest severity of envenoming has been notified since the beginning of the 21st century. This review aims to provide an in-depth assessment of public data and reports on symptoms and epidemiology of envenoming, ecological aspects of scorpions, and characterization of venoms and toxins to access the gaps that need to be filled in the knowledge of the scorpion species of medical importance from the Brazilian Amazon. A systematic search using the string words "Amazon" and "scorpion" was performed on 11 databases. No restriction on date, language or status of the publication was applied. Reports not related to the Brazilian Amazon were excluded. Therefore, 88 studies remained. It is shown that populations of scorpions of medical importance, even of the same species, may present significant toxic variations peculiar to some regions in the Brazilian Amazon, and commercial scorpion antivenoms were not able to shorten the intensity and duration of neurological manifestations in patients stung by T. silvestris, T. apiacas or T. obscurus. It is also highlighted that the toxins responsible for triggering these alterations have not been elucidated yet and this is a fruitful field for the development of more efficient antivenoms. Furthermore, the geographic distribution of scorpions of the genus Tityus in the Brazilian Amazon was revised and updated. The cumulative and detailed information provided in this review may help physicians and scientists interested in scorpionism in the Brazilian Amazon.(AU)

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RESUMO

Scorpionism is a relevant medical condition in Brazil. It is responsible for most accidents involving venomous animals in the country, which leads to severe symptoms that can evolve to death. In recent years, an increase of almost 50% in the incidence of scorpionism has been observed in the Northern Region, where the highest severity of envenoming has been notified since the beginning of the 21st century. This review aims to provide an in-depth assessment of public data and reports on symptoms and epidemiology of envenoming, ecological aspects of scorpions, and characterization of venoms and toxins to access the gaps that need to be filled in the knowledge of the scorpion species of medical importance from the Brazilian Amazon. A systematic search using the string words "Amazon" and "scorpion" was performed on 11 databases. No restriction on date, language or status of the publication was applied. Reports not related to the Brazilian Amazon were excluded. Therefore, 88 studies remained. It is shown that populations of scorpions of medical importance, even of the same species, may present significant toxic variations peculiar to some regions in the Brazilian Amazon, and commercial scorpion antivenoms were not able to shorten the intensity and duration of neurological manifestations in patients stung by T. silvestris, T. apiacas or T. obscurus. It is also highlighted that the toxins responsible for triggering these alterations have not been elucidated yet and this is a fruitful field for the development of more efficient antivenoms. Furthermore, the geographic distribution of scorpions of the genus Tityus in the Brazilian Amazon was revised and updated. The cumulative and detailed information provided in this review may help physicians and scientists interested in scorpionism in the Brazilian Amazon.(AU)

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Food scarcity or abundance are factors regulating termites' foraging behavior in general. The aim of the present study is to evaluate the influence of four amounts of Eucalyptus grandis on foraging behavior events shown by worker and soldier of Nasutitermes corniger during laboratory tests. The tests were carried out with adult and active N. corniger colonies found in nests collected in the field, which were stored in glass cubes connected to the test arenas. Four different amounts of wood blocks were used in the tests and each amount concerned a treatment and defined a different experimental group: 1, 2, 3 and 4 blocks/arenas, with 5 repetitions. Each test lasted 60 minutes and consisted in observing, or not, the occurrence of behavioral events shown by foragers when they had contact with the treatment. The duration of each event was recorded, whenever it was observed. The number of recruited foragers and the number of workers consuming the blocks were recorded at the end of each test applied to each treatment. Nasutitermes corniger presented the three behavioral events in all treatments; however, there was not significant difference between treatments in the occurrence of the two first events, in the time taken from test start to the occurrence of a new event, in the number of recruited termites and in the number of gnawing workers. Only workers' mass recruiting was influenced by the amount of wood available. The occurrence of this event was significantly higher in treatments with greater amounts of wood. Thus, N. corniger adjusts its mass recruitment behavior in response to available food amount, which should be considered when developing baiting system for its control. (AU)

