Dead Birds Research Articles

Investigation of risk factors for introduction of highly pathogenic avian influenza H5N1 infection among commercial turkey operations in the United States, 2022: a case-control study.

The 2022-2023 highly pathogenic avian influenza (HPAI) H5N1 outbreak in the United States (U.S.) is the largest and most costly animal health event in U.S. history. Approximately 70% of commercial farms affected during this outbreak have been turkey farms. We conducted a case-control study to identify potential risk factors for introduction of HPAI virus onto commercial meat turkey operations. Data were collected from 66 case farms and 59 control farms in 12 states. Univariate and multivariable analyses were conducted to compare management and biosecurity factors on case and control farms. Factors associated with increased risk of infection included being in an existing control zone, having both brooders and growers, having toms, seeing wild waterfowl or shorebirds in the closest field, and using rendering for dead bird disposal. Protective factors included having a restroom facility, including portable, available to crews that visit the farm and workers having access and using a shower at least some of the time when entering a specified barn. Study results provide a better understanding of risk factors for HPAI infection and can be used to inform prevention and control measures for HPAI on U.S. turkey farms.

Invitro Anticoccidial Effect of Fractions of Chromolaena Odorata Extract on Sporulating Eimeria Tenalla Oocysts

Coccidiosis is an important cause of digestive system disorders in birds, especially the poultry. The aim of this study was to evaluate the in-vitro anticoccidial effects of the different fractions of Chromolaena odorata extracts on sporulated Eimeria tenella oocysts. Sporulation inhibition bioassay was used to evaluate the activity of crude methanol fraction of Chromolaena odorata extracts; n-hexane, ethyl acetate, and methanol fractions of Chromolaena odorata on sporulation of Eimeria tenella, which was used to cause coccidiosis. in the birds following oral inoculation of experimental broiler birds with oocysts. Post-mortem examination of dead birds showed lesions consistent with Eimeria tenella. The fractions of the Chromolaena odorata were examined for the oocysticidal activities. Amprolium an anticoccidial drug was used as control. The fractions were used in 4 doses: 0 mg/ml; 0.1 mg/ml; 0.2 mg/ml and 0.4 mg/ml. The control drug was used in corresponding doses. The highest oocysticidal activity of tested plant extracts and fractions was recorded. The n-hexane fraction of Chromolaena odorata gave the highest oocysticidal activity. This oocysticidal activity was noticed at lower concentrations but activity was found to be dose-dependent. The highest oocysticidal activity for the n-hexane fraction of Chromolaena odorata was at 65.67±2.08%. Amprolium showed no oocysticidal activity at all concentrations. However, other fractions of the Chromolaena odorata showed different levels of oocysticidal activities. The methanol fractions were secondary to the n-hexane while the ethyl acetate was the least. In conclusion, this study provides the basis for using Chromolaena odorata, especially the n-hexane fraction as preventive agents against coccidiosis and suggests their use as a feed additive in the control of coccidiosis.

West Nile Virus Lineage 2 in Free-Living Corvus cornix Birds in Poland.

The summer temperatures recorded in Poland in 2022 were among the highest in over 30 years and, combined with higher-than-expected rainfall, gave the impression of an almost tropical climate. Such climatic conditions were ideal for the transmission of vector-borne zoonotic diseases such as West Nile fever. In northeastern Poland, in the Mazowieckie region, the Polish event-based surveillance network reported increased fatalities of free-living hooded crows (Corvus corone cornix). West Nile virus (WNV) lineage 2 was identified for the first time as the etiological agent responsible for the death of the birds. WNV was detected in 17 out of the 99 (17.17%) free-living birds tested in this study. All the WNV-infected dead birds were collected in the same area and were diagnosed in September by the NVRI and confirmed by the EURL for equine diseases, ANSES, in October 2022. Unnaturally high temperatures recorded in Poland in 2022 likely favored the infection and spread of the virus in the avian population. A nationwide alert and awareness raising of blood transfusion centers and hospitals was carried out to prevent human infections by WNV.

