Subtropical Broad-Leaved Urban Forests as the Foremost Dynamic and Complex Habitats for a Wide Range of Bird Species

Broad-leaved subtropical forests are the most productive, diversified, and complex ecosystems on the planet. Unfortunately, they are currently under severe threat from anthropogenic activities, such as. deforestation, housing settlements, and agricultural expansion. In response to these severe effects, the present study was conducted to explore the current conservation status and population structure of a wide range of bird species inhabiting different subtropical broad-leaved urban forests of Pakistan. In total, 2879 individuals comprising 53 species and 28 families were detected between December 2017 and November 2018 as revealed through the distance sampling line transect method. The habitat selection among bird species varied according to vegetation structure and composition, food resources, adjoining habitats, and human settlements. According to IUCN Red List data, one species was deemed vulnerable out of 53 bird species, while the remaining 52 species were ranked as ofleast concern. The findings of the density analysis revealed that bird density varied between six subtropical broad-leaved forests. Palamar (3.954 ± 0.221 birds/ha) and Kityari (3.138 ± 0.162 birds/ha) were densely populated, whereas Kamal Khan (1.102 ± 0.178 birds/ha) was of the least concern. Likewise, the diversity analysis showed that Kamal Khan was a more diverse habitat (Shannon–Wiener Index; H’ = 3.581 ± 0.021). Shahabad was richer (Margalef Richness Index; R1 = 8.007 ± 0.053) and Dob Ghar was evenly distributed (Pielou J Evenness Index; E = 0.940 ± 0.005) compared to other urban habitats studied. Eight foraging guilds were identified among the bird species. Insectivores were the most abundant bird species utilizing the urban dwelling habitats. carnivores/piscivores/insectivores utilized Dob Ghar forest, while more frugivores utilized Kamal Khan and Dob Ghar. Based on the data, it was concluded that subtropical broad-leaved urban forests are dynamic, complex, and of vital significance for a diverse range of bird species.

Field evidence of UK wild bird exposure to fludioxonil and extrapolation to other pesticides used as seed treatments

We determine the exposure of wild birds to pesticides via consumption of fludioxonil-treated winter wheat seeds following autumn drilling. We recorded the density of seeds left on the soil surface, bird density, and consumption of pesticide-treated seed by birds using camera traps. We calculated the dose ingested by each bird species in a single feeding bout and if they ate treated seeds exclusively for 1 day. We extrapolated this for an additional 19 pesticides commonly used as seed treatments, assuming equal consumption rates. All three fields contained grains on the soil surface (mean 7.14 seeds/m2 on sowing day). In total, 1,374 granivorous birds spanning 18 different species were observed in the fields, with 11 species filmed eating the seeds. Fludioxonil appears to pose a low risk to birds, with <1.14% of the LD50 potentially ingested by a bird for a daily maximum amount of seeds. Analysis of the further 19 pesticides commonly used as seed dressings suggests that the neonicotinoid insecticides imidacloprid, clothianidin, and thiamethoxam represent the highest risk for granivorous birds. For example, chaffinch (Fringilla coelebs) could consume 63% of LD50 of imidacloprid in a single feeding bout, and 370% in a day. Further investigation is clearly required to determine whether seeds treated with these other pesticides are consumed as readily as those treated with fludioxonil, as if so this is likely to cause significant harm.

Beak trimming and stocking densities for laying and performance traits and behavioral patterns in Japanese quails

The present experiment was conducted to evaluate the productive performance, egg quality and behavioral patterns of Japanese quails (Coturnix coturnix japonica) with and without beak trimming submitted to two stocking densities. The study was conducted for 84 days. In total, 196 Japanese quails were randomly allocated to a 2 x 2 factorial scheme: submitted or not to beak trimming procedure and low (237.5 cm²/bird) and high stocking density (316.7 cm/bird) and its interaction. Eight replicates per treatment were used, totaling 32 experimental units. Collected data were submitted to analysis of variance and, means of parametric data were compared by Tukey test (p<0.05); otherwise non-parametric analysis of variance were applied for non-parametric data of quail behavior. Lower feed intake was observed in the high stocking density group (p<0.05) but did not affect other parameters (p>0.05). There was no interaction (p>0.05) between beak trimming and stocking density over performance and egg quality. Quails without beak trimming housed in higher density showed more aggressiveness and stress. Egg quality as well as performance parameters of Japanese quails are not affected by applying 316.7 cm2/bird density.

Land Use and Endemic Avian Biodiversity on Nusa Penida

Understanding anthropogenic alterations to land use and their effects can inform conservation efforts in tropical biodiversity hotspots. In 2004 the Indonesian Palau Penida Archipelago, off the coast of Bali, was established as an unofficial bird reserve; however, studies of the island's land use and avian biodiversity were never conducted and have not been monitored. I surveyed birds across 32 transects in land use categories designated: agriculture, deforested, developed, and forest. Forest transects presented the greatest endemic species richness, but overall, Shannon diversity different significantly among land use categories, particularly forested and deforested. ANOVA indicated exotic bird density was significantly higher than endemic bird density across all transects. Birds serve as a common biodiversity barometer and this study can serve to inform land use management decisions on the Archipelago and throughout reserves and protected areas throughout the tropics.

Quantifying year-round nocturnal bird migration with a fluid dynamics model

To understand the influence of biomass flows on ecosystems, we need to characterize and quantify migrations at various spatial and temporal scales. Representing the movements of migrating birds as a fluid, we applied a flow model to bird density and velocity maps retrieved from the European weather radar network, covering almost a year. We quantified how many birds take-off, fly, and land across Western Europe to (1) track bird migration waves between nights, (2) cumulate the number of birds on the ground and (3) quantify the seasonal flow into and out of the study area through several regional transects. Our results identified several migration waves that crossed the study area in 4 days only and included up to 188 million (M) birds that took-off in a single night. In spring, we estimated that 494 M birds entered the study area, 251 M left it, and 243 M birds remained within the study area. In autumn, 314 M birds entered the study area while 858 M left it. In addition to identifying fundamental quantities, our study highlights the potential of combining interdisciplinary data and methods to elucidate the dynamics of avian migration from nightly to yearly time scales and from regional to continental spatial scales.

