Effects of Climatic Fluctuations on Polar Bears in Greenland
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Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), pp 1-227.
In September 2008, the publishers of Vibe's monograph, now known as MoG, stated that they will commence digitizing Vibe's monograph and other selected historical editions of the journal later this year. The publisher is currently taking recommendations for which editions should be digitized. --Nichole Hoskin 15:08, 21 September 2008 (EST)
--Nichole Hoskin 10:12, 4 September 2008 (EST)
“The history of Greenland is a testimony of prosperity and poverty following each other in rapid succession. Oral as well as written records from the last centuries, and archaeological finds from the last four-five thousand years, unfold the same picture: The periods of prosperity, after a few scores or at most a few hundred years, were succeeded by correspondingly long periods of decline, when settlements, part of the country, or all of Greenland were depopulated and lay uninhabited.”[1]
“The climatic fluctuations forced the sea mammals and sea birds of Greenland to look for new foraging grounds, during which they did not follow the coast from north to south, but crossed Baffin Bay and Davis Strait several times, as an immigration also took place from the coast of East Greenland to the sea north of Iceland. In all cases migration during changing climatic periods moved periodically towards Greenland and then away from Greenland again, leaving Man starving behind.”[2]
“The best material for throwing light on animal life and climatic fluctuations in Greenland in the past, has been uncovered by the archaeologists in their excavations of Eskimo and Norse settlements, and considerable bone material has been brought home for determination by the specialists of the Zoological Museum in Copenhagen.
This bone material, as well as historical records, shows that the favourable game areas have in some periods been located in North Greenland, in other periods in Northeast or Southwest Greenland, and that the location of good whaling and sealing grounds has varied a great deal through the ages.”[3]
“The present author has brought to light further material from the Greenland accounts, in particular regarding sea mammals, sea birds, and land mammals, demonstrating that during the course of time these animals have been subject to great quantitative fluctuations and great geographical shifts.”[4]
“On the face of it, the quantitative fluctuations at different places run courses independent of each other; this, however, is not the case, in that a drop in one geographic area very often corresponds to a rise in another. All animals are dependent on the climate, the various factors of which may influence one biotype (e.g. The coast) favourably and at the same time another biotype (e.g. the tundra) unfavourably —and they may have favourable effect in one geographic area and at the same time an unfavourable effect in another.”[5]
“At the present time, the two cold surface currents carry great amounts of drift-ice from the Arctic Ocean into the Atlantic and Davis Strait. The drift-ice varies in quantity from year to year. During certain epochs of time it appears not to have reached South Greenland at all, while in others it has occurred in great volume. The time of year of its main arrival has alternated between early spring and late summer (or between winter and summer). It is shown in the present paper that this alteration causes serious ecological disturbances in Davis Strait and surrounding land areas.”[6]
“In their studies of drift-ice TH. Thoroddsen (1916-17), C.I.H. Speerschneider (1931) and Lauge Koch (1945) have brought to light much valuable material to elucidate the intensity and duration of the drift-ice periods of the last millennium. The works of these authors, together with studies of temperature, precipitation and wind activity, have been an important clue to the understanding of many of the natural conditions which determine the fluctuations in number of Arctic and Atlantic species in Greenland, and their shifting geographic distribution.”[7]
“Three drift-ice stages are recognised, i.e., (A) stagnation stage 1810-60, (B) pulsation stage 1860-1910, and (C) melting stage 1910-60. These drift-ice stages play an important role for climate and ecology in all Greenland and in all Arctic.”[8]
The Role of drift-ice stages for the climate and ecology of Greenland:
--Nichole Hoskin 19:14, 4 September 2008 (EST)
Describing the drift-ice stagnation stage, Vibe states,
“The East Greenland Ice does not advance far north into Davis Strait where the Canadian Current has a dominating influence. The climate of northern West Greenland is relatively cold, dry and stable. The populations of sea mammals and sea birds concentrate at central West Greenland. The winter climate is favourable for the Reindeer in central and northern West Greenland, and the population increases and culminates. The population of white Arctic Fox increases and culminates in southeastern Canadian Arctic. The white percentage increases in West Greenland. The Cod occurs along the coast of southern West Greenland, but it is not abundant, except for short periods of little drift-ice. The drift-ice is relatively stable throughout the winter off Northeast Greenland where the climate is favourable for Reindeer and the Musk Ox. The populations increase.”[9]
Describing the drift-ice pulsation stage, Vibe states,
“The ice of the Arctic drifts into the Atlantic in larger amounts than before. The East Greenland Current and the East Greenland Ice advance far north into Davis Strait either early or late in summer. The populations of sea mammals and sea birds decrease in central West Greenland. The climate becomes relatively unstable and wet. The wet winters are unfavourable for the Reindeer in West Greenland and the population decreases. The population of white Arctic Fox decreases in Canadian Eastern Arctic and that of the blue Arctic Fox increases in central and northern West Greenland. The white percentage stagnates or decreases in northern West Greenland. Cod occur only occasionally in short periods with early drift-ice in Davis Strait. The drift-ice moves relatively fast off Northeast Greenland where the population of Musk Ox stagnates owing to wet winters. The Reindeer becomes extinct in Northeast Greenland. The population of Greenland Whale stagnates in the Atlantic region.”[10]
Describing the drift-ice melting stage, Vibe states,
“The East Greenland Ice decreases in Davis Strait where the Irminger Current has a dominating influence on climate and production. The population of sea mammals and sea birds increase in northern West Greenland and in East Greenland. The Reindeer population of West Greenland has ample summer grazing, but the winter pastures are often covered by snow and ice—and the population stagnates in all West Greenland, except for the short dry period 1910-20. The population of white Arctic Fox increases and culminates in all eastern Canadian Arctic and in Northeast Greenland, and that of blue Arctic Fox in all West Greenland. The white percentage decreases in central and increases in northern West Greenland. Cod occur abundantly along the coast of West Greenland and multiple in Greenlandic waters. The population increases in periods with little or early drift-ice and decreases in periods of late drift-ice in Davis Strait. Northeast Greenland has ample vegetation and the Musk Ox population usually thrives and increases, but is often threatened by catastrophe in wet autumns and winters when Greenland Sea has little or no drift-ice. At present a new “drift-ice stagnation stage” is beginning (approx 1960-?).”[11]
The Role of drift-ice stages for the climate and ecology of the Atlantic:
--Nichole Hoskin 19:13, 4 September 2008 (EST)
“The east and west sides of Baffin Bay and Davis Strait constitute one common living space for the sea mammals and certain sea birds of the area.
