Good timing: evaluating anuran activity and detectability patterns in the Brazilian Atlantic Forest

2019 ◽  
Vol 46 (7) ◽  
pp. 566 ◽  
Author(s):  
Juliane Pereira-Ribeiro ◽  
Atilla Colombo Ferreguetti ◽  
Helena Godoy Bergallo ◽  
Carlos Frederico Duarte Rocha

Abstract ContextAnimal activity patterns throughout the day constitute an important dimension of their ecological niche, and may have ecological and evolutionary implications; for an organism to be active during the day or night period, a series of conditions requiring different anatomical, physiological and behavioural adaptations must be met. AimsTo study the anuran community in an area of Atlantic Forest in Brazil, to evaluate the species activity period as well as the diurnal and nocturnal detection probabilities of anurans, and to relate these activities to environmental variables such as air temperature, relative humidity and precipitation. MethodsThe anurans were sampled along 21 plot transects in the diurnal period and during a nocturnal period, with temperature and relative humidity measured in each plot. Species were considered predominantly diurnal or nocturnal if 35% or more individuals were recorded during one of these periods. Anuran detectability was estimated using single-season occupancy models, relating to environmental variables. Key resultsOf the individuals recorded, 12% were recorded during diurnal sampling and 88% were recorded during nocturnal sampling, with Ololygon agilis being the only species considered diurnal. The probability of detection was affected by only two variables (period and humidity). ConclusionsThe anuran community in the study area was essentially nocturnal, with only one species that could be considered diurnal. Additionally, detectability was higher at night, with humidity being the most important variable affecting species detection. ImplicationsSurveys can be planned under climatic conditions that positively influence the probabilities of detection to improve the effectiveness of monitoring species and/or anurans community.

Mammalia ◽  
2019 ◽  
Vol 83 (4) ◽  
pp. 363-371 ◽  
Author(s):  
Atilla C. Ferreguetti ◽  
Walfrido M. Tomas ◽  
Helena G. Bergallo

Abstract The spotted paca Cuniculus paca (Linnaeus, 1766) is a medium-sized caviomorph rodent of the Cuniculidae family that mainly inhabits tropical forests, but may occur in other habitat types, often associated with water bodies. We aimed to verify which factors influence the spatial and temporal distribution of C. paca in the Vale Natural Reserve (VNR), Espírito Santo, Brazil. We used 39 camera traps to model occupancy and detectability and to estimate the species activity period. The spotted paca showed high occupancy at low distances from water resources and high densities of palm species. The species avoided areas with high poaching intensity, and activity frequency was reduced by extreme temperature and by a higher intensity of poaching. We conclude that in the VNR, the C. paca is a nocturnal species and that it is necessary to assess other elements that could potentially affect the spatial and temporal distribution of the spotted paca in the Atlantic Forest.


2016 ◽  
Vol 9 (6) ◽  
pp. 1644 ◽  
Author(s):  
Thábia Ottília Hofstetter Padoin ◽  
Andressa Müller ◽  
Jairo Lizandro Schmitt

O clima de uma área é um dos fatores determinantes da dinâmica da vegetação e a fenologia estuda a ocorrência dos eventos vegetativos e reprodutivos das plantas desencadeados principalmente pela precipitação, temperatura e fotoperíodo. Os estudos fenológicos com samambaias, no mundo, aumentaram nas últimas décadas, porém os seus resultados são geralmente descritivos e restritos a poucos locais e a poucas espécies. Foram determinados o padrão e a sazonalidade das fenofases de Blechnum acutum, em Floresta Atlântica subtropical, relacionando-as com os fatores climáticos, a partir do monitoramento de 20 indivíduos, durante 18 meses. Para verificar a sazonalidade das fenofases foi utilizada a estatística circular. Blechnum acutum apresentou maior intensidade da renovação foliar em janeiro (38%), com maior período de atividade entre janeiro e abril de 2014. A formação de esporângios foi a fenofase que demonstrou o padrão sazonal mais evidente e ocorreu com maior intensidade e atividade em outubro de 2014 (25%). A senescência foliar manifestou maior intensidade em fevereiro de 2014 (23%), com 80% dos indivíduos encontrando-se nesta fenofase, em março de 2015. Os padrões fenológicos não demonstraram a mesma continuidade e regularidade em decorrência principalmente da falta de homogeneidade na manifestação da renovação e senescência das folhas pelos indivíduos na população. Os ritmos fenológicos de B. acutum também não foram igualmente influenciados pelas variáveis ambientais analisadas, sendo que a renovação foliar foi a única fenofase relacionada com temperatura e fotoperíodo.     A B S T R A C T The climate of an area is one of the determining factors of the vegetation’s dynamics and phenology studies. The occurrence of vegetative and reproductive events of plants mainly triggered by rainfall, temperature and photoperiod. The phenological studies with ferns in the world have increased in recent decades, but the results are usually descriptive and restricted to few places and few species. It was determined the pattern and seasonality of phenophases of Blechnum acutum in subtropical Atlantic Forest, relating them to the climatic factors, from monitoring 20 individuals for 18 months. To check the seasonality of phenophases the circular statistics were used. Blechnum acutum showed greater intensity of foliar renovation in January (38%), with higher activity period between January and April 2014. The sporangia formation was the phenophase that showed the most obvious seasonal pattern and was more intense and activity in October 2014 (25%). The leaf senescence showed greater intensity in February 2014 (23%), with 80% of individuals meeting in this phenophase in March 2015. The phenological patterns did not show the same continuity and regularity mainly due to the lack of homogeneity in the manifestation renewal and senescence of leaves by individuals in the population. The phenological rhythms of B. acutum were not also influenced by environmental variables, and the leaf renewal was the only phenophase related to temperature and photoperiod. Keywords: climate, photoperiod, sazonality, phenophase, fern.[1]                                                            


