| haematology, weight and condition of captive red grouse (lagopus lagopus scoticus) infected with caecal threadworm (trichostrongylus tenuis). | red grouse infected with the caecal threadworm trichostrongylus tenuis developed a mild anaemia. haemoglobin and albumin levels in the blood fell but there were no significant changes in the number of red blood cells or their size. in infected birds the numbers of circulating eosinophils and heterophils increase, as did the concentration of alpha, beta and gamma globulin. body weights did not change but muscle masses shrank. birds that subsequently died had the lowest concentration of haemoglobi ... | 1978 | 749086 |
| ecology of helminth parasitism in bobwhites from northern florida. | examination of 700 northern bobwhites (colinus virginianus), 50 each february from 1971 through 1984, from tall timbers research station, leon county, florida, disclosed 15 species of helminth parasites. nine species (raillietina cesticillus, r. colinia, aproctella stoddardi, cheilospirura spinosa, cyrnea colini, dispharynx nasuta, heterakis isolonche, tetrameres pattersoni, and trichostrongylus tenuis) generally were found on an annual basis and were considered characteristic components of the ... | 1991 | 2067041 |
| effects of the caecal nematode trichostrongylus tenuis on egg-laying by captive red grouse. | captive hen red grouse infected with trichostrongylus tenuis larvae started to lay later in spring and laid fewer eggs at a slower rate than uninfected hens. march-infected hen grouse showed greater effects than december-infected ones, probably because developing larvae were more pathogenic than adult worms. the mechanism by which parasites interfered with egg production involved reduction in food intake. infected hens also gained less weight than controls before laying. | 1990 | 2300717 |
| the role of parasite fecundity and longevity in the success of trichostrongylus tenuis in low density red grouse populations. | the prevalence of the caecal threadworm trichostrongylus tenuis in red grouse in the north of scotland was high despite low grouse densities. prevalence, intensity and aggregation of threadworms was higher in old than in young grouse. infections were long-lasting: populations of adult worms could survive for over 2 years in grouse, with little mortality. parasite egg output decreased with the age of a worm population, largely as a result of a decrease in the fecundity of ageing female worms. sea ... | 1989 | 2594416 |
| factors affecting the establishment of the caecal threadworm trichostrongylus tenuis in red grouse (lagopus lagopus scoticus). | the resistance of captive reared red grouse to trichostrongylus tenuis was measured as the proportion of ingested infective 3rd-stage larvae which failed to develop to adult worms. individual grouse showed wide, repeatable variations in resistance. seasonal variations may also have occurred. red grouse acquired little or no effective immunity to reinfection after challenge with a single dose of infective larvae. in trickle-dosed grouse, however, adult worms weakly inhibited the establishment of ... | 1989 | 2594417 |
| helminths of california quail (callipepla californica) and mountain quail (oreortyx pictus) in western oregon. | eighty california quail (callipepla californica), collected from the e. e. wilson wildlife area near monmouth, oregon (usa) during a 22 mo period, were examined for gastrointestinal helminths. eight birds were infected with three species of nematodes, heterakis isolonche, dispharynx nasuta, and capillaria sp., and two species of cestodes, rhabdometra odiosa and davainea sp. except for d. nasuta, prevalence did not exceed 5% despite mesic conditions in the collection area. two mountain quail (ore ... | 1989 | 2761017 |
| development and survival of the free-living stages of trichostrongylus tenuis, a caecal parasite of red grouse lagopus lagopus scoticus. | in the laboratory, yields of infective 3rd-stage larvae of trichostrongylus tenuis were determined by temperature when moisture was adequate. on the moor, eggs in caecal faeces did not develop to infective larvae during the winter. in summer, development did occur and yields of infective larvae were related to temperature: greatest yields were obtained when mean monthly soil surface temperatures ranged between 7.6 and 10.3 degrees c. rainfall was unimportant, as was desiccation. during summer th ... | 1989 | 2797866 |
