Of observers whose writings are extant, Aristotle, naturalist and
philosopher of ancient Greece, was one of the first to discuss the
subject of bird migration. He noted that cranes traveled from the
steppes of Scythia to the marshes at the headwaters of the Nile,
and that pelicans, geese, swans, rails, doves, and many other
birds likewise passed to warmer regions to spend the winter. In
the earliest years of the Christian era, the elder Pliny, Roman
naturalist, in his Historia Naturalis, repeated much of what
Aristotle had said on migration, and added comments of his own
concerning the movements of the European blackbird, the starling, and
the thrushes.
In spite of the keen perception shown in some of his statements,
Aristotle also sponsored some superstitions on bird migration that
persisted for several centuries. One of these, that of hibernation,
became so firmly rooted that in 1878, the American ornithologist
Coues (_20_)[2] listed the titles of no less than 182 papers dealing
with the hibernation of swallows (Hirundinidae). The hibernation
theory accounted for the autumnal disappearance of certain species
of birds as their passing the cold season in a torpid state, hidden
in hollow trees, caves, or the mud of marshes. Aristotle ascribed
hibernation not only to swallows but also to storks, kites, doves,
and others. Some early naturalists wrote fantastic accounts of flocks
of swallows seen congregating in the marshes until their accumulated
weight bent into the water the reeds on which they clung and thus
submerged the birds. It was even recorded that when fishermen in
northern waters drew up their nets they sometimes had a mixed "catch"
purported to consist of fish and hibernating swallows. Clarke (_4_)
quotes Olaus Magnus, Archbishop of Upsala, who in 1555 published a
work entitled "Historia de Gentibus Septentrionalibus et Natura",
wherein he observed that if swallows so caught were taken into a warm
room they soon begin to fly about but would live only a short time.
[Footnote 2: Ttalic numbers in parentheses refer to the Bibliography,
p. 66.]
The hibernation theory survived for more than 2,000 years and is
still occasionally repeated by credulous persons to account for
failure to locate definitely the winter home of the chimney swifts
(_Chaetura pelagica_), which each autumn gather in immense flocks in
southern Georgia and northern Florida and then suddenly disappear.
Thereare, however, records of occurrence during migration for a
few points in the West Indies, Mexico, and Central America, and it
is probable that these birds spend the winter season in the great
rain-forest area of the Amazon Valley in Brazil, passing most of the
daytime high in the air with other swifts that are local residents.
Aristotle was also the originator of the theory of transmutation,
basing it upon the fact that frequently one species will arrive
from the north just as another species departs for more southerly
latitudes. From this he reasoned that although it was commonly
believed that such birds were of two different species, there really
was only one, and that this one assumed the different plumages to
correspond with the summer and winter seasons.
Probably the most remarkable theory that has been advanced to account
for migration is contained in a pamphlet mentioned by Clarke (_4, v.
1, pp. 9-11_), as published in 1703 under the title: "An Essay Toward
the Probable Solution of this Question: Whence Come the Stork and
the Turtle, the Crane, and the Swallow, when they Know and Observe
the Appointed Time of their Coming." It was written "By a Person of
Learning and Piety", whose "probable solution" was that migratory
birds flew to the moon and there spent the winter.
Some who easily accepted the disappearance of the larger birds
as migratory travelers were unable to understand how the smaller
species, some of them notoriously poor fliers, could make similar
journeys. They contended that the larger species, as the storks
and cranes, carried their smaller companions as living freight. In
some of the Mediterranean countries it is still believed that these
broad-pinioned birds serve as aerial transports for the hosts of
small birds that congregate on the shores of the Mediterranean Sea,
awaiting opportunity for this kind of passage to their winter homes
in Africa. Similar beliefs are found among some tribes of North
American Indians.