Their varying distribution is dependent on changing current and drift-ice conditions.”[12]
“The breeding grounds of the Eider in West Greenland has its greatest southern extension during the first half of the nineteenth century. After that time the population suffered great losses because of heavy advances of East Greenland Ice in Davis Strait in the late summer, especially since 1840 and in the long period 1860-1910. During periods with drift-ice late in summer the Eider had better opportunities for breeding in the northern parts of Davis Strait and Baffin Bay than in the south.
The great drop in the population of breeding Eider in Central West Greenland after the middle of the 19th century was caused more by currents and drift-ice than hunting.”[13]
“The Ringed Seals of Greenland are divided into two large populations; one is associated with the Baffin Bay Ice, and the other with the East Greenland Ice. During the period before and after 1800, with strong movements in the Baffin Bay Ice, there were few Ringed Seals in northern West Greenland south of Melville Bugt. With increasing stagnation of the Baffin Bay Ice after 1817 the number of Ringed Seals began to rise in the central areas of West Greenland toward the north to Umanak, and after 1860, also in Upernavik.
During periods when the East Greenland Ice in Davis Strait made heavy advances late in summer, e.g. 1860-1910, the Ringed Seal of East Greenland followed with the drift-ice in great numbers round Kap Farvel to Julianehåb Bugt. These were presumably mainly young Ringed Seals, unable to winter in the heavy drift-ice on the east coast.
Since 1910, there has been little East Greenland Ice, and this has not advanced very far north into Davis Strait (the drift-ice melting stage). The East Greenland Ringed Seals remain on the east coast, where great numbers occur at Angmagssalik and Scoresby Sund. At the same time, the Ringed Seals of Baffin Bay are most numerous at Upernavik and Thule. Colder winters 1945-60 caused their number to increase once more in the central parts of West Greenland. A new drift-ice stagnation stage is developing.”[14]
“The Polar Bear was on the increase in Northwest Greenland simultaneously with the increase of the Ringed Seal population in West Greenland after 1817. It arrived from the west or north side of Baffin Bay and decreased after 1868. The Polar Bears of Southwest Greenland arrive via the East Greenland Ice, the greatest number being killed during the mass advances of the drift-ice in the period 1860-1910. Since that time drift-ice masses in Davis Strait have been smaller, and the Polar Bear has preferred to remain in East Greenland and in Svalbard, where hunting is now good. At Angmagssalik and Julianehåb this animal is closely associated with the drift-ice, and in a like manner, occurs in typical 11-year periods.”[15]
The Polar Bear:
--Nichole Hoskin 19:13, 4 September 2008 (EST)
“The most important food of the Polar Bear (Thalarctos maritimus PHIPPS) is the Ringed Seal. In Greenland it has three important breeding places today, i.e. Northwest Greenland and the shores of Melville Bugt and Kane Basin. It is most often found with small cubs on the firm winter ice along the coasts of the breeding places mentioned. Around 1900, females with cubs were also seen in the drift-ice near Julianehåb in Southwest Greenland.”[16]
“Lone Polar Bears may be found all over Greenland, although the animal is rare along the west coast between Frederikshåb and Disko. On the latter stretch it is now found only every other year, or more rarely. In a few cases it is now found on and near the ice cap under circumstances indicating that from time to time stragglers wander across the inland ice (from east to west?).”[17]
“To the Eskimo populations, the Polar Bear was always a desired prey, the skin being used for clothing and trading. From before 1800 to 1950, the skin was purchased in the stores of the Royal Greenland Trade Department as a monopoly commodity, so that it is safe to assume that the majority of the bag in the monopolized area was purchased and registered. As all Polar Bear skins in Thule are used for winter trousers for men and children, skins from there have evaded the stores. In Upernavik, Scoresbysund, and Angmagssalik some skins are used for the same purpose. In other parts of Greenland, skins of Seal, Dog and Reindeer are preferred for clothing.”[18]
“The hunt for Polar Bears around Greenland was never particularly great, perhaps owing to the fact that a large number of the East Greenland Polar Bears keep far out in the drift-ice where they cannot normally be reached from land. The yearly bag at present, 1964, around 100 animals, including the weather stations with 15-20 and Thule with 20-30 bears a year, although exact figures cannot be given.”[19]
“the Polar Bear catch as a whole was rising in Northwest Greenland until approximately 1865, while falling in Southwest Greenland during the same period. The position was then reversed. After about 1865 the bag rose in Southwest Greenland and dropped in Northwest Greenland. After 1930 the bag was poor all over West Greenland but still high in East Greenland.