| primary and secondary infection of the domestic chicken with trichostrongylus tenuis (nematoda), a parasite of red grouse, with observations on the effect on the caecal mucosa. | the course of primary and secondary infections with trichostrongylus tenuis in the domestic chicken was investigated. primary infections were established after the administration of single and trickle doses of infective-stage larvae. the worm burden in the caeca was highest after a single dose of 500 infective-stage larvae; this gave a mean of 87 nematodes per bird on days 89 of infection, 20 nematodes on day 14 and 0 on day 28 of infection. following trickle doses of 60, 100, 200, 300, 400 or 5 ... | 1988 | 3174241 |
| arrested development of trichostrongylus tenuis as third stage larvae in red grouse. | worms were counted in red grouse (lagopus lagopus scoticus) in north east scotland in march, april, august, september, november and december 1986. immature worms occurred as third (l3) and fourth (l4) stage larvae throughout. two kinds of evidence suggest that l3 larvae spent much of the winter in a state of arrested development. first, recently acquired l3 larvae could be distinguished by the fact that they retained outer l2 cuticles for a few days; these were present only in the august and sep ... | 1988 | 3194598 |
| gastrointestinal helminths of the northern bobwhite in florida: 1968 and 1983. | we collected 153 northern bobwhites (colinus virginianus) over a 10-mo period from tall timbers research station near tallahassee, florida, usa. five species of gastrointestinal helminths were encountered commonly (greater than 30% prevalence): cyrnea colini, raillietina cesticillus, r. colinia, heterakis isolonche, and trichostrongylus tenuis. other helminths included brachylaima sp., rhabdometra odiosa, mediorhynchus papillosis, cheilospirura spinosa, dispharynx nasuta, gongylonema ingluvicola ... | 1986 | 3503136 |
| seasonal comparison of endoparasites of northern bobwhites from two types of habitat in southern texas. | two nematode species, one acanthocephalan species, and unidentified cestodes were recovered from a total of 481 northern bobwhites (colinus virginianus) collected from january 1982 to december 1983 in southern texas. the nematodes aulonocephalus lindquisti and trichostrongylus tenuis varied in prevalence with month and locality. mediorhynchus papillosis was recovered from only two birds. monthly and yearly rainfall patterns were not correlated with endoparasite intensity and prevalence, which in ... | 1987 | 3586203 |
| the effect of trichostrongylus tenuis on the caecal mucosa of young, old and anthelmintic-treated wild red grouse, lagopus lagopus scoticus. | the caecal mucosa of wild young and adult grouse infected naturally with trichostrongylus tenuis was examined by means of scanning electron microscopy and compared with adult grouse which had been treated with an anthelmintic. the caecal mucosa of young red grouse with low worm burdens possessed longitudinal plicae and exhibited little damage. the caeca from adult grouse, most of which carried high worm burdens, showed a localized depression of plicae and atrophy and cell disruption in areas of ... | 1987 | 3588017 |
| blood eosinophilia in adult bantams naturally infected with trichostrongylus tenuis. | blood eosinophilia was seen in 36 per cent of 115 adult bantams naturally infested with trichostrongylus tenuis; the maximum individual count was 56 per cent eosinophils. there were no measurable levels of ige in the plasma samples and no foci of eosinophils were found in the tissues. | 1985 | 4035087 |
| [propagation and treatment of the trichostrongylus tenuis infestations]. | | 1971 | 5099764 |
| [helminths in broiler geese fattened in runs]. | the occurrence of helminths in broiler geese was studied in the rapid-fattening technological system in 1974-1978. the birds were kept on grassy run adjacent to water. helminthological examination was performed in 1065 broilers and the following 16 helminth species were revealed: notocotylus attenuatus (0.3%), apatemon gracilis (1.5%), cotyrulus cornutus (0.1%), hypoderaeum conoideum (0.1%), retinometra longicirrosa (3.2%), drepanidotaenia lanceolata (3.1%), sobolevicanthus fragilis (0.7%), dior ... | 1980 | 6781122 |
| seasonal trends of helminth parasites of bobwhite quail. | helminthologic examination of 120 adult and 65 juvenile bobwhites (colinus virginianus) from leon county, florida, during a one-year period revealed seven common (> 30% prevalence) species including raillietina cesticillus, r. colinia, cheilospirura spinosa, cyrnea colini, heterakis bonasae, tetrameres pattersoni, and trichostrongylus tenuis. less frequently found helminths included hymenolepis sp., rhabdometra odiosa, mediorhynchus papillosis, aproctella stoddardi, dispharynx nasuta, gongylonem ... | 1980 | 7411743 |
