Comparative molecular analyses of Eimeria Schneider (Apicomplexa: Eimeriidae) species from rock ptarmigan in Iceland, Svalbard-Norway, and Japan

The rock ptarmigan (Lagopus muta) has a Holarctic breeding distribution and is found in arctic and sub-arctic regions. Isolated populations and glacial relicts occur in alpine areas south of the main range, like the Pyrenees in Europe, the Pamir mountains in Central Asia, and the Japanese Alps. In recent decades considerable effort has been made to clarify parasite infections in the rock ptarmigan. Seven Eimeria spp. have been reported parasitizing rock ptarmigan. Two of those species, E. uekii and E. raichoi parasitizing rock ptarmigan (L. m. japonica) in Japan, have been identified genetically. Here we compare partial sequences of nuclear (18S rRNA) and mitochondrial (COI) genes and we detail the morphology of sporulated oocysts of E. uekii and E. raichoi from Japan, E. muta and E. rjupa, from the rock ptarmigan (L. m. islandorum) in Iceland, and two undescribed eimerian morphotypes, Eimeria sp. A, and Eimeria sp. B, from rock ptarmigan (L. m. hyperborea) in Norway (Svalbard in the Norwegian Archipelago). Two morphotypes, ellipsoidal and spheroidal, are recognized for each of the three host subspecies. Our phylogenetic analysis suggests that the ellipsoidal oocyst types, E. uekii, E. muta, and Eimeria sp. A (Svalbard-Norway) are identical and infects rock ptarmigan in Japan, Iceland, and Svalbard-Norway, respectively. Eimeria uekii was first described in Japan in 1981 so that E. muta, described in Iceland in 2007, and Eimeria sp. A in Svalbard-Norway are junior synonyms of E. uekii. Also, phylogenetic analysis shows that the spheroidal oocyst types, E. rjupa and Eimeria sp. B (Svalbard-Norway), are identical, indicating that rock ptarmigan in Iceland and Svalbard-Norway are infected by the same Eimeria species and differ from E. raichoi in Japan.

Some gastrointestinal nematodes and ixodid ticks shared by several wildlife species in the Kruger National Park, South Africa

Parasite surveys were conducted for 1–2 years in the Kruger National Park (KNP), South Africa on blue wildebeest, impalas, greater kudus, common warthogs and scrub hares. The host associations of some of the gastrointestinal nematode species infecting ≥60% of at least one of the five host species, were determined. These were Agriostomum gorgonis, Cooperia acutispiculum, Cooperia connochaeti, Cooperia hungi, Cooperia neitzi, Cooperioides hamiltoni, Gaigeria pachyscelis, Haemonchus bedfordi, Haemonchus krugeri, Haemonchus vegliai, Impalaia tuberculata, Longistrongylus sabie, Strongyloides papillosus, Trichostrongylus deflexus and Trichostrongylus thomasi. Although the prevalence of Trichostrongylus falculatus did not exceed 50% in any host species, it was present in all five hosts. Nematodes in the KNP range from those exhibiting strict host associations to generalists. Nematode-host associations may be determined by host feeding patterns and habitat use. Eight ixodid tick species were commonly collected from the same animals and in 2–3 year long surveys from plains zebras and helmeted guinea fowls: Amblyomma hebraeum, Amblyomma marmoreum, Hyalomma truncatum, Rhipicephalus appendiculatus, Rhipicephalus decoloratus, Rhipicephalus evertsi evertsi, Rhipicephalus simus and Rhipicephalus zambeziensis. Host specificity was less pronounced in ixodid tick species than in nematodes and the immature stages of five tick species infested all host species examined.

Syngamus asphyxiation in a captive ring-necked pheasant

A deceased ring-necked pheasant (Phasianus colchicus) presented for necropsy following a history of chronic wasting. Necropsy revealed nematodes consistent with the genus Syngamus partially obstructing the trachea. Phylogentic analysis failed to reveal conclusive results regarding the species. Syngamus spp. can cause obstruction of the trachea in several different hosts. Additional genetic data from this taxon would aid in the more precise identification of diagnostic specimens.

Occurrence of a Cryptosporidium xiaoi-like genotype in peafowl (Pavo cristatus) in China

The aim of this study was to survey the Cryptosporidium species in peafowls (Pavo cristatus) in Henan Province, China. A total of 143 fecal specimens collected from a breeding farm were tested for Cryptosporidium by nested PCR targeting the small subunit rRNA (SSU rRNA), 70-kDa heat shock protein (HSP70), and actin genes of Cryptosporidium followed by sequence analysis. Only one isolate from an asymptomatic host was obtained, and the isolate differed from a new C. xiaoi-like genotype by one nucleotide and from C. xiaoi or C. bovis at the SSU rRNA locus by six nucleotides. Likewise, the actin gene shared 99% identity with the C. xiaoi-like genotype, accompanied by four nucleotide mutations. A complete sequence of the HSP70 gene was obtained, and exhibited 96% similarity with that from C. xiaoi and differed by one nucleotide from that with the C. xiaoi-like genotype. Phylogenetic analysis of the current isolate revealed genetic relatedness to the C. xiaoi-like genotype and distinction from C. xiaoi and C. bovis. Therefore, our results provided the first documentation of avian infection with a C. xiaoi-like genotype in China and further insight into the diversity of Cryptosporidium spp. in avians.

Serological and molecular detection of Toxoplasma gondii in terrestrial and marine wildlife harvested for food in Nunavik, Canada

BACKGROUND

Toxoplasma gondii, a zoonotic protozoan parasite, infects mammals and birds worldwide. Infection in humans is often asymptomatic, though illnesses can occur in immunocompromised hosts and the fetuses of susceptible women infected during pregnancy. In Nunavik, Canada, 60% of the Inuit population has measurable antibodies against T. gondii. Handling and consumption of wildlife have been identified as risk factors for exposure. Serological evidence of exposure has been reported for wildlife in Nunavik; however, T. gondii has not been detected in wildlife tissues commonly consumed by Inuit.

METHODS

We used a magnetic capture DNA extraction and real-time PCR protocol to extract and amplify T. gondii DNA from large quantities of tissues (up to 100 g) of 441 individual animals in Nunavik: 166 ptarmigan (Lagopus lagopus), 156 geese (Branta canadensis and Chen caerulescens), 61 ringed seals (Pusa hispida), 31 caribou (Rangifer tarandus) and 27 walruses (Odobenus rosmarus).

