Incursion of H5N8 high pathogenicity avian influenza virus (HPAIV) into gamebirds in England.

The 2016-17 European outbreak of H5N8 HPAIV (Clade 2.3.4.4b) affected a wider range of avian species than the previous H5N8 outbreak (2014-15), including an incursion of H5N8 HPAIV into gamebirds in England. Natural infection of captive-reared pheasants (Phasianus colchicus) led to variable disease presentation; clinical signs included ruffled feathers, reluctance to move, bright green faeces, and/or sudden mortality. Several birds exhibited neurological signs (nystagmus, torticollis, ataxia). Birds exhibiting even mild clinical signs maintained substantial levels of virus replication and shedding, with preferential shedding via the oropharyngeal route. Gross pathology was consistent with HPAIV, in gallinaceous species but diphtheroid plaques in oropharyngeal mucosa associated with necrotising stomatitis were novel but consistent findings. However, minimal or modest microscopic pathological lesions were detected despite the systemic dissemination of the virus. Serology results indicated differences in the timeframe of exposure for each case (n = 3). This supported epidemiological conclusions confirming that the movement of birds between sites and other standard husbandry practices with limited hygiene involved in pheasant rearing (including several fomite pathways) contributed to virus spread between premises.

Top-down effects of raptor predation on northern bobwhite.

Understanding how predators affect prey species is a central endeavor in applied ecology. Game birds are a culturally and economically important group of birds throughout the world. Specifically, northern bobwhite (Colinus virginianus) is an imperiled game bird native to North America that has declined precipitously over the past 65 years. Concurrently, raptor populations increased substantially as a result of pesticide bans and legal protections. However, relationships between raptors and bobwhites are not well-understood because of limited long-term data. We analyzed long-term raptor survey and bobwhite survival datasets from 2008 to 2018 to determine if oscillations in raptor abundance affected bobwhite survival. We used a novel open multi-species dynamics hierarchical distance sampling model to estimate the abundance of raptors. We used a known-fate survival model to determine if variation in raptor abundance affected bobwhite survival. We had multiple working hypotheses regarding biological relationships between raptor abundance and bobwhite survival. Raptors affected bobwhites in every biological season but were more influential in the breeding season and late winter supporting the notion of bobwhite behavior and raptor migration were driving observed patterns. Our results suggest that even in areas with abundant habitat, predators exert top-down influences on vital rates suggesting similar or greater influences on populations under poor habitat conditions.

Gastrointestinal nematodes in two galliform birds from South Africa: patterns associated with host sex and age.

Parasite ecology has recently focused on elucidating patterns and processes that shape helminth communities in avian hosts. However, helminths parasitizing gamebirds are still poorly understood. Here we describe the gastrointestinal nematode fauna of Swainson's spurfowl, Pternistis swainsonii (Phasianidae) and helmeted guineafowl, Numida meleagris (Numididae), collected at three and four localities, respectively, in South Africa and analyze the prevalence, mean abundance and diversity of their helminth communities. Eleven nematode species were collected from spurfowl, which had a mean number of nematode species per host of 3.01 ± 0.18, whereas guineafowl harboured 15 nematode species, with a mean number of nematode species per host of 3.93 ± 0.12. Focusing on the most prevalent species, we also asked if host sex and/or age were associated with infracommunity structure with regard to nematode counts and species richness, as well as the species and taxonomic composition of infracommunities. While pooling data of nematode species masked the influence of host characteristics on helminth communities, analysis of individual nematode species revealed a number of patterns. In particular, adult female bias was seen in Tetrameres swainsonii in spurfowl and in Allodapa dentigera and Gongylonema congolense in guineafowl; Acuaria gruveli reached higher numbers in adult spurfowl than in juveniles, and helminth infracommunities in juvenile male guineafowl were more species rich than those in adult males. Combined, our results suggest that helminth communities of spurfowl and guineafowl are associated with a complex interplay of numerous factors, including host characteristics, parasite traits and environmental conditions.

Meat quality and lipid fatty acid profile from wild thrush (Turdus philomelos), woodcock (Scolopax rusticola) and starling (Sturnus vulgaris): a preliminary comparative study.

