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temporal changes in kin structure through a population cycle in a territorial bird, the red grouse lagopus lagopus scoticus.populations of red grouse (lagopus lagopus scoticus) undergo regular multiannual cycles in abundance. the 'kinship hypothesis' posits that such cycles are caused by changes in kin structure among territorial males producing delayed density-dependent changes in aggressiveness, which in turn influence recruitment and regulate density. the kinship hypothesis makes several specific predictions about the levels of kinship, aggressiveness and recruitment through a population cycle: (i) kin structure w ...200818430149
characterising functionally important and ecologically meaningful genetic diversity using a candidate gene approach.over the past two decades the fields of molecular ecology and population genetics have been dominated by the use of putatively neutral dna markers, primarily to resolve spatio-temporal patterns of genetic variation to inform our understanding of population structure, gene flow and pedigree. recent emphasis in comparative functional genomics, however, has fuelled a resurgence of interest in functionally important genetic variation that underpins phenotypic traits of adaptive or ecological signifi ...201018803023
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: cervida ...200818816272
monitoring of raptors and their contamination levels in norway.this article summarizes results from raptor monitoring and contamination studies in norway of the golden eagle, gyrfalcon, white-tailed sea eagle, osprey, peregrine, and merlin. golden eagle and gyrfalcon populations have been monitored since 1990 as part of the "monitoring programme for terrestrial ecosystems" (tov). no long-term trend in the population size or productivity of golden eagle has been shown in any of the 5 study areas. the reproductive output of gyrfalcon is monitored in 3 areas. ...200818833794
factors affecting unintentional harvesting selectivity in a monomorphic species.1. changes in the abundance of populations have always perplexed ecologists but long-term studies are revealing new insights into population dynamic processes. long-term data are often derived from harvest records although many wild populations face high harvesting pressures leading to overharvesting and extinction. additionally, harvest records used to describe population processes such as fluctuations in abundance and reproductive success often assume a random off-take. 2. selective harvesting ...200919021782
interactions between harvesting, noise and territoriality in a model of red grouse population cycles.1. population cycles are mostly thought to arise through extrinsic rather than intrinsic processes. however, in red grouse (lagopus lagopus scoticus), intrinsic male territoriality has been proposed as a driver of the cycles, possibly in conjunction with an extrinsic interaction with specialist parasitic worms. here we examine how harvesting and environmental noise may also interact with territoriality to determine how grouse populations cycle. 2. a stochastic model of grouse dynamics based on t ...200919021784
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 ...200819027239
a multilocus assay reveals high nucleotide diversity and limited differentiation among scandinavian willow grouse (lagopus lagopus).there is so far very little data on autosomal nucleotide diversity in birds, except for data from the domesticated chicken and some passerines species. estimates of nucleotide diversity reported so far in birds have been high (approximately 10(-3)) and a likely explanation for this is the generally higher effective population sizes compared to mammals. in this study, the level of nucleotide diversity has been examined in the willow grouse, a non-domesticated bird species from the order galliform ...200819099558
bone lead levels and lead isotope ratios in red grouse from scottish and yorkshire moors.leg and foot bones of adult and juvenile red grouse (lagopus lagopus scoticus) were collected from hunter-shot birds on two scottish estates (glendye and invermark) and one yorkshire estate in september, 2003. the lead content of bones was measured by atomic absorption spectrophotometry, and corresponding stable lead isotopes (pb(204, 206, 207, 208)) by inductively coupled plasma mass spectrometry. at the glendye (n=111) and invermark (n=85) estates, relatively few birds (5.4% and 3.5%, respecti ...200919264349
physiological stress mediates the honesty of social signals.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, ...200919319197
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 ...200919627232