RESULTS

DNA from T. gondii was detected in 9% (95% CI: 3-15%) of geese from four communities in western and southern Nunavik, but DNA was not detected in other wildlife species including 20% (95% CI: 12-31%) of ringed seals and 26% (95% CI: 14-43%) of caribou positive on a commercial modified agglutination test (MAT) using thawed heart muscle juice. In geese, tissue parasite burden was highest in heart, followed by brain, breast muscle, liver and gizzard. Serological results did not correlate well with tissue infection status for any wildlife species.

CONCLUSIONS

To our knowledge, this is the first report on the detection, quantification, and characterization of DNA of T. gondii (clonal lineage II in one goose) from wildlife harvested for food in Nunavik, which supports the hypothesis that migratory geese can carry T. gondii into Nunavik where feline definitive hosts are rare. This study suggests that direct detection methods may be useful for detection of T. gondii in wildlife harvested for human consumption and provides data needed for a quantitative exposure assessment that will determine the risk of T. gondii exposure for Inuit who harvest and consume geese in Nunavik.

Heterakis isolonche Linstow, 1906 – a new nematode species found in ornamental pheasants in Poland

Studies were carried out on 25 pheasants belonging to 13 Phasianinae species of the Phasianidae family. The research material was collected from private breeders – both Polish and from abroad. The results confirm that the most frequent nematode is Heterakis gallinarum, while for the first time in the country – in two of the examined birds of Polish flocks – the occurrence of Heterakis isolonche was found.

Pathological and molecular studies of the renal trematode Paratanaisia bragai in Indian peafowls (Pavo cristatus)

Endoparasitic diseases are commonly encountered in free-ranging birds. Although not all endoparasites cause disease, persistent infection with large numbers of parasites almost always affects normal physiological functions, leading to deleterious effects on the host. This paper describes the anatomopathological alterations caused by the renal trematode Paratanaisia bragai in Indian peafowl (n = 3) and examines the phylogeny of these and related parasites. Peafowl from forests in and around the Bareilly region, Uttar Pradesh, India, were necropsied, and microscopic and molecular investigations were performed. The peafowl were confirmed to be infected with P. bragai. Significant gross pathological lesions suggested nephrosis, and microscopic findings indicated a mild-to-moderate degree of nephrosis caused by the parasites in the tissue. The parasites were identified as P. bragai by histomorphological analysis of adult and eggs in the ureters, and the identification was confirmed by PCR and phylogenetic analysis. Nucleotide sequencing of the PCR products from the renal trematodes recovered from Indian peafowl revealed a close association with P. bragai from Columbiformes in the United Kingdom and Spain. The pathology and molecular epidemiology of parasitic diseases affecting peafowl is not well understood in India. This is the first report from India and the second report worldwide to document P. bragai infection in peafowl.

Safety of fenbendazole in common peafowl (Pavo cristatus)

The present study was undertaken to find out the safety levels of fenbendazole in common peafowl. This bird, raised on aviaries and zoos, can be severely parasitized with Ascaridia galli (enteric worms) and Syngamus trachea (gapeworm) along with other parasitic worms. Fenbendazole is a highly effective benzimidazole-class anthelmintic in animals. The objective of this work was to provide target animal safety data in young peafowl and to demonstrate reproductive safety in adult birds. During the experimental study, diets containing fenbendazole at 0, 100, 200 and 300 ppm were fed for 21 days (three times the normal treatment duration). Data for feed consumption, feed conversion rate, and body weights were recorded for each bird in each group. Drug concentrations in different tissues of birds were determined to correlate concentrations with clinical observations, clinical pathology, and histologic findings. There were no morbidities or mortalities after study day 21. Additionally, there were no statistically significant treatment-related differences among above mentioned parameters. Analysis of fenbendazole concentrations in kidney, liver, leg/thigh, and breast muscle and skin with associated fat revealed that, even at the highest dose level used and with no feed withdrawal, fenbendazole concentrations were relatively low in these tissues. These findings indicate that fenbendazole has a relatively wide margin of safety in young peafowl and that the proposed dose of 100 ppm in the feed for 7 consecutive days is well within the margin of safety. In the reproductive safety study, five breeder peafowl farms fed fendbendazole at 100ppm for 7 days and collected data on hatching percentage of peahen eggs before and after treatment. Reproductive performance in peahen was not adversely affected.

Host-Parasite Interactions and Population Dynamics of Rock Ptarmigan

Populations of rock ptarmigan (Lagopus muta) in Iceland fluctuate in multiannual cycles with peak numbers c. every 10 years. We studied the ptarmigan-parasite community and how parasites relate to ptarmigan age, body condition, and population density. We collected 632 ptarmigan in northeast Iceland in early October from 2006 to 2012; 630 (99.7%) were infected with at least one parasite species, 616 (98%) with ectoparasites, and 536 (85%) with endoparasites. We analysed indices for the combined parasite community (16 species) and known pathogenic parasites, two coccidian protozoans Eimeria muta and Eimeria rjupa, two nematodes Capillaria caudinflata and Trichostrongylus tenuis, one chewing louse Amyrsidea lagopi, and one skin mite Metamicrolichus islandicus. Juveniles overall had more ectoparasites than adults, but endoparasite levels were similar in both groups. Ptarmigan population density was associated with endoparasites, and in particular prevalence of the coccidian parasite Eimeria muta. Annual aggregation level of this eimerid fluctuated inversely with prevalence, with lows at prevalence peak and vice versa. Both prevalence and aggregation of E. muta tracked ptarmigan population density with a 1.5 year time lag. The time lag could be explained by the host specificity of this eimerid, host density dependent shedding of oocysts, and their persistence in the environment from one year to the next. Ptarmigan body condition was negatively associated with E. muta prevalence, an indication of their pathogenicity, and this eimerid was also positively associated with ptarmigan mortality and marginally inversely with fecundity. There were also significant associations between fecundity and chewing louse Amyrsidea lagopi prevalence (negative), excess juvenile mortality and nematode Capillaria caudinflata prevalence (positive), and adult mortality and skin mite Metamicrolichus islandicus prevalence (negative). Though this study is correlational, it provides strong evidence that E. muta through time-lag in prevalence with respect to host population size and by showing significant relations with host body condition, mortality, and fecundity could destabilize ptarmigan population dynamics in Iceland.

Health issues in young gamebirds

This article, prepared by the APHA Avian Expert Group, summarises some of the health issues affecting young gamebirds during the first few weeks of the rearing season.