2001 ◽  
Vol 22 (1) ◽  
pp. 103-111 ◽  
Author(s):  
André Eterovic ◽  
Otavio Marques ◽  
Whaldener Endo

AbstractSeasonal abundance of some snake species from the Atlantic forest in southeastern Brazil was inferred from collection data gathered throughout twelve years at the Instituto Butantan in São Paulo, Brazil. The number of collected individuals of Chironius spp., Liophis miliaris, Spilotes pullatus, Tropidodryas spp., Micrurus corallinus, and Bothrops jararaca was significantly higher during the rainy season, whereas the number of Sibynomorphus neuwiedi was higher during the dry season. Erythrolamprus aesculapii, Xenodon neuwiedii, Tomodon dorsatus and Bothrops jararacussu did not show significant differences in the number of individuals collected at each of these seasons. Seasonality in captures may result from seasonal activity patterns. Food availability, tolerance to climatic conditions, reproductive cycle, and phylogenetic constraints are considered the main factors responsible for the observed patterns. A multivariate approach is recommended for analysis of annual activity.


2013 ◽  
Vol 29 (3) ◽  
pp. 261-264 ◽  
Author(s):  
Melina de Souza Leite ◽  
Thiago Lopes Queiroz ◽  
Maron Galliez ◽  
Patrícia Pinto de Mendonça ◽  
Fernando A. S. Fernandez

Abstract:The activity of the water opossum Chironectes minimus was studied in Atlantic forest rivers in south-eastern Brazil using radiotracking, from October 2004 to October 2008. There were 439 nocturnal fixes of 11 males and four females. Activity patterns of the water opossum were compared among sexes and seasons, using linear and generalized linear mixed models. The water opossum is active mostly at night, showing a unimodal pattern, with activity increasing after sunset and decreasing thereafter along the night. Females were more active in the first quarter of the night and males in the second one. The activity period of males was longer in the dry season, while for females it was longer in the wet season. Sex and season were important determinants of the water opossum activity patterns, mainly because of different sex strategies in a promiscuous/polygynous mating system. However, despite those influences the overall distribution of activity along the night was similar to most Neotropical marsupials. Therefore, similarities in the activity patterns are probably due to phylogenetic constraints and to the absence or weakness of selective pressures modifying the activity of the water opossum.


2021 ◽  
pp. 1-7
Author(s):  
Rômulo Ribon ◽  
Luane Reis dos Santos ◽  
Paulo De Marco ◽  
Miguel Ângelo Marini

Abstract The spatial distribution of Neotropical birds at local scales is often associated with plant successional stages and unique microhabitats such as bamboo stands and treefall gaps. Only 15% of the Atlantic Forest remains, yet this habitat is home to more than 200 endemic birds. Understanding the distribution of bird species within the Atlantic Forest can improve the test of ecological hypotheses related to habitat use and habitat selection. This study analyses the distribution of birds among different types of relief (lowlands, ravines, hillsides, and hilltops) in 41 forest fragments of different sizes (1 to 384.5 ha) within the Atlantic Forest, south east Brazil. The presence and absence data were analysed with dynamic occupancy models to determine the influence of area and topography in the distribution of bird species. Of the 169 species detected, we were able to estimate an occupancy probability of 67. Among them, relief type was an important variable for 26 species (39%). Most species showed a preference for lowlands and ravines, and some showed an association of combinations of these two reliefs with hillsides and hilltops. These preferences might be related to distribution of preferred food, nesting microhabitats, and thermoregulation. For the endemic and threatened Atlantic Forest mountain birds, the ecological association with areas of relief is a strong, and previously unsuspected, spatial distribution pattern. Our results suggest that the ecology and distribution of birds in tropical forests across hilly regions could be better understood if topography is considered. This pattern should be better investigated among other taxa in tropical forests.


