There is only one continuous statistical record of the abundance
of animals, that is the returns of the fur trade. These have been
kept for over 200 years, and if we begin after the whole continent
was covered by fur-traders, they are an accurate gauge of the
abundance of each species. Obviously, this must be so, for the whole
country is trapped over every year, all the furs are marketed, most
of them through the Hudson's Bay Company, and whatever falls into
other hands is about the same percentage each year, therefore the
H. B. Co. returns are an accurate gauge of the relative rise and
fall of the population.
Through the courtesy of its officials I have secured the Company's
returns for the 85 years - 1821-1905 inclusive. I take 1821 as the
starting-point, as that was the first year when the whole region
was covered by the Hudson's Bay Company to the exclusion of all
important rivals.
First, I have given these accounts graphic tabulation, and at once
many interesting facts are presented to the eye. The Rabbit line
prior to 1845 is not reliable. Its subsequent close coincidence
with that of Lynx, Marten, Skunk, and Fox is evidently cause and
effect.
The Mink coincides fairly well with Skunk and Marten.
The Muskrat's variation probably has relation chiefly to the amount
of water, which, as is well known, is cyclic in the north-West.
The general resemblance of Beaver and Otter lines may not mean
anything. If, as said, the Otter occasionally preys on the Beaver,
these lines should in some degree correspond.
The Wolf line does not manifest any special relationship and seems
to be in a class by itself. The great destruction from 1840 to 1870
was probably due to strychnine, newly introduced about then.
The Bear, Badger, and Wolverine go along with little variation.
Probably the Coon does the same; the enormous rise in 1867 from
an average of 3,500 per annum. to 24,000 was most likely a result
of accidental accumulation and not representative of any special
abundance. Finally, each and every line manifests extraordinary
variability in the '30's. It is not to be supposed that the
population fluctuated so enormously from one year to another, but
rather that the facilities for export were irregular.
The case is further complicated by the fact that some of the totals
represent part of this year and part of last; nevertheless, upon
the whole, the following general principles are deducible:
(a) The high points for each species are with fair regularity 10
years apart.
(b) In the different species these are not exactly coincident.
(c) To explain the variations we must seek not the reason for the
increase - that is normal - but for the destructive agency that ended
the increase.
This is different in three different groups.