Morphological characteristics of Mesocestoides canislagopodis (Krabbe 1865) tetrathyridia found in rock ptarmigan (Lagopus muta) in Iceland

Necropsies of 1010 rock ptarmigans (Lagopus muta) sampled in autumn 2006-2015 in northeast Iceland revealed Mesocestoides canislagopodis tetrathyridia infections in six birds (0.6 %), two juvenile birds (3 month old), and four adult birds (15 months or older). Four birds had tetrathyridia in the body cavity, one bird in the liver, and one bird both in the body cavity and the liver. There were more tetrathyridia in the body cavity of the two juveniles (c. 50 in each) than in three adults (10-40), possibly indicating a host-age-related tetrathyridia mortality. Approximately, half of tetrathyridia in the body cavity were free or loosely attached to the serosa, the other half were encapsulated in a thin, loose connective tissue stroma, frequently attached to the lungs and the liver. Tetrathyridia in the liver parenchyma incited variably intense inflammation. Tetrathyridia from the juvenile hosts were whitish, heart-shaped, and flattened, with unsegmented bodies with a slightly pointed posterior end. In the adult hosts, tetrathyridia were sometimes almost rectangular-shaped, slightly wider compared to those in the juveniles, but more than twice as long as the younger-aged tetrathyridia. Tetrathyridia infections are most likely acquired during the brief insectivorous feeding phase of ptarmigan chicks, and the tetrathyridia persist throughout the lifespan of the birds.

Ultrastructure of Ascaridia galli (Schrank, 1788) (Nematoda: Ascaridida) from the endangered green peafowl Pavo muticus Linnaeus (Galliformes: Phasianidae)

Ascaridia galli (Schrank, 1788) is a common parasite of various galliform birds worldwide. Although A. galli has been extensively studied by many author, knowledge of the morphology of this species in detail is still insufficient. In the present paper, the detailed morphology of A. galli was further studied using light and scanning electron microscopy, based on specimens collected from the endangered green peafowl Pavo muticus Linnaeus (Galliformes: Phasianidae) in China. The results revealed some erroneous and previously unreported morphological features, including the lips lacking real denticles, the lateral alae beginning at some distance posterior to the base of the ventrolateral lips and the caudal papillae with 4 different morphotypes. The present morphological and morphometric data complement previous descriptions and enable us to recognize this species more precisely.

Sublethal Pb exposure produces season-dependent effects on immune response, oxidative balance and investment in carotenoid-based coloration in red-legged partridges

Ingestion of lead (Pb) shot pellets constitutes the main cause of Pb poisoning in avifauna. We studied the effects of sublethal Pb exposure on immunity, carotenoid-based coloration, oxidative stress and trade-offs among these types of responses during spring and autumn in red-legged partridges (Alectoris rufa). We evaluated constitutive immunity testing lysozyme and natural antibody levels, and blood bactericidal and phagocytic activities. We studied induced immunity by testing PHA and humoral responses. We analyzed fecal parasite and bacterial abundance and oxidative stress biomarkers. Pb exposure in spring reduced natural antibody levels, whereas in autumn, it reduced lysozyme levels and increased phagocytic activity. Pb exposure increased PHA response in both seasons, and decreased T-independent humoral response in autumn. Pb exposure also increased noncoliform and decreased coliform Gram-negative gut bacteria. In spring, Pb exposure decreased antioxidant levels and increased coloration in males, whereas in autumn, it increased retinol levels but reduced coloration in both genders. Our results suggest that in spring, Pb-exposed females used antioxidants to cope with oxidative stress at the expense of coloration, whereas Pb-exposed males increased coloration, which may reflect an increased breeding investment. In autumn, both genders prioritized oxidative balance maintenance at the expense of coloration.

The parasitic eyeworm Oxyspirura petrowi as a possible cause of decline in the threatened lesser prairie-chicken (Tympanuchus pallidicinctus)

Lesser prairie-chickens (Tympanuchus pallidicinctus) have been declining range wide since the early 1900's despite efforts to establish conservation and improve their habitat. In early 2014, the lesser prairie-chicken was listed as a threatened species under the U.S Endangered Species Act and the need to find out why they are declining is more important than ever. Nine hunter shot lesser prairie-chickens were donated and sampled for the presence or absence of the eyeworm Oxyspirura petrowi, a known parasite that can cause damage to the eye of its host, and common environmental contaminants. Eyeworm infection was found in 7 of 9 birds (78% infection rate) with an infection range between 0-16 O. petrowi per bird. Breast, liver, and fat tissue samples from the lesser prairie-chickens were analyzed for the frequency of 20 organochlorine pesticides. Femurs and livers were also tested on these birds for metal contaminants. Pesticides were found in several samples above the detection limits but were still in the low ng/g range. Notable was the ubiquitous presence of endrin aldehyde across all tissues. One femur showed 5.66 µg/g of lead (Pb) but this is still relatively low. No liver samples had elevated mercury (Hg) above detection limits. The presence of these organochlorines is consistent with the historic use of pesticides in this region. With pesticide and metals found in such low levels and parasitic nematode infections at rather high levels, it is recommended that these parasites be further evaluated as a contributing factor to the decline of the lesser prairie-chicken.

Intra-sexual competition alters the relationship between testosterone and ornament expression in a wild territorial bird

In a reliable signalling system, individual quality is expected to mediate the costs associated with ornamental displays, with relatively lower costs being paid by individuals of higher quality. These relative costs should depend not only on individual quality, but also on levels of intra-sexual competition. We explored the current and delayed effects that testosterone implants have on bird ornamentation in populations with contrasted population densities, as a proxy for intra-sexual competition. In a replicated experiment, we manipulated testosterone in 196 yearling male red grouse Lagopus lagopus scoticus in autumn in populations of high and low levels of intra-sexual competition. Males were assigned to one of three exogenous testosterone (T) treatments: empty implants (T0), small T implants (T1) or larger T implants (T2). We monitored subsequent changes in testosterone levels, ornament size and carotenoid-based colouration, carotenoid levels and body condition from autumn to spring. Testosterone implants increased testosterone levels, comb redness and comb size, and decreased body condition but these effects depended on levels of intra-sexual competition. Specifically, T2-implanted birds increased testosterone levels and comb size more, and reduced body condition more, in populations where intra-sexual competition was low. In the following spring, testosterone levels of T2-treated birds kept increasing in populations where intra-sexual competition was high but not in populations where intra-sexual competition was low. Our results highlight that levels of intra-sexual competition alter the relationship between testosterone levels and ornament expression, influencing their condition-dependence; they also indicate that the outcome of standard hormone manipulation conducted in free-living animals vary depending on the population context.

