scholarly journals Comparing the efficiency of monofilament and traditional nets for capturing bats

2021 ◽  
Author(s):  
Silvia Chaves Ramirez ◽  
Christian Castillo Salazar ◽  
Mariela Sanchez Chavarria ◽  
Hellen Solis Hernandez ◽  
Gloriana Chaverri
Keyword(s):  
Species Diversity ◽  
Tropical Forest ◽  
Rare Species ◽  
Sampling Method ◽  
Sampling Period ◽  
Capture Efficiency ◽  
Species Accumulation Curves ◽  
Lowland Tropical Forest ◽  
Accumulation Curves ◽  
Capture Rates

Traditional mist nets used for capturing bats have several drawbacks, particularly that they are inefficient at sampling many insectivorous species. One possible alternative is to use monofilament nets, whose netting is made of single strands of yarn instead of several as regular nets, making them less detectable. To date, no study has quantified the capture efficiency of monofilament nets compared to regular mist nets for the study of bats. Here we compare capture efficiency of monofilament and regular mist nets, focusing on bat abundance and species diversity at a lowland tropical forest in southwestern Costa Rica. During our sampling period, we captured 90 individuals and 14 species in regular nets and 125 individuals and 20 species in monofilament nets. The use of monofilament nets increased overall capture rates, but most notably for insectivorous species. Species accumulation curves indicate that samples based on regular nets are significantly underestimating species diversity, most notably as these nets fail at sampling rare species. We show that incorporating monofilament nets into bat studies offers an opportunity to expand records of different guilds and rare bat species and to improve our understanding of poorly-known bat assemblages while using a popular, relatively cheap and portable sampling method.

scholarly journals Comparing the efficiency of monofilament and regular nets for capturing bats

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Silvia Chaves-Ramírez ◽  
Christian Castillo-Salazar ◽  
Mariela Sánchez-Chavarría ◽  
Hellen Solís-Hernández ◽  
Gloriana Chaverri
Keyword(s):  
Species Diversity ◽  
Rare Species ◽  
Sampling Method ◽  
Sampling Efficiency ◽  
Species Accumulation Curves ◽  
Species Accumulation ◽  
Accumulation Curves ◽  
Capture Rates

Regular nylon or polyester mist nets used for capturing bats have several drawbacks, particularly that they are inefficient at sampling insectivorous species. One possible alternative is to use monofilament nets, whose netting is made of single strands of yarn instead of several as regular nets, making them less detectable. To date, only one study has quantified the differences in capture rates between monofilament and regular mist nets for the study of bats, yet surprisingly, its findings suggest that the latter are more efficient than the former. Here, we provide further evidence of the differences in sampling efficiency between these two nets. We captured 90 individuals and 14 species in regular nets and 125 individuals and 20 species in monofilament nets. The use of monofilament nets increased overall capture rates, particularly for insectivorous species. Species accumulation curves indicate that samples based on regular nets are significantly underestimating species diversity, most notably as these nets fail at sampling rare species. We show that incorporating monofilament nets into bat studies offers an opportunity to expand records of different guilds and rare bat species and to improve our understanding of poorly known bat assemblages while using a popular, relatively cheap and portable sampling method.

scholarly journals Snakes in a seasonally dry tropical forest in northeastern Brazil

2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Washington Luiz Silva Vieira ◽  
Jayene Aysla Mendonça Brito ◽  
Erivágna Rodrigues de Morais ◽  
Daniel Chaves Vieira ◽  
Kleber Silva Vieira ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Activity Patterns ◽  
Northeastern Brazil ◽  
Semiarid Region ◽  
Species Accumulation Curves ◽  
Seasonally Dry Tropical Forest ◽  
Dry Tropical Forest ◽  
Seasonally Dry ◽  
Caatinga Vegetation ◽  
Accumulation Curves

Abstract: This study aimed to provide information on composition, abundance, and estimated snakes richness in an area of arboreal Caatinga (seasonally dry tropical forest) and analyze patterns of faunistic similarity between assemblages of snakes in the semiarid region of northeastern Brazil. The snakes found within the Fazenda Almas Natural Private Reserve (RPPN Fazenda Almas) were sampled during a 10-year period, with monthly monitoring, employing time constrained search, pitfall traps with drift fences, and donations from local collectors. Twenty-two snake species were recorded, with a predominance of terrestrial species with diurnal-nocturnal activity patterns. The species accumulation curves reached its asymptote, indicating that all possible species in the study area had been recorded. Our results indicated that the snake fauna in the study area is similar to other snake assemblages in localities with Caatinga vegetation in the Sertaneja Depression (“Depressão Sertaneja”) drylands, and that those assemblages constitute faunistic units typical of the interior of northeastern Brazil.

Species diversity and abundance patterns of epiphytic orchids in Aralam Wildlife Sanctuary in Kerala, India

2021 ◽  
Vol 13 (8) ◽  
pp. 19060-19069
Author(s):  
Jis Sebastian ◽  
Durairaj Kathiresan ◽  
Giby Kuriakose
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Wildlife Sanctuary ◽  
Species Accumulation Curves ◽  
Orchid Species ◽  
Epiphytic Orchids ◽  
Abundance Patterns ◽  
Line Transects ◽  
Accumulation Curves ◽  
The Difference

Species diversity and abundance patterns of epiphytic orchids were studied in Aralam Wildlife Sanctuary, in the Western Ghats of northern Kerala. Habitats sampled were wet evergreen (EVEG), montane wet evergreen (MEVG), moist deciduous (MDEC), and semi evergreen (SEVG), on a gradient of altitude from 60 to 1,589 m. Selective tree scanning on linear line transects was deployed (n= 40) across spatial units. A total of 39 orchid species were recorded. Rarefied species richness was maximum in the EVEG (20) habitat. Best suited rank abundance models were analysed for epiphytic orchids in each habitat and checked for significant differences. Bootstrap and Jackknife-1 estimators and species accumulation curves suggested higher species richness than observed, therefore more effort in sampling was needed in order to record all epiphytic orchids of the area. The difference in species richness between habitat types was not statistically significant (ANOVA). 38% of recorded epiphytic orchid species were endemic.

