Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| 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 |
| cestodiasis in the red grouse in scotland. | little is known about the cestode parasites of red grouse lagopus lagopus scoticus. the carcasses of 71 free-living and grouse collected from northeastern scotland (uk) between june 1991 and september 1992 were examined for the cestode paroniella urogalli. over 70% of young and old birds were infected in summer and winter. cestode abundance ranged from 0 to 29 (mean +/- se = 5.54 +/- 0.81) worms per host and did not differ significantly between young and old grouse, or between seasons. cestode i ... | 1999 | 10231751 |
| local genetic structure in red grouse (lagopus lagopus scoticus): evidence from microsatellite dna markers. | allelic variation at seven hypervariable tri- and tetranucleotide microsatellite loci was used to determine levels of population differentiation between 14 populations of red grouse (lagopus lagopus scoticus) in northeast scotland, uk. despite the potential for long-distance dispersal in grouse, and a semicontinuous habitat, significant population divergence was observed (mean rst = 0.153; p < 0.01) and an isolation-by-distance effect detected (mantel test: p < 0.001). examination of the spatial ... | 1998 | 9859199 |
| isolation and characterization of hypervariable microsatellites in the red grouse lagopus lagopus scoticus. | 1997 | 9004522 | |
| transmission dynamics and host-parasite interactions of trichostrongylus tenuis in red grouse (lagopus lagopus scoticus). | two components of the transmission dynamics of trichostrongylus tenuis in red grouse are examined and quantified, namely parasite transmission rate and density-dependent reductions in egg production. age-intensity data for birds of known age suggest that the rate of parasite uptake increases during the first 6 mo of a bird's life and this increase reflects an increase in feeding rate with age and exhibits no signs of self-cure. analysis of these age-intensity curves permits us to estimate the tr ... | 1997 | 9105295 |
| efficacy of acaricidal tags and pour-on as prophylaxis against ticks and louping-ill in red grouse. | this paper examines the efficacy of 10% lambdacyhalothrin-impregnated plastic tags and a deltamethrin pour-on preparation in protecting red grouse chicks from parasitism by ticks and subsequent infection with the louping-ill virus. in 1995, ten red grouse hens (lagopus lagopus scoticus) in a free-living population in north-east scotland were fitted with lambdacyhalothrin-impregnated plastic tags, glued to radio transmitters. chicks of more than 10 days of age from a further ten untreated radio-c ... | 1997 | 9430120 |
| the epidemiology of louping-ill, a tick borne infection of red grouse (lagopus lagopus scoticus). | the epidemiology of louping-ill in red grouse was studied in northern britain concentrating on the possible role of other species and mechanisms of disease persistence. this tick borne viral disease caused heavy mortality in red grouse, particularly chicks. louping-ill induced mortality reduced the strength of the density dependence that generates the tendency of grouse populations to cycle and in some populations may cause population sinks. four routes of transmission were examined and non-vira ... | 1997 | 9802086 |
| the effect of parasites on wildlife. | populations of animals which live in the wild are regulated by many biotic and abiotic factors. parasites are one of the biotic factors. parasites may influence their hosts in different ways. they may cause the death of the host due to a direct lethal effect or an indirect effect. direct lethal effects may occur if killing is a part of the life cycle of the parasite or if hosts and parasites have not developed an equilibrium. the introduction of hosts or parasites into a new environment with sui ... | 1996 | 8933697 |
| 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 |
| 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 | |
| host specificity of trichostrongylus tenuis from red grouse and northern bobwhites in experimental infections of northern bobwhites. | the red grouse (lagopus lagopus scoticus) and northern bobwhite (colinus virginianus) are parasitized by the cecal nematode, trichostrongylus tenuis. our objective was to determine if t. tenuis from red grouse is infective in bobwhites. we inoculated bobwhites with infective-stage t. tenuis larvae that originated from red grouse in northern england and bobwhites in florida. we also inoculated domestic chickens with larvae from the same sources. none of the 6 bobwhites inoculated with larvae from ... | 1993 | 8331474 |