BACKGROUND: The present study aimed to evaluate the nutritional proximate composition, some qualitative traits and fatty acid profile of meat from wild thrush, woodcock and starling hunted in Southern Italy in 2017 and 2018. METHODS: Nutritive composition and physical traits of meat and lipid fatty acid profile were evaluated in breast muscle (Pectoralis major) of gamebirds. RESULTS: From findings, the meat pH was significantly (P < 0.001) higher in starling when compared to the other two species. Thrush meat was significantly (P = 0.002) darker and had higher redness (P < 0.001) and yellowness (P = 0.004) in comparison to starling and woodcock. Thrush breast muscle showed the highest (P < 0.001) level of lipids and lowest (P < 0.001) protein content. Meat from thrush showed the best lipid fatty acid profile based on the higher (P < 0.001) monounsaturated fatty acids (MUFA) and lower (P < 0.001) saturated fatty acids (SFA) concentrations. Starling breast muscle reported the highest (P = 0.002) polyunsaturated fatty acids (PUFA) level compared to both thrush and woodcock, whereas no differences were detected on total n-3. The ratio n-6/n-3 was higher (P = 0.001) in starling muscle. Thrush breast muscle had the lowest (P < 0.001) atherogenic and thrombogenic indices compared to the other gamebirds. CONCLUSIONS: The findings indicated that meat from the three investigated gamebirds species may represent a healthily lipid food source for human consumption in relation to the prevention of cardiovascular diseases.

The influence of post-mortem conditioning on the tenderness of Egyptian goose (Alopochen aegyptiacus) breast meat (M. pectoralis major).

BACKGROUND: Egyptian goose breast meat has been found to be very tough compared to the meat of other well-known fowl species. In attempting to clarify the toughness of the meat, the physical and biochemical changes during post-mortem conditioning (14 days) was investigated. RESULTS: Although there was increased cathepsin (B, B & L and H) activity, together with a decrease (P ≤ 0.05) in myofibrillar fragmentation lengths (32-25 µm) with conditioning, no change (decline) in shear force values was observed. The higher (P ≤ 0.05) shear force of the male breast portions may be linked to the higher (P ≤ 0.05) concentrations of total and insoluble collagen. CONCLUSIONS: No significant change (decline) in shear force values was observed. Conditioning of Egyptian goose meat as a means of improving the overall toughness cannot therefore not be proposed. The higher shear force and lower sensory tenderness of the male breast portions, as previously observed, may be linked to higher concentrations of total and insoluble collagen.

Post mortem rigor development in the Egyptian goose (Alopochen aegyptiacus) breast muscle (pectoralis): factors which may affect the tenderness.

BACKGROUND: Baseline research on the toughness of Egyptian goose meat is required. This study therefore investigates the post mortem pH and temperature decline (15 min-4 h 15 min post mortem) in the pectoralis muscle (breast portion) of this gamebird species. It also explores the enzyme activity of the Ca(2+)-dependent protease (calpain system) and the lysosomal cathepsins during the rigor mortis period. RESULTS: No differences were found for any of the variables between genders. The pH decline in the pectoralis muscle occurs quite rapidly (c = -0.806; ultimate pH ∼ 5.86) compared with other species and it is speculated that the high rigor temperature (>20 °C) may contribute to the increased toughness. No calpain I was found in Egyptian goose meat and the µ/m-calpain activity remained constant during the rigor period, while a decrease in calpastatin activity was observed. The cathepsin B, B & L and H activity increased over the rigor period. CONCLUSION: Further research into the connective tissue content and myofibrillar breakdown during aging is required in order to know if the proteolytic enzymes do in actual fact contribute to tenderisation.

The fatty acid, amino acid, and mineral composition of Egyptian goose meat as affected by season, gender, and portion.

With the current absence of scientific information on the nutritive aspects it is essential to investigate the fatty acid, mineral, and amino acid composition of Egyptian geese as well as the factors of influence. The forage vs. grain based diets of Egyptian geese during certain periods of the yr leads to variation in the content of the key fatty acids such as oleic acid, linoleic acid, and α-linolenic acid. The differences in these fatty acids results in variation between the n-6/n-3 ratios of the seasons; the portions from winter (July) are within the recommendations (ratio <5) and those from summer (November) not. This study indicates that Egyptian goose meat does not only vary in nutritional composition but season may also have a substantial effect on the flavor profile and ultimate uniformity of the meat. The season and portion effects were, however, interlinked but the general tendency shows that the portions, especially the breast and thigh do differ concerning the major fatty acids. No substantial differences were found in the mineral composition of the breast portion on account of season and gender; however there were some variation in certain amino acids such as lysine and arginine due to season/diet. This research provides essential information that should be considered not only regarding the everyday consumption of Egyptian goose meat but the potential utilization and ultimate consistency of this meat product.

Health impacts of gastrointestinal and ocular parasites in northern bobwhite (Colinus virginianus) in western Oklahoma, USA.