| further studies on the development and survival at low temperatures of the free living stages of trichostrongylus tenuis. | to assess the ability of the free living stages of trichostrongylus tenuis, a pathogen of red grouse, to survive the winter in significant numbers, the temperatures prevailing during the autumn, winter and spring of 1991-92 on the north yorkshire moors were simulated in an incubator into which replicate cultures of t tenuis eggs were placed at intervals. september and early october eggs developed into larvae which survived over winter and were infective the following spring. few november to febr ... | 1994 | 7817009 |
| host specificity of trichostrongylus tenuis from red grouse and northern bobwhites in experimental infections of northern bobwhites. | the red grouse (lagopus lagopus scoticus) and northern bobwhite (colinus virginianus) are parasitized by the cecal nematode, trichostrongylus tenuis. our objective was to determine if t. tenuis from red grouse is infective in bobwhites. we inoculated bobwhites with infective-stage t. tenuis larvae that originated from red grouse in northern england and bobwhites in florida. we also inoculated domestic chickens with larvae from the same sources. none of the 6 bobwhites inoculated with larvae from ... | 1993 | 8331474 |
| development and survival at low temperature of the free living stages of trichostrongylus tenuis. | to test the ability of trichostrongylus tenuis eggs to survive and develop at temperatures similar to those they might experience in late winter on a grouse moor, they were exposed in replicate faecal cultures to various low temperature regimes in the laboratory. yields in experimental cultures were compared with those in control cultures incubated at 21 to 23 degrees c. eggs in caecal faeces were also placed outside on grass plots at intervals through the winter. in addition to this, infective ... | 1993 | 8378608 |
| caecal threadworms trichostrongylus tenuis in red grouse lagopus lagopus scoticus: effects of weather and host density upon estimated worm burdens. | trichostrongylus tenuis eggs were counted in faeces from individually marked wild red grouse for 8 years. egg counts varied seasonally and annually. in some years, a sudden increase in mid-april was consistent with delayed maturation of larvae which had overwintered in the birds in a hypobiotic state. a more gradual increase in summer was probably due to uninterrupted maturation of larvae ingested then. despite 30-fold year-to-year variation in mean egg counts, relative differences in egg counts ... | 1993 | 8414674 |
| hypobiosis of trichostrongylus tenuis in experimentally infected grey partridges. | storage of infective larvae (l3) of trichostrongylus tenuis at +4 degrees c for six weeks before being given as single infections to grey partridges (perdix perdix) did not increase the proportion of worms subsequently found to be hypobiotic. however, after repeated infections, hypobiotic larvae were numerous. three infections given over three weeks resulted not only in the presence of many hypobiotic larvae, but also in the coincident loss of most adult worms. this indication of the role of imm ... | 1993 | 8460270 |
| the effect of parasites on wildlife. | populations of animals which live in the wild are regulated by many biotic and abiotic factors. parasites are one of the biotic factors. parasites may influence their hosts in different ways. they may cause the death of the host due to a direct lethal effect or an indirect effect. direct lethal effects may occur if killing is a part of the life cycle of the parasite or if hosts and parasites have not developed an equilibrium. the introduction of hosts or parasites into a new environment with sui ... | 1996 | 8933697 |
| transmission dynamics and host-parasite interactions of trichostrongylus tenuis in red grouse (lagopus lagopus scoticus). | two components of the transmission dynamics of trichostrongylus tenuis in red grouse are examined and quantified, namely parasite transmission rate and density-dependent reductions in egg production. age-intensity data for birds of known age suggest that the rate of parasite uptake increases during the first 6 mo of a bird's life and this increase reflects an increase in feeding rate with age and exhibits no signs of self-cure. analysis of these age-intensity curves permits us to estimate the tr ... | 1997 | 9105295 |