First data on plasmodial slime moulds (Myxomycetes = Myxogastrea) of Rdeysky Nature Reserve (Novgorod Region, Russia)

2021 ◽  
Vol 55 (2) ◽  
pp. 361-377
Author(s):  
N. I. Borzov ◽  
F. M. Bortnikov ◽  
A. V. Matveev ◽  
V. I. Gmoshinskiy
Keyword(s):  
Species Diversity ◽  
Rare Species ◽  
Nature Reserve ◽  
Common Species ◽  
Slime Moulds ◽  
State Nature Reserve ◽  
Plasmodial Slime Moulds ◽  
State Nature

The results of the first study of the species diversity of myxomycetes of the Rdeysky State Nature Reserve are presented. The 201 field specimens of sporophores belonging to 56 morphospecies from 27 genera, ten families, and six orders were collected from September 30 to October 5, 2020. Fifty-two species of these were new for the Novgorod Region. The most common species at the reserve were Arcyria affinis, Hemitrichia calyculata, Lycogala epidendrum, Metatrichia vesparia, Physarum album, Trichia decipiens, and T. varia. Additionally, detailed morphological descriptions of two rare species Amaurochaete trechispora and Trichia crateriformis are given.

Tree density, basal area and species diversity in a disturbed dry tropical forest of northern India: implications for conservation

2006 ◽  
Vol 33 (3) ◽  
pp. 256-262 ◽  
Author(s):  
R. SAGAR ◽  
J.S. SINGH
Keyword(s):  
Species Diversity ◽  
Tropical Forest ◽  
Basal Area ◽  
Tree Density ◽  
Dry Forest ◽  
Conservation Strategies ◽  
Stem Density ◽  
Dry Tropical Forest ◽  
Number Of Species ◽  
Northern India

Dry tropical forest communities are among the world's most threatened systems and urgent measures are required to protect and restore them in degraded landscapes. For planning conservation strategies, there is a need to determine the few essential measurable properties, such as number of species and basal area, that best describe the dry forest vegetation and its environment, and to document quantitative relationships among them. This paper examines the relationships between forest basal area and diversity components (number of species and evenness) for a disturbed dry tropical forest of northern India. Data were collected from five sites located in the Vindhyan dry tropical forest of India, selected on the basis of satellite images and field observations to represent the entire range of conditions in terms of canopy cover and disturbance regimes. These sites represented different communities in terms of species composition. The forest was poorer in species richness, and lower in stem density and basal area than wet forests of the tropics. Across sites (communities), the diversity components and tree density were positively related with total tree basal area. Considering basal area as a surrogate of biomass and net production, diversity is found to be positively associated with productivity. A positive relationship between basal area, tree density and species diversity may be an important characteristic of the dry forest, where recurring disturbance does not permit concentration of biomass or stems in only a few strong competitors. However, the relationships of basal area with density, alpha diversity and evenness remain statistically significant only when data from all sites, including the extremely disturbed one, are used in the analysis. In some sites there was a greater coefficient of variation (CV) of basal area than in others, attributed to patchy distribution of stems and resultant blanks. Therefore, to enhance the tree diversity of these forests, the variability in tree basal area must be reduced by regulating local disturbances. Conservation activities, particularly fuelwood plantations near human settlements, deferred grazing and canopy enrichment through multi-species plantations of nursery-raised or wild-collected seedlings of desirable species within the forest patches of low basal area, will be needed to attain restoration goals, but reforestation programmes will have to be made attractive to the forest-dwelling communities.

scholarly journals The macrozoobenthos under clam farm (the Black Sea, Sevastopol region)

2018 ◽  
Vol 3 (1) ◽  
pp. 9-22 ◽  
Author(s):  
N. A. Boltacheva ◽  
M. V. Makarov ◽  
L. V. Bondarenko ◽  
M. A. Kovaleva
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Black Sea ◽  
Rare Species ◽  
Trophic Structure ◽  
Bivalve Mollusk ◽  
The Black Sea ◽  
Density And Biomass

During 2015–2106 the macrozoobenthos under the clam farm located in the area of Sevastopol was investigated. The aim of the study is to consider species composition, density and biomass of macrozoobenthos in the area of the clam farm. The samples were taken using standard benthic techniques. Relatively low species diversity was observed, with 56 species of macrozoobenthos identified. The density was 500–975 ind. per m², the biomass varied from 0.8 to 381.1 g·m-2. The community of the bivalve mollusk Lucinella divaricata (Linnaeus, 1758) was found. Trophic structure of the community with high quantity of detritus feeders dominated by small polychaetes was determined. The dominating, typical and rare species were identified. Comparison with the data obtained in 1957 in Evpatoriya – Sevastopol area at the same depths and sediments was made.

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