GEOGRAPHIC VARIATION IN SIZE IN NORTH AMERICAN BROWN BEARS, URSUS ARCTOS L., AS INDICATED BY CONDYLOBASAL LENGTH

1963 ◽  
Vol 41 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Robert L. Rausch
Keyword(s):  
North America ◽  
Ursus Arctos ◽  
Yukon Territory ◽  
The Arctic ◽  
Species Variation ◽  
Brown Bears ◽  
Mean Values ◽  
Condylobasal Length ◽  
Mean Size ◽  
Arctic Coast

Variation in size of brown bears, Ursus arctos Linnaeus, indicated by condylobasal length of the skull, has been studied in 357 specimens comprising series from 26 regions in North America. These were selected by criteria defined from a previous study of growth in black bears, U. americanus Pallas, since it was determined that the growth pattern is essentially the same for the two species. Variation in mean condylobasal length in the series studied is clinal; a well-defined gradient exists along the coastal zone from Bella Coola, British Columbia, to the end of the Alaska Peninsula, with mean condylobasal length increasing from south to northwest. A similar gradient was evident along the Arctic Coast, beginning in the region of Coronation Gulf. In the interior, small mean values were obtained for samples from the western Yukon Territory, with mean size increasing toward both the southeast and the northwest. It is concluded that formal recognition of segments of intergrading populations of brown bears at the subspecific level is not justified. Brown bears on Kodiak–Afognak–Shuyak Islands comprise a reproductively isolated population possessing distinctive cranial characteristics, and to them the name U. arctos middendorffi Merriam is applicable. It is proposed that U. a. horribilis Ord be used for brown bears over the greater part of the range of the species in North America. The number of subspecies of U. arctos recognized in Eurasia also may be reduced, with the study of comparable series of skulls.

Pleistocene remains of the lion-like cat (Panthera atrox) from the Yukon Territory and northern Alaska

1969 ◽  
Vol 6 (5) ◽  
pp. 1277-1288 ◽  
Author(s):  
C. R. Harington
Keyword(s):  
North America ◽  
Yukon Territory ◽  
The Arctic ◽  
Panthera Leo ◽  
Arctic Coast ◽  
Northern Alaska ◽  
Panthera Atrox

Skull and forelimb fragments of the large, extinct cat (Panthera atrox) from Pleistocene sediments in the Dawson area, Yukon Territory, are the first records of the species for Canada. A further specimen from the Kaolak River, near the arctic coast of Alaska, significantly extends the known northward range of this cat. The species has been reported from approximately 26 localities from Alaska to Peru, and may have migrated from Eurasia just prior to the Sangamon interglacial. Data reviewed suggest that Panthera atrox from North America, the Eurasian "cave lion" Panthera leo spelaea, and the large Chinese cat Panthera youngi are conspecific.

Flake Tools in the American Arctic: Some Speculations

1964 ◽  
Vol 29 (3) ◽  
pp. 338-344 ◽  
Author(s):  
Edwin N. Wilmsen
Keyword(s):  
North America ◽  
Central Asia ◽  
New World ◽  
Yukon Territory ◽  
River Delta ◽  
The Arctic ◽  
Land Bridge ◽  
Bering Land Bridge

AbstractTwo sites, Kogruk (at the summit of Anaktuvuk Pass, Alaska) and Engigstciak (at the head of the Firth River delta, Yukon Territory, Canada), have recently yielded flake-tool assemblages which show striking resemblances to a Eurasiatic flake-blade tradition based on a Levallois-Mousterian stone-chipping technique, and to the Clovis flake-blade tradition of America which appears to be based on a similar chipping technique. It is suggested that these traditions are historically related and that the Arctic sites provide a possible link between the two. The presence of incipient fluting in Siberia and at Engigstciak may prove significant. Dating is discussed in terms of the ecology and geology of the sites and is correlated with the probable periods of availability of the Bering land bridge. An upland-foothills zone is seen to be essentially continuous from central Asia to central North America. It is suggested that this zone provided the only environmentally compatible link between the two continents, and that it was therefore the most probable route of early hunting peoples into the New World.

