Search Results (12)

In this study, we used a causal analysis approach to assess the impact of deforestation on bird abundance in Mexico. Based on records in the eBird and GBIF databases, ten species were selected in 807 grids on the mainland. Relative abundances by species were estimated using a fixed-effects panel data regression for the period 2016–2018. Deforestation was used as a quasi-natural experiment, classifying treatment and control groups according to the distribution of relative abundances by quintiles of gross deforestation rates during the period 2001–2018. The treatment group was defined as relative abundances of birds present in grids in the last deforestation quintile (≥4% to 12%); the control group included relative abundances of birds present in grids of the first four quintiles (<4%). Extended regression models were used to estimate the impacts of high deforestation rates on the relative abundance of birds, finding mixed causal effects: five showed statistically significant declines in abundance (Ruddy Ground Dove (Columbina talpacoti), Black Vulture (Coragyps atratus), Melodious Blackbird (Dives dives), Bewick’s Wren (Thryomanes bewickii), and Rufous-backed Thrush (Turdus rufopalliatus)), while one specie Yellow-winged Cacique (Cassiculus melanicterus) exhibited significant increases. These findings highlight the importance of causal effect studies in contributing to empirical evidence-based conservation decision-making. Full article

This study aimed to assess the beaks of Neotropical birds using two scanning techniques—CT and a dental intraoral scanner—along with macroscopic analysis. Six specimens per family were selected, including parakeets, red-legged seriemas, and black vultures. The upper beaks were measured in the CT sagittal view for length along the longitudinal axis and height on the transverse axis. The same measurements were performed on the 3D images. Additionally, beak width in the middle of the naris area, as well as the length and height of the nares, were measured on the 3D images. The closed polygon tool outlined the beak, generating volume in cm². The 3D images obtained with the dental scanner were measured, similarly to those from 3D-CT scans for the beaks’ length, height, and width. Macroscopic measurements of the beaks were also conducted. Some differences in beak measurements between imaging methods were verified. In conclusion, both techniques are effective, but CT provides more detailed information. The combination of both methods would be ideal for developing and applying beak prostheses. Full article

A first attempt has been made to present a general composition of birds found in Chalcolithic settlements in the plains and lowlands of Bulgaria. Based on data from 21 settlements, 78 bird taxa (including 3 domestic forms) have been identified. Of these, 56 species have been identified to the species level. They constitute 13.4% (almost 1/7) of the 417 recorded bird species in the country. Aquatic birds (waterfowl, grebes, loons, herons, etc.) predominate (29 species). There are 12 species inhabiting woodland landscapes. Ten species are field/openland birds, and five are petrophilous species that inhabit rocky and stony habitats. Five species have disappeared as nesting in the country—bearded vulture, great bustard, common crane, colchic pheasant (native colchicus ssp.), and black grouse. These five species constitute 8.9% of the established composition of birds in the Chalcolithic settlements in the country. One extinct subspecies of the Eurasian coot has been described from one of these settlements. Full article

Human activities significantly influence the changes in wildlife habitats and biodiversity, highlighting the necessity to enhance public knowledge, perceptions, and practices (KPP) to mitigate their consequences. Previous research suggests that many people in Bangladesh do not consider wildlife and biodiversity conservation a crucial issue. However, enhancing their KPP could be essential in developing effective and sustainable conservation efforts in Bangladesh. So, the current study aimed to evaluate the public’s KPP of wildlife conservation and biodiversity management in Bangladesh. A total of 3060 individuals’ data were collected from various sociodemographic backgrounds using a structured questionnaire followed by statistical analyses including Pearson’s chi-square, Spearman’s correlation, and logistic regression analysis, which were performed to assess the correlations and trends among variables using STATA and SPSS. The results revealed a significant heterogeneity in KPP across different sociodemographic groups. Importantly, the younger respondents (ages 21–30) indicated a high level of KPP, and respondents without formal education and belonging to older ages demonstrated markedly low levels of KPP. In the country’s divisional levels, respondents from Khulna and Rangpur revealed the highest and lowest KPP levels, respectively. Our study also revealed that students represented the major occupational demographic and displayed moderate levels of KPP. Notably, respondents highlighted the decline or absence of several wild animal species, including black bears, deer, vultures, wild cats, hanuman monkeys, and rhesus monkeys, from their local areas over the past decades. Public opinion on wildlife protection revealed 78.6% and 73.4% disapproving of hunting rejection and wildlife trading, respectively. Nonetheless, a lack of knowledge remained, as 16.89% of respondents were unaware of measures to alleviate human-wildlife conflict. The correlation analysis indicated a favorable association among KPP components, especially between knowledge and perception (correlation coefficient = 0.438), underscoring the essential influence of awareness on conservation actions. This study offers critical insights for developing interventions to enhance KPP among local communities and stakeholders, hence promoting sustainable wildlife conservation and biodiversity management in Bangladesh. Taken together, the findings provide baseline data for safeguarding biodiversity and fostering long-term wildlife sustainability in Bangladesh. Full article

