Testing a key assumption of using drones as frightening devices: Do birds perceive drones as risky?

Wildlife managers have recently suggested the use of unmanned aircraft systems or drones as nonlethal hazing tools to deter birds from areas of human-wildlife conflict. However, it remains unclear if birds perceive common drone platforms as threatening. Based on field studies assessing behavioral and physiological responses, it is generally assumed that birds perceive less risk from drones than from predators. However, studies controlling for multiple confounding effects have not been conducted. Our goal was to establish the degree to which the perception of risk by birds would vary between common drone platforms relative to a predator model when flown at different approach types. We evaluated the behavioral responses of individual Red-winged Blackbirds (Agelaius phoeniceus) to 3 drone platforms: a predator model, a fixed-wing resembling an airplane, and a multirotor, approaching either head-on or overhead. Blackbirds became alert earlier (by 13.7 s), alarm-called more frequently (by a factor of 12), returned to forage later (by a factor of 4.7), and increased vigilance (by a factor of 1.3) in response to the predator model compared with the multirotor. Blackbirds also perceived the fixed-wing as riskier than the multirotor, but less risky than the predator model. Overhead approaches mostly failed to elicit flight in blackbirds across all platform types, and no blackbirds took flight in response to the multirotor at either overhead or head-on approaches. Our findings demonstrate that birds perceived drones with predatory characteristics as riskier than common drone models (i.e. fixed-wing and multirotor platforms). We recommend that drones be modified with additional stimuli to increase perceived risk when used as frightening devices, but avoided if used for wildlife monitoring. RESUMEN Los gestores de vida silvestre han sugerido recientemente el uso de sistemas aéreos no tripulados o drones como herramientas no letales de atosigamiento para disuadir a las aves de áreas de conflicto entre humanos y vida silvestre. Sin embargo, aún no está claro si las aves perciben a los drones comunes como una amenaza. Tomando como base los estudios de campo que evalúan las respuestas comportamentales y fisiológicas, por lo general se asume que las aves perciben un riesgo menor de parte de los drones que de los depredadores. Sin embargo, no se han realizado estudios que controlen los múltiples efectos contrapuestos. Nuestro objetivo fue establecer la variación en el grado de percepción de riesgo de las aves frente a drones comunes y a un modelo de depredador, considerando diferentes tipos de acercamiento de vuelo. Evaluamos las respuestas de comportamiento de individuos de Agelaius phoeniceus frente a tres tipos de drones: un modelo depredador, un modelo de ala rígida parecido a un avión y un modelo multi-rotor, todos acercándose ya sea de frente o por encima. Los individuos de A. phoeniceus se alertaron antes (por 13.7 s), realizaron llamados de alarma más frecuentemente (por un factor de 12), regresaron a forrajear más tarde (por un factor de 4.7) y aumentaron la vigilancia (por un factor de 1.3) en respuesta al modelo de depredador comparado con el multi-rotor. A. phoeniceus también percibió el modelo de ala fija como más riesgoso que el multi-rotor, pero menos riesgoso que el depredador. La mayoría de los acercamientos por encima, considerando todos los tipos de drones, no provocaron el vuelo de A. phoeniceus, y ningún individuo de A. phoeniceus voló en respuesta al multi-rotor, ya sea en los acercamientos de frente o por encima. Nuestros resultados demuestran que las aves perciben a los drones con características de depredador como más riesgosos que los modelos de drone comunes (i.e. de ala fija o multi-rotor). Recomendamos que los drones sean modificados con estímulos adicionales para aumentar el riesgo percibido cuando se los usa como dispositivos de intimidación, pero evitar modificarlos si se los usa para monitoreo de fauna silvestre

Evaluating Blackbird Behavioral Response Toward Unmanned Aircraft Systems (UASs) : Exploiting Antipredator Behavior to Enhance Avoidance