scholarly journals Use of salmon (Oncorhynchus spp.) by Brown Bears (Ursus arctos) in an Arctic, interior, montane environment

2019 ◽  
Vol 133 (2) ◽  
pp. 151 ◽  
Author(s):  
Mathew S. Sorum ◽  
Kyle Joly ◽  
Matthew D. Cameron
Keyword(s):  
National Park ◽  
Ursus Arctos ◽  
Brown Bear ◽  
The Arctic ◽  
Brooks Range ◽  
Brown Bears ◽  
Arctic Circle ◽  
Aerial Surveys

Salmon (Oncorhynchus spp.) is a key dietary item for temperate coastal Brown Bears (Ursus arctos) across much of their circumpolar range. Brown Bears living in Arctic, interior, and montane environments without large annual runs of salmon tend to be smaller bodied and occur at much lower densities than coastal populations. We conducted ground and aerial surveys to assess whether Brown Bears fished for salmon above the Arctic Circle, in and around Gates of the Arctic National Park and Preserve. Here, we document the use of salmon by interior Brown Bears in the Arctic mountains of the central Brooks Range of Alaska. We believe our findings could be important for understanding the breadth of the species’ diet across major biomes, as well as visitor safety in the park and Brown Bear conservation in the region.

Winter blood values of selected parameters in a group of non-hibernating captive brown bears (Ursus arctos)

2015 ◽  
Vol 18 (4) ◽  
pp. 885-888
Author(s):  
A. Sergiel ◽  
M. Bednarski ◽  
R. Maślak ◽  
T. Piasecki ◽  
D. Huber
Keyword(s):  
Ursus Arctos ◽  
Winter Season ◽  
Blood Parameters ◽  
Free Living ◽  
Brown Bears ◽  
Mean Values ◽  
Physiological Indicators

Abstract Bears undergo some significant changes reflected in blood values during winter season. The most significant are reduced urea and increased creatinine, by some authors considered to be physiological indicators of hibernation. Studied group of six captive brown bears (Ursus arctos) showed decreased activity in winter but were accepting food and walked outdoors. Blood parameters assessed in February 2011 revealed mean values of leucocytes and neutrophils as significantly lower, and creatinine significantly increased compared to captive and free living bears sampled during other seasons when bears are active.

Late Pleistocene fish fossils of Coregonus, Stenodus, Thymallus, Catostomus, Lota, and Cottus from the Old Crow basin, northern Yukon, Canada

1981 ◽  
Vol 18 (11) ◽  
pp. 1740-1754 ◽  
Author(s):  
Stephen L. Cumbaa ◽  
Don E. McAllister ◽  
Richard E. Morlan
Keyword(s):  
North America ◽  
Geographic Variation ◽  
Glacial Refugia ◽  
Yukon Territory ◽  
The Arctic ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Freshwater Sculpin ◽  
Longnose Sucker ◽  
First Time

Fossils of the broad whitefish, Coregonus nasus; the inconnu, Stenodus leucichthys; the longnose sucker, Catostomus catostomus; and the burbot, Lota lota, are reported for the first time from North America and a freshwater sculpin, Cottus, for the first time from Yukon Territory. The known fossil occurrence of the Arctic grayling, Thymallus arcticus, in North America is extended from 32 000 to about 60 000 years BP. These six fossils represent about one sixth of the present-day Yukon freshwater ichthyofauna of 35 species.These fossils provide a major test for the method of determining glacial refugia based on geographic variation of morphological or protein characters. They confirm that these taxa were present prior to and presumably survived the Wisconsinan glaciation in a Beringian refugium.The occurrence of these fossils, all subarctic or subarctic–boreal species known at present in the same area, does not suggest a paleoenvironment greatly different from the present one.

