| 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 |
| 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 |
| 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 |
| territory occupancy rate of goshawk and gyrfalcon: no evidence of delayed numerical response to grouse numbers. | two recent studies on territory occupancy rates of goshawk accipiter gentilis and gyrfalcon falco rusticolus report a 2-3-year-delayed numerical response to grouse numbers, which is a requirement for a hypothesis of predator-generated grouse cycles. the time lags were assumed to reflect the average age of sexual maturity in the raptor species. in southern norway, however, subadult (two-year-old) goshawk hens occupied only 18-25% of territories where occupancy was not recorded in the preceding ye ... | 2007 | 17549523 |
| 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 ... | 2015 | 25065712 |
| 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 ... | 2014 | 25047582 |
| 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 ... | 2015 | 25992609 |
| 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 ... | 2015 | 25692786 |
| 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 ... | 2016 | 26881329 |
| 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 ... | 2017 | 28260532 |
| 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 ... | 2017 | 27762483 |
| 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 ... | 2015 | 25728915 |
| 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 ... | 2015 | 25698142 |
| 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 ... | 2014 | 24698833 |
| 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 ... | 2012 | 22841824 |
| 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 ... | 2010 | 20428241 |
| cadmium concentrations in tissues of willow ptarmigan (lagopus lagopus) and rock ptarmigan (lagopus muta) in nunavik, northern québec. | willow and rock ptarmigan were obtained from northern québec. willow ptarmigan were found to have mean cadmium concentrations of 179.7 microg/g (dw) in the kidneys and 25.8 microg/g (dw) in the liver; these levels were three times higher than those found in the rock ptarmigan. the cadmium levels in the ptarmigan were below the threshold above which adverse effects can be observed in birds. the difference between the two ptarmigan species in cadmium content is explained by the diet. a comparison ... | 2007 | 17223236 |
| accumulation of heavy metals in circumpolar willow ptarmigan (lagopus l. lagopus) populations. | a circumpolar survey of heavy metals in willow ptarmigan liver and kidney revealed considerable variations in cd content in canada and scandinavia. the cd content in central canada was comparable with that in scandinavia and russia, at least for kidney. however, in both liver and kidney the median for canada as a whole was much higher than in the other countries. some canadian locations had exceptionally high levels, several birds having >50 mg kg(-1) in liver and >400 mg kg(-1) in kidney. in no ... | 2006 | 17055034 |
| lead exposure of small herbivorous vertebrates from atmospheric pollution. | concentrations of pb in livers of willow grouse (lagopus lagopus), black grouse (tetrao tetrix), and hare (lepus timidus) were determined in samples collected during the period 1990-92 from 77 locations distributed across norway. our objective was to elucidate the impact of long-range atmospheric transport on the pb exposure of the animals. the moss hylocomium splendens was measured for atmospheric pb deposition and pb in soil at 60-cm depth was determined to reflect the natural geochemical back ... | 2000 | 15093005 |
| cospeciation and horizontal transmission of avian sarcoma and leukosis virus gag genes in galliform birds. | in a study of the evolution and distribution of avian retroviruses, we found avian sarcoma and leukosis virus (aslv) gag genes in 26 species of galliform birds from north america, central america, eastern europe, asia, and africa. nineteen of the 26 host species from whom aslvs were sequenced were not previously known to contain aslvs. we assessed congruence between aslv phylogenies based on a total of 110 gag gene sequences and aslv-host phylogenies based on mitochondrial 12s ribosomal dna and ... | 2000 | 10756010 |
| 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 ... | 1995 | 24197780 |
