Volume XXVI I, No. 2
PUBLISHED BY THE ORNITHOLOGY GROUP, OUTDOOR NATURE CLUB, HOUSTON, TEXAS
June & July There will be no OG meetings or field trips.
June 25 Deadline for SPOONBILL articles, notices, etc. (We are looking forward
to some accounts of birding experiences from you early vacationers).
July 3 Deadline for Clearing House (Earlier If possible).
July 1-14 HAS tour to Washington S+a+e and the Pacific Northwest. This would be
a great vacation: beautiful scenery, bird specialties of +he area, three
experienced naturalists to lead you—a cool escape from the heat and humidity of our upper Texas coast summer. P.O.Box 19687, Houston, 77024.
SPRING MIGRATION ON THE UTC by Jim Morgan
In early April Margaret Jones asked me to do an analysis of the 1978 spring migration on the UTC. Margaret's request was stimulated by many people asking her "where
are the birds?" She remembered that in early April, 1977, the same question was
being repeatedly asked, and, therefore, she felt tt might be worthwhile to put this
year's migration in perspective.
When we think of migration we often describe bird movements and associated events
with the terms "fallout", "push", and "wave". In general a "fallout" Is a rapid
Increase In the number of birds tn a local area (generally a migrant trap) usually
caused by turbulent weather or a rainy cold front. In just one or two hours a
small patch of woods starting with 100 or less migrants can be deluged with birds
until 1,000 or more birds are swarming in the trees and underbrush. The migrants
literally "fallout" (seek cover) from the effects of the adverse weather. A "push"
of a migrant species Is a build up of 20-30 Individuals (for most species; more or
less for more common or scarce species) of this particular species, the numbers
being less than what a fallout brings. A "wave" of migrants usually Is any noticeable Increase of migrants in a given area. The period of the wave can vary as can
the number of birds In any "wave". A wave generally has less birds per species
than a push but the varie+y of species is often quite good. The above terms Just
defined are obviously variable, relative, and very subjective unless one Is careful
to count birds accurately and record the results.
A good migration (for the birder) Is one that can be defined by saying that a lot
of birders saw lots of birds, or more precisely, birders observed a few fallouts
and numerous good pushes and waves during the migration. Fred Webster, commenting
In American Birds about the 1977 spring migration, stated that "a poor migration
may be defined as one In which birders are more conspicuous than birds."
A quick review of the 1977 spring migration on the UTC is in order. Generally,
the shorebird migration was rated good, but the passerine migration poor—at least
most of the time. Two good fallou+s, two or three strong pushes and a few more
waves of passerines were all that were observed in Spring, 1977. Most observers
t'elt the migration was one to two weeks late and there was good data to support
Now, on to Spring, 1978. March started off normal enough with a sprinkling of migrants found on the coast during the first two weeks. The first strong cold front
came through the night of March 23 and a cold northwest wind was blowing early the
following morning. This day, March 24, was the best shorebird day this observer
ever witnessed. A count of 25,000 shorebirds was made that day at High Island,
Bolivar Flats,.and on Galveston Island. Included were 300 Piping Plovers, 1,500
Dunlins, 1,500 Long-billed Dowitchers, 500 Least Sandpipers and 5,000 Sandpiper
species. Passerines were conspicuously absent that day, but on the following day,