. Bulletin. Royal Ontario Museum of Zoology; Zoology; Zoology. ROYAL ONTARIO MUSEl'M OF ZOOLOGY 13 lemmings, but all are large, long-haired relatives of the meadow mouse and all live in the Arctic regions. Their peaks of abundance occur at four year intervals on the average. Unlike the hares, lem- mings do not remain at home and die of epidemics; when they become crowded through population pressure, the lemmings migrate away from their homelands. In Scandinavia these periodic lemming emi- grations ha^'e been spectacular occurrences for hundreds of years, "The lemmings march chiefly at nig
. Bulletin. Royal Ontario Museum of Zoology; Zoology; Zoology. ROYAL ONTARIO MUSEl'M OF ZOOLOGY 13 lemmings, but all are large, long-haired relatives of the meadow mouse and all live in the Arctic regions. Their peaks of abundance occur at four year intervals on the average. Unlike the hares, lem- mings do not remain at home and die of epidemics; when they become crowded through population pressure, the lemmings migrate away from their homelands. In Scandinavia these periodic lemming emi- grations ha^'e been spectacular occurrences for hundreds of years, "The lemmings march chiefly at night, and may traverse more than a hundred miles of country before reaching the sea, into which they plunge unhesitatingly and continue to swim on until they ; By such wholesale emigrations their crowded numbers are reduced to more normal proportions. Lemming migrations have not been a conspicuous feature of the Canadian Arctic although alternating periods of great abundance and scarcity are known to occur usually at four year intervals. Just as lynx, fox, horned owl, goshawk and other animals that feed on hares show the same periods of scarcity and abundance as the hares, so the animals that feed on lemmings in the Arctic are alternatingly abundant and scarce every four years on the average following the ups and downs of the lemming population. Lemming Numbers Affect Arctic Fox and Snowy Owl Numbers ^ \ The Arctic fox and the snowy owl are two animals whose popu- lation numbers appear to be con- trolled by the lemming populations. With plenty of lemming to eat, Arctic foxes and snowy owls in- crease in numbers and become abundant too. When lemmings get scarce there are a lot of hungry foxes and owls and, just as gos- hawks come south approximately every ten years following the disappearance of hares, so snowy owls come south more or less at four year intervals when lemmings get scarce. Below are given in parallel columns the years in which Arctic fox pelts were traded i
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1928