| caecal threadworms trichostrongylus tenuis in red grouse lagopus lagopus scoticus: effects of weather and host density upon estimated worm burdens. | trichostrongylus tenuis eggs were counted in faeces from individually marked wild red grouse for 8 years. egg counts varied seasonally and annually. in some years, a sudden increase in mid-april was consistent with delayed maturation of larvae which had overwintered in the birds in a hypobiotic state. a more gradual increase in summer was probably due to uninterrupted maturation of larvae ingested then. despite 30-fold year-to-year variation in mean egg counts, relative differences in egg counts ... | 1993 | 8414674 |
| hypobiosis of trichostrongylus tenuis in experimentally infected grey partridges. | storage of infective larvae (l3) of trichostrongylus tenuis at +4 degrees c for six weeks before being given as single infections to grey partridges (perdix perdix) did not increase the proportion of worms subsequently found to be hypobiotic. however, after repeated infections, hypobiotic larvae were numerous. three infections given over three weeks resulted not only in the presence of many hypobiotic larvae, but also in the coincident loss of most adult worms. this indication of the role of imm ... | 1993 | 8460270 |
| multilocus dna fingerprints in gallinaceous birds: general approach and problems. | multilocus profiles were investigated in five different species of galliformes (ring-necked pheasant phasianus colchicus, indian peafowl pavo cristatus, japanese quail coturnix coturnix japonica, domestic chicken gallus gallus, and red grouse lagopus lagopus scoticus) using two human multilocus probes (33.6 and 33.15) in combination with each of four restriction enzymes (alui, ddei, haeiii or hinfi). all the species show a dna fingerprint-like pattern using at least one restriction enzyme in com ... | 1992 | 1612925 |
| 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 |
| 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 |
| factors affecting the establishment of the caecal threadworm trichostrongylus tenuis in red grouse (lagopus lagopus scoticus). | the resistance of captive reared red grouse to trichostrongylus tenuis was measured as the proportion of ingested infective 3rd-stage larvae which failed to develop to adult worms. individual grouse showed wide, repeatable variations in resistance. seasonal variations may also have occurred. red grouse acquired little or no effective immunity to reinfection after challenge with a single dose of infective larvae. in trickle-dosed grouse, however, adult worms weakly inhibited the establishment of ... | 1989 | 2594417 |
| development and survival of the free-living stages of trichostrongylus tenuis, a caecal parasite of red grouse lagopus lagopus scoticus. | in the laboratory, yields of infective 3rd-stage larvae of trichostrongylus tenuis were determined by temperature when moisture was adequate. on the moor, eggs in caecal faeces did not develop to infective larvae during the winter. in summer, development did occur and yields of infective larvae were related to temperature: greatest yields were obtained when mean monthly soil surface temperatures ranged between 7.6 and 10.3 degrees c. rainfall was unimportant, as was desiccation. during summer th ... | 1989 | 2797866 |
| population biology of trichostrongylus tenuis, a parasite of economic importance for red grouse management. | the caecal nematode, trichostrongylus tenuis, is associated with dramatic decreases in the density of red grouse (lagopus lagopus scoticus) resulting in a significant loss of sporting income to many upland estates in the uk. in this article peter hudson and andrew dobson describe the dynamics of the grouse-t. tenuis system, show that the parasites can cause population crashes and present preliminary findings from the development of new control methods. | 1989 | 15463233 |
| arrested development of trichostrongylus tenuis as third stage larvae in red grouse. | worms were counted in red grouse (lagopus lagopus scoticus) in north east scotland in march, april, august, september, november and december 1986. immature worms occurred as third (l3) and fourth (l4) stage larvae throughout. two kinds of evidence suggest that l3 larvae spent much of the winter in a state of arrested development. first, recently acquired l3 larvae could be distinguished by the fact that they retained outer l2 cuticles for a few days; these were present only in the august and sep ... | 1988 | 3194598 |
| endocrine changes in photostimulated willow ptarmigan (lagopus lagopus lagopus) and svalbard ptarmigan (lagopus mutus hyperboreus). | changes in plasma luteinizing hormone (lh), testosterone, thyroxine (t4), and triiodothyronine (t3) and the height of supraorbital combs were compared in captive willow ptarmigan (lagopus lagopus lagopus) and svalbard ptarmigan (lagopus mutus hyperboreus) exposed to an artificial annual cycle of daylength simulating that at 70 degrees n. plasma lh and testosterone and comb height increased more slowly in svalbard than in willow ptarmigan as daylength increased. in both species, plasma lh and tes ... | 1988 | 3371650 |