| willow ptarmigan (lagopus lagopus) as a biomonitor of environmental metal levels in norway. | the purpose of this study was to examine the potential of a native wild bird, lagopus lagopus, as a monitor of environmental metal levels, in particular with respect to the influence of atmospheric deposition of metals from long-range transport. specimens of willow ptarmigan were collected from ten different locations in norway. the concentrations of cadmium, zinc and copper were determined in kidneys of birds from all sites. mean cadmium levels in adult ptarmigan kidney ranged from 6.6 to 48.5 ... | 1994 | 15091659 |
| age-dependent accumulation of cadmium and zinc in the liver and kidneys of norwegian willow ptarmigan. | | 1993 | 8219593 |
| 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 ... | 1990 | 28564303 |
| 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 ... | 1989 | 28312638 |
| physiological aspects of freezing behaviour in willow ptarmigan hens. | when threatened, wild willow ptarmigan (lagopus lagopus lagopus) hens displayed freezing behaviour, i.e. motionless, crouched with head down and eyes open. but while non-incubating hens showed increased heart (hr) (from 229 +/- 18 to 254 +/- 33 beats min-1) and ventilation rates (vr) (from 25 +/- 2 to 31 +/- 4 breaths min-1), incubating hens showed bradycardia (from 208 +/- 40 to 102 +/- 13 beats min-1) and reduced vr (from 25 +/- 2 to 10 +/- 2 breaths min-1), which could be maintained for as lo ... | 1988 | 3227948 |
| 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 ... | 1988 | 28312204 |
| appropriate and inappropriate hypothalamic cold thermosensitivity in willow ptarmigan. | hypothalamic thermosensitivity has been investigated in conscious willow ptarmigan (lagopus lagopus lagopus) provided with chronically implanted hypothalamic perfusion thermodes. the birds were exposed to either cold (ta - 10 degrees c) or warm (ta + 25 degrees c) ambient conditions while hypothalamic temperature (thy) was clamped for periods of 20 min at different set levels between 28 degrees c and 43 degrees c. the responses of the animals to hypothalamic thermal stimulation were classified b ... | 1987 | 3673613 |
| 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 ... | 1987 | 28312220 |
| 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 ... | 1985 | 28311033 |
| 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 ... | 1985 | 28563653 |
| 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 ... | 1984 | 28311638 |
| 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 ... | 1984 | 28310892 |
| the development of photorefractoriness in castrated willow ptarmigan (lagopus lagopus lagopus). | changes in plasma lh levels were observed in castrated willow ptarmigan exposed to different lighting patterns to determine whether they become photorefractory. lh levels did not increase in long-term castrated birds exposed to a natural (70 degrees n) increase in daylength and did not fall abruptly in june when intact birds become photorefractory. plasma lh levels in naturally photostimulated, long-term castrates fell gradually during the summer and fall. plasma lh levels increased steeply when ... | 1984 | 6735157 |
| effects of different diets on viability, and gut morphology and bacteriology in captive willow ptarmigan chicks (lagopus l. lagopus). | | 1984 | 6464926 |
| plasma thyroxine and triiodothyronine levels during the development of photorefractoriness in willow ptarmigan (lagopus lagopus lagopus) exposed to different photoperiods. | | 1982 | 7084662 |
| effect of natural feed, antibiotics, tannin, diphenyliodoniumchloride and salicylic acid supplement on plasma uric acid concentration in captive willow ptarmigan (lagopus l. lagopus). | | 1982 | 7180790 |
| chick nutrition and mortality in captive willow ptarmigan (lagopus l. lagopus). | | 1982 | 7180789 |
| nephritis and uric acid diathesis in captive willow ptarmigan (lagopus l. lagopus). effect of feed protein concentration and grass meal admixture. | | 1982 | 7180788 |
| parental nutrition and chick production in captive willow ptarmigan (lagopus l. lagopus). | | 1982 | 7168429 |
| seasonal prevalence of hematozoa in willow ptarmigan (lagopus lagopus) from northwestern british columbia. | | 1981 | 6787186 |
| caecal decomposition of uric acid in captive and free ranging willow ptarmigan (lagopus lagopus lagopus). | urine entering the caeca of birds contains significant amounts of uric acid. the discovery of great numbers of bacteria utilizing uric acid in the caeca has encouraged the discussion about nitrogen recycling in birds. in this work caecal decomposition of uric acid in wild and captive willow ptarmigan has been investigated using radioactively labelled uric acid injected directly into one of the caeca. the appearance of radioactive co2 in the expired air was taken as an indication of uric acid bre ... | 1981 | 7282388 |