Is sexual ornamentation an honest signal of male quality in the Chinese grouse (Tetrastes sewerzowi)?

We examined the variation in sexual ornamentation of male Chinese grouse (Tetrastes sewerzowi) in the Gansu Province, China, seeking to identify factors involved in whether ornament size and brightness are honest signals of male quality. Compared to unmated males, mated males had significantly larger and redder combs and, although they did not have significantly larger territories, they defended them more vigorously. Mated males had significantly higher blood carotenoid and testosterone levels, significantly better body condition, and significantly lower parasite loads than unmated males. Our findings are thus consistent with the hypothesis that comb size and color are honest signals of better male quality in the grouse, mediated through lower parasite loads and/or higher testosterone levels.

Oxyspiruriasis in zoo birds

Oxyspiruriasis caused by the bird eyeworm, Oxyspirura mansoni, a thelaziid nematode, in three species of pheasants, 3 Chrysolophus pictus (golden pheasant), 7 Lophura nycthemera (silver pheasant) and 9 Phasianus colchicus (common pheasant) in Zoo Negara Malaysia are reported. Birds with the disease were treated with a solution of 0.5% iodine or 0.5% lysol. Antistress powder for 4 days in water and non-strep vitamin powder in water was also provided. Control measures included removal of the cockroach intermediate host, Pycnoscelus surinamensis (Surinam cockroach) from the vicinity of the birds. The golden pheasant is a new host for O. mansoni in peninsular Malaysia.

[Helminths of pheasant (Phasianus colchicus) detected by necropsy and faecal examination in Samsun, Turkey]

OBJECTIVE

This study was performed at the Gelemen Pheasant Procreation Farm affiliated to the General Directorate of Nature Conservation and National Parks, Ministry of Forest and Water Affairs.

METHODS

A total of 203 faecal samples and 17 necropsies were examined.

RESULTS

In the faecal examination, Capillaria spp. accounted for 28.6% and Heterakis spp. for 17.2% of eggs; in necropsy, Capillaria annulata (17.6%), C. bursata (35.3%), C. caudinflata (23.5%), C. contorta (64.7%), C. obsignata (5.9%) and Heterakis gallinarum (58.8%) were detected.

DISCUSSION

Syngamus trachea, often reported in helminths in pheasant, could be found neither upon faecal examination nor on necropsy.

CONCLUSION

This study is the first extensive research to identify helminths of pheasants in Turkey. Capillaria bursata, C. caudinflata, C. contorta, C. obsignata and H. gallinarum are the first reports from pheasants in Turkey.

Physiological stress mediates the honesty of social signals

BACKGROUND

Extravagant ornaments used as social signals evolved to advertise their bearers' quality. The Immunocompetence Handicap Hypothesis proposes that testosterone-dependent ornaments reliably signal health and parasite resistance; however, empirical studies have shown mixed support. Alternatively, immune function and parasite resistance may be indirectly or directly related to glucocorticoid stress hormones. We propose that an understanding of the interplay between the individual and its environment, particularly how they cope with stressors, is crucial for understanding the honesty of social signals.

METHODOLOGY/PRINCIPAL FINDINGS

We analyzed corticosterone deposited in growing feathers as an integrated measure of hypothalamic-pituitary-adrenal activity in a wild territorial bird, the red grouse Lagopus lagopus scoticus. We manipulated two key, interrelated components, parasites and testosterone, which influence both ornamentation and fitness. Birds were initially purged of parasites, and later challenged with parasites or not, while at the same time being given testosterone or control implants, using a factorial experimental design. At the treatment level, testosterone enhanced ornamentation, while parasites reduced it, but only in males not implanted with testosterone. Among individuals, the degree to which both parasites and testosterone had an effect was strongly dependent on the amount of corticosterone in the feather grown during the experiment. The more stressors birds had experienced (i.e., higher corticosterone), the more parasites developed, and the less testosterone enhanced ornamentation.

CONCLUSIONS/SIGNIFICANCE

With this unique focus on the individual, and a novel, integrative, measure of response to stressors, we show that ornamentation is ultimately a product of the cumulative physiological response to environmental challenges. These findings lead toward a more realistic concept of honesty in signaling as well as a broader discussion of the concept of stress.

Trends in ixodid tick abundance and distribution in Great Britain

The popular, but rarely documented, view in Britain is that ticks have increased in distribution and abundance over recent years. To assess this, we gathered evidence for changes in tick distribution and abundance by distributing a survey questionnaire throughout Britain and by analysing trends in the prevalence of tick infestation on red grouse chicks Lagopus lagopus scoticus Latham (Galliformes: Tetranoidae), gathered over 19 years at three Scottish sites, and on deer (Cetartiodactyla: Cervidae) culled over 11 years on 26 Ministry of Defence (MoD) estates. Based on the survey, the current known distribution of Ixodes ricinus Linnaeus (Acari: Ixodidae) has expanded by 17% in comparison with the previously known distribution. The survey indicated that people perceive there to be more ticks today than in the past at 73% of locations throughout Britain. Reported increases in tick numbers coincided spatially with perceived increases in deer numbers. At locations where both tick and deer numbers were reported to have increased, these perceived changes occurred at similar times, raising the possibility of a causal link. At other locations, tick numbers were perceived to have increased despite reported declines in deer numbers. The perceptions revealed by the survey were corroborated by quantitative data from red grouse chicks and culled deer. Tick infestation prevalence increased over time on all grouse moors and 77% of MoD estates and decreased at six locations.

Nematode parasites reduce carotenoid-based signalling in male red grouse

Carotenoids determine the yellow-red colours of many ornaments, which often function as signals of quality. Carotenoid-based signalling may reliably advertise health and should be particularly sensitive to parasite infections. Nematodes are among the commonest parasites of vertebrates, with well-documented negative effects on their hosts. However, to date, little is known about the effects that these parasites may have on carotenoid-based signalling. Tetraonid birds (grouse) exhibit supra-orbital combs, which are bright integumentary ornaments pigmented by carotenoids. We tested the effect of the nematode parasite Trichostrongylus tenuis on signalling in free-living male red grouse Lagopus lagopus scoticus. We show that experimentally reduced nematode infection increases plasma carotenoid concentration and comb redness, demonstrating for the first time that nematodes can influence carotenoid-based signals.