altitudinal patterns of tick and host abundance: a potential role for climate change in regulating tick-borne diseases?the impact of climate change on vector-borne infectious diseases is currently controversial. in europe the primary arthropod vectors of zoonotic diseases are ticks, which transmit borrelia burgdorferi sensu lato (the agent of lyme disease), tick-borne encephalitis virus and louping ill virus between humans, livestock and wildlife. ixodes ricinus ticks and reported tick-borne disease cases are currently increasing in the uk. theories for this include climate change and increasing host abundance. ...201019685082
physiological stress links parasites to carotenoid-based colour signals.vertebrates commonly use carotenoid-based traits as social signals. these can reliably advertise current nutritional status and health because carotenoids must be acquired through the diet and their allocation to ornaments is traded-off against other self-maintenance needs. we propose that the coloration more generally reveals an individual's ability to cope with stressful conditions. we tested this idea by manipulating the nematode parasite infection in free-living red grouse (lagopus lagopus s ...201020074170
oxidative stress and the effect of parasites on a carotenoid-based ornament.oxidative stress, the physiological condition whereby the production of reactive oxygen and nitrogen species overwhelms the capacity of antioxidant defences, causes damage to key bio-molecules. it has been implicated in many diseases, and is proposed as a reliable currency in the trade-off between individual health and ornamentation. whether oxidative stress mediates the expression of carotenoid-based signals, which are among the commonest signals of many birds, fish and reptiles, remains contro ...201020086124
sequence polymorphism in candidate genes for differences in winter plumage between scottish and scandinavian willow grouse (lagopus lagopus).population variation in the degree of seasonal polymorphism is rare in birds, and the genetic basis of this phenomenon remains largely undescribed. both sexes of scandinavian and scottish willow grouse (lagopus lagopus) display marked differences in their winter phenotypes, with scottish grouse retaining a pigmented plumage year-round and scandinavian willow grouse molting to a white morph during winter. a widely studied pathway implicated in vertebrate pigmentation is the melanin system, for wh ...201020428241
testing the interactive effects of testosterone and parasites on carotenoid-based ornamentation in a wild bird.testosterone underlies the expression of most secondary sexual traits, playing a key role in sexual selection. however, high levels might be associated with physiological costs, such as immunosuppression. immunostimulant carotenoids underpin the expression of many red-yellow ornaments, but are regulated by testosterone and constrained by parasites. we manipulated testosterone and nematode burdens in red grouse (lagopus lagopus scoticus) in two populations to tease apart their effects on caroteno ...201020536879
genetic diversity and differentiation among lagopus lagopus populations in scandinavia and scotland: evolutionary significant units confirmed by snp markers.single nucleotide polymorphism in four scandinavian populations of willow grouse (lagopus lagopus) and two scottish populations of red grouse (lagopus lagopus scoticus) were assessed at 13 protein-coding loci. we found high levels of diversity, with one substitution every 55 bp as an average and a total of 76 unlinked parsimony informative snps. different estimators of genetic diversity such as: number of synonymous and non-synonymous sites, average number of alleles, number and percentage of po ...201020636891
is hunting mortality additive or compensatory to natural mortality? effects of experimental harvest on the survival and cause-specific mortality of willow ptarmigan.1. the effects of harvest on the annual and seasonal survival of willow ptarmigan lagopus lagopus l. were tested in a large-scale harvest experiment. management units were randomly assigned to one of three experimental treatments: 0%, 15% or 30% harvest. seasonal quotas were based on the experimental treatment and estimates of bird density before the hunting season. survival rates and hazard functions for radio-marked ptarmigan were then estimated under the competing risks of harvest and natural ...201021054381
transcriptomic response of red grouse to gastro-intestinal nematode parasites and testosterone: implications for population dynamics.a central issue in ecology is in understanding the relative influences of intrinsic and extrinsic effects on population regulation. previous studies on the cyclic population dynamics of red grouse (lagopus lagopus scoticus) have emphasized the destabilizing effects of either nematode parasites or territorial behaviour and aggression. the potential interacting effects of these processes, mediated through density-dependent, environmentally induced alterations of host immunocompetence influencing s ...201021073676
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 ...201021236579
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, ...201121247939
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 ...201121429137
