Dams are crucial for water supply in human populations and are becoming more common globally for hydroelectric power generation. Dams alter natural habitats and their biodiversity; however, studies are inconclusive about their effects on them. This study aimed to examine the effects of dams on vertebrates and the determinants of changes in global biodiversity and their relationship with critical areas for conservation. We evaluated the effects of dams on vertebrate richness and abundance. We performed a meta-analysis based on 120 case studies. We evaluated the overall effect on richness and abundance and examined these effects regarding taxa, disturbance type, latitudinal zone, zoogeographic zone, biodiversity hotspots, dam size and purpose, and species extinction risk. We conducted an overall analysis that included all species, and then we conducted separate analyses for terrestrial and aquatic species. Dams had a negative effect on vertebrate richness but not on vertebrate abundance. These effects were influenced by larger dams with fragmentation and were more pronounced within hotspots and in countries with a low species extinction risk. Such negative effects were explained by terrestrial vertebrates (particularly birds and mammals) because species richness and the abundance of aquatic vertebrates (fish) were not affected by dams in any case. Our results showed that habitat fragmentation created by large dams changes vertebrate communities, negatively affecting species richness in some areas of conservation concern. We propose implementing reservoirs in areas where they would have a lower impact on biodiversity and avoiding large dams in priority areas for conservation and where endangered species inhabit.

Agricultural systems have increased in extension and intensity worldwide, altering vertebrate functional diversity, ecosystem functioning, and ecosystemic services. However, the effects of open monoculture crops on bird functional diversity remain little explored, particularly in highly biodiverse regions such as the tropical Andes. We aim to assess the functional diversity differences of bird guilds between monoculture crops (coffee, cocoa, and citrus) and secondary forests. We use four functional diversity indices (Rao Q, Functional Richness, Functional Evenness, and Functional Divergence) related to relevant morphological, life history, and behavioral traits. We find significant differences in functional diversity between agroecosystem and forest habitats. Particularly, bird functional diversity is quite homogeneous among crop types. Functional traits related to locomotion (body weight, wing-chord length, and tail length), nest type (closed), and foraging strata (canopy and understory) are dominant at the agroecosystems. The bird assemblages found at the agroecosystems are more homogeneous in terms of functional diversity than those found at the secondary forests, as a result of crop structure and management. We recommend promoting more diverse agroecosystems to enhance bird functional diversity and reduce their effects on biodiversity.

Landscape structure and configuration may affect bird body condition, with contrasting effects on resident and migratory species. There is little empirical evidence to support this hypothesis in tropical regions, where land-use change poses a major threat to biodiversity. We aimed to assess the effects of landscape structure and configuration on the body condition of neotropical migrant and resident bird species. We compiled body condition data (using the scaled mass index) of nine bird species (five resident and four migratory). We characterized landscape structure and configuration at 26 localities. We evaluated the effects of landscape metrics on bird body condition using Bayesian linear mixed models. The landscapes in our study largely varied in forest, crop, and grassland cover, as well as in landscape metrics. When we examined migrant birds, we found a positive effect of landscape connectivity and crop cover on body condition. Similarly, body condition of resident birds was positively affected by connectivity and crop cover, but also by forest patch area and capture day. Changes in landscape structure and configuration may indirectly alter the access to resources, causing additional energy expenditures, leading to a deteriorated body condition. Conversely, landscape heterogeneity may have a positive effect on bird body condition. Therefore, we recommend maintaining connectivity and complementary resources in the landscape.

The genus Borrelia encompasses spirochetal species that are part of three well-defined groups. Two of these groups contain pathogens that affect humans: the group causing Lyme disease (LDG) and the relapsing fever group (RFG). Lyme disease is caused by Borrelia burgdorferi s.l., which is distributed in the Northern Hemisphere, and relapsing fevers are caused by Borrelia spp., which are found in temperate and tropical countries and are an emerging but neglected pathogens. In some departments of Colombia, there are records of the presence of Borrelia sp. in humans and bats. However, little is known about the impact and circulation of Borrelia spp. in the country, especially in wildlife, which can act as a reservoir and/or amplifying host. In this context, the objective of our research was to detect and identify the Borrelia species present in wild mammals in the departments of Caldas and Risaralda in Colombia. For morphological detection, blood smears and organ imprints were performed, and molecular identification was carried out through a nested PCR directed on the flagellin B (flaB) gene. A total of 105 mammals belonging to three orders (Chiroptera, Didelphimorphia and Rodentia) were analyzed, of which 15.24% (n = 16) were positive for Borrelia. Molecularly, the presence of Borrelia burgdorferi s.s. in lung tissues of Thomasomys aureus and blood of Mus musculus (Rodentia) was detected, with 99.64 and 100% identity, respectively. Borrelia sp. genospecies from a clade branch of a bat-associated LDG sister group were identified in seven individuals of bat species, such as Artibeus lituratus, Carollia brevicauda, Sturnira erythromos, and Glossophaga soricina. Furthermore, two Borrelia genospecies from the RFG in seven individuals of bats (A. lituratus, Artibeus jamaicensis, Platyrrhinus helleri, Mesophylla macconnelli, Rhynchonycteris naso) and rodents (Coendou rufescens, Microryzomys altissimus) were documented. Additionally, the presence of a spirochete was detected by microscopy in the liver of a Sturnira erythromos bat specimen. These results contain the first molecular evidence of the presence of B. burgdorferi s.s. in South America, which merits the need for comprehensive studies involving arthropods and vertebrates (including humans) in other departments of Colombia, as well as neighboring countries, to understand the current status of the circulation of Borrelia spp. in South America.

The Colombian Tropical Andes are one of the regions with highest bird diversity on Earth. However, information on bird morphology, reproductive phenology, and molt is particularly scarce in this region. Also, this region is heavily impacted by deforestation, and it is vulnerable to climate change. Hence, providing baseline information on life history and morphological traits will be essential to support future research on functional diversity, climate change effects, conservation, evolution, and phenology. To fill this gap, we have compiled information on bird distribution, morphology, molt, and reproductive phenology at 52 localities of the Department of Caldas, covering an elevation range between 148 and 3845 m. This compilation comprises a wide range of habitats, including native forests, forestry plantations, croplands, and paramo. Our database presents information for 3,398 records belonging to 379 bird species (representing 23 orders, 53 families, and 258 genera). From those records, 2,843 correspond to information collected in the field between 2008 and 2019, and the remaining 555 records correspond to specimens deposited in the Natural History Museum of the Caldas University, collected between 1969 and 2014. We measured nine morphological traits from all specimens: total culmen, gape, bill width, bill depth, tarsus, wing length, tail length, total length, and mass. We also have reproductive condition information for 257 species and molt information available for 378 species. The information contained in this data set represents ~20% of the Colombian avifauna and ~11% of the bird species richness in South America. This data set is released for non‐commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY‐NC‐SA).