Silent killers? The widespread exposure of predatory nocturnal birds to anticoagulant rodenticides

Anticoagulant rodenticides (ARs) influence predator populations and threaten the stability of ecosystems. Understanding the prevalence and impact of rodenticides in predators is crucial to inform conservation planning and policy. We collected dead birds of four nocturnal predatory species across differing landscapes: forests, agricultural, urban. Liver samples were analysed for eight ARs: three First Generation ARs (FGARs) and five SGARs (Second Generation ARs). We investigated interspecific differences in liver concentrations and whether landscape composition influenced this. FGARs were rarely detected, except pindone at low concentrations in powerful owls Ninox strenua. SGARs, however, were detected in every species and 92 % of birds analysed. Concentrations of SGARs were at levels where potential toxicological or lethal impacts would have occurred in 33 % of powerful owls, 68 % of tawny frogmouths Podargus strigoides, 42 % of southern boobooks N. bookbook and 80 % of barn owls Tyto javanica. When multiple SGARs were detected, the likelihood of potentially lethal concentrations of rodenticides increased. There was no association between landscape composition and SGAR exposure, or the presence of multiple SGARs, suggesting rodenticide poisoning is ubiquitous across all landscapes sampled. This widespread human-driven contamination in wildlife is a major threat to wildlife health. Given the high prevalence and concentrations of SGARs in these birds across all landscape types, we support the formal consideration of SGARs as a threatening process. Furthermore, given species that do not primarily eat rodents (tawny frogmouths, powerful owls) have comparable liver rodenticide concentrations to rodent predators (southern boobook, eastern barn owl), it appears there is broader contamination of the food-web than anticipated. We provide evidence that SGARs have the potential to pose a threat to the survival of avian predator populations. Given the functional importance of predators in ecosystems, combined with the animal welfare impacts of these chemicals, we propose governments should regulate the use of SGARs.

Illegal shooting is now a leading cause of death of birds along power lines in the western USA

Human actions, both legal and illegal, affect wildlife in many ways. Inaccurate diagnosis of cause of death undermines law enforcement, management, threat assessment, and mitigation. We found 410 dead birds collected along 196km of power lines in four western USA states during 2019-2022. We necropsied these carcasses to test conventional wisdom suggesting that electrocution is the leading cause of death of birds at electrical infrastructure. Of 175 birds with a known cause of death, 66% died from gunshot. Both raptors and corvids were more likely to die from gunshot than from other causes, along both transmission and distribution lines. Past mitigation to reduce avian deaths along power lines has focused almost exclusively on reducing electrocutions or collisions. Our work suggests that, although electrocution and collision remain important, addressing illegal shooting now may have greater relevance for avian conservation.

Effect of light sources with and without UVA on selected behavior and health indicators in commercial broiler breeder flocks

As new light sources are being developed for poultry houses, systematic investigations on how these influence behavior and health in commercial broiler breeders are needed. Therefore, the aim of this study was to investigate the effects of 2 light sources (Evolys with UVA (LED) and Biolux 965 (CFL)) on the behavior and health of 2 broiler breeder hybrids during the production period. Eight commercial breeder flocks (Ross 308 n=4, Hubbard JA757 n=4) with Evolys (Ross n=2, Hubbard n=2) or Biolux (Ross n=2, Hubbard n=2) were visited at 25 and 50 wk of age to record behavior and health. Behaviors included resting, locomotion, exploration, comfort, feather pecking, aggression, and mating, while health was recorded by a transect walk, scoring the number of birds observed with: feather loss (FL) on head, back/wings, breast, and tail, wounds on head, back/wings, and tail, dirty plumage, lameness, sickness, and dead birds. The most common behaviors were resting, locomotion, comfort, and exploration, and these were influenced by a 3-way interaction between light source, hybrid, and age. Light source did not affect behavior in Hubbard birds at any age. In contrast, Ross birds housed in Evolys rested less at 50 wk compared to Biolux (P=0.04) and showed more locomotion at 25 wk in Biolux compared to Evolys (P < 0.0001). Ross birds at 25 wk explored more in Biolux compared to Evolys (P=0.0007). More comfort behavior was performed in Evolys in 25-wk-old Ross (P=0.002), but not at 50 wk. These inconsistencies might be due to low sample size, which is a limitation in the study. The most common health indicators were FL on back/wings (mean 3.9%), wounds on back/wings (mean 0.22%), and FL head (mean 0.18%), with no effect of light source, hybrid, or age on FL back/wings, breast, or tail, but with increased FL on the head with increased age (P=0.0008). In conclusion, the behavior of Ross birds seemed to be affected by light source, while the Hubbard birds were not. Light source had minor effects on the selected health indicators in the 2 hybrids.

