(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.
Tundra
Definition:
(n.) A rolling, marshy, mossy plain of Northern Siberia.
Example Sentences:
(1) Strains of the causative agent of tularemia were for the first time isolated by the authors from the objects of the external environment in the tundra zone of Eastern Taimir; this indicates a possibility of preservation of the microbe under conditions of the extreme north.
(2) Drainage melioration in the Polesye resulted in a sharp increase in the number of tundra vole (Microtus oeconomus Pall.)
(3) 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.
(4) The postoncospheral development and cycle of Taenia polyacantha Leuckart, 1856, an holarctic species of cestode, were investigated in the laboratory as well as in the tundra of northern Alaska.
(5) There were found 26 parasitic and nonparasitic species of Gamasoidea, 3 species of Ixodidae and 2 species of Trombiculidae, 10 species of Aphaniptera, 3 species of Anoplura but there was found no species specific only for the tundra vole.
(6) Tundra peregrine eggs contain an average of 889 parts of DDE per million (lipid basis); taiga peregrine eggs contain 673 parts per million; Aleutian peregrine eggs contain 167 parts per million; rough-legged hawk eggs contain 22.5 parts per million; and gyrfalcon eggs contain 3.88 parts per million.
(7) Although the coastal natives' diet was higher in calories and fats than tundra inhabitants'; it was rich in polyunsaturated fatty acids, the main source of which was sea-animal meat.
(8) "That's why increasing tundra wildfires have the potential to accelerate the melting in Greenland," Box said.
(9) Temperature rises in excess of this may trigger a "tipping point" in places such as the Arctic tundra where permafrost would melt rapidly, releasing large amounts of methane which has a global warming effect eight times greater than CO2.
(10) Tundra and taiga peregrines have fledged progressively fewer young each year since 1966.
(11) Packers 7-6 49ers, 5:50, 2nd quarter Rodgers on the move - he's running to his right, and fires a strike to Nelson who MAKES THE CATCH and falls to the not-so-frozen tundra (they have sub-turf heating)!
(12) More than 1,000bn tonnes of carbon are stored in the soils beneath the Arctic tundra, double humanity’s emissions since the industrial revolution.
(13) Structural and functional features of plants from cold regions such as high mountain and tundra environments are characterized.
(14) Even though it has a great sense of smell - it can sniff a dog 35ft away - and can jump two feet to catch a beetle, and that a Russian hedgehog once found its way back home after it had been dropped 48 miles away across the tundra, the hedgehog is not, on the whole, a very clever creature.
(15) and Greyjoy fight one another while otherworldly ice demons rise in the northern tundra, and the Westerosi equivalent of nuclear weapons – dragons – are reaching maturity on a distant continent.
(16) The species was found in the rhizosphere of Vaccinum uliginosum and Arctous alpina from the mountain tundra of Kamchatka.
(17) The high northern latitudes are warming more rapidly than other parts of the Earth, with climate models predicting a northward shift of Arctic vegetation that will see the boreal biome (coniferous forest across North America and Eurasia) migrate into what is currently tundra (treeless plains of the Arctic).
(18) On land, shrubs are spreading across the lower Arctic because of a longer growing season, but other tundra plant types – such as moss and lichen – are declining.
(19) The mass radioisotope (32P) labelling of all tundra voles excreting Zeptospira, infected urine was carried out over the area of 1 ha, and the results of the experiment analyzed by the method of planar coherent graphs, showed the irregular (spotted) distribution of "infected spots", i. e. soil patches contaminated by Zeptospira.
(20) Speaking to a handful of journalists at Sporting’s training field yesterday (including one pale, bearded specimen huddled into the corner of his office nearest the baseboard heater), Vermes recalled playing in a game in freezing rain at the Rutgers Bowl, before airily gesturing at the tundra beyond his window and saying, “this is nothing.” I expect him to wear one of those t-shirts with a shirt and tie printed on it for the final.