A escassez ou abundância de alimento são fatores que regulam o forrageamento do térmitas em geral. No presente estudo, avaliou-se a influência de quatro quantidades de madeira de Eucalyptus grandis em eventos comportamentais do forrageamento exibidos por operárias e soldados de Nasutitermes corniger em testes de laboratório. Os testes foram realizados com colônias maduras e ativas de N. cornigerpresentes em ninhos coletados a campo, os quais foram acondicionados em cubas de vidro conectadas a arenas testes. Blocos de madeira de mesma dimensão foram ofertados aos térmitas em quatro quantidades: 1, 2, 3 e 4 blocos/arena, com 5 repetições. Cada teste durou 60 minutos e consistiu na observação ou não da ocorrência de eventos comportamentais exibidos pelos forrageadores quando foi dado acesso a cada tratamento. Quando cada evento foi observado, o tempo de sua duração foi registrado. Ao final de cada teste registrou-se, em cada tratamento, o número de térmitas forrageadores recrutados e o número de operários consumindo os blocos. Observou-se que N. corniger exibiu os três eventos comportamentais em todos os tratamentos. Todavia, não houve diferença significativa entre os tratamentos com relação à ocorrência dos dois primeiros eventos, aos tempos transcorridos desde o início do teste até a ocorrência de cada evento, aos números de térmitas recrutados e ao número de operários em roedura. Apenas a ocorrência de recrutamento em massa dos operários foi influenciada pela quantidade de madeira ofertada, sendo que foi significativamente superior quando se ofertou os blocos de madeira na maior quantidade. Dessa forma, N. corniger ajusta seu comportamento de recrutamento em massa em resposta a quantidade de alimento disponível, o que deve ser considerado ao se desenvolver um sistema de isca para seu controle. (AU)

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Habitat loss and fragmentation are leading threats to biodiversity today, and primates are particularly vulnerable to anthropogenic habitat disturbance. However, few studies have examined how differential effects of variation in forest fragment characteristics on males and females in a primate population may affect demography and population persistence. We quantified the effects of variation in forest fragment characteristics on the within-fragment demography of black howler monkeys (Alouatta pigra) in forest fragments around Palenque National Park, Mexico, and how these effects differed between adult males and females. We quantified forest loss in the landscape between 2000 and 2017, and used a redundancy analysis to examine the effects of 15 variables quantifying fragment dimensions, forest composition and physical structure, and isolation on fragment population size and density, the proportion of adult males and females in the fragment population, and the mean number of adult males and females per group in 34 fragments (N = 393 monkeys). We hypothesized that (i) population size is positively correlated with fragment area, while population density is negatively correlated, and (ii) the composition of fragment populations results from differential effects of fragment variables on adult males and females. Forest cover decreased by 23.3% from 2000 to 2017. Our results showed a significant effect of fragment variables on population demography in fragments, accounting for 0.69 of the variance in the demographic response variables. Population size increased with fragment area and connectivity, while density decreased. Larger, less isolated fragments with better connectivity, characteristics indicative of abundant secondary growth, and those with more diverse vegetation but lower Simpson's evenness indices tended to have more adult females per group and a higher proportion of adult females in the population. In contrast, fragments that were largely similar in characteristics of forest composition and structure, but that were more isolated from nearby fragments, had more adult males per group and a higher proportion of adult males. These results may stem from black howler females preferentially remaining in natal groups and fragments when possible, and dispersing shorter distances when they disperse, while males may be more likely to disperse between fragments, traveling longer distances through the matrix to more isolated fragments. These differential effects on males and females have important conservation implications: if females are more abundant in larger, less isolated fragments, while males are more abundant in more isolated fragments, then to effectively conserve this population, both landscape connectivity and fragment areas should be maintained and increased.

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Arboreal environments present considerable biomechanical challenges for animals moving and foraging among substrates varying in diameter, orientation and compliance. Most studies of quadrupedal gait kinematics in primates and other arboreal mammals have focused on symmetrical walking gaits and the significance of diagonal sequence gaits. Considerably less research has examined asymmetrical gaits, despite their prevalence in small-bodied arboreal taxa. Here, we examined whether and how free-ranging callitrichine primates adjust asymmetrical gait kinematics to changes in substrate diameter and orientation, as well as how variation in gait kinematics affects substrate displacement. We used high-speed video to film free-ranging Saguinus tripartitus and Cebuella pygmaea inhabiting the Tiputini Biodiversity Station, Ecuador. We found that S. tripartitus used bounding and half-bounding gaits on larger substrates versus gallops and symmetrical gaits on smaller substrates, and also shifted several kinematic parameters consistent with attenuating forces transferred from the animal to the substrate. Similarly, C. pygmaea shifted from high-impact bounding gaits on larger substrates to using more half-bounding gaits on smaller substrates; however, kinematic adjustments to substrate diameter were not as profound as in S. tripartitus Both species adjusted gait kinematics to changes in substrate orientation; however, gait kinematics did not significantly affect empirical measures of substrate displacement in either species. Because of their small body size, claw-like nails and reduced grasping capabilities, callitrichines arguably represent extant biomechanical analogs for an early stage in primate evolution. As such, greater attention should be placed on understanding asymmetrical gait dynamics for insight into hypotheses concerning early primate locomotor evolution. .