This brings to mind the drift-ice conditions in Baffin Bay and Davis Strait and of East Greenland. Before 1817 the moving drift-ice blocked Baffin Bay during the summer (and kept moving through the winter?). The Atlantic climate penetrated far north into Davis Strait. The Ringed Seals were few in Greenland from Holsteinsborg to Upernavik. They stayed north of Melville Bugt—as did the Polar Bear. It was a poor period for the Eskimo population of West Greenland. Presumably the hunting was better north of Melville Bugt.
In southern West Greenland small numbers of Polar Bears arrived on the East Greenland Ice, but most of the bears stayed on the east coast—as they do today.
After 1817 the drift-ice stagnated in the northern part of Baffin Bay during winter and the Ringed Seal and Polar Bears appeared in northern West Greenland in great numbers.”[20]
“Simultaneously the East Greenland Ice stagnated off East Greenland during winter. The eastern Ringed Seals had to make for the ice edge far out into Greenland Sea—or along the north coast of Iceland. During the whole ‘drift-ice stagnation stage’ 1810-60 the Ringed Seals and Polar Bears were scarce in Southwest Greenland.”[21]
“The Polar Bear bag curve for Northwest Greenland resembles the bag curve of Ringed Seals for Egedesminde (which is rising until about 1864, and then fell) and the Narwhal bag curve at Umanak (which culminated in 1866).”[22]
“During the following period (the drift-ice pulsation stage 1860-1910), the Ringed Seal decreased in the central districts of West Greenland but increased in the northern districts. It is thus obvious that the winter climate was becoming milder farther and farther northwards in Davis Strait and Baffin Bay. The Polar Bear decreased slowly in Melville Bugt.
During the same period vast quantities of drift-ice were released from the Atlantic Ocean and carried by the East Greenland Current into the Atlantic around Kap Farvel to southern Davis Strait. The bag of Ringed Seal at Julianehåb increased far beyond the usual level, as did the Polar Bear bag. The explanation seems to be that the fast moving large ice masses of East Greenland served the Ringed Seals and Polar Bear as means of transportation and took them away from East Greenland. It was to be a time of severe hunger in East Greenland.”[23]
“Once the great ice advances ceased, the large numbers of Ringed Seal and Polar Bear in Southwest Greenland also terminated. These remained at the east coast of Greenland and at Svalbard. Simultaneously the bears of Northwest Greenland moved northwest to Ellesmere Island and to regions north of Kane Basin, from where some went around North Greenland to Peary Land.”[24]
“Today Polar Bear mothers with small cubs are regularly seen in the drift-ice off Northeast Greenland, less numerous in Melville Bugt, and Kane Basin. Many are seen off the east coast of Ellesmere Island, south of 79º N. According to the Canadian Wildlife Service (1965), dens are regularly found on northeastern Baffin Island.”[25]
“All through its extensive area of distribution the Polar Bear is closely related to the population of old breeding Ringed Seals, and occurs in numbers when Ringed Seals are plentiful.”[26]
“If we compare the sun-spot curve with the Polar Bear curve for Southwest Greenland for the period 1870-1930, during which time the fluctuations are very evident, we find that they tend to alternate. The sun-spot curve may influence the acceleration of the drift-ice, which serves the Polar Bears as biotype and as means of transportation.”[27]
“The climatic conditions of today on both sides of southern Greenland are too unstable for the country to maintain a very great population of Ringed Seal and Polar Bear. Breeding in dens, these animals need a constant Arctic climate without periods of thaw and melting of snow in winter.”[28]
References
--Nichole Hoskin 10:12, 4 September 2008 (EST)
1. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 13.
2. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 13.
3. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), pp 13-14.
4. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 14.
5. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 15.
6. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 18.
7. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 18.
8. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 20.
9. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 7.
10. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 7.
11. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 7.
12. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 194.
13. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 194.
14. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), pp 194-195.
15. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 195.
16. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 57.
17. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 57.
18. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 57.
19. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 58.
20. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 58.
21. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 59.
22. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 60.
23. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 60.
24. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 62.
25. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 62.
26. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 62.
27. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 62.
28. Christian Vibe, Arctic Animals in Relation to Climatic Fluctuations, in Meddelelser om Grønland (1967) 170(5), p 62.