Annual trading patterns and risk factors of avian influenza A/H5 and A/H9 virus circulation in turkey birds (Meleagris gallopavo) at live bird markets in Dhaka city, Bangladesh.

The impacts of the avian influenza virus (AIV) on farmed poultry and wild birds affect human health, livelihoods, food security, and international trade. The movement patterns of turkey birds from farms to live bird markets (LBMs) and infection of AIV are poorly understood in Bangladesh. Thus, we conducted weekly longitudinal surveillance in LBMs to understand the trading patterns, temporal trends, and risk factors of AIV circulation in turkey birds. We sampled a total of 423 turkeys from two LBMs in Dhaka between May 2018 and September 2019. We tested the swab samples for the AIV matrix gene (M-gene) followed by H5, H7, and H9 subtypes using real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). We used exploratory analysis to investigate trading patterns, annual cyclic trends of AIV and its subtypes, and a generalized estimating equation (GEE) logistic model to determine the factors that influence the infection of H5 and H9 in turkeys. Furthermore, we conducted an observational study and informal interviews with traders and vendors to record turkey trading patterns, demand, and supply and turkey handling practices in LBM. We found that all trade routes of turkey birds to northern Dhaka are unidirectional and originate from the northwestern and southern regions of Bangladesh. The number of trades from the source district to Dhaka depends on the turkey density. The median distance that turkey was traded from its source district to Dhaka was 188 km (Q1 = 165, Q3 = 210, IQR = 45.5). We observed seasonal variation in the median and average distance of turkey. The qualitative findings revealed that turkey farming initially became reasonably profitable in 2018 and at the beginning of 2019. However, the fall in demand and production in the middle of 2019 may be related to unstable market pricing, high feed costs, a shortfall of adequate marketing facilities, poor consumer knowledge, and a lack of advertising. The overall prevalence of AIV, H5, and H9 subtypes in turkeys was 31% (95% CI: 26.6-35.4), 16.3% (95% CI: 12.8-19.8), and 10.2% (95% CI: 7.3-13.1) respectively. None of the samples were positive for H7. The circulation of AIV and H9 across the annual cycle showed no seasonality, whereas the circulation of H5 showed significant seasonality. The GEE revealed that detection of AIV increases in retail vendor business (OR: 1.71; 95% CI: 1.12-2.62) and the bird's health status is sick (OR: 10.77; 95% CI: 4.31-26.94) or dead (OR: 11.33; 95% CI: 4.30-29.89). We also observed that winter season (OR: 5.83; 95% CI: 2.80-12.14) than summer season, dead birds (OR: 61.71; 95% CI: 25.78-147.75) and sick birds (OR 8.33; 95% CI: 3.36-20.64) compared to healthy birds has a higher risk of H5 infection in turkeys. This study revealed that the turkeys movements vary by time and season from the farm to the LBM. This surveillance indicated year-round circulation of AIV with H5 and H9 subtypes in turkey birds in LBMs. The seasonality and health condition of birds influence H5 infection in birds. The trading pattern of turkey may play a role in the transmission of AIV viruses in the birds. The selling of sick turkeys infected with H5 and H9 highlights the possibility of virus transmission to other species of birds sold at LBMs and to people.