| the development of photorefractoriness in willow ptarmigan (lagopus lagopus lagopus) after the suppression of photoinduced lh release with implants of testosterone. | | 1980 | 7409454 |
| the roles of day length and the testes in the regulation of plasma lh levels in photosensitive and photorefractory willow ptarmigan (lagopus lagopus lagopus). | | 1980 | 7409453 |
| seasonal changes in the concentrations of plasma luteinizing hormone and testosterone in willow ptarmigan (lagopus lagopus lagopus) with observations on the effects of permanent short days. | | 1980 | 7353781 |
| tachycardia during egg-hypothermia in incubating ptarmigan (lagopus lagopus). | incubating birds regulate the egg temperature by varying their posture and the distance between eggs and brood patch. in the present study, we show that this homeostatic process is further assisted by varying the brood patch blood flow according to the temperature of the eggs. when female ptarmigan resume incubation of cooled eggs (e.g. after a period of foraging), they immediately develop pronounced tachycardia (4 times noraml in wild, 2-3 times in captive birds). tachycardia is maintained, alt ... | 1979 | 539457 |
| a comparison of the microbiological conditions in the small intestine and caeca of wild and captive willow grouse (lagopus lagopus lagopus). | | 1979 | 506874 |
| uric acid metabolism in the caeca of grouse (lagopus lagopus) [proceedings]. | | 1978 | 569701 |
| "emotional" bradycardia: a telemetry study on incubating willow grouse (lagopus lagopus). | | 1977 | 888715 |
| 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 ... | 1977 | 24924106 |
| social rank, mating and egg fertilization in willow ptarmigan (lagopus lagopus lagopus). | when captive ptarmigan were allowed to choose their mates freely, the social rank of the male and female correlated significantly. when mates were allocated by the experimenter, without regard to similarity in social rank, fertility was low. when birds of similar social rank were paired, the fertility was high. it is suggested that fertility in captive ptarmigan may be increased if the relative social rank of mating birds is considered. | 1977 | 605022 |
| thermoregulation and muscular development in cold exposed willow ptarmigan chicks (lagopus lagopus l.). | | 1976 | 9239 |
| hind gut function in the grouse (lagopus lagopus). | | 1976 | 5245 |
| the pectoral muscles and the development of thermoregulation in chicks of willow ptarmigan (lagopus lagopus). | | 1976 | 3317 |
| volatile fatty acids and metabolizable energy derived from cecal fermentation in the willow ptarmigan. | | 1976 | 177 |
| metabolic thermoregulatory responses in eggs and chicks of willow ptarmigan (lagopus lagopus). | | 1975 | 237680 |
| pulmonary phycomycosis in captive rock ptarmigan (lagopus mutus) and willow ptarmigan (lagopus lagopus) chicks. | | 1975 | 1136901 |
| variation in the visceral characteristics of the willow ptarmigan (lagopus albus) and common ptarmigan (lagopus mutus) in the taimir peninsula. | | 1974 | 4843924 |
| 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 ... | 2017 | 29194726 |
| 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 ... | 2018 | 29435257 |
| 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 ... | 2018 | 30502792 |
| 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 ... | 2019 | 30944016 |
| 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 ... | 2018 | 29874270 |
| 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 ... | 2018 | 29504224 |
| 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 ... | 2018 | 30038766 |
| 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 ... | 2019 | 31430344 |
| 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 ... | 2019 | 31641457 |
| 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 ( ... | 2020 | 33144955 |
| 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 ... | 2020 | 32607182 |
| 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 ... | 2020 | 32332914 |
| 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 ... | 2020 | 32159900 |
| 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 ... | 2020 | 31545656 |
| 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 ... | 2020 | 31073984 |
| 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 ... | 2019 | 31019007 |
| 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 ... | 2018 | 30285717 |
| 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. | 2018 | 29463303 |
| 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 ... | 2021 | 33822153 |