| cestodiasis in the red grouse in scotland. | little is known about the cestode parasites of red grouse lagopus lagopus scoticus. the carcasses of 71 free-living and grouse collected from northeastern scotland (uk) between june 1991 and september 1992 were examined for the cestode paroniella urogalli. over 70% of young and old birds were infected in summer and winter. cestode abundance ranged from 0 to 29 (mean +/- se = 5.54 +/- 0.81) worms per host and did not differ significantly between young and old grouse, or between seasons. cestode i ... | 1999 | 10231751 |
| a survey of parasitic nematode infections of chickens in rural zimbabwe. | a survey to determine the nematode species in rural chickens reared extensively was carried out in six districts of zimbabwe. two-hundred-and-seventy chickens were randomly collected from the districts and processed for helminth recovery. one genus and 10 species were identified from the gastrointestinal tract but no parasites were found in the respiratory tract and eyes. skrjabinocerca sp., capillaria obsignata, capillaria contorta and trichostrongylus tenuis are new records in zimbabwe. alloda ... | 2001 | 11769349 |
| strategies for nematode transmission: selective migration of trichostrongylus tenuis infective larvae. | successful transmission of macroparasites is dependent on exposure of susceptible hosts to free-living infective stages. when these hosts are herbivores that feed mostly on a single food plant then natural selection should favour those infective larvae that selectively ascend this main food plant. red grouse feed predominantly on heather, calluna vulgaris, so we predict that the infective larvae (l3) of the caecal nematode trichostrongylus tenuis selectively locate and ascend heather plants. to ... | 2001 | 11818056 |
| a comparison of the prevalence and burdens of helminth infections in growers and adult free-range chickens. | matched samples of 100 chickens of each of growers and adult rural free-range chickens in morogoro, tanzania, were purchased from the beginning to the end of the long rainy season. at necropsy, the trachea, the gastrointestinal tract and the oviduct were examined for helminth infections. the helminth species isolated comprised 18 nematodes and 8 cestodes but no trematodes. tetrameres fissispina is a new record in tanzania. all the chickens harboured at least three different helminth species. gro ... | 2002 | 12094676 |
| trophic interactions and population growth rates: describing patterns and identifying mechanisms. | while the concept of population growth rate has been of central importance in the development of the theory of population dynamics, few empirical studies consider the intrinsic growth rate in detail, let alone how it may vary within and between populations of the same species. in an attempt to link theory with data we take two approaches. first, we address the question 'what growth rate patterns does theory predict we should see in time-series?' the models make a number of predictions, which in ... | 2002 | 12396517 |
| correlates of helminth community in the red-legged partridge (alectoris rufa l.) in spain. | between 1992 and 1996, 587 wild red-legged partridges (alectoris rufa) from 16 spanish provinces were examined to study the variations of helminth communities in this game species across a broad geographical area. the survey revealed 13 species of helminth parasites. dicrocoelium sp.. rhabdometra nigropunctata, and cheilospirura gruweli were the most common species, whereas raillietina bolivari, choanotaenia infundibulum, tetrameres sp., and capillaria anatis were the most rare. subulura suctori ... | 2003 | 12880240 |
| faecal egg counts provide a reliable measure of trichostrongylus tenuis intensities in free-living red grouse lagopus lagopus scoticus. | the reliability of different egg counting methods for estimating the intensity of trichostrongylus tenuis infections in red grouse, lagopus lagopus scoticus, was investigated in the autumn, when grouse may harbour high parasite intensities. possible limitations to the use of these methods were also examined. faecal egg counts were found to accurately estimate t. tenuis worm intensities, at least up to an observed maximum of c. 8000 worms. two egg counting methods (smear and mcmaster) gave consis ... | 2004 | 14972040 |
| population biology of trichostrongylus tenuis, a parasite of economic importance for red grouse management. | the caecal nematode, trichostrongylus tenuis, is associated with dramatic decreases in the density of red grouse (lagopus lagopus scoticus) resulting in a significant loss of sporting income to many upland estates in the uk. in this article peter hudson and andrew dobson describe the dynamics of the grouse-t. tenuis system, show that the parasites can cause population crashes and present preliminary findings from the development of new control methods. | 1989 | 15463233 |