Poultry waste management in Nigeria: a neglected sector

The recent surge in poultry production has led to an increase in poultry waste production. Waste from poultry production often includes hatchery waste, dead birds, condemned carcasses, and manure. Manure is normally applied to agricultural soils as a source of fertilizer. Excessive production of waste from poultry farms and its improper disposal has led to air pollution and contamination of agricultural farmlands and eventually surface and water groundwater pollution and this has become a major public health concern to the society. Improper disposal of poultry waste affects poultry farmers, individuals residing close to the farms, and the environment. Published articles on poultry production and poultry waste management were retrieved from the search engine Google Scholar and were used to summarize the impact of poultry waste as a source of contamination and/or pollution to the environment with associated public health implications on animals and humans. Options for proper disposal and utilization of waste from poultry production are further discussed.

Modern rodenticides and non-target species

It is generally recognized that environmental pollution with agrotechnical substances is the major problem for the conservation of biological diversity and human food security. However, their use cannot be completely excluded. Of particular importance are modern rodenticides, i.e. superwarfarins, designed to reduce the numbers of rodents damaging agriculture, i.e. to destroy animals. However, these poisons are highly toxic and are passed up the food chains. Besides, it is impossible to draw a line between agrocenoses in their classical sense and the natural or slightly modified environment. The absence of clear physical boundaries of agrocenoses means that the processes occurring therein affect the biological diversity of adjacent territories, which are considered natural. Animals use both fields and the spaces adjacent to them. In addition, there is a water exchange between cultivated fields and the adjacent natural areas and reservoirs. Modern changes in the structure of agrocenoses increase the segment of fields which rodenticides are used on. The plowing of ravines, riversides and other inconvenient lands (due to an improved quality of equipment) facilitates the ingress of rodenticides into water bodies. Data on the consequences of the use of superwarfarins in some anthropogenic biocenoses of the southern regions of the Russian Federation are presented. Facts of mass destruction of consumers of the 1st and 2nd order (the so-called non-target species), directly related to rodenticid use, are given. Complex pathomorphological and toxicological studies of animals died in nature were carried out for the first time in the Russian Federation. The presence of bromadiolone in tissue samples was confirmed by chemical analysis, and the descriptions of autopsies of dead birds have been processed. Recommendations on the specific features for the collecting and storage of materials sent for research have been prepared.

Study on Management Status and Disease aspects of Pheasant (Phasianus colhicus) of Kathmandu Valley, Nepal

Even though Nepal has several wild pheasant species, captive pheasant rearing for human consumption is a relatively new farming practice in Nepal. Pheasant farming is a growing practice among Nepalese farmers. However, farmers lack understanding and background in pheasant management techniques and associated diseases. The purpose of this study was to investigate the distribution, location, management status, and disease characteristics of commercial pheasant farming in the Kathmandu valley. A retrospective cross-sectional study was conducted in Kathmandu valley and the Central Veterinary Laboratory (CVL), from July to September 2021. The case records from 2017 to 2021 were analyzed at CVL and the farms were mapped based on their locations. The top ten pheasant diseases reported in CVL were identified and the disease outbreak farms were followed to get additional information on management aspects. A total of 42 pheasant farms were visited to collect data, and dead birds from these pheasant farms were submitted to CVL for postmortem and bacterial culture. MS-EXCEL and the online software “Open Epi” were used for statistical analysis. Sixty percent of the surveyed farms exclusively raised pheasants, while 40 percent practiced mixed farming. The source of hatching eggs was from abroad (12%), local breeding center (70%) and inter-district farms (18%). Ninety percent of the farms practiced some extent of biosecurity such as clothes changes and visitors log maintained. The temporal analysis identified that pheasant mortality was highest in July, followed by June and August. Of the total cases reported in retrospective study urolithiasis was responsible for 20.27 percent of deaths, Newcastle disease and Mycotoxicosis each were responsible for 13.51 percent of deaths of birds. Though urolithiasis is one of the leading causes of death there was no significant statistical associations (p&gt;0.05) with ages and the flock size. The study collected the baseline data on management practices and disease distributions among the commercial pheasant farming in Kathmandu valley. We suggest, further studies on morbidity, mortality, seasonal stress, and economic aspects of commercial pheasant farming. Prior knowledge and expertise on management and health aspects related to farming is needed for sustainable pheasant farming in Nepal.

