Image from the Biodiversity Heritage Library.
Contributed by Museum of Vertebrate Zoology, University of California, Berkeley.
| www.biodiversitylibrary.org
Transcription
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Formerly, if he saw her coming, he always stopped, but today he did
not follow this procedure invariably. To see how far he had progress-
ed in asserting his rights I tossed a worm at a time about equi-
distant from the two birds. Brownie got most of them, but Greenie
was pretty persistent and on one occasion this caused a combat in
which both birds fought in the manner of barnyard cocks, confronting
each other at close quarters and jumping up into the air breast to
breast, striking with bills and feet. They did this about 5 times
before separating by mutual consent, but there did not seem to be
any aftermath of ill feeling. Greenie got the worm.
When these birds fly up into my hand when it is held a couple
of feet above the ground, they tuck their legs up neatly and close
their feet into compact fists every time. In view of the shortness of
the flight it seems an unnecessary refinement of form! Their weight
is sufficient to cause considerable impact and, although I am prepared
for the shock, it is impossible to avoid dropping the hand slightly.
The reverse is the case when they take off with a strong push of the
feet. They do not clasp a finger strongly when sitting on it quietly,
seeming to depend more upon balance of the body to maintain position.
However, if they lean forward so that their centers of gravity are
no longer above the finger they grip strongly. I have often noticed
that birds, including the common barnyard fowl on which I used to
experiment as a youngster, try to keep their heads immovable in space
when their bodies are moved about by some effect beyond their control.
These thrashers are no exception. Thus (provided it does not fly off)
hand
when one of these birds is sitting on a finger I can move my an inch or
so gently in any direction and the bird's head remains absolutely
stationary.
I get the impression that these birds do move their upper eye-
lids, but of this I am not as yet certain.