(n.) Any grouse of the genus Lagopus, of which numerous species are known. The feet are completely feathered. Most of the species are brown in summer, but turn white, or nearly white, in winter.
Example Sentences:
(1) Flight behavior was also typical for willow ptarmigan incubating in captivity.
(2) In wild incubating willow ptarmigan, further approach led to tachycardia and increased respiration.
(3) When female ptarmigan resume incubation of cooled eggs (e.g.
(4) Hundreds of miles of forest roads and trails stretch out in the surrounding high country, with hikes up nearby Ptarmigan Hill and Battle Mountain, and mountain bike access to the singletrack Colorado Trail.
(5) However, maximum plasma LH levels and comb size were higher in free-living than in captive Svalbard ptarmigan.
(6) Two of the four incubating Svalbard ptarmigan hens showed the OR followed by freezing behavior accompanied by decreased heart and respiration rates.
(7) In contrast to the results reported for the Willow Ptarmigan, ascorbic acid does not appear to be involved in the development of tibial dyschondroplasia in the young broiler chicken.
(8) Comparison with free-living Svalbard ptarmigan (K.-A.
(9) Hypothalamic thermosensitivity has been investigated in conscious Willow Ptarmigan (Lagopus lagopus lagopus) provided with chronically implanted hypothalamic perfusion thermodes.
(10) 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.
(11) When captive ptarmigan were allowed to choose their mates freely, the social rank of the male and female correlated significantly.
(12) Experiments showed that ptarmigans prefer stones with diameters between 2-5 mm.
(13) Biochemical determination of ascorbic acid synthesis in the kidney of ptarmigan chicks indicated a rate of synthesis five times that found in livers of growing white rats.
(14) In both species of ptarmigan, the development of long-day refractoriness was associated with increased plasma prolactin.
(15) The observation of a weak mammalian-like cold hypothalamic thermosensitivity in Willow Ptarmigan indicates that these birds possess some specific cold thermosensors in the hypothalamic region.
(16) Eimeria leucuri is described from white-tailed ptarmigan (Lagopus leucurus), and E. oreoecetes from white-tailed ptarmigan and blue grouse (Dendragapus obscurus) from Colorado.
(17) Food intake (FI), feeding activity (FA), and body mass (BM) were recorded continuously throughout a 13-mo period in Svalbard rock ptarmigan kept under natural conditions of light and ambient temperature at Svalbard (79 degrees N).
(18) The following Arctic birds were therefore examined in an endeavour to find the reservoir of infection: snow geese in their Arctic nesting grounds; migrating geese in the spring and in the fall; ptarmigan, raven, and snow bunting on the Arctic Circle in the late winter.
(19) When eating Empetrum berries, ptarmigan digested lignin and tannins and excreted ornithurates.
(20) Fluctuations in grit composition in the gizzards of willow ptarmigans and the grinding ability of various grit assortments from wild ptarmigans were examined.
Subarctic
Definition:
(a.) Approximately arctic; belonging to a region just without the arctic circle.
Example Sentences:
(1) Mosquito-borne arboviruses are prevalent throughout subarctic regions of Canada and Alaska, principally in the boreal forest extending between latitudes 53 and 66 degrees N, but they have been identified in tundra regions as far north as 70 degrees N. All mosquito-borne agents have been bunyaviruses, comprising principally the snowshoe hare subtype of California encephalitis (CE) virus, but also Northway virus.
(2) T6 is present in carnivores in the subarctic-temperate area of the Nearctic region; and T7 (T. nelsoni) in Hyaenidae and Felidae of Equatorial Africa.
(3) This study examined whether cold, short day or melatonin causes reproductive regression and stimulates nonshivering thermogenesis in a subarctic rodent Clethrionomys rutilus.
(4) Replication of a subarctic Bunyavirus, California encephalitis (snowshoe hare subtype), was detected in salivary glands and thoraces of wild-caught Aedes communis mosquitoes from the Yokon Territory, after intrathoracic inoculation with 0.1 to 100 mouse LD50 virus, and incubation for 7 to 21 days throughout their viable temperature range of 0 to 23 degrees C. Immunoperoxidase staining confirmed that viral replication occurred in the cytoplasm of acinar cells of salivary glands, both by ligh microscopy and electron microscopy.
(5) The results suggest that small arctic-subarctic rodents have a greater capacity for NE stimulated NST than rodents from temperate latitudes probably because they are acclimatized to colder seasonal condtions.
(6) Iceland is a rugged subarctic island 600 miles from Norway and 500 miles from Scotland.
(7) Moving and still air 0 degrees C to -35 degrees C in both laboratory and subarctic outdoor settings were used.
(8) Athapaskan populations evidently moved south from Beringia sometime after the Paleoindian migration when the "ice free" corridor had widened and contained environments and resources more typical of subarctic latitudes.
(9) The applicability of A. R. Omran's 'epidemiologic transition' theory to subarctic Indians in Canada is examined in a historical review of health and demographic data.
(10) Antigenically-related viruses have therefore now been isolated from I. uriae in both subarctic and subantarctic regions.
(11) Reindeer inhabit a severe arctic or subarctic environment, with the young born in early spring under adverse weather conditions.
(12) Among the Cree-Ojibwa Indians in the subarctic boreal forest of northern Manitoba and Ontario, a high prevalence of clinical gallbladder disease (18.5% among women aged 20-64) was observed.
(13) Interactive simultaneity draws on the human-living-health model of nurse theorist Rosemarie Parse and the author's research on the healing activity of arctic and subarctic medicine women to enhance contemporary clinical practice in a variety of situations.
(14) The absence of these subarctic leeches from Baikal itself is explained by their rheophily.
(15) Radionuclides, especially the long-lived 137Cs (physical half-life 30 years), are accumulated efficiently in the northern, subarctic, lichen-reindeer-man foodchain.
(16) Two field experiments in a subarctic environment are described.
(17) Sediment samples were collected from a subarctic salt marsh on James Bay, Ontario in May 1976.
(18) An analysis of seasonal changes in energy budget of the farmed polecat (Mustela putorius) was performed in subarctic climate.
(19) T2 (T. nativa) is present in terrestrial mammals and seldom in sea mammals of arctic and subarctic regions.
(20) Although fish tapeworm infections in arctic and subarctic residents are often attributed to the cestode Diphyllobothrium latum, other Diphyllobothrium species are frequently responsible.