Studies of Birds Killed in Nocturnal MigrationTordoff, Harrison Bruce
Science
Studies of Birds Killed in Nocturnal Migration
Tordoff, Harrison Bruce
Birds -- Migration
According to Carson (1954c:27), the majority of birds killed on nights
of heavy flight fell "between three and four o'clock in the morning
when skies were overcast and a cool front moved in from the north. Due
to the cooperation of the watchmen it is thought that most of the
birds that were killed were recovered. Of course some injured birds in
hiding were not found and some were lost to predators."
DESCRIPTION OF WIBW-TV TOWER.--The tower is 950 feet tall and stands
on a hill approximately 1000 feet above sea level. The fact that the
tower is on a hill places the top of the tower at 1010 feet above the
elevation of the average local terrain. The tower is triangular in
cross-section, each face seven feet wide, and is constructed of
six-inch steel L-beams with three-inch cross-members every seven feet
and smaller diagonal cross-members. It has no taper and bears a
transmitting antenna on the top. The tower is supported by 12 guy
wires, 3 wires attaching at each of 4 levels. The cables extend south,
WNW, and NNE from the tower and are 1-1/2 inches in diameter. The
tower is lighted by a series of red lights, some flashing and others
steady. The transmitter was not in operation when the accidents took
place.
WEATHER CONDITIONS.--All major kills at Topeka occurred when migrating
birds encountered either a cold front or a stationary front lying over
eastern Kansas. Typically, this frontal weather included rain, fog,
and cloud ceilings down to as low as 800 to 1000 feet. Weather of this
type presumably forces the migrating birds to fly below the cloud
ceiling and thus brings them within the altitudinal range of the
television towers.
Acknowledgments
We gratefully acknowledge our debt to the Topeka Audubon Society for
making this study possible by carefully collecting birds killed at the
television tower. L. B. Carson deserves special mention for his
general supervision of the bird collecting by the members of the
Topeka Audubon Society. Members of the Society and others who picked
up birds under the television tower were: Mrs. Lloyd Biggs, Elaine
Carson, L. B. Carson, Jesse A. Eddy, Elizabeth Fisher, Mrs. Walter
Huxman, Florence McKinney, Mrs. Charles Martin, Mrs. Fred P. Martin,
T. W. Nelson, Fred Prebble, Grace Prebble, Orville Rice, Mrs. G.
Warren Scholl, E. W. Senne, and Beatrice Swenson.
We received equally important assistance from students and staff of
the University of Kansas in recording of data and preparation of
specimens. The following helped in these ways: Rollin H. Baker, R. W.
Dickerman, David L. Hardy, J. W. Hardy, Jane S. Mengel, Larry D.
Mosby, Richard Van Gelder, South G. Van Hoose, and Glen E. Woolfenden.
We are indebted to the Interlibrary Loan Service of the University of
Kansas Library for help in securing certain reference works. Robert
Sokal of the University of Kansas gave helpful advice concerning
statistical procedures.
Notes on the Species Killed at Topeka
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account