impact of unintentional selective harvesting on the population dynamics of red grouse.1. the effect of selective exploitation of certain age, stage or sex classes (e.g., trophy hunting) on population dynamics is relatively well studied in fisheries and sexually dimorphic mammals. 2. harvesting of terrestrial species with no morphological differences visible between the different age and sex classes (monomorphic species) is usually assumed to be nonselective because monomorphicity makes intentionally selective harvesting pointless and impractical. but harvesting of the red grouse ...201121595686
the importance of willow thickets for ptarmigan and hares in shrub tundra: the more the better?in patchy habitats, the relationship between animal abundance and cover of a preferred habitat may change with the availability of that habitat, resulting in a functional response in habitat use. here, we investigate the relationship of two specialized herbivores, willow ptarmigan (lagopus lagopus) and mountain hare (lepus timidus), to willows (salix spp.) in three regions of the shrub tundra zone-northern norway, northern european russia and western siberia. shrub tundra is a naturally patchy h ...201121833646
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 ...201121858505
environmental heterogeneity influences the reliability of secondary sexual traits as condition indicators.numerous studies have shown positive associations between ornaments and condition, as predicted by indicator models of sexual selection. however, this idea is continuously challenged by opposite results, which reveal our lack of full understanding of how sexual selection works. environmental heterogeneity may explain such inconsistencies, but valid field tests of this idea are currently lacking. we first analysed the relationship between condition and ornament expression from nine populations ov ...201222022806
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 ...199622077112
Enhanced control of sheep ticks in upland sheep flocks: repercussions for red grouse co-hosts.Sheep ticks Ixodes ricinus (Acari: Ixodidae) and tick-borne diseases cause major economic losses in both upland sheep farming and moorland shoots of red grouse Lagopus lagopus scoticus. Sheep were treated with acaricide four times between March and October and double-vaccinated against louping ill virus (LIV), instead of the conventional regime of two acaricide treatments and no vaccinations, on two moors in northern England. Enhanced treatment started at Westerdale Moor in 1995 and at Danby Moo ...201122112150
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 ...201222617268
social context decouples the relationship between a sexual ornament and testosterone levels in a male wild bird.in order to maximise fitness individuals should adjust their level of signalling according to their surrounding social environment. however, field experiments showing such adjustment of current signalling associated to changes in social context are lacking. here, we manipulated levels of male aggressive- and dominance-related displays in a wild bird in our treated area by increasing testosterone levels using implants in a subset of males. we then compared the expression of sexual signals (i.e. c ...201222841824
an alternative to killing? treatment of reservoir hosts to control a vector and pathogen in a susceptible species.parasite-mediated apparent competition occurs when one species affects another through the action of a shared parasite. one way of controlling the parasite in the more susceptible host is to manage the reservoir host. culling can cause issues in terms of ethics and biodiversity impacts, therefore we ask: can treating, as compared to culling, a wildlife host protect a target species from the shared parasite? we used susceptible infected recovered (sir) models parameterized for the tick-borne loup ...201322939093
a model to test how ticks and louping ill virus can be controlled by treating red grouse with acaricide.ticks are the most important vectors of disease-causing pathogens in europe. in the u.k., ixodes ricinus l. (ixodida: ixodidae) transmits louping ill virus (liv; flaviviridae), which kills livestock and red grouse, lagopus lagopus scoticus lath. (galliformes: phasianidae), a valuable game bird. tick burdens on grouse have been increasing. one novel method to reduce ticks and liv in grouse may be acaricide treatment. here, we use a mathematical model parameterized with empirical data to investiga ...201323088727
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 ...201423800249
metals and selenium in wild animals from norwegian areas close to russian nickel smelters.this paper reports the concentrations of metals (al, as, cd, cr, cu, hg, ni, pb, and/or zn) and selenium (se) in kidney and/or liver samples from capercaillie (tetrao urogallus), willow ptarmigan (lagopus lagopus), hares (lepus timidus), common shrews (sorex araneus) and grey-sided voles (clethrionomus rufocanus) from the norwegian areas most heavily contaminated by pollutants from the russian smelters on the kola peninsula. in addition to comparing areas that differed in expected pollution rate ...199524197780
