The Amazon rainforest has approximately 23% of its sampled area dedicated to bats, making it one of the least sampled and most diverse regions for bats in Brazil. The lack of sampling results in a lack of knowledge regarding the accurate geographical distribution of bat species. This lack is referred to as the Wallacean shortfall, which should be addressed with primary data obtained from in situ collections. However, the use of Species Distribution Models (SDMs) can help alleviate this gap. The states of Pará and Acre are located in the Brazilian Amazon. So, our objective is to decrease the Wallacean shortfall concerning Amazonian bat species. To achieve this, we provide (i) a list of bat species sampled in the states of Pará and Acre in the last 5 years (2017 to 2022); (ii) the potential distribution of species considered as new occurrences for the region; and (iii) the potential distribution of species classified as Data Deficient (DD) and Near Threatened (NT) according to the IUCN classification. With 96 nights of collection and 129,600 m²h of mist netting, we obtained 75 bat species, with an estimated total of 94.78 species. Additionally, 21 species were considered as range extensions. The Brazilian Amazon region has a vast geographic expanse and few established research centers, resulting in a limited sampling of bats and other biological groups. Furthermore, we draw attention to the significant number of bat species with expanded geographical distributions, with 21 out of the 75 sampled species. This should be a reminder that primary biogeographic data is still necessary for the neotropical region.

In this study we described the diet of Hylaeamys megacephalus (G. Fisher, 1814) and investigated the degree of individual variation in the diet of this species among the Amazon Forest and the oil palm plantation. We analyzed the stomach contents of 36 individuals, of whom 11 were collected in the forest and 25 captured in the palm oil palm plantation. The H. megacephalus diet consisted of 18 food items, of which 12 were animal composition and eight were vegetable composition. The niche amplitude of the species was narrower in the forest area (Ba_forest = 0.013) compared to the palm tree plantation area (Ba_palm = 0.478). This shows that individuals have greater niche overlap in forest areas, while in the plantation areas the animals expand their food niche. In addition, the values of the mean of the individual diet in relation to the diet of the entire population were lower in the palm oil palm plantation environment (IS_palm = 0.164) than in the Forest environment (IS_forest = 0.357), indicating a high specialization in the palm oil plantation. These results indicate a population mechanism to reduce intraspecific competition in response to scarce resources.

Considering the hypothesis that there is a relationship between morphology and the choice or feeding habit in anurans, our objective was to identify the food items present in the anurans' diet; verify the existence of a pattern in the diet of the anurans collected; and show the relationship between diet and species morphology. Sampling was carried out using an active search methodology carried out by three people, lasting approximately three hours per unit. For that work, only species that had an abundance equal to or greater than five individuals were considered. We identified dietary patterns in taxonomic groups and tested their significance, in addition to groupings by family, genus and species and the relationship between morphology and diet. 148 individuals were collected, belonging to 41 anuran species, 16 genera and nine families, 44 items were observed, highlighting the Formicidae family and Tadpoles, with shrimp and crab being the least frequently found items. We concluded that there was a relationship between morphology and diet, in addition to the formation of a guild of insectivorous anurans, indicating a greater frequency of Hymenoptera as a food resource, mainly composed of the genus Rhinella.