An outbreak of disease associated with cryptosporidia on a red-legged partridge (Alectoris rufa) game farm

An outbreak of disease associated with cryptosporidia on a red-legged partridge (Alectoris rufa) game farm is described. Morbidity (diarrhoea and cough) was between 60% and 70% during the first weeks of life (4 to 25 days) and mortality was higher than 50%. The results of bacteriological and virological analyses were negative. Histological examination and antigenic diagnosis by enzyme-linked immunosorbent analysis revealed the presence of Cryptosporidium spp. in respiratory and intestinal tracts. The application of polymerase chain reaction-restriction fragment length polymorphism techniques and sequencing of a Cryptosporidium oocyst wall protein gene fragment confirmed the existence of Cryptosporidium meleagridis in faecal samples. The results obtained suggest that avian cryptosporidiosis should be included among respiratory and enteric diseases routinely tested for in farmed birds.

Two new Eimeria species (Protozoa: Eimeriidae) from wild rock ptarmigans, Lagopus muta islandorum, in Iceland

One hundred rock ptarmigans, Lagopus muta islandorum (Faber, 1822), were collected in early October 2006 in northeastern Iceland and examined for coccidian parasites. Two Eimeria species were identified, and each is described as a new species. Sporulated oocysts of one species are ellipsoidal, 24.9 x 16.6 (19.5-30 x 14.5-19) microm. Oocysts have a small micropyle and a two-layered, smooth wall approximately 1.0 microm thick. An oocyst residuum is absent, but one to three polar granules are present. Sporocysts have a rounded end opposite a nipple-like Stieda body and are 14.3 x 6.3 (12-16.5 x 5.5-7) microm. Sporocysts contain one refractile body and a diffuse granular residuum; the entire contents of each sporocyst is enclosed by a thin membrane. Sporulated oocysts of the second eimerian are subspherical, 24.7 x 22.2 (20-28 x 18-24.5) microm. The oocysts are without a micropyle but with a two-layered wall, which is approximately 1.5 microm thick, with the outer layer having a rough surface texture. Oocyst residuum is absent, but one to two polar granules are present. Sporocysts have a rounded end opposite the nipple-like Stieda body atop a prominent sub-Stieda body and are 14.4 x 8.0 (12-15.5 x 6.5-9) microm. Sporocysts contain a diffuse granular residuum, and each sporozoite has two different-sized refractile bodies.

The effect of an indirect anthelmintic treatment on parasites and breeding success of free-living pheasantsPhasianus colchicus

In Great Britain free-living common pheasantsPhasianus colchicusare often managed at high densities owing to their popularity as a quarry species. They are prone to infection by a range of parasite species includingHeterakis gallinarum,Capillariaspp. andSyngamus trachea. In 1995 the efficacy of an indirect anthelmintic technique for controlling parasitic worm burdens of pheasants was determined in a pilot study on a shooting estate in the south of England. Between 2000 and 2003 a large-scale field experiment was conducted on nine estates in eastern England to determine the effect of the technique on parasite burden and pheasant breeding success. In the absence of anthelmintic treatment worm burdens increased rapidly through March and April, whereas birds given anthelmintic-treated grain had lower worm burdens during the same period. The breeding success of pheasants was significantly higher on plots provided with anthelmintic treatment, although no long-term increases in population densities were observed. The burdens of the most common parasiteH. gallinarumwere significantly lower in pheasants from treatment plots six weeks after the anthelmintic treatment had ceased, but spring treatment did not influence parasite burden in the following winter.

The helminth fauna of the barbary partridgeAlectoris barbarain Tenerife, Canary Islands

The helminth fauna of the barbary partridge (Alectoris barbara) in Tenerife Island (Canary Archipelago) was studied from 2001 to 2002, as there were no records of helminths from this host in the Canary Islands. Seven helminth species were identified: two cestodesChoanotaenia infundibulumandLyruterina nigropunctata, and five nematodesAonchotheca caudinflata,Baruscapillaria obsignata,Eucoleus annulatus,Ascaridia galliandHeterakis gallinarum.Lyruterina nigropunctata,A. galli and E. annulatusare recorded for first time inA. barbara. An analysis of available data onAlectorisspp. reveals the importance of intermediate hosts such as arthropods and earthworms in the diet of partridges. Terrestrial helminths are dominant species, with monoxenous and heteroxenous species being present in similar numbers in differentAlectorisspecies along their geographical distribution. Helminth species found in Tenerife fromA. barbaraare poor indicators of the host colonization from North Africa because these helminths are species that are commonly found in fowl with a cosmopolitan distribution.

Haematology and biochemistry in healthy young pheasants and red-legged partridges and effects of spironucleosis on these parameters

Plasma biochemical and haematological parameters were examined in 4-week-old to 12-week-old game birds. Healthy, uninfected pheasants and partridges had similar levels of total protein, albumin, osmolality, Na+, Cl-, K+, Mg2+ and glucose. Triglyceride, globulin and Ca2+ were significantly higher and PO43- was lower in the partridges. Pheasants carrying a light to moderate infection with Spironucleus had significantly lower total protein, albumin, osmolality, Na+, Cl-, Ca2+ and PO43-. In severely affected pheasants, the osmolality, Na+ and Cl- fell further. Triglyceride and glucose were significantly lower than in healthy birds, and Mg2+ was higher. Similar data were obtained from infected partridges. Red cell parameters rose significantly in pheasants severely affected by spironucleosis, and the percent of heterophils was significantly higher and lymphocytes and basophils lower in their blood smears. The breast and leg muscle wet weight from severely affected pheasants was 22.2 and 37.7% that of uninfected birds, although the water content of the breast muscle was significantly higher.

Two Eimeria species isolated from wild Japanese rock ptarmigans (Lagopus mutus japonicus) in Japan

Fecal samples were collected from 64 Japanese rock ptarmigans (Lagopus mutus japonicus) at 13 locations in the alpine zone of Japan and examined for internal parasites. We found 2 morphologically different types of eimerian oocysts. Based on morphological characteristics, one was identified as Eimeria uekii, which had already been found from Japanese rock ptarmigans in 1981, and the other was likely a new type of Eimeria. The new type of eimerian oocysts required a longer sporulation time than E. uekii. The prevalence of both eimerian oocysts in Japanese rock ptarmigans was 62.5%, while that of E. uekii was 60.9% and the new type 29.7%. Mixed infection of both types was found in 28.1%.