helminths from willow grouse ( lagopus lagopus ) in two localities in north norway.a total of 77 adult and 123 juvenile willow grouse ( lagopus lagopus ) from the island of karlsöy, and 75 adult and 63 juvenile willow grouse from sennaland on the mainland of north norway were examined for helminths. raillietina urogalli and hymenolepis microps , and ascaridia compar and syngamus trachea were found. all four species occurred regularly in grouse from karlsöy between april and september-october, but only h. microps was frequently found in birds from sennaland. s. trachea only par ...197724228962
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 ...201424698833
the response of willow grouse chicks to auditory stimuli 1. preference for hen grouse calls.willow grouse (lagopus lagopus lagopus) chicks newly hatched from mechanically incubated eggs were exposed to different combinations of sounds in a heated runway. they approached a loudspeaker playing grouse hen calls, which they had never heard, in preference to one playing the noise of the hatching machine from which they had just been removed. similarly they preferred the hen call to another novel sound. when the three sounds were played singly instead of in pairs, only the hen call was appro ...197724924106
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 ...201424933821
spread of cryptosporidium baileyi in red grouse lagopus lagopus scoticus. 201424934399
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 ...201424943398
herbivores influence the growth, reproduction, and morphology of a widespread arctic willow.shrubs have expanded in arctic ecosystems over the past century, resulting in significant changes to albedo, ecosystem function, and plant community composition. willow and rock ptarmigan (lagopus lagopus, l. muta) and moose (alces alces) extensively browse arctic shrubs, and may influence their architecture, growth, and reproduction. furthermore, these herbivores may alter forage plants in such a way as to increase the quantity and accessibility of their own food source. we estimated the effect ...201425047582
inferring the nature of anthropogenic threats from long-term abundance records.diagnosing the processes that threaten species persistence is critical for recovery planning and risk forecasting. dominant threats are typically inferred by experts on the basis of a patchwork of informal methods. transparent, quantitative diagnostic tools would contribute much-needed consistency, objectivity, and rigor to the process of diagnosing anthropogenic threats. long-term census records, available for an increasingly large and diverse set of taxa, may exhibit characteristic signatures ...201525065712
rough-legged buzzards, arctic foxes and red foxes in a tundra ecosystem without rodents.small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming arctic. here we document for the first time how three normally rodent-dependent predator species-rough-legged b ...201525692786
experimental evidence that ptarmigan regulate willow bud production to their own advantage.in some ecosystems, vertebrate herbivores increase the nutritional quality and biomass of their food source through repeated grazing, thereby manipulating their environment to support higher densities of animals. we tested whether ptarmigan (lagopus lagopus and l. muta) are capable of regulating the nutritional quality, abundance, and availability of feltleaf willow (salix alaxensis) buds using a simulated browsing experiment and a feeding preference study with wild birds. simulated ptarmigan br ...201525698142
vegetation management with fire modifies peatland soil thermal regime.vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. in the uk, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (lagopus lagopus scotica) by rotational burning of shrub vegetation. to date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of t ...201525728915
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 ...201525752450
the long term response of birds to climate change: new results from a cold stage avifauna in northern england.the early mis 3 (55-40 kyr bp associated with middle palaeolithic archaeology) bird remains from pin hole, creswell crags, derbyshire, england are analysed in the context of the new dating of the site's stratigraphy. the analysis is restricted to the material from the early mis 3 level of the cave because the upper fauna is now known to include holocene material as well as that from the late glacial. the results of the analysis confirm the presence of the taxa, possibly unexpected for a late ple ...201525992609
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 ...201526179597
