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Although forest-dependent, tropical island endemic birds are particularly at risk of extinction, they remain largely understudied. In this context, we assessed the spatial occupancy, local abundance, and diel activity in three forest columbid species of hunting interest, the Ruddy Quail-Dove (RQD), Geotrygon montana; the Bridled Quail-Dove (BQD), Geotrygon mystacea; and the Zenaida Dove (ZD), Zenaida aurita, in Guadeloupe (French West Indies), using 5 camera-traps over 14 days on 24 survey stations, resulting in 1680 trap days. The number of observed RQD was too small to allow for a statistical comparison between habitats. BQD were more frequently observed at camera-trap stations that were dominated by tropical rainforest than those that were dominated by flooded forest. Conversely, ZD were more frequently observed at stations that were dominated by flooded forest and dry forest than at those that were dominated by tropical rainforest. High temperatures negatively affected the abundance of BQD, while the abundance of ZD was significantly lower in tropical rainforests compared to dry and flooded forests and tended to increase with canopy openness. The three species were diurnal. BQD significantly positively co-occurred spatially and temporally with small Indian mongooses, Urva auropunctata, whereas the temporal and spatial distribution of ZD overlapped significantly with that of domestic dogs, Canis familiaris, and domestic cats, Felis catus. Our results provide firm evidence that RQD remains scarce and is largely outnumbered by BQD in Guadeloupe which is in contrast with has been reported for other Caribbean islands.

A beloved emblem of world peace--the dove--comes to life in this moving story that introduces Pablo Picasso and his art to young readers.

Although sex ratios at conception are close to 1:1 in most species of birds, skewed adult sex ratios (ASRs) are not uncommon in populations of birds, and occur frequendy at local and temporal scales. ASRs are a key variable influencing population demography, breeding systems, and many aspects of the behavior of birds. However, factors contributing to variation in ASRs, particularly for tropical species of birds, remain poorly understood. By compiling information from field sites and records from bird collections, we found that the ASRs of four species of Columbina ground doves from Venezuela deviated significantly from parity. Males of all species outnumbered females at all held sites and in all museum samples. ASR, expressed as the proportion of males, ranged from 0.59 for Common Ground Doves (Columbina passerina) to 0.65 for Plain-breasted Ground Doves (Columbina minuta) in the overall samples. Males outnumbered females by ~ 44% in Common Ground Doves and by 85% in Plain-breasted Ground Doves. Our samples included birds collected as specimens over many decades and across broad geographic areas, suggesting that skewed ASRs are characteristic of Venezuelan ground doves. Because these ground doves do not exhibit pronounced sexual size dimorphism and have socially monogamous breeding systems, selection would be expected to favor equal investment in males and females at hatching. As such, we argue that greater post-hatching mortality of females, rather than deviations in the sex ratio of embryos, is the main cause of the biased ASRs of Venezuelan ground doves. Proporcion sexual sesgada en adultos de especies de Columbina de Venezuela Si bien las relaciones sexuales en la concepcion son cercanas a 1:1 en la mayoria de las especies de aves, las proporciones sexuales (ASR) sesgadas no son infrecuentes en sus poblaciones, y ocurren con frecuencia a escalas locales y temporales. Las ASRs son una variable clave que innuye en la demografia de las poblaciones, sistemas de apareamiento y muchos aspectos del comportamiento de las aves. Sin embargo, los factures que contribuyen a la variacion en las ASRs, en particular para las especies de aves tropicales, siguen siendo poco conocidas. Al compilar informacion de sitios de campo y registros de colecciones de aves, encontramos que las ASRs de cuatro especies de tortolitas (Columbina) de Venezuela se desviaron significativamente de la paridad. Los machos de todas las especies superaron numéricamente a las hembras en todos los sitios de campo y en las muestras de museos. La ASR, expresada como la proporcion de machos, oscilo entre 0.59 en la Tortolita Grisacea (Columbina passerina) y 0.65 en la Tortolita Sabanera (Columbina minuta) en las muestras globales. Los machos superaron en numéro a las hembras en ~ 44% en las Tortolita Grisaceas y en un 85% en las Tortolita Sabaneras. Nuestras muestras incluyeron especimenes recolectados durante muchas décadas y a lo largo de amplias areas geograficas, lo que sugiere que las ASRs sesgadas son caracteristicas de las tortolitas venezolanas. Debido a que estas tortolitas no exhiben un dimorfismo sexual pronunciado y son socialmente monogamas, se esperaria que la seleccion favoreciera una inversion igual en machos y hembras al momento de la eclosion. lo tanto, argumentamos que la mayor mortalidad de las hembras después de la eclosion, en lugar de desviaciones en la proporcion de sexos de los embriones, es la causa principal de las ASRs sesgadas de las tortolitas venezolanas.