Changes in parasite transmission stage excretion after pheasant release

The production of parasite transmission stages was investigated in the faeces of 77 farm-bred ring-necked pheasants (Phasianus colchicus). Coccidian oocysts (Eimeria sp.), and nematode eggs (Heterakis sp., and Capillaria-like eggs) were recovered before and after release but all birds were treated prior to release. Treatment with fenbendazole significantly reduced the abundance of transmission-stage excretion for all parasites, and reduced the prevalence in the case of Eimeria sp. and Heterakis sp. Nonetheless, a significant increase in the excretion abundance for all parasites and in the prevalence of Eimeria sp. and Heterakis sp. was found after release. Eggs of Ascaridia sp. were found only after releasing, suggesting infection ocurred in the wild. A negative relationship was found between the pheasant body condition and Heterakis excretion abundance and a higher abundance of Capillaria sp. eggs in female birds. No significant relationship was found between parasite excretion abundance and pheasant survival. Despite this, results suggest that an increase in the excretion of parasite transmission stages follows the release of captive pheasants into the wild. This can in part explain restocking failures, but also means that autochtonous free-living birds may become exposed to new and potentially harmful pathogens. To avoid these risks it is proposed that improved prophylactic measures should be taken.

[The helminth and coccidial fauna of pheasants (Phasianus colchicus) in view of the specific environmental conditions in pheasantries and in the wild]

Between October 1999 and January 2000 all together 151 male pheasants were examined for endoparasites. 33 one-year-old birds came from two pheasantries, the remaining 118 birds, aged between one and five years, were wildlife animals. The infestation extensy of all pheasants with endoparasites were 96.7%. A mostly low infestation with coccidia of the three species Eimeria (E.) phasiani, E. duodenalis and E. tetartooimia were detected in 41% of all birds. E. tetartooimia was found in Germany for the first time. In 67.5% of the pheasants the five different species of capillaria (Capillaria (C.) annulata, C. bursata, C. contorta, C. perforans, C. phasianina) and in 84.1% the nematode Heterakis gallinarum were present. Pheasants in the capture group showed higher infestation intensy and extensy. In 51.5% of the pheasants of the capture group Syngamus trachea was present. In one pheasant an acanthocephalus (Plagiorhynchus cylindraceus) was detected for the first time in Germany and in two pheasants a trematode of the genus Echinostoma was present.

Testing the role of parasites in driving the cyclic population dynamics of a gamebird

The role of parasites in regulating populations has been the subject of debate. We tested whether parasites caused population cycles in red grouse by manipulating parasite intensities in four, paired 1 km(2) study areas during cyclic population declines over 4 years. Parasite reductions led to (1) larger grouse broods, (2) higher population densities in both autumn and spring, (3) reduced autumn population declines in one of two regions, and (4) reduced spring declines, but only in the first year. We infer that a single trophic interaction between a parasite and its host does not explain cyclic dynamics in spring breeding density in this species, although it contributed to the start of a cyclic decline. Another process was operating to drive the populations down. Together with our other results these findings emphasize that both trophic and intrinsic processes may act within populations to cause unstable dynamics.

Avoiding bias in parasite excretion estimates: the effect of sampling time and type of faeces

The study of host-parasite relationships usually requires reliable estimates of parasite intensity, which is often estimated from parasite propagule concentration in faeces. However, parasite excretion in faeces may be subject to variation due to endogenous or exogenous factors that must be identified to obtain reliable results. We analysed the effect of the hour of sample collection on propagule counts of 2 intestinal parasites infecting the red-legged partridge: the capillarid nematode Aonchoteca caudinflata and coccidia of the genus Eimeria (Protozoa). Also, we test whether there are differences in propagule counts between caecal and intestinal faeces. Individual faecal samples from infected birds were collected daily at 4 different hours during several days. The hour of the day exerted a very strong effect on propagule counts, excretion of both types of parasites showing a clear and constant increase from dawn to dusk. Also, capillarid eggs were more abundant in intestinal than in caecal faeces, whereas the inverse pattern was found for coccidian oocysts. Standardization of the hour of sample collection or statistical control of this variable is recommendable to prevent bias. Similarly, in bird species with long caeca, consistent collection of one type of faeces may avoid significant errors in parasite burden estimates.

Interactions between intrinsic and extrinsic mechanisms in a cyclic species: testosterone increases parasite infection in red grouse

Field studies of mechanisms involved in population regulation have tended to focus on the roles of either intrinsic or extrinsic factors, but these are rarely mutually exclusive and their interactions can be crucial in determining dynamics. Experiments on red grouse Lagopus lagopus scoticus have shown that population instability can be caused both by the effects of a parasitic nematode, Trichostrongylus tenuis, on host production or by changes in testosterone influencing aggressive behaviour and recruitment. We experimentally tested for an interaction between testosterone and T. tenuis in free-living male grouse. A total of 123 grouse were caught in autumn, treated with an anthelmintic to remove parasites, and then given either testosterone or empty, control, implants. After one month grouse were re-infected with a standard dose of parasites. We show that males with increased testosterone levels had greater parasite intensities than controls after one year. We discuss possible physiological and behavioural mechanisms linking testosterone and increased parasite intensity, and the implications for our understanding of complex, unstable population dynamics.

[Cuclotogaster heterographus (Mallophaga: Lipeuridae) infestation on ring-necked pheasants (Phasianus colchicus) in Konya]

The aim of this study was to detect ectoparasites on ring-necked pheasants (Phasianus colchicus) in Konya. On the Research and Experimental Farm of the Faculty of Veterinary Medicine at Selcuk University, 55 ring-necked pheasants were observed to be infested with ectoparasites. Because of this, the pheasants were put into a large cartoon-box, the bottom of which was covered with a white paper and were treated with propoxur for a few minutes. The ectoparasites that had fallen on the paper were transferred to a tube containing 70% ethyl alcohol. After being cleared in lactophenol for a few days, they were mounted on slides in Faure-Forte medium. All of the ectoparasites were identified as the chewing lice (Mallophaga), Cuclotogaster heterographus. This is the first study that has recorded the presence of C. heterographus on ring-necked pheasants in Turkey.

Fluid absorption in the small intestine of healthy game birds and those infected with Spironucleus spp

Absorption of fluid by the small intestine of 4-week-old to 12-week-old farmed pheasants and partridges has been studied using an inverted sac technique. The mean rate of absorption was 54 +/- 4 (mean +/- standard error of the mean) microl/g dry tissue/min in pheasants and 49 +/- 3 microl/g dry tissue/min in partridges. Use of inhibitors and ion substitution suggested transepithelial transport driven by baso-lateral Na+/K+ pumps, in combination with mucosal Na+-coupled transporters, including Cl(-)-coupled transporters. Absorption was more than halved to 17 +/- 2 microl/g dry tissue/min (P < 0.001) in birds that were very heavily infected with Spironucleus spp. in their small intestine and showing a syndrome of diarrhoea, depression and loss of weight to severe emaciation. Birds carrying light to moderate levels of infection with Spironucleus had very variable rates of absorption that were statistically similar to the controls. Doubling the glucose concentration in the buffer to 40 mM significantly enhanced absorption.