The northern bobwhite (Colinus virginianus) is a popular upland game bird that is suffering from severe and ongoing population decline. In this study, we investigated the potential health impacts of gastrointestinal and periorbital parasites in bobwhite in western Oklahoma, USA. A sample of 206 bobwhites from 2018 to 2020 indicated a low prevalence and diversity of parasites. However, at least one gastrointestinal or ocular parasite species was detected in 112 bobwhite (54.4%). A total of three gastrointestinal parasite species were detected, including Aulonocephalus pennula (54% prevalence, mean intensity 71.6 ± 99.8), Raillietina spp. (7%, 4.2 ± 1.9), and a single immature Mediorhynchus sp. acanthocephalan (0.5%). Burdens of A. pennula infections were negatively associated with fat stores in their bobwhite host. Low intensities (range 1-10, mean 3.9 ± 2.9) of eyeworms (Oxyspirura petrowi) were observed in 12.6% (26/206) of bobwhite sampled and were not associated with fat stores. No significant histologic lesions were associated with O. petrowi worms in ocular and surrounding tissues of 68 quail eyes examined, of which 26 (38%) were positive for eyeworms. Overall, the prevalence and intensity of parasites in bobwhite in Oklahoma were lower than in previous studies in Texas in similar physiographic regions. However, continued studies on the impacts of these parasites on quail health are needed as environmental and climate changes could alter the ecology and significance of these parasites.

Mismatches between Morphology and DNA in Italian Partridges May Not Be Explained Only by Recent Artificial Release of Farm-Reared Birds.

Translocations and releases of farm-reared birds are considered among the major drivers of genetic pollution with consequent loss of genetic diversity in wild populations. In this study, we aimed to assess the extent of hybridization and introgression in the Italian partridges as a consequence of translocation. We surveyed two mitochondrial markers and one nuclear marker of Alectoris and Perdix from collections (museums and private collections), extant wild populations and farms. Consistent with previous studies, we found haplotypes of allochthonous species within the same genus, likely due to introductions for hunting activities. In addition, we found hybrids between Perdix and Alectoris species with genetic markers from both genera in single individuals. Such introgression was bidirectional and in both mitochondrial and nuclear markers. Counterintuitively, most of the hybrid samples came from collections before the 1950s, when large-scale translocations started, from wild populations where Grey Partridge (Perdix perdix) and Rock Partridge (Alectoris graeca) overlap in their distribution, whereas only one hybrid occurred among the farmed birds. Our results suggest that Perdix and Alectoris species can hybridize in nature and that artificial translocations and releases of farm-reared birds for restocking or reintroduction purposes may be only partially responsible for the genomic mismatches of Italian partridges.

Common Diseases of Michigan Gamebirds: A Retrospective Study.

Michigan has abundant resources for outdoor activity including upland gamebird hunting in the wild and on licensed hunting preserves. Due to the popularity of hunting, Michigan had a thriving gamebird industry before the economic downturn of 2008/2009. After the economic downturn, the number of gamebird preserves decreased. To understand the health issues faced by captive gamebird raisers while the industry was thriving, a 25-year retrospective study of gamebird submissions to the Michigan State University Veterinary Diagnostic Laboratory from 1983 through 2008 was undertaken. Although pheasants, quail, partridges, grouse, and mallard ducks were raised, pheasants greatly outnumbered all other gamebird species, both in numbers and submissions, and quail were the next most predominant species. Causes for submission included parasitic, bacterial, viral, and miscellaneous causes. Parasitic diseases were predominant, with coccidiosis being the leading diagnosis in pheasants and partridges and Capillaria spp. infestation of the crop prevailing in quail. Bacterial diseases were the next most predominant affliction, with clostridial enteritis, both necrotic and ulcerative, in quail, and a variety of bacterial diseases were found in pheasants and partridges. Rotaviral enteritis and adenovirus were the most prevalent viral diseases in pheasants, with adenovirus being the predominant viral disease in quail and paramyxovirus the most prevalent in partridges. From these findings, we conclude that gamebird submissions should be closely screened for parasitic diseases and the diagnosis confirmed at necropsy through scraping and examination of affected tissues.