| 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 po ... | 2005 | 15716952 |
| 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 ... | 2005 | 15891828 |
| 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 ... | 2005 | 16191643 |
| vector-borne parasites decrease host mobility: a field test of freeze or flee behaviour of willow ptarmigan. | transmission mode has been suggested to be a strong predictor of virulence. according to theory, the transmission of vector-borne parasites should be less dependent on host mobility than directly transmitted parasites. this could select for increased exploitation of host resources in parasites transmitted by vectors, which may be manifested as higher virulence. here, we test the prediction that there is an association between transmission mode and the effect on host mobility by comparing parasit ... | 2006 | 16696980 |
| abundant variation in microsatellites of the parasitic nematode trichostrongylus tenuis and linkage to a tandem repeat. | an understanding of how genes move between and within populations of parasitic nematodes is important in combating the evolution and spread of anthelmintic resistance. much has been learned by studying mitochondrial dna markers, but autosomal markers such as microsatellites have been applied to only a few nematode species, despite their many advantages for studying gene flow in eukaryotes. here, we describe the isolation of 307 microsatellites from trichostrongylus tenuis, an intestinal nematode ... | 2006 | 16765463 |
| climate disruption and parasite-host dynamics: patterns and processes associated with warming and the frequency of extreme climatic events. | levels of parasitism and the dynamics of helminth systems is subject to the impact of environmental conditions such that we may expect long term increases in temperature will increase the force of infection and the parasite's basic reproduction number, r0. we postulate that an increase in the force of infection will only lead to an increase in mean intensity of adults when adult parasite mortality is not determined by acquired immunity. preliminary examination of long term trends of parasites of ... | 2006 | 16768860 |
| [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 ... | 1999 | 16886377 |
| macrogeographic population structure in a parasitic nematode with avian hosts. | much remains to be discovered about the population genetic structure of parasites, despite the importance of such knowledge to understanding the processes involved in the spread of drug resistance through populations. here we present a study of population genetic diversity in trichostrongylus tenuis, an avian parasitic nematode infecting both poultry and game birds, where anthelmintic use is common. we examined diversity of nicotinamide dehydrogenase subunit 4 (nad4) mtdna sequences within and b ... | 2007 | 17097808 |
| 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-orbita ... | 2007 | 17264052 |
| [use of mebendazole for helminthiases in chickens and geese]. | 103 chickens experimentally infected with capillaria obsignata were treated with mebendazol at a dose of 30 mg/kg body-weight daily for 3 consecutive days. the effectiveness of the drug on the 4th stage larvae as well as immature and mature 5th stage forms were 92,5%, 98% and 98,8% respectively. in another experiment to 32 chickens experimentally infected with syngamus trachea mebendazol was given at 40 mg/kg body-weight on 3 successive days. mebendazol removed the immature and mature gape worms ... | 1973 | 18777386 |
| absence of three known benzimidazole resistance mutations in trichostrongylus tenuis, a nematode parasite of avian hosts. | benzimidazole (bz) resistance is widespread in nematode parasites of livestock, but very little is known about the levels of bz resistance in parasites with avian hosts. we investigated bz resistance in trichostrongylus tenuis, a nematode parasite of red grouse, lagopus lagopus scotica. bz anthelmintics had been in use in this system for up to 15 years, yet existing phenotypic evidence for resistance was inconclusive. we screened 1530 individuals from 14 populations at the principal beta-tubulin ... | 2008 | 19027239 |
