Comparing the efficiency of monofilament and regular nets for capturing bats

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.

Bats in wetlands: composition and structure of assemblage in Reserva Natural Don Luis, Esteros del Iberá, Argentina

We report diversity data and ecological aspects (richness, abundance and guilds) of bat assemblages in the Esteros del Iberá. We sampled four sites at Reserva Natural Don Luis, with an effort of 75 nights, 256 nets and 12 harp traps over six years. We made a species accumulation curve, Whittaker diagram, and calculated inventory completeness. A complete inventory for the area included 471 individuals belonging to 14 species of Phyllostomidae, Vespertilionidae, and Molossidae families. Insectivorous guilds present the greatest richness and abundance. Esteros del Iberá shelters a diversity of guilds, one threatened species, and a new bat record for the region.

Mammal species richness and new records in protected natural areas of the northern part of the metropolitan area of the Valley of México

Sierra de Guadalupe is the only mountain range in the northern part of the Valley of Mexico metropolitan area. The accelerated urban expansion over the past decades has turned Sierra de Guadalupe into an isolated natural area immersed within the urban matrix. This study aimed to gather a documented inventory of the mammals of Sierra de Guadalupe as such information is useful to improve the management, restoration, and conservation of this important natural area of the basin of Mexico. Mammal collection records were extensively surveyed in the literature, collection databases, web pages, and scientific collections; field surveys were also conducted. A taxonomic list of the mammal species and their conservation status in the four Protected Natural Areas of Sierra de Guadalupe was compiled. A species-accumulation curve was constructed using the Chao 1 model and a map showing the distribution of collection records was produced. This work reveals that the mammals of Sierra de Guadalupe include 29 species, 23 genera, 15 families, and six orders. Six species are endemic to Mexico; two of them, Choeronycteris mexicana and Cratogeomys fumosus, are listed as threatened and one, Leptonycteris yerbabuenae, as under special protection. Collection records were gathered from 62 different localities. The largest number of species records and collections were made between 2009 and 2020. The species-accumulation curve projects a total of 36 mammal species. This is the first documented inventory ever compiled of the wild mammals of Sierra de Guadalupe. The species richness observed in this area is remarkable, considering its extension and environmental stressors; in addition, it harbors species endemic to Mexico, some of which are threatened. This is the first time that the species Sorex saussurei, Choeronycteris mexicana, Leptonycteris yerbabuenae, Cratogeomys merriami, Neotomodon alstoni, and Peromyscus melanophryshave been recorded in this area. The species-accumulation curve indicates that our inventory provides a good representation of the local species assemblage. This information can support the formulation of action plans for the conservation and restoration of the biological diversity of these important Protected Natural Areas and the last significant natural area remaining in the northern part of the Valley of Mexico Metropolitan Area.

Effect of Phosphorus Application on Arsenic Species Accumulation and Co-Deposition of Polyphenols in Rice Grain: Phyto and Food Safety Evaluation

The present study was aimed at exploring the effect of soil application of different concentrations of orthophosphate (P) (0, 10, 20, 30, and 40 mg kg−1) on rice agronomic and yield parameters, arsenic (As) species accumulation, and polyphenol levels in the grain of rice grown under As spiked soil (10 mg kg−1). The contents of As species (As(V), As (III), MMA and DMA) and polyphenols in rice grain samples were estimated using LC-ICP-MS and LC-MS/MS, respectively. P treatments significantly reduced the toxic effects of As on agronomic parameters such as root weight and length, shoot and spike length, straw, and grain yield. Among the treatments studied, only the treatment of 30 mg kg−1 P helps to decrease the elevated levels of As (V), As (III), and DMA in rice grains due to As application. The study revealed that 30 mg kg−1 was the optimal P application amount to minimize AS accumulation in rice grains and As-linked toxicity on agronomic parameters and chlorophyll biosynthesis. Furthermore, the levels of trans-ferulic acid, chlorogenic acid, caffeic acid, and apigenin-7-glucoside increased in response to accumulation of As in the rice grain. In conclusion, the precise use of phosphorus may help to mitigate arsenic linked phytotoxicity and enhance the food safety aspect of rice grain.