rous at their breeding-places in winter as in summer ; and they pair
and begin to lay eggs in the month of March,—nearly three months
earlier than any other bird in those quarters.
The distribution of the migratory and resident birds is evidently
governed, as far as climate is concerned, by very different laws. The
winter temperature, regulating the depth and duration of the snow
and ice, and consequently the supply of vegetable productions, insects
or fish at that season exerting a principal influence on the number
of resident birds, whose distribution may be considered as bearing
much analogy to that of quadrupeds. While the influx of migratory
birds into the northern regions for the purpose of rearing their young
is more connected with the high summer temperature of those parallels,
the mean annual heat, which is very low, being no criterion as
to the number or variety of summer visiters *.
* The following Table gives a view of the temperatures of various stations in North America, the
extrêmes being forty-five degrees of latitude apart. Our limita do not admit of the Table being
more extended, but' the reader who wishes to enter fully into the subject, may consult Dr. Lovell’s
valuable tables, appended to the Narrative of Long’s Expedition to St. Peter’s River, from which the
temperatures for Fort St. Philip and Philadelphia have been extracted, and the Edinburgh Philosophical
Journal for April, 1825, or the Appendices to_ Sir Edward Parry’s and Sir. John Franklin’s
several Narratives, which furnished the materials for the rest of the Table. It may be observed, that
the mean annual temperature decreases as we advance northwards 14° F. for each degree of latitude,
while the decrease of mean heat in July does not exceed 1°. The three last lines are omitted.in thip
calculation, as the observations recorded in them were made among fields of ice, which, reduce the
Summer temperature greatly below what it is even a few miles inland. The snow is-perpetual™ no
part of the Fur Countries, except on the elevated peaks of the Rocky Mountains,
Places.
Positiop. Mean temperature of the Air.
iMu athxe. | iMn iinh.e Lat. .Long.
-Year.
Yea?.
N.
W..
Haebiogvhet
in feet.
Annual.
SuJmumneer,.., AJuogiuys,t.
DWecienmtebre.r, FJeabnruuaarryy,.
WMaornmtehs, t July.
Fahr. Fahr. Fahr. Fahr. Fahr. Fahr.
Fort St. Philip 29 29 89 21 -f-70.07 +82°. 89 +54°. 08 +81°. 53 +92.0 +28.0
Philadelphia 39 57 75 9 -{-53.38 +72.75 +29.77 +75.32 +87-0 r-0 .7
Penetanguishene 44 48 80 40 600 -{—45.28 +69.91 +22.68 +73.15 +92.0 -20.0
Cumberland House 53 57 102 17 800 -{-32.01 +67.80 -4.62 +69.80 +87-0 -44.0
Fort Chipewyan 58 43 111 18 500 +30.00 +62.41 +3:67 +63.42 +9*7 *0 -31.0
Fort Enterprise 64 0 113 6 850 +14.19 +51.71 -23.03 +53.20 +78.0 -57-0
Fort Franklin 65 12 132 13 230 +17.50 +50.40 -16.81 +52.10 +80.0 -58.0
Winter Island 66 11 83 30 +6.84 +35.00 -24.96 +36134 +54.0 -42.5
Igloolik 69 19 82 30 -+2.20 +34.63 -26.76 +40.04 +50.0 -60.0
Melville Island 74 45 111 0 -1.71 +36.44 -33.02 +42.41 +60.0 -55.0
The nature of the country, whether prairie or wooded, rocky and
barren, or marshy, must also be taken into account in all speculations
on the distribution of the feathered tribes. Several of the Grallatores,
for instance, that feed by thrusting their bills into soft marshy soil,
frequent the Saskatchewan prairies only in spring,-and as soon as the
warm and comparatively early summer renders the soil dry and unfit to
yield them support, they retire to their breeding-quarters in the Arctic
lands. There, the frozen sub-soil acted upon by the rays of a sun
constantly above the horizon, keeps th e : surface wet and spongy
during the two short summer months which suffice these birds for
rearing their young. This office performed, they depart to the southward,
and '■ halt in the autumn on the flat shores of Hudson’s Bay,
which, owing to accumulations of ice drifted into the Bay from the
northward, are kept in a low temperature all the summer, and are
not thawed to the same extent with the more interior Arctic lands
before the beginning of autumn. They quit these haunts on the
setting in of the September frosts, and passing along the coasts of the
United States, retire within the Tropics in the winter.
Many species, which are purely summer visiters of the high latitudes,
are resident within certain parallels of the United States, detachments
advancing to the north in the spring for the purpose of
rearing their young and retiring to the south of the resident stations
in winter. It is obviously very difficult to ascertain whether the
individuals of these species which breed in the higher latitudes are
the same that retire farthest southwards in winter, those remaining
in the intermediate districts in winter being the pairs which bred
there, though from analogy we are led to think that such is the case.
Of the strictly resident birds in Europe it is known that many (the
House-Sparrow, for instance) shelter themselves in winter in their
nests and summer haunts; and of the migratory ones, the same pair
have been observed to build several successive seasons in the same
spot. Some species seem to claim a right of property within a certain
beat, chasing away with great pertinacity all the other birds that they
can master. In the instance also of the Falconidte and some other