| [determination of parasite fauna of chicken in the van region]. | the aim of this study was to determine the parasite fauna of the chicken in van province in 2002 and 2003. the material of the present study included endoparasites and ectoparasites determined by rutine parasitological examinations. direct, flotation and sedimentation techniques for endoparasites were used. the total of endoparasites and ectoparasites were determined as 85% and 76% respectively. the ratios of endoparasites obtained from the chicken were coccidial oocystis 65%, echinostoma spp. 2 ... | 2009 | 19598095 |
| fitting models of multiple hypotheses to partial population data: investigating the causes of cycles in red grouse. | there are two postulated causes for the observed periodic fluctuations (cycles) in red grouse (lagopus lagopus scoticus). the first involves interaction with the parasitic nematode trichostrongylus tenuis. the second invokes delayed regulation through the effect of male aggressiveness on territoriality. empirical evidence exists to support both hypotheses, and each hypothesis has been modeled deterministically. however, little effort has gone into looking at the combined effects of the two mecha ... | 2009 | 19627232 |
| bayesian paternity analysis and mating patterns in a parasitic nematode, trichostrongylus tenuis. | mating behaviour is a fundamental aspect of the evolutionary ecology of sexually reproducing species, but one that has been under-researched in parasitic nematodes. we analysed mating behaviour in the parasitic nematode trichostrongylus tenuis by performing a paternity analysis in a population from a single red grouse host. paternity of the 150 larval offspring of 25 mothers (sampled from one of the two host caeca) was assigned among 294 candidate fathers (sampled from both caeca). each candidat ... | 2010 | 19826438 |
| quantifying fenbendazole and its metabolites in self-medicating wild red grouse lagopus lagopus scoticus using an hplc-ms-ms approach. | on red grouse estates in the uk the nematode parasite trichostrongylus tenuis is often controlled by application of grit medicated with the anthelmintic fenbendazole (fbz). to date, assessment of the efficacy has been inhibited by the inability to quantify uptake of fbz by the birds. we have developed a simple and sensitive hplc-ms-ms method for detecting and quantifying fbz and its metabolites from a 300 mg sample of red grouse liver. this method could be used to improve the efficacy of medicat ... | 2010 | 21236579 |
| condition- and parasite-dependent expression of a male-like trait in a female bird. | in many species, females display brightly coloured and elaborate traits similar to those that males use in intra- and inter-sexual selection processes. these female characters are sometimes related to fitness, and might function as secondary sexual characteristics that have evolved through sexual selection. here, we used descriptive data from 674 females in 10 populations and an experimental removal of trichostrongylus tenuis parasites in four populations, to examine the effects of season, age, ... | 2011 | 21247939 |
| identification of genes responding to nematode infection in red grouse. | the identification of genes involved in a host's response to parasite infection provides both a means for understanding the pathways involved in immune defence and a target for examining host-parasite co-evolution. most studies rely on a candidate gene approach derived from model systems to identify gene targets of interest, and there have been a dearth of studies geared towards providing a holistic overview of immune response from natural populations. we carried out an experiment in a natural p ... | 2011 | 21429137 |
| The ornament-condition relationship varies with parasite abundance at population level in a female bird. | Environmental heterogeneity is expected to create variation in the ornament-condition relationship. This topic has been studied in males with less attention being given to females. Here, we explore inter-population variation in the relationship between the size of a male-like trait, supra-orbital combs, and body mass in female red grouse Lagopus lagopus scoticus. We used the abundance of the nematode Trichostrongylus tenuis, a parasite with strong negative effects on this species, as a proxy of ... | 2011 | 21858505 |
| gastrointestinal parasites of free-range chickens. | the aim of the study was to determine the prevalence and intensity of parasitic gastrointestinal infections in free-range chickens from the west pomerania province. experimental material for the study was taken from 10 farms. breeds raised in farms participating in the study included miniature chickens called polish lilliputians and green- legged partridge. a total of 104 samples of faeces were examined. the willis-schlaff flotation method was used to assess the prevalence of infection, and mcma ... | 2014 | 25706430 |