Prevalence and molecular characterization of circoviruses, astroviruses and hepadnaviruses in the avifauna of Kopački rit Nature Park, Croatia

Wild birds harbour a plethora of viruses but the research into them has mainly focused on those possessing zoonotic potential or causing significant economic losses in poultry, while others, such as astroviruses (AstVs), circoviruses (CV) and hepadnaviruses (HBV), remain neglected. In this study, 35 dead wild birds belonging to at least 21 species from five orders, collected in Kopački rit Nature Park were tested for the presence of AstVs, CV and HBV using PCR with subsequent nucleotide sequencing. A positive result was found in 18 birds. AstVs were found in three passerine birds, CV was detected in 11 birds belonging to Accipitriformes, Anseriformes, Charadriiformes, Passeriformes or Piciformes orders while HBV was found in four birds belonging to either Anseriformes or Passeriformes. More than one virus was found in a single species (AstV and CV) although in two separate birds. Phylogenetic analysis revealed divergent AstVs somewhat similar to different unclassified AstVs detected in undetermined birds. One AstV shared the highest homology with a bat AstV (98.77%). All CV found in the study resemble avian CV, but none of them clusters in the phylogenetic tree with any avian or avian-like CV sequence. All four HBV sequences detected in this study cluster within the duck HBV group, indicating unusual interspecies transmission to cohabitating passerines. The results of this study represent an important contribution to knowledge about the prevalence, ecology and epidemiology of AstVs, CV and HBV in different wild bird species, indicating the need for further studies, including whole genome sequencing of the detected viruses.

Colloidal gold based immunochromatographic detection of Mycoplasmopsis synoviae infection and its prevalence in avian species of Karachi, Pakistan

Avian mycoplasmosis is an infection that commonly prevails in birds, particularly in poultry chickens. Among mycoplasmosis causing organisms, Mycoplasmopsis synoviae is a predominant and lethal pathogen to the aves. Considering the increased incidence of infections by M. synoviae, the prevalence of M. synoviae was deduced in poultry chickens and fancy birds of Karachi region. The lungs and tracheal samples from chicken and dead fancy birds and swab samples from live fancy birds were collected and investigated by amplifying 16 s rRNA gene of M. synoviae. Biochemical characteristics of M. synoviae was also evaluated. Furthermore, surface-associated membrane proteins, that represent key antigens for diagnosis of M. synoviae infection was extracted by Triton X- 114 method. Results showed that M. synoviae was detected more frequently in lungs than in trachea, that could be due to its invasion capacity and tissue affinity. SDS PAGE analysis of extracted membrane proteins showed two prominent hydrophobic proteins of different molecular mass including proteins of 150 and 50 kDa. Protein of 150 kDa was purified by size exclusion chromatography and it exhibited agglutinogen activity. Purified protein was used in the development of one-step immunochromatographic (ICT) assay for the detection of antibodies against M. synoviae using gold nanoparticles coated with polyclonal antibodies. Low levels of antibodies were detected by the developed ICT kit, which has 88% sensitivity with 92% specificity.

