Martín Alejandro Montes

The bats of northeastern Brazil: a panorama

Due to the lack of studies with a regional focus on the richness and distribution of the fauna of chiropterans in northeastern Brazil, this paper presents a collection of these data gathered in an extensive literature review. The data analyzed include technical reports of environment consulting agencies, abstracts presented in scientific meetings, monographs, dissertations, theses, papers, scientific notes, short communications, book chapters and books on bats of South America, Brazil and the biomes Amazon, Caatinga, Cerrado and Atlantic Forest. The numbers of municipalities surveyed per biome and the localities, municipalities and species richness for each state and biome in northeastern Brazil were determined. This information indicated the regions lacking more consistent Chiroptera sampling efforts, namely large areas in the Amazon, Caatinga and Cerrado. However, bat surveys in Atlantic Forest environments in most northeastern Brazilian states were considered representative. Although bat populations in some states have been poorly surveyed, the results of this review afford to conclude that a large part of the diversity of bat species known in Brazil has been reported for the northeastern region of the country. This review enlarges the knowledge on bat species richness and distribution in northeastern Brazil, and indicates areas suffering from wide survey gaps.

The heterogeneity of Caatinga biome: an overview of the bat fauna

Abstract In semiarid regions like the Brazilian Caatinga, the long dry season suggests that it is a homogeneous environment. However, differences in climate, soil, relief, and duration of the dry season across this biome has prompted the division of Caatinga in eight ecoregions. Here, we test the validity of these ecoregions for bats, which play a fundamental role in the balance of ecosystems. A literature review was carried out to investigate the distribution of bat species in all Caatinga ecoregions, and the lack of sampling efforts. In total, 90 chiropteran species were recorded in the biome. Bat distribution is not homogeneous, and almost all ecoregions present exclusive species. Gaps in chiropteran sampling efforts occur in all ecoregions. A robust and significant correlation was observed between the number of studies reporting samples and bat richness of each ecoregion, indicating that more research will increase recorded richness in these areas, and in the Caatinga as a whole. The existence of at least four ecoregions in the Caatinga was also supported. This underlines the importance of these areas to conservation initiatives.

Richness and abundance of the cardini group of Drosophila (Diptera, Drosophilidae) in the Caatinga and Atlantic Forest biomes in northeastern Brazil

Brazil has a high diversity of flies of the genus Drosophila, and part of this richness is represented by the cardini group. We analyzed the fluctuations in the richness and abundance of this group, in environments that had never previously been studied in the northeastern region of Brazil. Among the 28,204 drosophilids sampled, 1,294 belonged to the cardini group and were represented by D. polymorpha, D. cardini, D. neocardini and D. cardinoides. Occurrences of D. neocardini and D. cardinoides were registered for the first time in the Caatinga. In this biome, D. cardini stood out as having the highest abundance, and D. polymorpha was not observed. In the coastal Atlantic Forest, D. cardini was not registered, but D. polymorpha was found in all the localities investigated. Mangrove swamps were the environment with the lowest abundance and richness of the cardini group. The High-altitude Forest presented the highest richness of this group. We suggest that the high abundance of D. polymorpha in the High-altitude Forest and in the coastal Atlantic Forest may be a reflection of the historical relationship between these two environments.

Abundance and Richness of Cryptic Species of the willistoni Group of Drosophila (Diptera: Drosophilidae) in the Biomes Caatinga and Atlantic Forest, Northeastern Brazil

ABSTRACT Cryptic species meet the biological definition of species, but are morphologically identical or quite similar. Several ecological studies underestimate richness and neglect important information on cryptic species, as they are rather difficult to identify. Among insects, drosophilids of the willistoni subgroup, which includes Drosophila willistoni Sturtevant, Drosophila paulistorum Dobzhansky & Pavan, Drosophila equinoxialis Dobzhansky, Drosophila tropicalis Burla & da Cunha, Drosophila insularis Dobzhansky, and Drosophila pavlovskiana Kastritsis & Dobzhansky, are good examples of cryptic species. Although several studies have shown that this subgroup is one of the most abundant in the Neotropical region, no identification to species level has been reported for areas where these individuals live in sympatry. This study evaluates the seasonal oscillations in abundance of this subgroup in biomes with contrasting vegetation and rainfall regimes: the Caatinga and the Atlantic Forest, in northeastern Brazil. Approximately 39,000 drosophilids were captured in 24 collections, of which 18,000 belonged to the willistoni subgroup. The most abundant were D. willistoni, D. paulistorum, and D. equinoxialis, in this order. D. equinoxialis was recorded in only one of the environments surveyed, represented by few individuals. In all environments, individuals of the willistoni subgroup were more abundant in the rainy season, when richness often was higher. The results underline the importance of humidity and of temperature for the subgroup willistoni and indicate the ecological versatility of some of its species.