scholarly journals Variation in dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) assemblages in a tropical forest remnant from a Mexican National Park

2021 ◽  
Vol 61 ◽  
pp. e20216150
Author(s):  
Gibrán Sánchez-Hernández ◽  
Benigno Gómez ◽  
Misraim Edivaldo Rodríguez-López ◽  
Rolando Antonio Dávila-Sánchez ◽  
Eduardo Rafael Chamé-Vázquez

The Cañón del Sumidero National Park (PNCS) is a priority area for conservation, but there are few studies on its fauna, which evidences the need for further basic studies to produce adequate knowledge on its biodiversity. This study aimed to determine dung beetle assemblages temporal distribution, trophic preference, and daily activity patterns. We conducted samplings using baited pitfall traps in a PNCS tropical sub deciduous forest remnant, during the dry and rainy seasons between 2014 and 2015. We captured a total of 863 individuals of 20 species, 12 genera, and five tribes of Scarabaeinae. Estimators suggest that we obtained high faunistic representation (> 80%), but species richness is low compared to other regional studies. The community was characterized by a high number of rare species and few dominant species. We captured the greatest richness and abundance during rainy months, however, species composition between seasons did not differ significantly. Trophic preference was mainly generalist and we considered only four species as specialists to tapir dung. We observed a clear segregation between activity hours. Nevertheless, we determined only nine species as specialists (six nocturnal and three diurnal) and two others had generalist habits. The low diversity we found could be influenced by the constant pressure of the urban area and non-native species within the park, which alter the dung beetle assemblages. However, performing samplings for longer periods and using a wider range of resources would help us obtain more robust results and better understand species distribution patterns.

2018 ◽  
Vol 44 (2) ◽  
pp. 300-312
Author(s):  
Pedro G. da Silva ◽  
Jorge M. Lobo ◽  
Malva Isabel Medina Hernández

The Holocene ◽  
2021 ◽  
pp. 095968362110604
Author(s):  
Bert Kohlmann ◽  
Alfonsina Arriaga-Jiménez ◽  
Renato Portela Salomão

Several studies have tested the Elevational Rapoport Rule (ERR) in arthropods, especially in the Neotropical mountains. Nonetheless, different approaches should be used for a more nuanced comprehension of ERR patterns and assemblage altitudinal distribution patterns, such as the biogeographical, ecological, and evolutionary contexts. This study aims to test the ERR for elevational gradients in Mexican mountains. For this study, dung beetle assemblages of the genus Onthophagus were used as a model organism, and their distribution was studied in several different mountain ranges of the Mexican tropics. Altitudinal distribution of Onthophagus species was analyzed, including ecological traits and biogeographical/phylogenetical contexts as covariables. The increase of altitude was positively correlated to the assemblage altitudinal range. Furthermore, altitudinal range, relative abundance, body size, and mountain’s topographic prominence were positively correlated to the mean altitudinal range of Onthophagus species. Nonetheless, different altitudinal relationships were observed, depending on the mountain. The results support the idea that species that inhabit higher altitudes appear to be more environmentally plastic and occur in wider altitudinal ranges than species from lower altitudes, thus supporting the ERR. The present findings stress that biogeographical, ecological, phylogenetical, and historical aspects, besides body size, are essential drivers of the altitudinal distribution of Onthophagus dung beetles.


2010 ◽  
Vol 8 (2) ◽  
pp. 341-349 ◽  
Author(s):  
Tatiane M Gogola ◽  
Vanessa S Daga ◽  
Pedro R. L. da Silva ◽  
Paulo V Sanches ◽  
Éder A Gubiani ◽  
...  

The aim of this work was to study the occurrence of ichthyoplankton in a region affected by water regulation by dams. The study area was located in the region of Ilha Grande National Park, upper Paraná River floodplain. Specifically, we examined the temporal and spatial distribution of Ichthyoplankton, identified spawning areas and established the relationships between the abundances of fish eggs and larvae and some limnological and hydrological variables. Samples were taken monthly between October and March from 2001 to 2005 at 24 sampling sites. For analytical purposes, the sampling sites were grouped into upper, middle and lower areas. The upper area of the National Park had the highest egg density and should be considered the primary spawning area. The middle area should be considered a drift area, and the lower area likely functions as a growth and feeding habitat. Statistical analyses showed that the spawning was influenced by water temperature, pH, fluviometric level and rainfall, and that larval density was influenced by pH, conductivity, dissolved oxygen and rainfall. The results also revealed that the tributaries apparently are used as migratory routes by fish, and and this shows the need to protect these sites.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9121
Author(s):  
Gustavo Cárdenas Hinojosa ◽  
Horacio de la Cueva ◽  
Tim Gerrodette ◽  
Armando M. Jaramillo-Legorreta

Baseline knowledge of spatial and temporal distribution patterns is essential for cetacean management and conservation. Such knowledge is particularly important in areas where gillnet fishing occurs, as the Upper Gulf of California, which increases the probability of bycatch of cetaceans. In this area, the vaquita porpoise (Phocoena sinus) has been widely studied, but the knowledge of other cetaceans is scarce and based on traditional visual survey methods. We used data collected by an array of acoustic click detectors (C-PODs) during the summers 2011 to 2015 to analyze the distribution of dolphins in the Vaquita Refuge in the Upper Gulf of California. We recorded 120,038 echolocation click trains of dolphins during 12,371 days of recording effort at 46 sampling sites. Based on simultaneous visual and acoustic data, we estimated a false positive acoustic detection rate of 19.4%. Dolphin acoustic activity varied among sites, with higher activity in the east of the Vaquita Refuge. Acoustic activity was higher at night than during the day. We used negative binomial generalized linear models to study the count of clicks of dolphins in relation to spatial, temporal, physical, biological and anthropogenic explanatory variables. The best model selected for the response variable included sampling site, day-night condition, and vertical component of tide speed. Patterns in the spatial distribution of predicted acoustic activity of dolphins were similar to the acoustic activity observed per sampling season. Higher acoustic activity was predicted at night, but the tide speed variable was not relevant under this condition. Acoustic activity patterns could be related to the availability of prey resources since echolocation click trains are associated with foraging activities of dolphins. This is the first study of the distribution of dolphins in Mexico using medium-term systematic passive acoustic monitoring, and the results can contribute to better management to the natural protected area located in the Upper Gulf of California.