Sentinel-2 (S2) imagery is used in many research areas and for diverse applications. Its spectral resolution and quality are high but its spatial resolutions, of at most 10 m, is not sufficient for fine scale analysis. A novel method was thus proposed to super-resolve S2 imagery to 2.5 m. For a given S2 tile, the 10 S2 bands (four at 10 m and six at 20 m) were fused with additional images acquired at higher spatial resolution by the PlanetScope (PS) constellation. The radiometric inconsistencies between PS microsatellites were normalized. Radiometric normalization and super-resolution were achieved simultaneously using state-of–the-art super-resolution residual convolutional neural networks adapted to the particularities of S2 and PS imageries (including masks of clouds and shadows). The method is described in detail, from image selection and downloading to neural network architecture, training, and prediction. The quality was thoroughly assessed visually (photointerpretation) and quantitatively, confirming that the proposed method is highly spatially and spectrally accurate. The method is also robust and can be applied to S2 images acquired worldwide at any date.

Aim: Urbanization broadly affects the phylogenetic and functional diversity of natural communities through a variety of processes including habitat loss and the introduction of non-native species. Due to the challenge of acquiring direct measurements, these effects have been studied primarily using \"space-for-time\" substitution where spatial urbanization gradients are used to infer the consequences of urbanization occurring across time. The ability of alternative sampling designs to replicate the findings derived using space-for-time substitution has not been tested. Location: Global. Methods: We contrasted the phylogenetic and functional diversity of breeding bird assemblages in 58 cities worldwide with the corresponding regional breeding bird assemblages estimated using geographic range maps. Results: Compared to regional assemblages, urban assemblages contained lower phylogenetic diversity, lower phylogenetic beta diversity, a reduction in the least evolutionary distinct species and the loss of the most evolutionary distinct species. We found no evidence that these effects were related to the presence of non-native species. Urban assemblages contained fewer aquatic species and fewer aquatic foraging species. The distribution of body size and range size narrowed for urban assemblages with the loss of species at both tails of the distribution, especially large bodied and broadly distributed species. Urban assemblages contained a greater proportion of species classified as passerines, doves or pigeons; species identified as granivores; species that forage within vegetation or in the air; and species with more generalized associations with foraging strata. Main conclusions: Urbanization is associated with the overall reduction and constriction of phylogenetic and functional diversity, results that largely replicate those generated using space-for-time substitution, increasing our confidence in the quality of the combined inferences. When direct measurements are unavailable, our findings emphasize the value of developing independent sampling methods that broaden and reinforce our understanding of the ecological implications of urbanization.

Understanding how land cover and potential competition with invasive species shape patterns of occupancy, extirpation, and colonization of native species across a landscape can help target management for declining native populations. Mourning dove (Zenaida macroura) populations have declined throughout the United States from 1965–2015. The expansion of the Eurasian collared-dove (Streptopelia decaocto), an introduced species with similar food preferences, may further threaten mourning dove populations. We analyzed data from 2009–2016 from a large-scale monitoring program in the Western Great Plains of the United States in a 2-species occupancy model to assess the effects of collared-doves on mourning dove distributions, while accounting for imperfect detection and variation in land cover across the landscape. Mourning dove occupancy was stable or increasing across our study area, and despite overlap in resource use and co-occurrence between mourning doves and Eurasian collared-doves, we found no evidence that collared-doves are extirpating mourning doves from preferred habitat during the breeding season.