Animals respond to nonlethal forms of human disturbance using behavior strategies adapted to detect, avoid, and evade natural predators. This phenomenon suggests antipredator behavior can be exploited to optimize efficacy of wildlife management tools such as visual deterrents. According to models of antipredator theory, wildlife managers could encourage animals to abandon a resource patch in zones of human-wildlife conflict by enhancing perceived predation risk associated with disturbance stimuli. One human-wildlife conflict of interest is the economic loss and human safety hazards caused by birds. For example, blackbirds (Icteridae) pose a significant risk to the commercial aviation industry through bird strikes and to agriculture through crop predation. Several nonlethal frightening devices have been used in an attempt to reduce negative impacts of large blackbird flocks with varying effectiveness, thus the need for new or optimized tools remains. A promising tool in the field of wildlife damage management is the unmanned aircraft system (UAS), which provides a dynamic object able to overcome mobility limitations faced by other nonlethal deterrents. We intend to evaluate antipredator response of blackbirds toward two UAS platforms. We will compare a multirotor quadcopter UAS with a radiocontrolled (RC) predator model. Current UASs show promise as precision agriculture tools and are easier to fly, but may not elicit an antipredator response due to lack of similarity with natural predators. We hypothesize that blackbirds will assess platforms with different intensities of perceived predation risk, and as a result, initiate flight at farther distances from the platform perceived as more threatening. Our objectives are to 1) compare the response of captive red-winged blackbirds (Agelaius phoeniceus) to a multirotor quadcopter UAS and a RC predator model approaching at direct and overhead trajectories; and 2) approach wild flocks of red-winged blackbirds to gauge response of free-ranging birds toward both UAS platforms. The results of this study will help develop UASs as potential hazing tools to disperse and deter birds from areas of human-wildlife conflict (i.e., airports, agricultural areas, and municipalities)

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Co-infections, secondary infections, and antimicrobial use in patients hospitalised with COVID-19 during the first pandemic wave from the ISARIC WHO CCP-UK study: a multicentre, prospective cohort study

Background: Microbiological characterisation of co-infections and secondary infections in patients with COVID-19 is lacking, and antimicrobial use is high. We aimed to describe microbiologically confirmed co-infections and secondary infections, and antimicrobial use, in patients admitted to hospital with COVID-19. Methods: The International Severe Acute Respiratory and Emerging Infections Consortium (ISARIC) WHO Clinical Characterisation Protocol UK (CCP-UK) study is an ongoing, prospective cohort study recruiting inpatients from 260 hospitals in England, Scotland, and Wales, conducted by the ISARIC Coronavirus Clinical Characterisation Consortium. Patients with a confirmed or clinician-defined high likelihood of SARS-CoV-2 infection were eligible for inclusion in the ISARIC WHO CCP-UK study. For this specific study, we excluded patients with a recorded negative SARS-CoV-2 test result and those without a recorded outcome at 28 days after admission. Demographic, clinical, laboratory, therapeutic, and outcome data were collected using a prespecified case report form. Organisms considered clinically insignificant were excluded. Findings: We analysed data from 48 902 patients admitted to hospital between Feb 6 and June 8, 2020. The median patient age was 74 years (IQR 59–84) and 20 786 (42·6%) of 48 765 patients were female. Microbiological investigations were recorded for 8649 (17·7%) of 48 902 patients, with clinically significant COVID-19-related respiratory or bloodstream culture results recorded for 1107 patients. 762 (70·6%) of 1080 infections were secondary, occurring more than 2 days after hospital admission. Staphylococcus aureus and Haemophilus influenzae were the most common pathogens causing respiratory co-infections (diagnosed ≤2 days after admission), with Enterobacteriaceae and S aureus most common in secondary respiratory infections. Bloodstream infections were most frequently caused by Escherichia coli and S aureus. Among patients with available data, 13 390 (37·0%) of 36 145 had received antimicrobials in the community for this illness episode before hospital admission and 39 258 (85·2%) of 46 061 patients with inpatient antimicrobial data received one or more antimicrobials at some point during their admission (highest for patients in critical care). We identified frequent use of broad-spectrum agents and use of carbapenems rather than carbapenem-sparing alternatives. Interpretation: In patients admitted to hospital with COVID-19, microbiologically confirmed bacterial infections are rare, and more likely to be secondary infections. Gram-negative organisms and S aureus are the predominant pathogens. The frequency and nature of antimicrobial use are concerning, but tractable targets for stewardship interventions exist. Funding: National Institute for Health Research (NIHR), UK Medical Research Council, Wellcome Trust, UK Department for International Development, Bill & Melinda Gates Foundation, EU Platform for European Preparedness Against (Re-)emerging Epidemics, NIHR Health Protection Research Unit (HPRU) in Emerging and Zoonotic Infections at University of Liverpool, and NIHR HPRU in Respiratory Infections at Imperial College London