louping ill virus in the uk: a review of the hosts, transmission and ecological consequences of control.louping ill virus (liv) is a tick-borne flavivirus that is part of the tick-borne encephalitis complex of viruses (tbev) and has economic and welfare importance by causing illness and death in livestock, especially sheep, ovies aries, and red grouse, lagopus lagopus scoticus, an economically valuable gamebird. unlike western tbev which is found primarily in woodlands and is reservoired by small rodents, liv is not generally transmitted by small rodents but instead by sheep, red grouse and mounta ...201626205612
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 ...201626578090
skydancerplex: a novel str multiplex validated for forensic use in the hen harrier (circus cyaneus).the hen harrier (circus cyaneus) is a bird of prey which is heavily persecuted in the uk because it preys on the game bird red grouse (lagopus lagopus scoticus). to help investigations into illegal killings of hen harrier, a str multiplex kit containing eight short tandem repeat (str) markers and a chromohelicase dna binding protein 1 (chd 1) sexing marker was developed. the multiplex kit was tested for species specificity, sensitivity, robustness, precision, accuracy and stability. full profile ...201626881329
can acaricide-impregnated leg bands fitted to female red grouse reduce sheep tick parasitization of chicks and increase chick survival?in parts of northern england, north wales and the scottish highlands, increasing numbers of sheep ticks ixodes ricinus (ixodida: ixodidae), and the louping ill virus they can carry, are considered to be important factors that reduce red grouse lagopus lagopus scotica productivity. the present study tested this hypothesis by fitting adult female grouse with leg bands impregnated with the acaricide cypermethrin to experimentally control ticks on their chicks on two managed grouse moors in northeas ...201627377883
range shifts or extinction? ancient dna and distribution modelling reveal past and future responses to climate warming in cold-adapted birds.global warming is predicted to cause substantial habitat rearrangements, with the most severe effects expected to occur in high-latitude biomes. however, one major uncertainty is whether species will be able to shift their ranges to keep pace with climate-driven environmental changes. many recent studies on mammals have shown that past range contractions have been associated with local extinctions rather than survival by habitat tracking. here, we have used an interdisciplinary approach that com ...201727762483
the role of chewing lice (phthiraptera: philopteridae) as intermediate hosts in the transmission of hymenolepis microps (cestoda: cyclophyllidea) from the willow ptarmigan lagopus lagopus (aves: tetraonidae).the cestode hymenolepis microps is an intestinal parasite of tetraonid birds, including the willow ptarmigan (lagopus lagopus). this parasite is able to maintain a high prevalence and intensity throughout the year, even in a subarctic environment in bird populations with relatively low host densities, indicating effective transmission routes. willow ptarmigan consume mainly vegetal material and active consumption of invertebrates is confined to the first two or three weeks of life. ptarmigan are ...201728260532
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.198328310590
general properties of predictive population models in red grouse (lagopus lagopus scoticus).the general properties of an empirical predictive model of population fluctuations in red grouse are discussed. the model incorporates two observed time-lagged relationships between (a) chick production and spring numbers two years earlier, and (b) overwinter survival and numbers in spring one year earlier. the model produced oscillations which were slowly damped with a period of nine years. the addition of randomly-imposed poor breeding sustained the amplitude of oscillations but did not affect ...198428310892
social class, socially-induced loss, recruitment and breeding of red grouse.individually marked red grouse (lagopus lagopus scoticus) could be distinguished as territorial or non-territorial from november till the next spring. territorial birds survived well and many reared young, but numerous nonterritorial birds died or disappeared, and none paired up or reared young. differences in spring sex ratio between years had already been set in the previous autumn's territorial stock. many old birds which had been territorial in earlier seasons lost territories after an annua ...198528311033
a genetic explanation for ten-year cycles of grouse.chitty's polymorphic behavioural hypothesis (chitty 1967) was logically reduced to three main assumptions that were mathematically modelled: 1) level of aggression is genetically determined by simple mendelian selection. 2) recruitment is inversely related to female parental level of aggression. 3) aggressives are completely successful in breeding competition. the model utilized data from willow ptarmigan populations, but was generalized to other grouse species. simulation results were indisting ...198428311638