Automatic Detection of Cage-Free Dead Hens with Deep Learning Methods

Poultry farming plays a significant role in ensuring food security and economic growth in many countries. However, various factors such as feeding management practices, environmental conditions, and diseases lead to poultry mortality (dead birds). Therefore, regular monitoring of flocks and timely veterinary assistance is crucial for maintaining poultry health, well-being, and the success of poultry farming operations. However, the current monitoring method relies on manual inspection by farm workers, which is time-consuming. Therefore, developing an automatic early mortality detection (MD) model with higher accuracy is necessary to prevent the spread of infectious diseases in poultry. This study aimed to develop, evaluate, and test the performance of YOLOv5-MD and YOLOv6-MD models in detecting poultry mortality under various cage-free (CF) housing settings, including camera height, litter condition, and feather coverage. The results demonstrated that the YOLOv5s-MD model performed exceptionally well, achieving a high mAP@0.50 score of 99.5%, a high FPS of 55.6, low GPU usage of 1.04 GB, and a fast-processing time of 0.4 h. Furthermore, this study also evaluated the models’ performances under different CF housing settings, including different levels of feather coverage, litter coverage, and camera height. The YOLOv5s-MD model with 0% feathered covering achieved the best overall performance in object detection, with the highest mAP@0.50 score of 99.4% and a high precision rate of 98.4%. However, 80% litter covering resulted in higher MD. Additionally, the model achieved 100% precision and recall in detecting hens’ mortality at the camera height of 0.5 m but faced challenges at greater heights such as 2 m. These findings suggest that YOLOv5s-MD can detect poultry mortality more accurately than other models, and its performance can be optimized by adjusting various CF housing settings. Therefore, the developed model can assist farmers in promptly responding to mortality events by isolating affected birds, implementing disease prevention measures, and seeking veterinary assistance, thereby helping to reduce the impact of poultry mortality on the industry, ensuring the well-being of poultry and the overall success of poultry farming operations.

Novel Avian Influenza Virus (H5N1) Clade 2.3.4.4b Reassortants in Migratory Birds, China

Two novel reassortant highly pathogenic avian influenza viruses (H5N1) clade 2.3.4.4b.2 were identified in dead migratory birds in China in November 2021. The viruses probably evolved among wild birds through different flyways connecting Europe and Asia. Their low antigenic reaction to vaccine antiserum indicates high risks to poultry and to public health.

Epidemiology and molecular characterization of avian influenza A viruses H5N1 and H3N8 subtypes in poultry farms and live bird markets in Bangladesh

Avian influenza virus (AIV) remains a global threat, with waterfowl serving as the primary reservoir from which viruses spread to other hosts. Highly pathogenic avian influenza (HPAI) H5 viruses continue to be a devastating threat to the poultry industry and an incipient threat to humans. A cross-sectional study was conducted in seven districts of Bangladesh to estimate the prevalence and subtypes (H3, H5, and H9) of AIV in poultry and identify underlying risk factors and phylogenetic analysis of AIVs subtypes H5N1 and H3N8. Cloacal and oropharyngeal swab samples were collected from 500 birds in live bird markets (LBMs) and poultry farms. Each bird was sampled by cloacal and oropharyngeal swabbing, and swabs were pooled for further analysis. Pooled samples were analyzed for the influenza A virus (IAV) matrix (M) gene, followed by H5 and H9 molecular subtyping using real-time reverse transcription-polymerase chain reaction (rRT-PCR). Non-H5 and Non-H9 influenza A virus positive samples were sequenced to identify possible subtypes. Selected H5 positive samples were subjected to hemagglutinin (HA) and neuraminidase (NA) gene sequencing. Multivariable logistic regression was used for risk factor analysis. We found that IAV M gene prevalence was 40.20% (95% CI 35.98–44.57), with 52.38%, 46.96%, and 31.11% detected in chicken, waterfowl, and turkey, respectively. Prevalence of H5, H3, and H9 reached 22%, 3.4%, and 6.9%, respectively. Waterfowl had a higher risk of having AIV (AOR: 4.75), and H5 (AOR: 5.71) compared to chicken; more virus was detected in the winter season than in the summer season (AOR: 4.93); dead birds had a higher risk of AIVs and H5 detection than healthy birds, and the odds of H5 detection increased in LBM. All six H5N1 viruses sequenced were clade 2.3.2.1a-R1 viruses circulating since 2015 in poultry and wild birds in Bangladesh. The 12 H3N8 viruses in our study formed two genetic groups that had more similarity to influenza viruses from wild birds in Mongolia and China than to previous H3N8 viruses from Bangladesh. The findings of this study may be used to modify guidelines on AIV control and prevention to account for the identified risk factors that impact their spread.

