Evening star. [volume] (Washington, D.C.) 1854-1972, 1935-06-20
STARS, MEN AND ATOMS
book of Science Progress in Field,
Laboratory and Study.
BY THOMAS r. HENRY.

strongly that birds are essentially gre
garious in their tendencies. 1t seems
that solitary nesting, rather than colo
NAL nesting, is the more recent de-
velopment and on the whole this is
borne out by the fact that the great
majority of the higher groups of birds
are solitary neSters, while the bulk of
gregariouS breeding species belong to the
lower ostensibly more primitive,
groups"
The curious phenomenon of terri
torialiSm" has been a vital factor in the
development of self Suf1ciency as op-
posed to group living, DR.. Friedman
points out. 1t is the condition in which
each breeding pair of birds tends to
lay claim to a sufficient area around the
nest to supply food for themselves and
their young. With such a contingent
territory the parents never are obliged
to go so far from the nest as to leave
the neStlingS unprotected.
Such a development is dependent on
the nature of the food supply to which
the bird has become accustomed and
dudHbCOs LII WOO1Q NC td1udU1C O1l1y W
such species as live on worms, seeds,
ETC., which have a wide and almost uni
verSal distribution. Such birds might
be compared to small farmers, or to
subsistence homeSteaderS.
In many species the males will sep
arate from the flock in the Spring and
each will isolate himself on an exclusive
breeding territory, strenuously resisting
the encroachment of any other males.
There also he makes himself conspicuous
by display and song, so as to attract a
mate. Apparently, according to DR..
Friedman, this kind of behavior started
early in bird evolution and represents
a great step away from gregariousness
and toward solitude. After the breeding
season the tendency was to return to the
flock once more for the annual
migration.
On the other hand there has been the
least development of family Self-Suf1-
cheney among those birds whose food
habits are such that they must cover
great distances in search of sustenance.
Such, for example, are those that feed
upon fish, or that capture the majority
of their sustenance on the wing. For
them territorialiSm could have no object.
The immediate environment of the nest
offers them very little to supply their
needs.
It is difficult, DR.. friedman points
out, to establish any widely applicable
statements on bird society to which
there are not outstanding exceptions.
Such societies range from merely form
less aggregationS of many individuals
and pairs to groups in which can be
discerned the vestiges of cooperative
endeavor. The nature of this apparent
cooperation differs with the bird family
and the ways of life. In some cases it
is cooperation for mutual defense. In
others, as among the penguins, it is
cooperation in food getting.
The bird colony, DR.. friedman con-
cludes, is an institution that has arisen
independently several times in widely
divergent groups with widely divergent
needs The formless mass has been re-
duced to various degrees of order or
split up into units of families, according
to the needs of the species. Not, of
course, that the birds ever got together
and organized any society, any more
than primitive man did. The societies
probably evolved through the mechanism
OF survival.