| gastrointestinal parasitic infections in chickens of upper gangetic plains of india with special reference to poultry coccidiosis. | studies on the prevalence of gastrointestinal parasites of chicken reared under backyard and intensive systems were carried out in two north indian states viz., uttar pradesh and uttarakhand. out of 58 poultry farms screened for gastrointestinal parasites, 81.03 % were positive for eimeria spp., 15.52 % for ascaridia galli, 3.45 % for hetarakis gallinarum, 1.72 % for syngamus trachea, 5.17 % for capillaria spp, 1.72 % for raillietina spp., 1.72 % for trichostrongylus tenuis, 1.72 % for choanotae ... | 2015 | 25698854 |
| 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 p ... | 2016 | 27870855 |
| helminth community structure in two species of arctic-breeding waterfowl. | climate change is occurring rapidly at high latitudes, and subsequent changes in parasite communities may have implications for hosts including wildlife and humans. waterfowl, in particular, harbor numerous parasites and may facilitate parasite movement across broad geographic areas due to migratory movements. however, little is known about helminth community structure of waterfowl at northern latitudes. we investigated the helminth communities of two avian herbivores that breed at high latitude ... | 2016 | 27709067 |
| the role of parasite-driven selection in shaping landscape genomic structure in red grouse (lagopus lagopus scotica). | landscape genomics promises to provide novel insights into how neutral and adaptive processes shape genome-wide variation within and among populations. however, there has been little emphasis on examining whether individual-based phenotype-genotype relationships derived from approaches such as genome-wide association (gwas) manifest themselves as a population-level signature of selection in a landscape context. the two may prove irreconcilable as individual-level patterns become diluted by high ... | 2016 | 26578090 |
| genome-wide association and genome partitioning reveal novel genomic regions underlying variation in gastrointestinal nematode burden in a wild bird. | identifying the genetic architecture underlying complex phenotypes is a notoriously difficult problem that often impedes progress in understanding adaptive eco-evolutionary processes in natural populations. host-parasite interactions are fundamentally important drivers of evolutionary processes, but a lack of understanding of the genes involved in the host's response to chronic parasite insult makes it particularly difficult to understand the mechanisms of host life history trade-offs and the ad ... | 2015 | 26179597 |
| digging for gold nuggets: uncovering novel candidate genes for variation in gastrointestinal nematode burden in a wild bird species. | the extent to which genotypic variation at a priori identified candidate genes can explain variation in complex phenotypes is a major debate in evolutionary biology. whereas some high-profile genes such as the mhc or mc1r clearly do account for variation in ecologically relevant characters, many complex phenotypes such as response to parasite infection may well be underpinned by a large number of genes, each of small and effectively undetectable effect. here, we characterize a suite of novel can ... | 2015 | 25752450 |
| seasonal forcing in a host-macroparasite system. | seasonal forcing represents a pervasive source of environmental variability in natural systems. whilst it is reasonably well understood in interacting populations and host-microparasite systems, it has not been studied in detail for host-macroparasite systems. in this paper we analyse the effect of seasonal forcing in a general host-macroparasite system with explicit inclusion of the parasite larval stage and seasonal forcing applied to the birth rate of the host. we emphasise the importance of ... | 2015 | 25445186 |
| fine-scale population epigenetic structure in relation to gastrointestinal parasite load in red grouse (lagopus lagopus scotica). | epigenetic modification of cytosine methylation states can be elicited by environmental stresses and may be a key process affecting phenotypic plasticity and adaptation. parasites are potent stressors with profound physiological and ecological effects on their host, but there is little understanding in how parasites may influence host methylation states. here, we estimate epigenetic diversity and differentiation among 21 populations of red grouse (lagopus lagopus scotica) in north-east scotland ... | 2014 | 24943398 |