Co-infections, secondary infections, and antimicrobial use in patients hospitalised with COVID-19 during the first pandemic wave from the ISARIC WHO CCP-UK study: a multicentre, prospective cohort study

Background: Microbiological characterisation of co-infections and secondary infections in patients with COVID-19 is lacking, and antimicrobial use is high. We aimed to describe microbiologically confirmed co-infections and secondary infections, and antimicrobial use, in patients admitted to hospital with COVID-19. Methods: The International Severe Acute Respiratory and Emerging Infections Consortium (ISARIC) WHO Clinical Characterisation Protocol UK (CCP-UK) study is an ongoing, prospective cohort study recruiting inpatients from 260 hospitals in England, Scotland, and Wales, conducted by the ISARIC Coronavirus Clinical Characterisation Consortium. Patients with a confirmed or clinician-defined high likelihood of SARS-CoV-2 infection were eligible for inclusion in the ISARIC WHO CCP-UK study. For this specific study, we excluded patients with a recorded negative SARS-CoV-2 test result and those without a recorded outcome at 28 days after admission. Demographic, clinical, laboratory, therapeutic, and outcome data were collected using a prespecified case report form. Organisms considered clinically insignificant were excluded. Findings: We analysed data from 48 902 patients admitted to hospital between Feb 6 and June 8, 2020. The median patient age was 74 years (IQR 59–84) and 20 786 (42·6%) of 48 765 patients were female. Microbiological investigations were recorded for 8649 (17·7%) of 48 902 patients, with clinically significant COVID-19-related respiratory or bloodstream culture results recorded for 1107 patients. 762 (70·6%) of 1080 infections were secondary, occurring more than 2 days after hospital admission. Staphylococcus aureus and Haemophilus influenzae were the most common pathogens causing respiratory co-infections (diagnosed ≤2 days after admission), with Enterobacteriaceae and S aureus most common in secondary respiratory infections. Bloodstream infections were most frequently caused by Escherichia coli and S aureus. Among patients with available data, 13 390 (37·0%) of 36 145 had received antimicrobials in the community for this illness episode before hospital admission and 39 258 (85·2%) of 46 061 patients with inpatient antimicrobial data received one or more antimicrobials at some point during their admission (highest for patients in critical care). We identified frequent use of broad-spectrum agents and use of carbapenems rather than carbapenem-sparing alternatives. Interpretation: In patients admitted to hospital with COVID-19, microbiologically confirmed bacterial infections are rare, and more likely to be secondary infections. Gram-negative organisms and S aureus are the predominant pathogens. The frequency and nature of antimicrobial use are concerning, but tractable targets for stewardship interventions exist. Funding: National Institute for Health Research (NIHR), UK Medical Research Council, Wellcome Trust, UK Department for International Development, Bill & Melinda Gates Foundation, EU Platform for European Preparedness Against (Re-)emerging Epidemics, NIHR Health Protection Research Unit (HPRU) in Emerging and Zoonotic Infections at University of Liverpool, and NIHR HPRU in Respiratory Infections at Imperial College London

Characterisation of in-hospital complications associated with COVID-19 using the ISARIC WHO Clinical Characterisation Protocol UK: a prospective, multicentre cohort study