Investigation of Newcastle Disease Virus Infection in Pet Birds in the Southwest of Iran.

Newcastle disease virus (NDV) is a serious threat to the international poultry industry. Therefore, to determine the role of pet birds (Psittaciformes and Passeriformes) in its spread and epidemiology, the presence of this virus in these birds was investigated. In this study, fecal and cloaca swabs from 63 Psittaciformes and 37 Passeriformes, along with tissue samples of dead birds, including proventriculus, trachea, lungs, and intestine, were collected from breeding and sales markets as well as the birds referred to Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Isolation of the virus was performed by injecting the suspension of the samples into the allantoic fluid of fertilized eggs, and NDV was detected in the achieved allantoic fluids by reverse transcription polymerase chain reaction. The NDV was detected in 13 allantoic samples. The partial F gene sequences of 10 positive samples were investigated, and their genetic relationship with each other as well as with other isolates in the gene bank was marked. Consequently, subgenotype VII.1.1 (VIId) was in the locus of all 10 viruses. By the amino acid cleavage site sequences of F protein, 10 isolates were determined as velogenic NDV. Moreover, all sequences were similar to each other and other Iranian isolates. Furthermore, the 112RRQKR/F117 pattern was the main amino acid (aa) sequence in the F-protein Cleavage site for VIId genotype isolates.

Historical changes in mortality patterns of diurnal and nocturnal raptors in the Czech Republic, Central Europe: 1913–2017

Raptors are apex predators and essential environmental indicators of ecosystem changes, with anthropogenic mortality heavily influencing their population trends. However, mortality factors can change over time, potentially diverting attention from the underlying drivers of raptor declines. Therefore, a broader perspective beyond studying contemporary mortality patterns for individual species is necessary to prioritize conservation efforts across raptor species. Our study analyzed data from six databases spanning 1913–2017 for the recoveries of 24,443 dead birds, including 24 diurnal and nocturnal raptor species in the Czech Republic. Our results showed that direct persecution historically dominated raptor mortality, but contemporary patterns are shaped by different sources of anthropogenic mortality. Mortality due to vehicle collisions, electrocution or collision at powerlines, and other anthropogenic sources gradually increased from 1913 until 2000 but began to decline in the last two decades. After 2000, vehicle collisions caused higher mortality rates than mortality linked to powerlines and other anthropogenic causes. Natural mortality was lower than average anthropogenic mortality during 1913–1990 but prevailed over anthropogenic mortality after 2000. Species-specific variation in raptor mortality causes was also detected. Direct persecution was the most common mortality factor for diurnal species with higher human-wildlife conflict. Powerline mortality affected mainly farmland and larger raptors, while vehicle collisions were the most significant mortality factor for most owl species and other anthropogenic mortality for barn owls Tyto alba. Raptor conservation efforts should prioritize reducing direct persecution, but coordinated actions to mitigate vehicle collision mortality are also necessary for nocturnal raptors.

The Role of Airborne Particles in the Epidemiology of Clade 2.3.4.4b H5N1 High Pathogenicity Avian Influenza Virus in Commercial Poultry Production Units.