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
László Somay ◽  
Viktor Szigeti ◽  
Gergely Boros ◽  
Réka Ádám ◽  
András Báldi

Wood pastures are home to a variety of species, including the dung beetle. Dung beetles are an important functional group in decomposition. Specifically, in terms of livestock manure, they not only contribute to nutrient cycling but are key players in supporting human and animal health. Dung beetles, however, are declining in population, and urgent recommendations are needed to reverse this trend. Recommendations need to be based on solid evidence and specific habitats. Herein, we aimed to investigate the role of an intermediate habitat type between forests and pastures. Wood pastures are key areas for dung beetle conservation. For this reason, we compared dung beetle assemblages among forests, wood pastures, and grasslands. We complemented this with studies on the effects of dung type and season at three Hungarian locations. Pitfall traps baited with cattle, sheep, or horse dung were used in forests, wood pastures, and pasture habitats in spring, summer, and autumn. Dung beetle assemblages of wood pastures showed transient characteristics between forests and pastures regarding their abundance, species richness, Shannon diversity, assemblage composition, and indicator species. We identified a strong effect of season and a weak of dung type. Assemblage composition proved to be the most sensitive measure of differences among habitats. The conservation of dung beetles, and the decomposition services they provide, need continuous livestock grazing to provide fresh dung, as well as the maintenance of wood pastures where dung beetle assemblages typical of forests and pastures can both survive.


Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 57
Author(s):  
Konstantinos Vantas ◽  
Epaminondas Sidiropoulos

The identification and recognition of temporal rainfall patterns is important and useful not only for climatological studies, but mainly for supporting rainfall–runoff modeling and water resources management. Clustering techniques applied to rainfall data provide meaningful ways for producing concise and inclusive pattern classifications. In this paper, a timeseries of rainfall data coming from the Greek National Bank of Hydrological and Meteorological Information are delineated to independent rainstorms and subjected to cluster analysis, in order to identify and extract representative patterns. The computational process is a custom-developed, domain-specific algorithm that produces temporal rainfall patterns using common characteristics from the data via fuzzy clustering in which (a) every storm may belong to more than one cluster, allowing for some equivocation in the data, (b) the number of the clusters is not assumed known a priori but is determined solely from the data and, finally, (c) intra-storm and seasonal temporal distribution patterns are produced. Traditional classification methods include prior empirical knowledge, while the proposed method is fully unsupervised, not presupposing any external elements and giving results superior to the former.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Richard S. Gashururu ◽  
Samuel M. Githigia ◽  
Methode N. Gasana ◽  
Richard Habimana ◽  
Ndichu Maingi ◽  
...  

Abstract Background Glossina (tsetse flies) biologically transmit trypanosomes that infect both humans and animals. Knowledge of their distribution patterns is a key element to better understand the transmission dynamics of trypanosomosis. Tsetse distribution in Rwanda has not been well enough documented, and little is known on their current distribution. This study determined the current spatial distribution, abundance, diversity, and seasonal variations of tsetse flies in and around the Akagera National Park. Methods A longitudinal stratified sampling following the seasons was used. Biconical traps were deployed in 55 sites for 6 consecutive days of each study month from May 2018 to June 2019 and emptied every 48 h. Flies were identified using FAO keys, and the number of flies per trap day (FTD) was used to determine the apparent density. Pearson chi-square (χ2) and parametrical tests (t-test and ANOVA) were used to determine the variations between the variables. The significance (p < 0.05) at 95% confidence interval was considered. Logistic regression was used to determine the association between tsetse occurrence and the associated predictors. Results A total of 39,516 tsetse flies were collected, of which 73.4 and 26.6% were from inside Akagera NP and the interface area, respectively. Female flies accounted for 61.3 while 38.7% were males. Two species were identified, i.e. G. pallidipes [n = 29,121, 7.4 flies/trap/day (FTD)] and G. morsitans centralis (n = 10,395; 2.6 FTD). The statistical difference in numbers was significant between the two species (p = 0.000). The flies were more abundant during the wet season (15.8 FTD) than the dry season (4.2 FTD). Large numbers of flies were trapped around the swamp areas (69.1 FTD) inside the park and in Nyagatare District (11.2 FTD) at the interface. Glossina morsitans was 0.218 times less likely to occur outside the park. The chance of co-existing between the two species reduced outside the protected area (0.021 times). Conclusions The occurrence of Glossina seems to be limited to the protected Akagera NP and a narrow band of its surrounding areas. This finding will be crucial to design appropriate control strategies. Glossina pallidipes was found in higher numbers and therefore is conceivably the most important vector of trypanosomosis. Regional coordinated control and regular monitoring of Glossina distribution are recommended. Graphic Abstract


Sign in / Sign up

Export Citation Format

Share Document