2013 ◽  
Vol 6 (1) ◽  
pp. 1269-1310 ◽  
Author(s):  
T. Zinner ◽  
C. Forster ◽  
E. de Coning ◽  
H.-D. Betz

Abstract. In this manuscript, recent changes to the DLR METEOSAT thunderstorm TRacking And Monitoring algorithm (Cb-TRAM) are presented as well as a validation of Cb-TRAM against the European ground-based LIghtning NETwork data (LINET) of Nowcast GmbH and Lightning Detection Network (LDN) data of the South African Weather Service (SAWS). The validation is conducted along the well known skill scores probability of detection (POD) and false alarm ratio (FAR) on the basis of METEOSAT/SEVIRI pixels as well as on the basis of thunderstorm objects. The values obtained demonstrate the limits of Cb-TRAM in specific as well as the limits of satellite methods in general which are based on thermal emission and solar reflectivity information from thunderstorm tops. Although the climatic conditions and the occurence of thunderstorms is quite different for Europe and South Africa, the quality score values are similar. Our conclusion is that Cb-TRAM provides robust results of well-defined quality for very different climatic regimes. The POD for a thunderstorm with intense lightning is about 80% during the day. The FAR for a Cb-TRAM detected thunderstorm which is not at least close to intense lightning activity is about 50%; if the proximity to any lightning activity is evaluated the FAR is even much lower at about 15%. Pixel-based analysis shows that the detected thunderstorm object size is not indiscriminately large, but well within the physical limitations of the method. Nighttime POD and FAR are somewhat worse as the detection scheme can not use high resolution visible information. Nowcasting scores show useful values up to approximatelly 30 min.


2013 ◽  
Vol 6 (6) ◽  
pp. 1567-1583 ◽  
Author(s):  
T. Zinner ◽  
C. Forster ◽  
E. de Coning ◽  
H.-D. Betz

Abstract. In this paper, recent changes to the Meteosat thunderstorm TRacking And Monitoring algorithm (Cb-TRAM) are presented as well as a validation of Cb-TRAM against data from the European ground-based LIghtning NETwork (LINET) of Nowcast GmbH and the South African Weather Service Lightning Detection Network (SAWS LDN). Validation is conducted along the well-known skill measures probability of detection (POD) and false alarm ratio (FAR) on the basis of Meteosat/SEVIRI pixels as well as on the basis of thunderstorm objects. The values obtained demonstrate specific limitations of Cb-TRAM, as well as limitations of satellite methods in general which are based on thermal emission and solar reflectivity information from thunderstorm cloud tops. Although the climatic conditions and the occurrence of thunderstorms are quite different for Europe and South Africa, quality score values are similar. Our conclusion is that Cb-TRAM provides robust results of well-defined quality for very different climatic regimes. The POD for a thunderstorm with intense lightning is about 80% during the day. The FAR for a Cb-TRAM detection which is not even close to intense lightning is about 50%. If only proximity to any lightning activity is required, FAR is much lower at about 15%. Pixel-based analysis shows that detected thunderstorm object size is not indiscriminately large, but well within physical limitations of the satellite method. Night-time POD and FAR are somewhat worse as the detection scheme does not use the high-resolution visible information during night-time hours. Nowcasting scores show useful values up to approximately 30 min in advance.


2003 ◽  
Vol 63 (3) ◽  
pp. 537-544 ◽  
Author(s):  
A. Turra ◽  
M. R. Denadai

This study describes the daily activity in a simulated high tide situation of four species of hermit crabs (Pagurus criniticornis, Clibanarius antillensis, C. sclopetarius, and C. vittatus) that coexist in an intertidal flat in southeastern Brazil. Observations were done in two-hour intervals during two subsequent days (48 h) in three replicate pools with thirty crabs each. Among species (between and within genera) there was an evident variation in activity patterns, of which three could be distinguished. The circadian activity patterns of C. antillensis and C. vittatus could be characterized as evening and nocturnal, with resting peaks during the morning and afternoon. The circadian activity pattern of C. sclopetarius was characterized by two marked peaks of inactivity, corresponding to dawn and evening, which could represent an intrinsic association with the semi-lunar tidal cycles of the study area. Pagurus criniticornis showed high activity not influenced by day/night conditions during the entire observed period. These activity pattern variations of the studied hermit crabs should be taken into account in designing further experiments. More precise and accurate interspecific behavioral comparisons among species could be achieved in nocturnal experiments, the high activity period of all species.


2009 ◽  
Vol 59 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Octavio Monroy-Vilchis ◽  
Vicente Urios ◽  
Martha Zarco-González ◽  
Clarita Rodríguez-Soto

AbstractIn this study the habitat use and activity patterns of the two of the largest cats of the Americas in central Mexico were studied. Three ways to detect felid presence were employed from August 2002 to May 2006: interviews, signs, and camera-traps. 478 records were obtained, from which 441 were from cougar and 37 from jaguar. These records included positive response in 118 of 140 interviews and 236 records of signs (mainly tracks and scats), and 124 photographs. Both felids preferred pine-oak forest habitats, with altitudes higher than 1800 m, distances between 3509 and 4377 m from roads, between 2329 and 4650 m from settlements, and distances to very steep slopes between 1048 and 2059 m, for jaguar, and for cougar lower than 1047 m. Jaguar activity was recorded mainly during nighttimes, between 0:00 and 6:00, whereas cougar was active between 4:00 and 6:00 and between 18:00 and 22:00 hours, avoiding the jaguar's principal activity period.


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