cycles in voles and small game in relation to variations in plant production indices in northern sweden.population dynamics for voles (cricetidae), tengmalm's owl (aegolius funereus (l.)), red fox (vulpes vulpes (l.)) willow grouse (lagopus lagopus (l.)), black grouse (lyrurus tetrix (l.)), capercaillie (tetrao urogallus l.), hazel hen (tetrastes bonasia (l.)), mountain hare (lepus timidus l.) and tularemia (francisella tularensis (mccoy & chapin)) and game bird recruitment were studied by index methods in northern sweden. in addition contemporary temperature records and spruce (picea abies (l.) k ...198628311702
the ten year cycle of the willow grouse of lower kolyma.the population of willow grouse (lagopus lagopus) in the lower kolyma district of yakutia, ussr, shows cycles of abundance with a period of about 10 years. observations habe been made for 2-5 months each year since 1977. this paper attempts to explain why the period of population depression is so long (3-4 years) and why the peak population density is so high. in "normal" years birds occupied only the 3%-4% of the whole area that consisted of preferred biotope, while during the population peak t ...198828312204
natal philopatry and recruitment of willow ptarmigan in north central and northwestern canada.natal philopatry and recruitment were measured in two populations of willow ptarmigan; one near churchill, manitoba and the other in northwestern british columbia. we examined the return of tagged offspring in subsequent years with respect to geographical area, annual variation, their age when tagged, their sex, their body weight, age and number of their parents, and time of hatch (first nest or renest). most chicks were tagged before they fledged, but chicks tagged after that had the highest ra ...198728312220
breeding site fidelity in willow ptarmigan: the influence of previous reproductive success and familiarity with partner and territory.breeding site fidelity is high in willow ptarmigan: only 9% of males and 31% of females switched territories between years. unpaired males were more likely to switch territories than paired males. for paired males, survival of their previous partner and reproductive success in year x did not influence probability of switching in year x+1. a female was more likely to switch territories if her previous partner disappeared. if her partner returned, she had a higher probability of switching if she d ...198928312638
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 ...199128313796
temporal allozyme frequency changes in density fluctuating populations of willow grouse (lagopus lagopus l.).the population density of willow grouse (lagopus lagopus l.) in northern scandinavia changes in synchrony with the cyclic density variations in populations of microtine rodents. to assess the genetic changes accompanying the variations in population number, allozyme variation was studied at 23 loci in 640 willow grouse, representing four mainland and one island locality sampled during high and low population density. the average heterozygosity (h = 8.3%) and proportion of polymorphic loci (p = 2 ...198528563653
genetic variation and territoriality in willow ptarmigan (lagopus lagopus lagopus).we examined eight polymorphic esterase loci in 526 juvenile and adult willow ptarmigan (lagopus lagopus lagopus) collected during autumn and spring over five years. the genetic structure of territorial birds during spring differed from birds on the study area in autumn. this can not be explained by selective winter mortality since juvenile birds in the autumn had the same genetic structure as the adults who had lived through at least one winter. in the spring, birds with intermediate heterozygos ...199028564303
the effects of acaricide treatment of sheep on red grouse lagopus lagopus scotica tick burdens and productivity in a multi-host system.ixodes ricinus (ixodida: ixodidae) ticks are of economic and pathogenic importance across europe. within the uplands of the u.k., management to reduce ticks is undertaken to benefit red grouse lagopus lagopus scotica (galliformes: phasianidae). management strategies focus on the acaricide treatment of domestic sheep ovis aries (artiodactyla: bovidae), but the effectiveness of this is less certain in the presence of wild hosts, particularly red deer cervus elaphus (artiodactyla: cervidae) and mou ...201729194726
bottom-up processes drive reproductive success in an apex predator.one of the central goals of the field of population ecology is to identify the drivers of population dynamics, particularly in the context of predator-prey relationships. understanding the relative role of top-down versus bottom-up drivers is of particular interest in understanding ecosystem dynamics. our goal was to explore predator-prey relationships in a boreal ecosystem in interior alaska through the use of multispecies long-term monitoring data. we used 29 years of field data and a dynamic ...201829435257