Separating Behavioral and Physiological Mechanisms in Testosterone‐Mediated Trade‐Offs

Testosterone often mediates trade-offs between reproduction and other life-history traits, which are usually investigated using testosterone implants. However, this approach does not distinguish between the physiological and behavioral effects of testosterone. We studied a wild game bird, the red grouse Lagopus lagopus scoticus, and took a new approach to investigate mechanisms linking elevated testosterone to increased parasite intensity. We caught males in autumn, removed their parasites, implanted them with the antiandrogen flutamide in combination with an aromatase inhibitor (FA males) or with empty implants (control males), and challenged them with parasites. The FA treatment increased testosterone concentration and physiological stress, but without enhancing testosterone-dependent behaviors, because testosterone receptors were blocked. FA males ended up with more parasites than the control males the following autumn, an effect similar to that of a testosterone treatment reported elsewhere. However, and unlike the testosterone treatment, the FA treatment did not affect home range, pairing, or breeding success. The results supported a physiological mechanism (increased susceptibility) linking elevated testosterone and increased parasite intensity. The FA treatment provided a new way of investigating testosterone-mediated trade-offs whereby testosterone concentration was increased while the effects on behavior were blocked, resulting in physiological costs without phenotypic benefits.

Survey on helminthofauna in pheasants from Eastern Europe

In order to assess the parasitological status in imported pheasants, 51 birds (Phasianus colchicus) coming from Poland and Rumania and used in Italy in repopulation interventions for hunting purposes were examined. From each animal the trachea, oesophagus, crop and intestine were collected and examined for the presence of nematodes. The examination of the oesophagi and crops of 5 birds revealed the presence of parasites pertaining to the family Capillariidae: Eucoleus contortus was found in all of the 5 animals, E. annulatus was present along with the previous parasite in one animal coming from Poland. The examination of the tracheae revealed the presence of Syngamus trachea in 5 animals (9.80%). Adult or larval stages of Heterakis gallinarum (37.25% of birds) and Capillariidae (35.29%) were found in the intestinal tracts. Aonchotheca caudinflata was detected only in one bird coming from Poland; the capillarids found in all of the remaining pheasants exhibited morphological characteristics referable to Capillaria phasianina, a species never reported in Italy. The release of game from foreign countries, therefore, may always constitute a risk for the autochthonous one due to the spread of new parasitic infections.

Pathology and first occurrence of the kidney trematode Paratanaisia bragai (Santos, 1934) Freitas, 1959 (Digenea: Eucotylidae) in Phasianus colchicus L., 1758, from Brazil

The kidney trematode Paratanaisia bragai is reported for the first time parasitizing the ring-necked pheasant (Phasianus colchicus L., 1758) and the pathological alterations associated to the parasitism are referred on the basis of 50 specimens of this bird from backyard flocks in 11 counties of the state of Rio de Janeiro, Brazil after clinical examination, necropsies, and histopathological analysis. The counting of the kidney flukes was based on worms recovered from one of the kidneys, since the other was fixed in 10% formalin and then routinely processed for histopathological procedures. The prevalence of P. bragai was of 22%, with a mean intensity of 44.3, mean abundance of 9.7, and range of infection of 3-153. Parasitized birds did not present with clinical signs and kidney gross lesions. Microscopic lesions were mild and characterized by dilatation of the renal medullary collecting ducts, occasional flattening of the lining epithelium of the ducts and inflammatory reaction of variable intensity with granulocytes around the ureter branches and medullary collecting ducts. The severity and pattern of the microscopic lesions seem not to be associated to the size of the worm burden and could be related to the mechanic action of the parasites, without traumatism, in despite of the presence of the tegumentar spines in specimens of P. bragai.

Spironucleosis (Hexamitiasis, Hexamitosis) in the ring-necked pheasant (Phasianus colchicus): detection of cysts and description of Spironucleus meleagridis in stained smears

Trophozoites and cysts of Spironucleus (Hexamita) meleagridis were detected in the intestinal fluid and mucus of pheasant poults with spironudeosis (hexamitiasis, hexamitosis) following staining with Heidenhain iron hematoxylin (HIH) and the Romanowsky-type stain Hemacolor. Their morphology was consistent with that of flagellates of the genus Spironucleus, and bright-field morphologic observations were confirmed by transmission electron microscopy. Cysts occurred mostly within intestinal mucus, which was firmly compressed between microscope slides prior to staining. The internal structures of cysts were similar to those of trophozoites, allowing them to be confidently recognized. Hemacolor provided differential color staining of trophozoites and cysts, allowing accurate identification of S. meleagridis life cycle stages, even in smears in which there was heavy background staining. While HIH often produced dearer and more detailed staining of protozoan structures, in the context of a diagnostic laboratory its use was outweighed by the ease of use, rapidity of results, and differential color staining provided by Hemacolor. The possible significance of a resistant cystic stage in the life cyde of S. meleagridis is discussed.

Interactions between population processes in a cyclic species: parasites reduce autumn territorial behaviour of male red grouse

The causes of population cycles fascinate and perplex ecologist. Most work have focused on single processes, whether extrinsic or intrinsic, more rarely on how different processes might interact to cause or mould the unstable population dynamics. In red grouse (Lagopus lagopus scoticus), two causal mechanisms have been supported: territorial behaviour (changes in autumn aggressiveness) and parasites (parasite induced reduction in fecundity). Here, we report on how these two regulatory processes might interact, by testing whether the parasite suspected to cause the grouse cycles, the nematode Trichostrongylus tenuis, reduces male autumn territorial behaviour. We either treated males with an anthelmintic, to remove parasites (dosed or D-males), or challenged them with infective T. tenuis larvae, to increase parasite intensity (challenged or C-males). We first show that dosing was effective in removing T. tenuis parasites, while parasite intensities increased in challenged birds during the autumn. Because old males initially had more parasites than young males, the treatments generated greater differences in parasite intensity in old than in young males. We also show that various aspects of territorial behaviour (increase in testosterone-dependent comb size in autumn, territorial call rate, likelihood of winning territorial interactions and over-winter survival) were significantly higher in dosed than in challenged males, but in old birds only. Our data thus supported the hypothesis that parasites reduce male aggressiveness during the autumn territorial contests, and could thereby influence recruitment. Our results also highlight that the territorial behaviour of young males, which have fewer parasites, is not as limited by parasites as that of old, previously territorial males. We discuss the implications of these findings for our understanding of the processes regulating red grouse populations and causing their complex, unstable population dynamics.