Despite the tremendous advances in aircraft design that led to successful powered flights of aircraft as heavy as the Antonov An-225 Mriya, which weighs 640 tons, or as fast as the NASA-X-43A, which reached a record of Mach 9.6, many characteristics of bird flight have yet to be utilized in aircraft designs. These characteristics enable various species of birds to fly efficiently in gusty environments and rapidly change their momentum in flight without having modern thrust vector control (TVC) systems. Vultures and seagulls, as examples of expert gliding birds, can fly for hours, covering more than 100 miles, without a single flap of their wings. Inspired by the Great Black-Backed Gull (GBBG), this paper presents “CGull”, a non-flapping unmanned aerial vehicle (UAV) with wing and tail morphing capabilities. A coupled two degree-of-freedom (DOF) morphing mechanism is used in CGull’s wings to sweep the middle wing forward and the outer feathered wing backward, replicating the GBBG’s wing deformation. A modular two DOF mechanism enables CGull to pitch and tilt its tail. A computational model was first developed in MachUpX to study the effects of wing and tail morphing on the generated forces and moments. Following the biological construction of birds’ feathers and bones, CGull’s structure is mainly constructed from carbon-fiber composite shells. The successful flight test of the proof-of-concept physical model proved the effectiveness of the proposed morphing mechanisms in controlling the UAV’s path. Full article

The New World Vultures (Cathartidae) include seven species of obligate scavengers that, despite their ecological relevance, present critical information gaps around their evolutionary history and conservation. Insights into their phylogenetic relationships in recent years has enabled the addressing of such information gaps through approaches based on phylogeny. We reconstructed the ancestral area in America of the current species using two regionalization schemes and methods: Biogeography with Bayesian Evolutionary Analysis (BioGeoBears) and Bayesian Binary Model–Monte Carlo Markov Chains (BBM–MCMC). Then, we identified the priority species and areas for conservation by means of the Evolutionary Distinctiveness index (ED), as a proxy of the uniqueness of species according to phylogeny, and the Global Endangerment index (GE), mapping phylogenetic diversity. We found that the ancestral area of New World Vultures in America corresponds to South America, with dispersal processes that led to a recolonization of North America by Coragyps atratus, Gymnogyps californianus and Cathartes aura. We identified the Black Vulture, G. californianus and Vultur gryphus as priority species based on ED and “Evolutionary Distinct Globally Endangered” (EDGE) indexes, and the lowlands of Amazon River basin and the Orinoco basin and some tributaries areas of the Guiana Shield were identified as the priority areas when mapping the phylogenetic diversity. This study highlights the importance of filling knowledge gaps of species of conservation concern through the integration of evolutionary and ecological information and tools and, thus, developing adequate strategies to enhance the preservation of these species in the face of the current loss of biodiversity. Full article

