Are birds more afraid in urban parks or cemeteries? A Latin American study contrasts with results from Europe.

The escape behaviour, measured as flight initiation distance (FID; the distance at which individuals take flight when approached by a potential predator, usually a human in the study systems), is a measure widely used to study fearfulness and risk-taking in animals. Previous studies have shown significant differences in the escape behaviour of birds inhabiting cemeteries and urban parks in European cities, where birds seem to be shyer in the latter. We collected a regional dataset of the FID of birds inhabiting cemeteries and parks across Latin America in peri-urban, suburban and urban parks and cemeteries. FIDs were recorded for eighty-one bird species. Mean species-specific FIDs ranged from 1.9 to 19.7 m for species with at least two observations (fifty-seven species). Using Bayesian regression modelling and controlling for the phylogenetic relatedness of the FID among bird species and city and country, we found that, in contrast to a recent publication from Europe, birds escape earlier in cemeteries than parks in the studied Latin American cities. FIDs were also significantly shorter in urban areas than in peri-urban areas and in areas with higher human density. Our results indicate that some idiosyncratic patterns in animal fearfulness towards humans may emerge among different geographic regions, highlighting difficulties with scaling up and application of regional findings to other ecosystems and world regions. Such differences could be associated with intrinsic differences between the pool of bird species from temperate European and mostly tropical Latin American cities, characterized by different evolutionary histories, but also with differences in the historical process of urbanization.

Human-modified landscapes narrow the isotopic niche of neotropical birds.

Deforestation and habitat loss resulting from land use changes are some of the utmost anthropogenic impacts that threaten tropical birds in human-modified landscapes (HMLs). The degree of these impacts on birds' diet, habitat use, and ecological niche can be measured by isotopic analysis. We investigated whether the isotopic niche width, food resources, and habitat use of bird trophic guilds differed between HMLs and natural landscapes (NLs) using stable carbon (δ13C) and nitrogen isotopes (δ15N). We analyzed feathers of 851 bird individuals from 28 landscapes in the Brazilian Atlantic Forest. We classified landscapes into two groups according to the percentage of forest cover (HMLs ≤ 30%; NLs ≥ 47%), and compared the isotopic niche width and mean values of δ13C and δ15N for each guild between landscape types. The niches of frugivores, insectivores, nectarivores, and omnivores were narrower in HMLs, whereas granivores showed the opposite pattern. In HMLs, nectarivores showed a reduction of 44% in niche width, while granivores presented an expansion of 26%. Individuals in HMLs consumed more resources from agricultural areas (C4 plants), but almost all guilds showed a preference for forest resources (C3 plants) in both landscape types, except granivores. Degraded and fragmented landscapes typically present a lower availability of habitat and food resources for many species, which was reflected by the reduction in niche width of birds in HMLs. Therefore, to protect the diversity of guilds in HMLs, landscape management strategies that offer birds more diverse habitats must be implemented in tropical regions.

Improvement of vegetation structure enhances bird functional traits and habitat resilience in an area of ongoing restoration in the Atlantic Forest.

Ecological restoration is a traditional option for recovering biodiversity and ecosystem functions. Birds perform pollination, seed dispersal, and pest-control services, which catalyze increases in habitat structure. Habitat complexity changes bird composition, but there is little evidence of its effects on bird functional diversity in Neotropical restorations. We tested whether bird functional diversity and composition respond to increased habitat complexity. Point-counts were performed (January-December 2015) in an area undergoing restoration (536 ha) in the Atlantic Forest of southeastern Brazil, in restorations with less and more structured vegetation and pastures and forest-fragments. The functional bird traits considered were diet, habitat, biomass, environmental sensitivity, and foraging strata. Increased habitat complexity was evaluated using plant characteristics (exotic grass, canopy, herbaceous cover, and diameter at breast height). A total of 172 bird species (5% endemic; 12% migratory) were recorded. Increased vegetation structure in both restored sites and forest-fragments drove a reorganization and addition of functional bird traits, which positively influenced functional richness, dispersion, and evenness. Shifts in plant-characteristics rearranged bird functional traits (diet-forest-dependence and diet-strata-foraging). The rapid development of vegetation structure is a key factor for restoration because it provides additional habitat for semi-dependent forest birds and enhances resilience and sustainability in new man-made forests.

ATLANTIC BIRD TRAITS: a data set of bird morphological traits from the Atlantic forests of South America.