| 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 |
| the effect of trichostrongylus tenuis on the caecal mucosa of young, old and anthelmintic-treated wild red grouse, lagopus lagopus scoticus. | the caecal mucosa of wild young and adult grouse infected naturally with trichostrongylus tenuis was examined by means of scanning electron microscopy and compared with adult grouse which had been treated with an anthelmintic. the caecal mucosa of young red grouse with low worm burdens possessed longitudinal plicae and exhibited little damage. the caeca from adult grouse, most of which carried high worm burdens, showed a localized depression of plicae and atrophy and cell disruption in areas of ... | 1987 | 3588017 |
| changes in aromatase activity in the neuroendocrine tissues of red grouse (lagopus lagopus scoticus) in relation to the development of long-day refractoriness. | changes in aromatase activity in the neuroendocrine tissues of captive male and female red grouse (lagopus lagopus scoticus) were measured during a photo-induced breeding cycle. the gonads enlarged and subsequently regressed, as a consequence of the development of long-day refractoriness, within 84 days of transferring photoinsensitive birds from a non-stimulatory to a stimulatory daylength. the object of the study was to determine whether long-day refractoriness is related to an increase in aro ... | 1986 | 3944533 |
| 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 ... | 1986 | 28311702 |
| 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 |
| the influence of ascorbic acid on the occurrence of tibial dyschondroplasia in young broiler chickens. | two distinctly different basal diets were used to test the influence of supplementary ascorbic acid on the occurrence of tibial dyschondroplasia. addition of either .1 or .25% ascorbic acid to these diets did not alter the occurrence of tibial dyschondroplasia in 25-day-old broiler chickens. however, supplementary ascorbic acid did increase the amounts of ascorbic acid present in blood plasma. also, individual differences in circulating ascorbic acid were not associated with this disease. furthe ... | 1985 | 4011557 |
| orienting and freezing responses in incubating ptarmigan hens. | behavior studies and telemetric recordings of heart and respiration rates were performed on five wild and two captive, incubating, willow ptarmigan hens (lagopus lagopus lagopus) and on four wild, incubating, svalbard ptarmigan hens (lagopus mutus hyperboreus). sounds and sight of approaching humans, egg predators, or dogs near the nests elicited behavior in the hens which we have interpreted as an orienting response (or) followed by freezing behavior. during both types of behavioral responses, ... | 1985 | 4059382 |
| 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 | |
| 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 |
| 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 | |
| clostridium perfringens type a toxins in relation to nephritis and uric acid diathesis in captive willow ptarmigan (lagopus l. lagopus). | 1982 | 6295118 | |
| yersinia pseudotuberculosis infection in captive black grouse (tetrao lyrurus) and willow ptarmigan (lagopus l. lagopus). | 1982 | 6762820 | |
| development of photorefractoriness in willow ptarmigan (lagopus lagopus lagopus) and red grouse (lagopus lagopus scoticus) exposed to different photoperiods. | 1982 | 7067969 | |
| annual cycle of plasma concentrations of growth hormone in red grouse (lagopus lagopus scoticus). | 1982 | 7152243 | |
| a comparison of the responses of captive willow ptarmigan (lagopus lagopus lagopus), red grouse (lagopus lagopus scoticus), and hybrids to increasing daylengths with observations on the modifying effects of nutrition and crowding in red grouse. | 1981 | 7286635 | |
| on caecal synthesis and absorption of amino acids and their importance for nitrogen recycling in willow ptarmigan (lagopus lagopus lagopus). | the willow ptarmigan has two large caeca housing dense populations of microorganisms. urine, containing uric acid, is transported from the cloaca into the caeca when these are filled. here the uric acid is rapidly broken down, suggesting that the caeca take part in a recycling of excretory nitrogen. in this work it is shown that ammonia produced by the uric acid decomposition is incorporated into new amino acids in a glutamic dehydrogenase catalyzed reaction. we have, however, not been able to d ... | 1981 | 7348031 |
| 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 | |
| the response of three grouse species (tetrao urogallus, lagopus mutus, lagopus lagopus) to louping-ill virus. | 1980 | 6253539 | |