Since October 2021, Europe has experienced the largest avian influenza virus (AIV) epizootic, caused by clade 2.3.4.4b H5N1 high pathogenicity AIV (HPAIV), with over 284 poultry infected premises (IPs) and 2480 dead H5N1-positive wild birds detected in Great Britain alone. Many IPs have presented as geographical clusters, raising questions about the lateral spread between premises by airborne particles. Airborne transmission over short distances has been observed for some AIV strains. However, the risk of airborne spread of this strain remains to be elucidated. We conducted extensive sampling from IPs where clade 2.3.4.4b H5N1 HPAIVs were confirmed during the 2022/23 epizootic, each representing a major poultry species (ducks, turkeys, and chickens). A range of environmental samples were collected inside and outside houses, including deposited dust, feathers, and other potential fomites. Viral RNA (vRNA) and infectious viruses were detected in air samples collected from inside and outside but in close proximity to infected houses, with vRNA alone being detected at greater distances (≤10 m) outside. Some dust samples collected outside of the affected houses contained infectious viruses, while feathers from the affected houses, located up to 80 m away, only contained vRNA. Together, these data suggest that airborne particles harboring infectious HPAIV can be translocated short distances (<10 m) through the air, while macroscopic particles containing vRNA might travel further (≤80 m). Therefore, the potential for airborne transmission of clade 2.3.4.4b H5N1 HPAIV between premises is considered low. Other factors, including indirect contact with wild birds and the efficiency of biosecurity, represent greater importance in disease incursion.

Chlamydia psittaci in garden birds in Sweden

Increased numbers of human infections with Chlamydia psittaci have been associated with bird feeding activities in southern Sweden. Information on occurrence and genotype of C. psittaci in garden birds in Sweden is required to corroborate this finding but data are limited. Additionally, pathogenicity of C. psittaci for garden birds is poorly understood. In this study, C. psittaci infection was investigated in 275 garden birds representing 22 species submitted for wildlife disease surveillance between 2009 and 2019. PCR was used to detect C. psittaci DNA in liver and lung. Positive samples were genotyped, additional PCR was performed on feces, and tissues were examined microscopically. C. psittaci was found in six (2.2 %) birds; three great tits (Parus major), two feral (Columba livia) and one wood pigeon (Columba palumbus). Two great tits and the wood pigeon had inflammatory lesions associated with C. psittaci. In the great tits and wood pigeon, C. psittaci genotype A, the cause of most human cases, was detected. Genotype B, considered endemic in pigeons, was detected in the feral pigeons. Low incidence of C. psittaci in dead Swedish garden birds was similar to studies on apparently healthy Swedish birds. Pathological findings were consistent with C. psittaci being fatal in half of the positive birds, which also had higher bacterial loads in feces. This highlights the risk for human infection via infected garden birds, especially regarding great tits and pigeons.

Economic and Environmental Impact of Poultry Production in Ilorin Metropolis, Kwara State, Nigeria

This study investigated the economic and environmental impact of poultry production in Ilorin, Kwara State. Primary data were used and a sample of 120 poultry farmers through a multistage sampling technique was drawn from the study. The data collected were analysed using descriptive statistics, gross margin analysis, OLS regression model and Likert-type scale. The results show that the enterprise incurred an average total variable cost of N135,450.0 and total revenue within the period was estimated to be N192,323.80 which was mainly generated from the sales of poultry birds. The gross margin was found to be N56,873.8 with N0.4199 can be obtained with a unit increase in the poultry production capacity. Thus, the broiler production is a profitable venture in the study area. The empirical finding based on the regression result indicate that, cost of labour, cost of chicks and marital status had positive coefficient and statistically significant in influencing the total revenue level. It means that any increase in their value will increase the revenue level. The result of vaccine/medication administered against diseases revealed that most of the poultry farmers uses Lasota vaccine (88%) against Newcastle disease, a combination of amprolium and coccimapro (27%) each for Coccidiosis, pox off (88%) for fowl pox disease, Gumboro vaccine (65%) for IBD gumboro and their sources of getting the medication/vaccines are majorly from Aromokeye agro vet and One step pharmacy. The analysis shows that among the various ways of waste management, the farmers uses the waste more for fertilizer (28%) followed by selling them (23%) while only (21%) of the farmers burn the waste (especially the dead birds) so as to prevent further spread of diseases on the farm. The empirical findings based on the environmental impact of poultry production reveals that waste generation is the major negative environmental impact of poultry production in the study area. Offensive odour also associated with poor waste management is ranked 2nd, diseases transmission, air pollution and water pollution are among the environmental impact of poultry production in the study area. Poor management system is perceived to be the major constraint, lack of security and government support ranked 2nd is seen as a problem.