Extreme weather events such as hurricanes and tornadoes have been found to change the spatial and temporal abundance of raptors by decreasing survival and forcing the emigration of individuals, or by increasing habitat heterogeneity and facilitating recolonization of disturbed areas. Nonetheless, little is known about how extreme weather events could affect raptors’ movements and their space use in areas disturbed by large-scale weather events. We studied how extreme weather affected the movements of black and turkey vultures (Coragyps atratus and Cathartes aura, respectively) in Mississippi, USA, facing Hurricane Zeta in November 2020, winter storm Viola in February 2021, and tornados MS-43 and MS-44 in May 2021. We GPS-tracked 28 vultures in the paths of these events. We compared movement rates, net-squared displacements, and use of forest cover, before, during, and after the events. Since storm avoidance behavior has been observed in other birds, we expected that vultures would shift their movements out of the path of these events before storms hit. Further, we forecasted that vultures would make greater use of forested areas as protection against harsh conditions such as strong winds and heavy rain. Vultures responded differently to each weather event; they shifted their movements out of the predicted path of the hurricane and tornadoes but not the snowstorm. These findings reveal that both species use avoidance behavior and adjust their navigation and hazard detection accordingly. Avoidance behavior was more pronounced in turkey vultures than in black vultures. In general, vultures did not make greater use of forest areas as we expected, but turkey vultures did select forest areas during the snowstorm. We propose that olfaction and audition may be key in vultures’ response to extreme weather events. Full article

In Corozalito beach, Costa Rica, Olive Ridley turtles (Lepidochelys olivacea) nest both solitarily and in arribadas. The predation of solitary nests was monitored from 2008 to 2021, recording date, time, sector of the beach, zone, status of nest (predated or partially predated) and predator when possible. We recorded 4450 predated nests in total (N = 30,148 nesting events); predation rates showed a fluctuating trend, with recent percentages reaching up to 30%, with four distinctive dips in 2010, 2014, 2016 and 2017. The spatial distribution of predated nests along the beach showed significant differences among the sectors regardless of the seasons (Friedman test, chi-squared = 14.778, df = 2, p-value = 0.000), with most predated nests (47.62%) occurring in the northern sectors of the beach. Predators were identified by their tracks and/or direct observations (N = 896, 24.08%). The most conspicuous predators identified were raccoons (55.69%) and black vultures (22.77%). As seen in Corozalito, predation rates have increased in recent years despite established conservation efforts. A comprehensive assessment of all threats towards the overall hatching success for clutches is needed, considering predation during mass nesting events, poaching and beach erosion, among other factors, to fully understand the nesting dynamics occurring in this beach. Full article

Traditional gas pipeline leak detection methods require task offload decisions in the cloud, which has low real time performance. The emergence of edge computing provides a solution by enabling offload decisions directly at the edge server, improving real-time performance; however, energy is the new bottleneck. Therefore, focusing on the gas transmission pipeline leakage detection scenario in real time, a novel detection algorithm that combines the benefits of both the heuristic algorithm and the advantage actor critic (AAC) algorithm is proposed in this paper. It aims at optimization with the goal of real-time guarantee of pipeline mapping analysis tasks and maximizing the survival time of portable gas leak detectors. Since the computing power of portable detection devices is limited, as they are powered by batteries, the main problem to be solved in this study is how to take into account the node energy overhead while guaranteeing the system performance requirements. By introducing the idea of edge computing and taking the mapping relationship between resource occupation and energy consumption as the starting point, the optimization model is established, with the goal to optimize the total system cost (TSC). This is composed of the node’s transmission energy consumption, local computing energy consumption, and residual electricity weight. In order to minimize TSC, the algorithm uses the AAC network to make task scheduling decisions and judge whether tasks need to be offloaded, and uses heuristic strategies and the Cauchy–Buniakowsky–Schwarz inequality to determine the allocation of communication resources. The experiments show that the proposed algorithm in this paper can meet the real-time requirements of the detector, and achieve lower energy consumption. The proposed algorithm saves approximately 56% of the system energy compared to the Deep Q Network (DQN) algorithm. Compared with the artificial gorilla troops Optimizer (GTO), the black widow optimization algorithm (BWOA), the exploration-enhanced grey wolf optimizer (EEGWO), the African vultures optimization algorithm (AVOA), and the driving training-based optimization (DTBO), it saves 21%, 38%, 30%, 31%, and 44% of energy consumption, respectively. Compared to the fully local computing and fully offloading algorithms, it saves 50% and 30%, respectively. Meanwhile, the task completion rate of this algorithm reaches 96.3%, which is the best real-time performance among these algorithms. Full article