| vitamin c deficiency in growing willow ptarmigan (lagopus lagopus lagopus). | willow ptarmigan chicks raised on a diet containing 265 mg ascorbic acid/kg develop scury-like symptoms and die by 4 weeks of age. if blueberry plants are given as an ad libitum supplement to this diet, the malady is prevented. we have described the clinical, pathological and histological changes which accompany this malnutrition and conclude that they are in accord with the description of scurvy in guinea pig and man. biochemical determination of ascorbic acid synthesis in the kidney of ptarmig ... | 1979 | 512712 |
| 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 | |
| atrophy of a breast muscle with a single fibre type (m. pectoralis) in fasting willow grouse, lagopus lagopus (l.). | the willow grouse (lagopus lagopus) are arctic gallinaceous birds with small fat stores and large muscles. in winter, these birds may starve for periods of several days. it was important to know which energy reserves were utlized during periods of starvation. body composition of female willow grouse and bantam hens was studied before and after fasting. grouse have much larger breast muscles than do bantams, but reproductive organs are larger in hens. the relative amounts of adipose tissue are ab ... | 1978 | 681910 |
| haematology, weight and condition of captive red grouse (lagopus lagopus scoticus) infected with caecal threadworm (trichostrongylus tenuis). | red grouse infected with the caecal threadworm trichostrongylus tenuis developed a mild anaemia. haemoglobin and albumin levels in the blood fell but there were no significant changes in the number of red blood cells or their size. in infected birds the numbers of circulating eosinophils and heterophils increase, as did the concentration of alpha, beta and gamma globulin. body weights did not change but muscle masses shrank. birds that subsequently died had the lowest concentration of haemoglobi ... | 1978 | 749086 |
| studies of louping-ill virus (flavivirus group) in wild red grouse (lagopus lagopus scoticus). | studies were made to find evidence of louping-ill virus infection in free-living red grouse and relate this to their breeding success. in areas where ticks were abundant 61 (84%) adult grouse had antibody to the virus compared with 1 (10%) in areas where ticks were relatively scarce. of 162 chicks tested 25 were shown to be viraemic. infected chicks were of significantly less weight than comparably aged uninfected birds and the probability that they died was much greater than that of uninfected ... | 1978 | 212479 |
| the effects of castration on concentrations of luteinizing hormone in the plasma of photorefractory red grouse (lagopus lagopus scoticus). | 1977 | 892416 | |
| "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 |
| 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 ... | 1977 | 24228962 |
| 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 | |
| the shivering pattern in an arctic (willow ptarmigan) and a tropical bird (bantam hen). | 1976 | 3318 | |
| the occurrence of gapeworm (syngamus trachea) in willow grouse. | 21.4% of the willow grouse (lagopus lagopus) examined from a coastal locality in northern norway were infected with syngamus trachea. none of the willow grouse examined from an inland locality with colder and longer winters were infected with the parasite. it is suggested that the parasite may influence survival of the grouse population. | 1975 | 124787 |
| proceedings: seasonal variations in plasma luteinizing hormone levels in male red grouse (lagopus lagopus scoticus). | 1975 | 1133531 | |
| thermoregulatory behavior and body temperature in chicks of willow grouse (lagopus lagopus lagopus). | clocal temperatures (tcl) of outdoor living captive willow grouse chicks (lagopus lagopus lagopus) were found to increase from 39.4 +/- 0.5 degrees c. the first day to 40.3 +/- 0.5 degrees c. the twelfth day after hatching. average tcl of adults was 40.7 +/- 0.3 degrees c. when left alone for 30 min. in a controlled test environment providing temperatures ranging from 21 degrees c. to 46 degrees c., the one day old chicks preferred significantly higher ambient temperatures than eight day old bir ... | 1975 | 1161703 |
| regulation and grinding ability of grit in the gizzard of norwegian willow ptarmigan (lagopus lagopus). | fluctuations in grit composition in the gizzards of willow ptarmigans and the grinding ability of various grit assortments from wild ptarmigans were examined. we confirmed reports of other investigators that larger, fewer and rounder stones were present in the winter than in the autumn. experiments showed that ptarmigans prefer stones with diameters between 2-5 mm. birds on a constant diet maintained a constant stone intake throughout the year. the composition of gizzard grit was influenced by t ... | 1975 | 1228713 |
| listeriosis among willow grouse (lagopus lagopus) in captivity. | 1975 | 803676 | |
| 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 digestion of heather (calluna vulgaris) by red grouse (lagopus lagopus scoticus). | 1972 | 5015248 |