| experimentally elevated levels of testosterone at independence reduce fitness in a territorial bird. | environmental conditions and individual strategies in early life may have a profound effect on fitness. a critical moment in the life of an organism occurs when an individual reaches independence and stops receiving benefits from its relatives. understanding the consequences of individual strategies at the time of independence requires quantification of their fitness effects. we explored this period in the red grouse (lagopus lagopus scoticus). in this system, testosterone and parasite (trichost ... | 2014 | 24933821 |
| insights into population ecology from long-term studies of red grouse lagopus lagopus scoticus. | long-term studies have been the backbone of population ecology. the red grouse lagopus lagopus scoticus is one species that has contributed widely to this field since the 1950s. this paper reviews the trajectory and profound impact that these studies have had. red grouse research has combined long-term studies of marked individuals with demographic studies over wide geographical areas and replicated individual- and population-level manipulations. a main focus has been on understanding the causes ... | 2014 | 23800249 |
| comparison of single and split-dose flubendazole treatment for the nematode parasite trichostrongylus tenuis in experimentally infected grey partridges perdix perdix. | different therapeutic regimes using flubendazole for the treatment of trichostrongylus tenuis infection in experimentally infected grey partridges perdix perdix were examined. flubendazole dosages of 4, 8 and 20 mg/kg were administered orally as a single dose or split into 3 or 9 parts given over 9 days. the efficacy against adult worms in the caeca improved with dose rate. split doses were at least as effective as single doses, which removed up to 83% of adult t. tenuis. a dose of 20 mg/kg admi ... | 2012 | 22850078 |
| associations between body composition and helminths of lesser snow geese during winter and spring migration. | costs of parasitism are predicted to be higher with greater parasite intensities and higher inter-parasite competition (diversity). we tested whether greater helminth intensities and diversity were associated with poorer body composition (whole-body fat, protein, mineral and true body mass) in lesser snow geese, chen caerulescens caerulescens. as part of a larger study on nutritional ecology, 828 wintering or migrating geese were shot between january and may 1983 in 27 different date-locations ( ... | 2012 | 22713759 |
| parasitized mates increase infection risk for partners. | individuals can gain fitness benefits and costs through their mates. however, studies on sexual selection have tended to focus on genetic benefits. a potentially widespread cost of pairing with a parasitized mate is that doing so will increase an individual's parasite abundance. such a cost has been overlooked in systems in which parasites are indirectly transmitted. we manipulated the abundance of the nematode parasite trichostrongylus tenuis, an indirectly transmitted parasite, within pairs of ... | 2012 | 22617268 |
| the effect of parasites on wildlife. | summary populations of animals which live in the wild are regulated by many biotic and abiotic factors. parasites are one of the biotic factors. parasites may influence their hosts in different ways. they may cause the death of the host due to a direct lethal effect or an indirect effect. direct lethal effects may occur if killing is a part of the life cycle of the parasite or if hosts and parasites have not developed an equilibrium. the introduction of hosts or parasites into a new environment ... | 1996 | 22077112 |
| parasites and scottish ptarmigan numbers. | unlike red grouse (lagopus lagopus scoticus), which have almost 100% prevalence of the parasitic threadworm trichostrongylus tenuis and frequently high tapeworm numbers, 70% (n=71) of scottish ptarmigan (lagopus mutus) had no threadworms and only 4% had tapeworms. other parasites and pathogenic bacteria were infrequent. threadworms occurred in 12% (n=25) of birds on granite hills where mean ptarmigan densities were low, and in 43% (n=46) of birds over schists and limestones where mean densities ... | 1991 | 28313796 |
| the pervalence of caecal threadworms (trichostrongylus tenuis) in red grouse (lagopus lagopus scoticus). | ninety percent of wild red grouse examined carried threadworms in their intenstinal caeca. old birds had 30 times as many worms as young birds. some infections were as high as 30,000 worms. the occurrence of worms in old grouse conformed to the negative binomial distribution. | 1983 | 28310590 |