Parasites and climate synchronize red grouse populations

There is circumstantial evidence that correlated climatic conditions can drive animal populations into synchronous fluctuations in abundance. However, it is unclear whether climate directly affects the survival and fecundity of individuals, or indirectly, by influencing food and natural enemies. Here we propose that climate affects trophic interactions and could be an important mechanism for synchronizing spatially distributed populations. We show that in specific years the size of red grouse populations in northern England either increases or decreases in synchrony. In these years, widespread and correlated climatic conditions during May and July affect populations regionally and influence the density-dependent transmission of the gastrointestinal nematode Trichostrongylus tenuis, a parasite that reduces grouse fecundity. This in turn forces grouse populations into synchrony. We conclude that specific climatic events may lead to outbreaks of infectious diseases or pests that may cause dramatic, synchronized changes in the abundance of their hosts.

A new genus and four new species of quill mites (Acari: Prostigmata: Syringophiudae) from phasianid birds (Galuformes: Phasianidae)

A new genus and four new species of the quill mites are described. Galliphilopsis gen. n. (G. francolinus sp. n., type species) differs from the closely related Dissonus Skoracki, 1999 by loss of leg setae dGII, the slightly divergent tips of epimeres I and the stylophore constricted posteriorly. Three new species of the genus Galliphilopsis gen. n. and one new species of the genus Mironovia Chirov and Kravtsova, 1995 are described from galliform birds (Phasianidae) collected at the Museum of Natural History, Wroclaw University (Poland): G. lophurus sp. n. from Lophura leucomelanos, G. bochkovi sp. n. from Tragopan sp. and Alectoris barbara, G. francolinus sp. n. from Francolinus levalliantoides, and Mironovia rouloul sp. n. from Rollulus rouloul.

Trichurid nematodes in ring-necked pheasants from backyard flocks of the State of Rio de Janeiro, Brazil: frequency and pathology

The present investigation is related to the frequency of infection and to the gross and microscopic lesions associated to the presence of trichurid worms in 50 ring-necked pheasants (Phasianus colchicus) from backyard flocks in the state of Rio de Janeiro, Brazil. In the investigated birds, the overall infection rate was of 74%, with the presence of Eucoleus perforans with 72% of prevalence and 21.2 of mean intensity, in the esophageal and crop mucosa and rarely in the junction of the proventriculus and esophagus, E. annulatus with 2% and 3 in the crop mucosa, Capillaria phasianina, with 12% and 4.3 in the cecum and small intestine and Baruscapillaria obsignata, for the first time referred in this host, with 2% and 1 in the small intestine. Clinical signs were absent. The gross lesions observed in the crop and esophagus of 14 (38.9%) pheasants parasitized with E. perforans were thickening, small nodules, congestion, and petechial haemorrhages in the mucosa. These birds presented a mean infection of 37.5 and a range of infection of 10-82. The microscopic lesions revealed chronic esophagitis with diffuse inflammatory process in the lamina propria characterized mostly by a mononuclear cell infiltrate and also with the presence of granulocytes. In the case of the parasitism of pheasants with C. phasianina, the gross lesions were absent; microscopic lesions were characterized by chronic typhlitis with mononuclear infiltrate. Gross and microscopic lesions were absent in the pheasants parasitized with E. annulatus and B. obsignata.

Leucocytozoon lovati Infections in Wild Rock Ptarmigan (Lagopus mutus) in Japan

Leucocytozoon lovati infections were detected in free-flying rock ptarmigan (Lagopus mutus), an endangered species that inhabits alpine areas in Japan. Eight of nine adult birds tested positive for L. lovati infection. For comparison, two captive rock ptarmigans hatched in a breeding facility at the foot of the mountains were examined. Both were negative for L. lovati infection. This is the first report of L. lovati infection in the rock ptarmigan in Japan.

Hexamita meleagridis (Spironucleus meleagridis) Infection in Chukar Partridges Associated with High Mortality and Intracellular Trophozoites

An outbreak of infectious catarrhal enteritis, associated with the flagellated protozoan Spironucleus meleagridis (syn. Hexamita meleagridis), is reported from a commercial flock of chukar partridges in California. The disease affected birds between the ages of 4 and 6 wk and resulted in diarrhea, listlessness, depression, and high mortality. Concurrent infection with other intestinal pathogens, including Cryptosporidia, group E Salmonella, long-segmented filamentous microorganisms (LSFMOs), and Rotavirus-like virus particles, was found in some but not all affected birds. Dermatitis of the face, shanks, and feet, suggestive of B-complex vitamin deficiency, was present in most affected birds as well. Flagellated protozoan parasites could be found in the lumen of the duodenum and jejunum and in the intestinal crypts. In some cases the flagellates were wedged between epithelial cells or were located intracellularly within cells of the mucosal epithelium and the intestinal lamina propria.

[Economic losses in pheasant breeding evoked with endoparasites]

Parasitical invasions constitute a serious veterinary-economic problem in pheasant breeding. The studies were carried out between 1995-1997 in a big breeding centre situated in the Middle Pomerania region, where the basic flock amounted to 1000-1200 bird individuals. The aim of the study was to determine a condition of the pheasants' affliction with nematodes, reasons for the invasion and possibilities of a decrease in the losses thus brought about. In the subsequent years, the flock affliction reached the following proportions: 40% in 1995, 42% in 1996, and 68% in 1997. Between 1995 and 1996, the findings revealed eggs of the nematode Capillaria sp (C. anatis and C. phasianina) in their faeces, with less frequent cases of Trichostrongylus tenuis, Heterakis isolonche and Syngamus trachea. Between 1995-1996 40% deaths in the afflicted flock were brought about by Syngamus trachea whilst in 1997 syngamosis resulted in 80% deaths among the afflicted birds. To determine reasons for the confirmed nematode invasion in the studied period during which all the requirements were fulfilled in the pheasant breeding, conclusions were drawn on the basis of the study. Also, preventive measures were suggested to stop any further appearance of syngamosis or losses due to other endoparasites, as those in 1997.