development and evaluation of 16 new microsatellite loci for the rock ptarmigan (lagopus muta) and cross-species amplification for the willow grouse (l. lagopus).the genetic markers designed for this study can facilitate future genetic studies on the rock ptarmigan (lagopus muta). to our knowledge no microsatellite markers have ever been developed specifically for this species before. these new microsatellite markers will be useful for population genetics studies and for future conservation projects.201829463303
function and underlying mechanisms of seasonal colour moulting in mammals and birds: what keeps them changing in a warming world?animals that occupy temperate and polar regions have specialized traits that help them survive in harsh, highly seasonal environments. one particularly important adaptation is seasonal coat colour (scc) moulting. over 20 species of birds and mammals distributed across the northern hemisphere undergo complete, biannual colour change from brown in the summer to completely white in the winter. but as climate change decreases duration of snow cover, seasonally winter white species (including the sno ...201829504224
the alternative prey hypothesis revisited: still valid for willow ptarmigan population dynamics.the alternative prey hypothesis predicts that the interaction between generalist predators and their main prey is a major driver of population dynamics of alternative prey species. in fennoscandia, changes in climate and human land use are assumed to alter the dynamics of cyclic small rodents (main prey) and lead to increased densities and range expansion of an important generalist predator, the red fox vulpes vulpes. in order to better understand the role of these potential changes in community ...201829874270
past and potential future population dynamics of three grouse species using ecological and whole genome coalescent modeling.studying demographic history of species provides insight into how the past has shaped the current levels of overall biodiversity and genetic composition of species, but also how these species may react to future perturbations. here we investigated the demographic history of the willow grouse (lagopus lagopus), rock ptarmigan (lagopus muta), and black grouse (tetrao tetrix) through the late pleistocene using two complementary methods and whole genome data. species distribution modeling (sdm) allo ...201830038766
quantifying suitable late summer brood habitats for willow ptarmigan in norway.habitat models provide information about which habitat management should target to avoid species extinctions or range contractions. the willow ptarmigan inhabits alpine- and arctic tundra habitats in the northern hemisphere and is listed as near threatened (nt) in the norwegian red list due to declining population size. habitat alteration is one of several factors affecting willow ptarmigan populations, but there is a lack of studies quantifying and describing habitat selection in willow ptarmig ...201830285717
a fatal case of louping-ill in a dog: immunolocalization and full genome sequencing of the virus.louping-ill (li), caused by louping-ill virus (liv), results in a frequently fatal encephalitis primarily affecting sheep and red grouse (lagopus lagopus scotica), but it does occur in other species. an adult male border collie dog was definitively diagnosed with fatal li and the lesion profile, liv antigen distribution and full genome sequence of the liv responsible were investigated to determine if this differed significantly from sheep-derived liv. no gross lesions were present. the histologi ...201830502792
serological and molecular detection of toxoplasma gondii in terrestrial and marine wildlife harvested for food in nunavik, canada.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 nuna ...201930944016
are trichostrongylus tenuis control and resistance avoidance simultaneously manageable by reducing anthelmintic intake by grouse?benzimidazole-based anthelmintics bound to grit (medicated grit) are annually prescribed on request by veterinary practices to grouse managers to control trichostrongylus tenuis an intestinal parasite of red grouse lagopus lagopus scotica those prescribing medication typically do without knowledge of parasite loads and hence often prescribe when loads are low and unlikely to impact the host. inappropriate use of anthelmintics in livestock has led to development of parasite resistance to anthelmi ...201931019007
circumpolar status of arctic ptarmigan: population dynamics and trends.rock ptarmigan (lagopus muta) and willow ptarmigan (l. lagopus) are arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. here, we compiled information from 90 ptarmigan study sites from 7 arctic countries, where almost half of the sites are still monitored. rock ptarmigan showed an overall negative trend on iceland and greenland, while svalbard and newfoundland had positive trends, and no significant tren ...202031073984