Background: COVID-19 is a multisystem disease and patients who survive might have in-hospital complications. These complications are likely to have important short-term and long-term consequences for patients, health-care utilisation, health-care system preparedness, and society amidst the ongoing COVID-19 pandemic. Our aim was to characterise the extent and effect of COVID-19 complications, particularly in those who survive, using the International Severe Acute Respiratory and Emerging Infections Consortium WHO Clinical Characterisation Protocol UK. Methods: We did a prospective, multicentre cohort study in 302 UK health-care facilities. Adult patients aged 19 years or older, with confirmed or highly suspected SARS-CoV-2 infection leading to COVID-19 were included in the study. The primary outcome of this study was the incidence of in-hospital complications, defined as organ-specific diagnoses occurring alone or in addition to any hallmarks of COVID-19 illness. We used multilevel logistic regression and survival models to explore associations between these outcomes and in-hospital complications, age, and pre-existing comorbidities. Findings: Between Jan 17 and Aug 4, 2020, 80 388 patients were included in the study. Of the patients admitted to hospital for management of COVID-19, 49·7% (36 367 of 73 197) had at least one complication. The mean age of our cohort was 71·1 years (SD 18·7), with 56·0% (41 025 of 73 197) being male and 81·0% (59 289 of 73 197) having at least one comorbidity. Males and those aged older than 60 years were most likely to have a complication (aged ≥60 years: 54·5% [16 579 of 30 416] in males and 48·2% [11 707 of 24 288] in females; aged <60 years: 48·8% [5179 of 10 609] in males and 36·6% [2814 of 7689] in females). Renal (24·3%, 17 752 of 73 197), complex respiratory (18·4%, 13 486 of 73 197), and systemic (16·3%, 11 895 of 73 197) complications were the most frequent. Cardiovascular (12·3%, 8973 of 73 197), neurological (4·3%, 3115 of 73 197), and gastrointestinal or liver (0·8%, 7901 of 73 197) complications were also reported. Interpretation: Complications and worse functional outcomes in patients admitted to hospital with COVID-19 are high, even in young, previously healthy individuals. Acute complications are associated with reduced ability to self-care at discharge, with neurological complications being associated with the worst functional outcomes. COVID-19 complications are likely to cause a substantial strain on health and social care in the coming years. These data will help in the design and provision of services aimed at the post-hospitalisation care of patients with COVID-19. Funding: National Institute for Health Research and the UK Medical Research Council

Dispersal of blackbird flocks from sunflower fields: efficacy influenced by flock and field size but not drone platform

Crop depredation by blackbirds (Icteridae) results in substantial economic losses to the United States sunflower industry, and a solution to effectively reduce damage remains elusive. We evaluated the utility of uncrewed aircraft systems (UAS), or drones, as hazing tools to deter foraging blackbirds from commercial sunflower (Helianthus annuus) fields in North Dakota, USA, between September and October 2017. We compared the efficacy of 3 drones: a fixed‐wing predator model mimicking the form of an aerial raptor, a fixed‐wing airplane of similar size, and a multirotor drone. Multirotor drones are relatively easy to fly and are a multifunctional tool for agricultural use; however, they may not be an effective avian deterrent due to a lack of similarity in appearance with natural predators. Free‐ranging blackbird flocks (n = 58) reacted to every drone approach by initiating flight and took flight 1.6 times sooner for the fixed‐wing predator model (flight initiation distance [FID] = 90m) and 1.8 times sooner for the fixed‐wing airplane (FID= 98m) compared to the multirotor drone (FID = 55 m). However, the probability of a blackbird flock (n = 53) abandoning a field was greater with smaller field and flock sizes, rather than the specific drone deployed. In an applied setting, the performance of drones as avian hazing devices will likely depend on a combination of factors including platform selection, drone trajectory, duration of use, season, landscape context, and natural history of the pest species

Dispersal of blackbird flocks from sunflower fields: efficacy influenced by flock and field size but not drone platform

Abstract Crop depredation by blackbirds (Icteridae) results in substantial economic losses to the United States sunflower industry, and a solution to effectively reduce damage remains elusive. We evaluated the utility of uncrewed aircraft systems (UAS), or drones, as hazing tools to deter foraging blackbirds from commercial sunflower (Helianthus annuus) fields in North Dakota, USA, between September and October 2017. We compared the efficacy of 3 drones: a fixed‐wing predator model mimicking the form of an aerial raptor, a fixed‐wing airplane of similar size, and a multirotor drone. Multirotor drones are relatively easy to fly and are a multifunctional tool for agricultural use; however, they may not be an effective avian deterrent due to a lack of similarity in appearance with natural predators. Free‐ranging blackbird flocks (n = 58) reacted to every drone approach by initiating flight and took flight 1.6 times sooner for the fixed‐wing predator model (flight initiation distance [FID] = 90 m) and 1.8 times sooner for the fixed‐wing airplane (FID = 98 m) compared to the multirotor drone (FID = 55 m). However, the probability of a blackbird flock (n = 53) abandoning a field was greater with smaller field and flock sizes, rather than the specific drone deployed. In an applied setting, the performance of drones as avian hazing devices will likely depend on a combination of factors including platform selection, drone trajectory, duration of use, season, landscape context, and natural history of the pest species