Toxoplasma gondii is a worldwide zoonotic parasite. According to the “One Health” approach, studies on toxoplasmosis are essential since it affects humans and domestic and wild animals. In the present study, antibodies to T. gondii were determined in serum samples from 263 wild birds located in five wildlife rehabilitation centres in mainland Portugal by using the modified agglutination test (MAT) with a cut-off titre of 20. An overall seroprevalence of 36.5% (95% confidence interval [CI]: 30.7–42.6) was observed. For the first time, antibodies to T. gondii were detected in some avian species, including pallid swift (Apus pallidus) (33.3%), black-backed gull (Larus fuscus) (39.3%), European turtle-dove (Streptopelia turtur) (100%), bee-eater (Merops apiaster) (50.0%), carrion crow (Corvus corone) (33.3%), and Egyptian vulture (Neophron percnopterus) (100%), which expands the list of intermediate hosts of T. gondii. A lower seroprevalence was found in juvenile birds (31.9%) compared to adults (48.7%) (p = 0.016). The central region of Portugal was considered a risk factor for T. gondii infection in wild birds (odds ratio: 3.61; 95% CI: 1.09–11.91). This pioneer study calls attention to the need for further studies, to provide a clearer understanding of T. gondii epidemiology in Portugal, because it reflects wide dispersion of T. gondii oocysts in the environment. Full article

The aim of the study was to investigate the intramuscular pharmacokinetics of enrofloxacin in black vultures (Coragyps atratus). The pharmacokinetics of a single intramuscular dose (10 mg/kg) of enrofloxacin was studied in six vultures. Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined by high-performance liquid chromatography (HPLCuv). Pharmacokinetic parameters were estimated using non-compartmental and compartmental analysis. After intramuscular administration, enrofloxacin showed a rapid and complete absorption, reaching a Cmax value of 3.26 ± 0.23 μg/mL at 1.75 ± 0.53 h. A long terminal half-life of 19.58 h has been observed. Using previously published MIC values to perform a PK/PD analysis, cumulative fraction responses obtained after Monte Carlo simulation for AUC/MIC > 30, 50 and 125 were 72.93%, 72.34% and 30.86% for E. coli and 89.29%, 88.89% and 58.57% for Mycoplasma synoviae, respectively. Cumulative fraction responses obtained for Cmax/MIC index were 33.93% and 40.18% for E. coli and M. synoviae, respectively. The intramuscular administration of 10 mg/kg could be appropriate to treat infectious diseases caused by gram-positive bacteria with MIC value lower than 1 µg/mL; however, although enrofloxacin showed a slow elimination in black vultures, plasma concentrations were insufficient to reach the gram-negative stablished breakpoints. Full article

The Eurasian Black Vulture is a globally threatened raptor that in Southeast Europe only occurs in an isolated population in Greece. We examined the population viability for the species under demographic fluctuations and conservation scenarios. The current population showed no possibility of extinction for the next 100 years. However, simulated scenarios showed that the most important factor affecting the viability of the species was medium and high poisoning, leading to 94.8% and 100% probability of extinction, respectively. Furthermore, high reduction of supplementary feeding highlighted an 18.6% extinction possibility. Also, a high increase of wind farms in the area may result in 17.4% extinction possibility. Additionally, the non-establishment of the feeding station in 1987 in the study area would have resulted in an extinction risk of 7%. The species can be translocated to the Olympus National Park by releasing 80 juveniles over 10 years. The implementation of the conservation scenarios concerning the establishment of a supplementary feeding site network, and the reintroduction of the Eurasian Black Vulture in its historic range, along with the elimination of threats posed by poisoning, low food availability, and wind farms would increase the probability of the species persistence and allow the population to become a source for dispersal across Southeast Europe. Full article