A habitat-based approach to determining the effects of drought on aridland bird communities

Aridland breeding bird communities of the United States are among the most vulnerable to drought, with many species showing significant population declines associated with decreasing precipitation and increasing temperature. Individual breeding bird species have varied responses to drought which suggests complex responses to changes in water availability. Here, we evaluated the influence of water deficit, an integrative metric of drought stress, on breeding bird communities within 3 distinct aridland habitat types: riparian, pinyon-juniper, and sagebrush shrubland. We used 12 years of breeding bird survey data from 11 national parks and monuments in the Northern Colorado Plateau Inventory and Monitoring Network (NCPN). We used a multivariate community-level approach to test for the effect of annual water deficit on the bird communities in the 3 habitats. We found that bird communities responded to water deficit in all 3 habitat types, and 70% of the 30 species–habitat combinations show significant relationships between density and variation in water deficit. Our analyses revealed that the direction and magnitude of species responses to water deficit were habitat-dependent. The habitat-specific responses we observed suggest that the adaptive capacity of some species depends on the habitat in which they occur, a pattern only elucidated with our habitat-based approach. The direction and magnitude of the relationships between predicted densities and annual water deficit can be used to predict the relative sensitivity of species within habitat climate changes. These results provide the first attempt to determine how the indirect effect of changes in water availability might affect aridland breeding birds in distinct habitat types. Linking breeding bird density to annual water deficit may be valuable for predicting changes in species persistence and distribution in response to climate change.

Temporal Patterns in Offshore Bird Abundance During the Breeding Season at the Dutch North Sea Coast

The expanding development of offshore wind farms brings a growing concern about the human impact on seabirds. To assess this impact a better understanding of offshore bird abundance is needed. The aim of this study was to investigate offshore bird abundance in the breeding season and model the effect of predictable environmental factors. We used a bird radar, situated at the edge of a wind farm (52.427827°N, 4.185345°E), to record hourly aerial bird abundance at the North Sea near the Dutch coast between May 1st and July 15th in 2019 and 2020.The effect of sun position, week in the breeding season, and astronomic tide on hourly bird abundance was evaluated using generalized additive modelling. Sun position and week in the breeding season had a modest and statistically significant (p<0.001) effect on bird abundance, while astronomic tide did not. Predicted abundance was higher during the day than during the night, with highest abundance in the morning. Abundance increased throughout the breeding season until the end of June, but decreased again in July. In total the model explained 18.5% of deviance in bird abundance, indicating offshore bird abundance is partially dependent on predictable external factors. The high variability in bird abundance at scales ranging from hours up to weeks emphasizes the need for long term and continuous data which radar technology can provide. The findings of this study can help improve offshore bird density estimations and provide context on the temporal fluctuations in bird abundance for marine policy making.

Prioritizing landscapes for grassland bird conservation with hierarchical community models

Context Given widespread population declines of birds breeding in North American grasslands, management that sustains wildlife while supporting rancher livelihoods is needed. However, management effects vary across landscapes, and identifying areas with the greatest potential bird response to conservation is a pressing research need. Objectives We developed a hierarchical modeling approach to study grassland bird response to habitat factors at multiple scales and levels. We then identified areas to prioritize for implementing a bird-friendly ranching program. Methods Using bird survey data from grassland passerine species and 175 sites (2009–2018) across northeast Wyoming, USA, we fit hierarchical community distance sampling models and evaluated drivers of site-level density and regional-level distribution. We then created spatially-explicit predictions of bird density and distribution for the study area and predicted outcomes from pasture-scale management scenarios. Results Cumulative overlap of species distributions revealed areas with greater potential community response to management. Within each species’ potential regional-level distribution, the grassland bird community generally responded negatively to cropland cover and vegetation productivity at local scales (up to 10 km of survey sites). Multiple species declined with increasing bare ground and litter cover, shrub cover, and grass height measured within sites. Conclusions We demonstrated a novel approach to multi-scale and multi-level prioritization for grassland bird conservation based on hierarchical community models and extensive population monitoring. Pasture-scale management scenarios also suggested the examined community may benefit from less bare ground cover and shorter grass height. Our approach could be extended to other bird guilds in this region and beyond.

Changes in Rice and Livestock Production and the Potential Emergence of Japanese Encephalitis in Africa

The known distribution of Japanese encephalitis (JE) is limited to Asia and Australasia. However, autochthonous transmission of Japanese encephalitis virus was reported in Africa for the first time in 2016. Reasons for the current geographic restriction of JE and the circumstances that may permit emergence in non-endemic areas are not well known. Here, I assess potential changes in vector breeding habitat and livestock production in Africa that are conducive to JEV transmission, using open-source data available from the Food and Agriculture Organization between 1961 and 2019. For 16 of 57 countries in Africa, there was evidence of existing, or an increase in, conditions potentially suitable for JE emergence. This comprised the area used for rice production and the predicted proportion of blood meals on pigs. Angola, where autochthonous transmission was reported, was one of these 16 countries. Studies to better quantify the role of alternative hosts, including domestic birds in transmission in endemic regions, would help to determine the potential for emergence elsewhere. In Africa, surveillance programs for arboviruses should not rule out the possibility of Japanese encephalitis virus (JEV) circulation in areas with high pig or bird density coincident with Culicine breeding habitats.