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Literature data suggests that Thamnodynastes strigatus (Serpentes, Dipsadidae) is a snake that actively forages for anurans near waterbodies, using several microhabitats for this activity (e.g., shrubs, soil, and water). However, herein we present dissonant data previously known to the species, both concerning type of prey and foraging strategy. A total of 72 observations were performed exclusively at night, when snakes were in vegetation near streams in 93% of the cases. Among these observations, 41 were active snakes, and most of them (97%) were in an ambush position on the vegetation, peering at fishes. On two occasions, the snakes used a lingual lure behavior in order to attract fishes. This is only the sixth species in which this behavior has been observed, and the first in South America. Therefore, we provide additional data on T. strigatus habitat activity and habitat use, as well as unpublished data on ambush and lingual lure behavior for the Neotropical genus Thamnodynastes

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OBJECTIVES: Primate diagonal sequence (DS) gaits are often argued to be an adaptation for moving and foraging in the fine-branch niche; however, existing data have come predominantly from laboratory studies that are limited in taxonomic breadth and fail to account for the structural and ecological variation of natural substrates. We test the extent to which substrate diameter and orientation influence gait sequence type and limb phase in free-ranging primates, as well as how phylogenetic relatedness might condition response patterns. MATERIALS AND METHODS: We filmed quadrupedal locomotion in 11 platyrrhine species at field sites in Ecuador and Costa Rica and measured the diameter and orientation of locomotor substrates using remote sensors. We quantified limb phase values and classified strides by gait sequence type (N = 988 strides). RESULTS: Our results show that most of the species in our sample consistently used DS gaits, regardless of substrate diameter or orientation; however, all taxa also used asymmetrical and/or lateral sequence gaits. By incorporating phylogenetic eigenvectors into our models, we found significant differences in gait sequence patterns and limb phase values among the major platyrrhine clades, suggesting that phylogeny may be a better predictor of gait than substrate diameter or orientation. DISCUSSION: Our field data generally corroborate locomotor patterns from laboratory studies but capture additional aspects of gait variability and flexibility in response to the complexity of natural environments. Overall, our results suggest that DS gaits are not exclusively tailored to narrow or oblique substrates but are used on arboreal substrates in general.

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O pitfall suspenso é uma forma nova e simples para capturar pequenos mamíferos arborícolas e escansoriais. É uma versão arbórea dos pitfalls terrestres, tradicionalmente usados para capturar anfíbios e répteis. Baldes com isca no interior são erguidos por cordas até que atinjam um galho de árvore na altura desejada. O método foi testado na Mata Atlântica em três diferentes locais da foz do Rio Doce, em Linhares, sudeste do Brasil. Em um deles, os pitfalls suspensos foram colocados em galhos de cacaueiros no sub-bosque de uma plantação sombreada de cacau (cabrucas) a alturas entre 2 e 3 m. Na outra, eles foram instalados entre 5 e 15 metros de altura em uma floresta nativa. No terceiro local, no sub-bosque de outra cabruca, os pitfalls suspensos foram testados em conjunto com outras armadilhas usadas até então. Os marsupiais Didelphis aurita, Caluromys philander, Marmosa (Micoureus) paraguayana, Gracilinanus microtarsus, Marmosa murina e o roedor Rhipidomys mastacalis foram capturados pelos pitfalls suspensos. Essa armadilha foi capaz de capturar pequenos mamíferos de todos os tamanhos, inclusive indivíduos jovens. Esse método provou ser funcional para a captura de vários pequenos mamíferos arborícolas e escansoriais e pode ser uma alternativa complementar para amostragem em estratos altos de florestas.