Scientists have long been trying to understand why the Neotropical region holds the highest diversity of birds on Earth. Recently, there has been increased interest in morphological variation between and within species, and in how climate, topography, and anthropogenic pressures may explain and affect phenotypic variation. Because morphological data are not always available for many species at the local or regional scale, we are limited in our understanding of intra- and interspecies spatial morphological variation. Here, we present the ATLANTIC BIRD TRAITS, a data set that includes measurements of up to 44 morphological traits in 67,197 bird records from 2,790 populations distributed throughout the Atlantic forests of South America. This data set comprises information, compiled over two centuries (1820-2018), for 711 bird species, which represent 80% of all known bird diversity in the Atlantic Forest. Among the most commonly reported traits are sex (n = 65,717), age (n = 63,852), body mass (n = 58,768), flight molt presence (n = 44,941), molt presence (n = 44,847), body molt presence (n = 44,606), tail length (n = 43,005), reproductive stage (n = 42,588), bill length (n = 37,409), body length (n = 28,394), right wing length (n = 21,950), tarsus length (n = 20,342), and wing length (n = 18,071). The most frequently recorded species are Chiroxiphia caudata (n = 1,837), Turdus albicollis (n = 1,658), Trichothraupis melanops (n = 1,468), Turdus leucomelas (n = 1,436), and Basileuterus culicivorus (n = 1,384). The species recorded in the greatest number of sampling localities are Basileuterus culicivorus (n = 243), Trichothraupis melanops (n = 242), Chiroxiphia caudata (n = 210), Platyrinchus mystaceus (n = 208), and Turdus rufiventris (n = 191). ATLANTIC BIRD TRAITS (ABT) is the most comprehensive data set on measurements of bird morphological traits found in a biodiversity hotspot; it provides data for basic and applied research at multiple scales, from individual to community, and from the local to the macroecological perspectives. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or teaching and educational activities.

Avifauna associada a um trecho urbano do rio Sorocaba, Sudeste do Brasil / Avifauna associated to an urban extend of the Sorocaba river, Southeastern Brazil

Este estudo teve como objetivo caracterizar a avifauna associada ao rio Sorocaba, um típico rio urbano, do sudeste do Brasil. Ele atravessa a cidade com o mesmo nome, ao longo do qual, várias atividades humanas são realizadas como recreação e pesca. Lá, várias espécies de aves devem encontrar locais para descanso, alimentação e nidificação. As aves foram observadas semanalmente, de setembro de 2008 a setembro de 2009 por meio de 16 pontos fixos (A1 a A16). O levantamento quantitativo registrou 65 espécies (32 passeriformes e 33 não - passeriformes), sendo que a família mais bem representada foi Tyrannidae (n = 9). As espécies mais freqüentes foram Egretta thula, Amazonetta brasiliensis, Vanellus chilensis, Pitangus sulphuratus, Ardea alba e Pygochelidon cyanoleuca (FO = 100%). Os maiores valores do índice pontual de abundância foram 46,5 (1626 contatos) para Pgochelidon cyanoleuca, 14,4 (500 contatos) para Phalacrocorax brasilianus e 12,9 (452 contatos) para Amazonetta brasiliensis. As categorias tróficas mais representativas foram dos insetívoros (n = 26), piscívoros (n = 11) e onívoros (n = 10). A análise de agrupamento revelou a existência de três pares de pontos muito semelhantes (100 e 95% semelhança). Diferenças conspícuas na composição da fauna de aves ao longo da área estudada foram detectadas, provavelmente devido às suas características ambientais e do grau de perturbação humana. Além disso, diferenças significativas nos avistamentos foram observadas entre as estações de seca e chuva, provavelmente em função das atividades reprodutivas e migratórias e do aumento na disponibilidade de recursos alimentares, que supostamente ocorrem no período chuvoso. Neste sentido, práticas conservacionistas devem permitir a manutenção a heterogeneidade de habitats, recuperação da vegetação ripária, praias e banhados, assim como o planejamento efetivo das atividades humanas em seu entorno.

This study aimed to characterize the avifauna associated to the Sorocaba River, a typical urban river in Southeastern Brazil. It crosses the city having the same name, along which different human activities are carried out as recreation and fishing. There, several bird species might find sites for resting, feeding and nesting. We surveyed birds weekly, from September 2008 to September 2009, by 16 point counts (A1 to A16). The quantitative survey registered 65 species (32 Passeres and 33 non-Passeres), and the most well-represented family was Tyrannidae (n = 9). The most frequent species were Egretta thula, Amazonetta brasiliensis, Vanellus chilensis, Pitangus sulphuratus, Ardea alba and Pygochelidon cyanoleuca (FO = 100%). The higher abundance index values were 46.5 (1626 contacts) for Pygochelidon cyanoleuca, 14.4 (500 contacts) for Phalacrocorax brasilianus and 12.9 (452 contacts) for Amazonetta brasiliensis. The most representative trophic categories were insectivores (n = 26), piscivores (n = 11) and omnivores (n = 10). The cluster analysis revealed the existence of three very similar pairs of points (100 and 95% of information remaining). Conspicuous differences in the composition of bird fauna along the studied area were detected, probably due to its environmental characteristics and the degree of human disturbance. Moreover, significant differences were observed between the sightings of dry and wet seasons, probably due to the reproductive and migratory activities and an increased availability of food resources that is supposed to happen in the wet season. In this sense, conservation practices should provide the maintenance of habitat heterogeneity, recovering the riparian forests, beaches and marshes, and an effective planning of human activities in their surroundings as well.