scholarly journals Composite study of aerosol export events from East Asia and North America

2012 ◽  
Vol 12 (8) ◽  
pp. 21977-22022 ◽  
Author(s):  
Y. Luan ◽  
L. Jaeglé
Keyword(s):  
Boundary Layer ◽  
North America ◽  
East Asia ◽  
Transport Model ◽  
Lower Troposphere ◽  
Temporal Variations ◽  
The Arctic ◽  
Chemical Transport Model ◽  
Mean Values ◽  
Warm Conveyor Belts

Abstract. We use satellite observations of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectrometer (MODIS) together with the GEOS-Chem global chemical transport model to contrast export of aerosols from East Asia and North America during 2004–2010. The GEOS-Chem model reproduces the spatial distribution and temporal variations of Asian aerosol outflow generally well, although a low bias (−30%) is found in the model fine mode AOD. We use the model to identify 244 aerosol pollution export events from E. Asia and 251 export events from N. America over our 7-yr study period. When these events are composited by season, we find that the AOD in the outflow is enhanced by 50–100% relative to seasonal mean values. The composite Asian plume splits into one branch going poleward towards the Arctic, with the other crossing the Pacific in 6–8 days. A fraction of the aerosols is trapped in the subtropical Pacific High. The N. American plume travels to the northeast Atlantic, reaching Europe after 4–5 days. Part of the composite plume turns anticyclonically in the Azores High, where it slowly decays. Both the Asian and N. American export events are favored by a dipole structure in sea-level pressure anomalies, associated with mid-latitude cyclone activity over the respective source regions. The observed AOD in the E. Asian outflow exhibits stronger seasonality, with a spring maximum, than the N. American outflow, with a weak summer maximum. The large spring AOD in the Asian outflow is the result of enhanced sulfate and dust aerosol concentrations, but is also due to a larger export efficiency of sulfate and SO2 from the Asian boundary layer relative to the N. American boundary layer. While the N. American sulfate outflow is mostly found in the lower troposphere (1–3 km altitude), the Asian sulfate outflow occurs at higher altitudes (2–6 km). In the Asian outflow 42–59% of the sulfate column is present above 2 km altitude, with only 24–35% in the N. American outflow. We link this to the factor of 2–5 lower precipitation in the warm conveyor belts (WCB) of midlatitude cyclones over E. Asia compared to N. America. This relative lack of precipitation makes Asian WCB very efficient for injecting aerosols in the middle troposphere.

Phaeogalera and Galerina in arctic-subarctic Alaska (U.S.A.) and the Yukon Territory (Canada)

1992 ◽  
Vol 70 (2) ◽  
pp. 414-433 ◽  
Author(s):  
E. Horak ◽  
O. K. Miller Jr.
Keyword(s):  
North America ◽  
Key Words ◽  
Arctic Tundra ◽  
Yukon Territory ◽  
The Arctic ◽  
North Slope ◽  
Wet Meadow ◽  
Alpine Habitats ◽  
Alaskan North Slope ◽  
First Time

Eleven taxa of Galerina and Phaeogalera are described. Galerina leptocystis, Galerina subarctica, and Galerina praticola are reported from arctic North America for the first time. Phaeogalra stagnina is only found in very humid, wet meadow tundra associated with Drepanocladus or Calliergon. Galerina arctica is reported for the first time from Alaska and Canada. One species, Galerina pseudocerina, is found only in arctic alpine habitats in Canada and not in the arctic tundra. Two forms of Galerina pseudomycenopsis represent the most common taxon observed in Alaskan North Slope wet meadow tundra on peat or associated with Calliergon, Drepanocladus, and Sphagnum. Two species, Galerina clavata and Galerina hypnorum, are common cosmopolitan taxa, but only G. clavata is frequently encountered on the Alaskan North Slope. The association of the Galerina taxa with mosses is presented and discussed, as well as their occurrence in microhabitats in wet meadow tundra and among polygons in coastal tundra on the Alaskan North Slope. Key words: Galerina, Phaeogalera, Cortinariaceae, Alaska, Yukon Territory, bryophytes.