The suspended pitfall demonstrates a new and simple mechanism to capture small arboreal and scansorial mammals. It is an arboreal version of the pitfalls traditionally used to capture terrestrial amphibians and reptiles. Buckets with bait inside are raised by a rope until they reach a tree branch at the desired height. Tests were performed in the Atlantic Forest at three different sites at the mouth of Doce River in Linhares, southeastern Brazil. In one of them suspended pitfalls were set up in the understory of a shaded cacao plantation (cabruca agroforest) in the branches of cacao trees between 2 and 3 m in height, and in the other they were placed in a native forest between 5 to 15 m in height. At the third site, suspended pitfalls were tested together with the other live traps used hitherto in the understory of other cabruca agroforest. The marsupials Didelphis aurita, Caluromys philander, Marmosa (Micoureus) paraguayana, Gracilinanus microtarsus, Marmosa murina and the rodent Rhipidomys mastacalis were captured by suspended pitfall. This live trap was capable of catching all sizes of small arboreal mammals, including juvenile individuals. This method proved to be functional for the capture of some small arboreal mammals and may be a complementary alternative for sampling in high forest strata.

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RESUMO

O pitfall suspenso é uma forma nova e simples para capturar pequenos mamíferos arborícolas e escansoriais. É uma versão arbórea dos pitfalls terrestres, tradicionalmente usados para capturar anfíbios e répteis. Baldes com isca no interior são erguidos por cordas até que atinjam um galho de árvore na altura desejada. O método foi testado na Mata Atlântica em três diferentes locais da foz do Rio Doce, em Linhares, sudeste do Brasil. Em um deles, os pitfalls suspensos foram colocados em galhos de cacaueiros no sub-bosque de uma plantação sombreada de cacau (cabrucas) a alturas entre 2 e 3 m. Na outra, eles foram instalados entre 5 e 15 metros de altura em uma floresta nativa. No terceiro local, no sub-bosque de outra cabruca, os pitfalls suspensos foram testados em conjunto com outras armadilhas usadas até então. Os marsupiais Didelphis aurita, Caluromys philander, Marmosa (Micoureus) paraguayana, Gracilinanus microtarsus, Marmosa murina e o roedor Rhipidomys mastacalis foram capturados pelos pitfalls suspensos. Essa armadilha foi capaz de capturar pequenos mamíferos de todos os tamanhos, inclusive indivíduos jovens. Esse método provou ser funcional para a captura de vários pequenos mamíferos arborícolas e escansoriais e pode ser uma alternativa complementar para amostragem em estratos altos de florestas.(AU)

The suspended pitfall demonstrates a new and simple mechanism to capture small arboreal and scansorial mammals. It is an arboreal version of the pitfalls traditionally used to capture terrestrial amphibians and reptiles. Buckets with bait inside are raised by a rope until they reach a tree branch at the desired height. Tests were performed in the Atlantic Forest at three different sites at the mouth of Doce River in Linhares, southeastern Brazil. In one of them suspended pitfalls were set up in the understory of a shaded cacao plantation (cabruca agroforest) in the branches of cacao trees between 2 and 3 m in height, and in the other they were placed in a native forest between 5 to 15 m in height. At the third site, suspended pitfalls were tested together with the other live traps used hitherto in the understory of other cabruca agroforest. The marsupials Didelphis aurita, Caluromys philander, Marmosa (Micoureus) paraguayana, Gracilinanus microtarsus, Marmosa murina and the rodent Rhipidomys mastacalis were captured by suspended pitfall. This live trap was capable of catching all sizes of small arboreal mammals, including juvenile individuals. This method proved to be functional for the capture of some small arboreal mammals and may be a complementary alternative for sampling in high forest strata.(AU)

Assuntos

RESUMO

Canopy ecology is a fast-growing field, but still a scientific frontier in many ecological aspects. For instance, the hypothesis that tree traits shape patterns in ant-plant interactions lacks data, notably for tropical canopies in different successional stages. In this study, we investigated canopy traits, such as tree height, the presence of extrafloral nectaries (EFNs), connectivity among tree crowns, and successional stage, structure ant-tree interactions in a tropical dry forest (TDF), examining whether these are the determinant factors for ant species richness. We collected ants on trees in early and late successional stages over 2 years, in rainy and dry seasons. In the late successional stage, ant species richness was greater in the taller trees; in the early successional stage, the smallest trees had a greater ant species richness than the taller trees. The EFNs and connectivity among treetops had no effect on ant species richness. We obtained a tree-ant network of the early successional stage, involving 786 interactions among 57 ant species and 75 trees; in the late successional stage, the network had 914 interactions among 60 ant species and 75 trees. There were 27 species of trees in our study, 11 of which (40.7% of all individual trees) had EFNs. The ant-plant interactions were not randomly distributed, suggesting that various biotic factors structured the ant assemblies. This study presents new insights into ant-tree interactions, showing that both tree height and successional stage influence the occurrence of many species of ants in tree canopies of tropical dry forests.

Assuntos