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SummaryCompetition between closely related species of migratory birds is thought to be important in determining their winter distributions, habitat and resource use. However, the role of active dominance interactions has generally been downplayed. In this paper we review the occurrence of interspecific feeding territories among certain Neotropical migrants. Aggressive dominants have been reported primarily at flowering plants, but also at the honeydew from scale insect infestations, the canopy of insect-rich pioneer trees and, occasionally, fruiting trees. Although the phenomenon is uncommon, aggressively dominant species may be important in certain habitats. The presence of such interspecific territorial systems argues for the poverty of resources in the habitat as a whole. Studying aggressive interactions among migrants is a way of using bird behaviour to define critical resources for conservation management.La competencia entre especies de aves migratorias estrechamente emparentadas entire si se considera importante para determinar su distribucion invernal, habitat y uso de recursos. Sin embargo, el papel de las interacciones de dominancia activa ha sido generalmente minimizado. En este trabajo revisamos la existencia de territorios de alimentacion interespedficos entre ciertos migrantes neotropicales. Se han observado casos de dominancia agresiva en plantas en floracion, pero tambien en el exudado producido por las plagas de ciertos insectos, en el dosel de arboles pioneros ricos en insectos y, ocasionalmente, en arboles frutales. Aunque el fen6meno no es comun, las especies dominantes agresivas pueden ser importantes en ciertos habitats. La presencia de estos sistemas territoriales interespedficos indica la pobreza de recursos en el habitat. El estudio de las interacciones agresivas entre migrantes es una manera de utilizar el comportamiento de las aves para identificar recursos criticos desde el punto de vista de la conservacion y el manejo.

In the present work, a target analysis method for simultaneously determining 24 diverse endocrine-disrupting compounds (EDCs) in urine (benzophenones, bisphenols, parabens, phthalates and antibacterials) was developed. The target analysis approach (including enzymatic hydrolysis, clean-up by solid-phase extraction and analysis by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS)) was optimized, validated and applied to volunteers’ samples, in which 67% of the target EDCs were quantified. For instance, benzophenone-3 (0.2–13 ng g−1), bisphenol A (7.7–13.7 ng g−1), methyl 3,5-dihydroxybenzoate (8–254 ng g−1), mono butyl phthalate (2–17 ng g−1) and triclosan (0.3–9 ng g−1) were found at the highest concentrations, but the presence of other analogues was detected as well. The developed target method was further extended to suspect and non-target screening (SNTS) by means of LC coupled to high-resolution MS/MS. First, well-defined workflows for SNTS were validated by applying the previously developed method to an extended list of compounds (83), and then, to the same real urine samples. From a list of approximately 4000 suspects, 33 were annotated at levels from 1 to 3, with food additives/ingredients and personal care products being the most abundant ones. In the non-target approach, the search was limited to molecules containing S, Cl and/or Br atoms, annotating 4 pharmaceuticals. The results from this study showed that the combination of the lower limits of detection of MS/MS and the identification power of high-resolution MS/MS is still compulsory for a more accurate definition of human exposome in urine samples. Graphical abstract

The Short-crested Coquette (Lophornis brachylophus) is an endangered species endemic to Mexico. Currently, its distribution area is estimated at 53 km². Little to no information exists on its natural history, abundance, and distribution. The purpose of the present study is to describe its food resources, behavior, and interactions with plants and other hummingbirds in addition to its abundance and distribution along an altitudinal gradient. We found that the Short-crested Coquette is sparsely distributed and ranges from tropical sub-deciduous forest to cloud forest. It can also occupy cultivated lands and forests with shade coffee plantations. It moves along an altitudinal gradient following the blooming of its floral resources, similar to other hummingbird species in the study region. It is a generalist, subordinate species that shares its distribution with 14 other hummingbird species. It interacts with some of these hummingbirds and plants in a nested network of interactions with low levels of connectance, visiting 8 of the 23 plant species commonly used by hummingbirds in the area. More in-depth studies on its reproduction and interaction with different plants and important crops in the area are required. The results of the present study can be used to propose programs for the management, conservation, or recovery of the habitats inhabited by the Short-crested Coquette and other hummingbirds. Coquette du Guerrero (Lophornis brachylophus), espèce endémique et en voie de disparition : ressources florales et interactionsRÉSUMÉ. La Coquette du Guerrero (Lophornis brachylophus) est une espèce en voie de disparition, endémique du Mexique. Son aire de répartition actuelle est évaluée à 53 km². On n'en connait peu, voire pas du tout, sur ses traits comportementaux, son abondance et sa répartition. L'objectif de la présente étude était de décrire ses ressources alimentaires, son comportement et ses interactions avec les plantes et les autres colibris, ainsi que son abondance et sa répartition le long d'un gradient altitudinal. Nous avons constaté que la répartition de la Coquette du Guerrero est clairsemée et s'étend de la forêt tropicale sub-décidue à la forêt brumeuse. La coquette fréquente également les terres cultivées et les forêts comportant des plantations de café d'ombre. Elle se déplace le long d'un gradient altitudinal en suivant la floraison de ses ressources florales, comme le font les autres espèces de colibris de la région d'étude. Il s'agit d'une espèce généraliste et subordonnée, qui partage sa répartition avec 14 autres espèces de colibris. Elle interagit avec certains de ces colibris et plantes dans un réseau imbriqué d'interactions à faibles niveaux de connectivité, visitant 8 des 23 espèces végétales communément utilisées par les colibris dans la région. Il serait nécessaire de mener des études plus approfondies sur sa reproduction et ses interactions avec différentes plantes et cultures importantes dans la région. Nos résultats peuvent servir à proposer des programmes de gestion, de conservation o...

Maintaining a diverse urban forest that provides ecosystem services can promote urban sustainability and resilience to environmental change. Around the world, cities have taken to inventorying their urban trees and quantifying their ecosystem services but more so in industrialized counties than in Latin America. Here we describe the results of an i-Tree inventory that established 206 survey plots in the National Municipal District of Santo Domingo (NMDSD). We used social-ecological theory to evaluate potential factors that may influence urban forest structure, composition, and ecosystem services diversity across three wards with distinct social and urban characteristics. Rarefaction curves showed a diverse urban forest dominated by non-native trees that have ornamental and medicinal uses. Wards differed in species composition with palms being particularly dominant in Wards 1 and 2 where the proportion of low-income houses is smaller. Ward 1 supports high-income residential areas and Ward 3 is the area with higher population and housing densities and lower income residents. On average, we found no significant differences among wards in tree species richness, average dbh, leaf area, and percent tree cover per plot. Trees in Ward 2 were taller, on average, than those in Ward 1 but were comparable to those in Ward 3. Likewise, tree density per plot was highest in Ward 2, followed by Ward 1 and Ward 3. Despite these significant differences in stem densities, average values in four ecosystem services involving measures of carbon, rainfall, and contaminants (C-sequestration, C-storage, avoided runoff, and removal of air pollutants) were non-significant across wards. We found disproportionately more street trees in Ward 1 relative to Wards 2 and 3 and more trees in public spaces in Wards 1 and 2 relative to Ward 3. Evidence for the luxury effect on tree distribution in the NMDSD was subtle and manifested mostly through differences in species composition and tree distribution across public and private domains as well as the amount of planting space. Overall results point to inequalities in the potential of reforestation among NMDS wards and an overabundance of non-native species, which should guide urban forest management with ecosystem services and conservation goals.