Reporte de caso­Enfermedades comunes de aves de caza en Michigan: Un estudio retrospectivo. Michigan tiene abundantes recursos para la actividad al aire libre, incluida la caza de aves silvestres en tierras altas silvestres y en cotos de caza autorizados. Debido a la popularidad de la caza, Michigan tenía una próspera industria de aves de caza antes de la recesión económica de los años 2008/2009. Después de la recesión económica, el número de reservas de aves de caza disminuyó. Para comprender los problemas de salud que enfrentan los criadores de aves de caza en cautiverio mientras la industria prosperaba, se realizó un estudio retrospectivo de 25 años de los casos de diagnóstico de aves de cacería remitidos al Laboratorio de Diagnóstico Veterinario de la Universidad Estatal de Michigan desde el año 1983 hasta el 2008. Aunque se criaron faisanes, codornices, perdices, urogallos y ánades reales, los faisanes superaron en gran medida a todas las demás especies de aves de caza, tanto en número como en casos clínicos y la codorniz fue la segunda especie más predominante. Las causas de envío de casos clínicos incluyeron infecciones parasitarias, bacterianas, virales y diversas. Predominaron las enfermedades parasitarias, siendo la coccidiosis el principal diagnóstico en faisanes y perdices y la infestación en el buche por Capillaria spp. fue predominante en codornices. Las enfermedades bacterianas fueron el segundo problema más predominante, con enteritis por clostridios, tanto necrótica como ulcerativa, en codornices, y una variedad de enfermedades bacterianas se encontraron en faisanes y perdices. La enteritis por rotavirus y los adenovirus fueron las enfermedades virales más prevalentes en los faisanes, siendo el adenovirus la enfermedad viral predominante en la codorniz y el paramixovirus la más prevalente en las perdices. A partir de estos hallazgos, concluimos que las presentaciones de aves de caza deben ser examinadas de cerca para detectar enfermedades parasitarias y el diagnóstico debe confirmarse en la necropsia mediante de raspados y examen de los tejidos afectados.

The effects of released pheasants on invertebrate populations in and around woodland release sites.

The release of gamebirds for recreational shooting exerts a series of effects on the ecosystems into which they are placed. Pheasants (Phasianus colchicus) are omnivorous and eat invertebrates, especially when young or, if females, when breeding. Consequently, the release of large numbers of pheasants into woodland release pens may affect local invertebrate populations. Previous studies have reported mixed evidence. We conducted pitfall trapping at 13 sites (49 pens) in central England over 2 years (totaling 65 pen measures), comprising three surveys annually, immediately prior to releases in mid-summer, 4 weeks later when most birds were still in the pens, and another 5 weeks later when most birds had dispersed. We compared traps inside and 25 m outside pens in the same wood. We considered release densities and whether the birds had prior experience of eating invertebrates. While accounting for overall seasonal declines in invertebrates trapped, we detected changes for total invertebrate biomass and total counts indicative of released pheasants causing local decreases inside pens, either directly by predation or indirectly by modifying vegetation. There were also relative decreases outside pens when the pheasants start to disperse, suggesting that the released pheasants may be affecting invertebrates in those nearby areas or that their earlier effects inside the pen, modifying vegetation or increasing invertebrate activity, increased the relative susceptibility of invertebrates there to trapping. However, these effects were not seen for specific invertebrate groups believed to be especially susceptible to pheasants. For slugs and detritivores, we detected small population increases inside pens. Across the study period, decreases for most measures were greater outside pens than inside them. We conclude that any effects pheasants have on invertebrate communities at release sites in woodlands are complex and that long-term and taxon-specific studies should be considered to understand the local net ecological effects of gamebird releases on invertebrates.

Has respiratory cryptosporidiosis spread to black grouse Tetrao tetrix?

Infection by Cryptosporidium baileyi was first confirmed in red grouse in northern England in 2010 and within three years spread to 48 per cent of moors. These form the last English stronghold for the rarer black grouse, and given the rapid spread of respiratory cryptosporidiosis among red grouse, concern has been expressed about possible infection. In 2010, the authors started screening black grouse for cryptosporidiosis in (1) dead birds taken for postmortem examination, (2) sample birds caught at night and (3) an observational study of birds attending leks. Between 2011 and 2016, five males were sent for postmortem examination, of which three had suspected cryptosporidiosis. No disease was found in one; the second had extensive, subacute to chronic sinusitis; and the third had severe sinusitis and unilateral conjunctivitis. PCR analysis detected cryptosporidial DNA in the third bird only; however, the parasite was not seen in stained preparations or on histopathology. No cryptosporidiosis clinical signs were observed in 69 birds caught at night or in 170 birds attending leks. The authors have no conclusive evidence that cryptosporidiosis is causing sinusitis in black grouse. However, a single positive cryptosporidia PCR result from an affected bird does raise the possibility that they may be infected with the parasite.