measures of predator diet alone may underestimate the collective impact on prey: common buzzard buteo buteo consumption of economically important red grouse lagopus lagopus scotica.human-wildlife conflicts often centre on economic loss caused by wildlife. yet despite being a major issue for land-managers, estimating total prey losses to predation can be difficult. estimating impacts of protected wildlife on economically important prey can also help management decisions to be evidence-led. the recovery in population and range of common buzzards buteo buteo in britain has brought them into conflict with some gamebird interests. however, the magnitude of any impact is poorly ...201931430344
correlates of pathological lesions associated with respiratory cryptosporidiosis prevalence in shot red grouse lagopus lagopus scotica from moors in northern england.infection of wild red grouse lagopus lagopus scotica by cryptosporidium baileyi was first diagnosed in 2010. within three years, signs of infection were reported from grouse on half of all grouse moors in northern england, bringing severe concerns of economic losses to grouse shooting. a total of 45,914 red grouse shot from 10 moors in northern england between 2013 and 2018 were visually screened for signs of respiratory cryptosporidiosis. prevalence varied with age, being twice as high in juven ...202031545656
the influence of different aspects of grouse moorland management on nontarget bird assemblages.conflict between stakeholders with opposing interests can hamper biodiversity conservation. when conflicts become entrenched, evidence from applied ecology can reveal new ways forward for their management. in particular, where disagreement exists over the efficacy or ethics of management actions, research clarifying the uncertain impacts of management on wildlife can move debates forwards to conciliation.here, we explore a case-study of entrenched conflict where uncertainty exists over the impac ...201931641457
end-user involvement to improve predictions and management of populations with complex dynamics and multiple drivers.sustainable management of wildlife populations can be aided by building models that both identify current drivers of natural dynamics and provide near-term predictions of future states. we employed a strategic foresight protocol (sfp) involving stakeholders to decide the purpose and structure of a dynamic state-space model for the population dynamics of the willow ptarmigan, a popular game species in norway. based on local knowledge of stakeholders, it was decided that the model should include f ...202032159900
decline of the boreal willow grouse (lagopus lagopus) has been accelerated by more frequent snow-free springs.climate change has influenced a range of species across the globe. yet, to state a noted decline in the abundance of a given species as a consequence of a specific environmental change, for instance, spatially explicit long-term data are a prerequisite. this study assessed the extent to which prolonged snow-free periods in autumn and spring have contributed to the decline of the willow grouse, the only forest grouse changing into a white winter plumage. time-series data of willow grouse numbers ...202032332914
effect of tower base painting on willow ptarmigan collision rates with wind turbines.birds colliding with turbine rotor blades is a well-known negative consequence of wind-power plants. however, there has been far less attention to the risk of birds colliding with the turbine towers, and how to mitigate this risk.based on data from the smøla wind-power plant in central norway, it seems highly likely that willow ptarmigan (the only gallinaceous species found on the island) is prone to collide with turbine towers. by employing a baci-approach, we tested if painting the lower parts ...202032607182
survival and cause-specific mortality of harvested willow ptarmigan (lagopus lagopus) in central norway.survival is a key demographic component that often varies as a result of human activities such as recreational harvest. detailed understanding of seasonal variation in mortality patterns and the role of various risk factors is thus crucial for understanding the link between environmental variation and wildlife population dynamics and to design sustainable harvest management systems. here, we report from a detailed seasonal and cause-specific decomposition of mortality risks in willow ptarmigan ( ...202033144955
louping-ill virus serosurvey of willow ptarmigan (lagopus lagopus lagopus) in norway.in norway, the willow ptarmigan (lagopus lagopus lagopus) is experiencing population declines and is nationally red listed as near threatened. although disease has not generally been regarded as an important factor behind population fluctuations for willow ptarmigan in norway, disease occurrence has been poorly investigated. both louping-ill virus (liv) and the closely related tick-borne encephalitis virus are found along the southern part of the norwegian coast. we assessed whether and where no ...202133822153
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