Anastrophyllum assimile and Marsupella revoluta, new to the interior of North America

1977 ◽  
Vol 55 (19) ◽  
pp. 2479-2484 ◽  
Author(s):  
Diana G. Horton
Keyword(s):  
British Columbia ◽  
North America ◽  
Northwest Territories ◽  
North American ◽  
Yukon Territory ◽  
The Arctic ◽  
Devon Island ◽  
New Localities ◽  
Central Eastern ◽  
Coastal British Columbia

Anastrophyllum assimile (Mitt.) Steph. and Marsupella revoluta (Nees) Lindb. are reported from the Keele Peak area, central-eastern Yukon Territory, Canada, and M. revoluta is also reported from Devon Island, Northwest Territories, Canada. These new localities extend a pattern of disjunct occurrences throughout the known range of both species, which further support the hypothesis of their relictual status. However, collections of A. assimile from coastal British Columbia and the Alexander Archipelago, Alaska, are indicative of strong oceanic affinities of North American populations of this species. Also, the arctic and alpine localities at which either A. assimile or M. revoluta might be expected to occur in the interior of Alaska and the Yukon are limited in number as both species invariably occur in association with siliceous substrates.

The first record of Leptodontium flexifolium (Pottiaceae, Bryophyta) for Arctic Alaska

2011 ◽  
Vol 45 ◽  
pp. 267-275 ◽  
Author(s):  
O. M. Afonina
Keyword(s):  
North Carolina ◽  
North America ◽  
First Record ◽  
Yukon Territory ◽  
The Arctic ◽  
Southern States ◽  
Arctic Alaska ◽  
First Time ◽  
The City ◽  
World Distribution

Leptodontium flexifolium (Dicks.) Hampe is reported for the first time from the Arctic Alaska, vicinity of the City of Nome (64°31′ N, 165°29′ W). The species is rare for North America and belongs to the genus with tropical and subtropical distribution. Earlier the species was known in North America from the southern states (Arizona, New Mexico, North Carolina, Texas) as well as from 60 000-years-old subfossils from the arctic part of the Yukon Territory (Arctic Canada). The description and illustration of this species based on the specimen from Alaska is given, the world distribution is considered.

scholarly journals Mammoth Extinction: Two Continents and Wrangel Island

Radiocarbon ◽  
1995 ◽  
Vol 37 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Paul S. Martin ◽  
Anthony J. Stuart
Keyword(s):  
North America ◽  
Western Europe ◽  
The Arctic ◽  
Striking Difference ◽  
Mammuthus Primigenius ◽  
Radiocarbon Dates ◽  
Wrangel Island ◽  
Arctic Coast

A harvest of 300 radiocarbon dates on extinct elephants (Proboscidea) from the northern parts of the New and Old Worlds has revealed a striking difference. While catastrophic in North America, elephant extinction was gradual in Eurasia (Stuart 1991), where straight-tusked elephants (Palaeoloxodon antiquus) vanished 50 millennia or more before woolly mammoths (Mammuthus primigenius). The range of the woolly mammoths started shrinking before 20 ka ago (Vartanyan et al. 1995). By 12 ka bp, the beasts were very scarce or absent in western Europe. Until the dating of Wrangel Island tusks and teeth (Vartanyan, Garrutt and Sher 1993), mammoths appeared to make their last stand on the Arctic coast of Siberia ca. 10 ka bp. The Wrangel Island find of dwarf mammoths by Sergy Vartanyan, V. E. Garrut and Andrei Sher (1993) stretched the extinction chronology of mammoths another 6 ka, into the time of the pharaohs.

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