State College Bird
23 Sept. 2009
The State College Bird Club met at Foxdale Village on 23 Sept.
2009. Twenty-seven members and guests attended; Deb Grove
Nan Butkovich read the minutes. Dorothy Bordner read the
treasurer's report and checklist. Attendees reported
___ species within a 25-mile radius of Old Main since 1 Sept.
2009. Species of note included Olive-sided Flycatcher,
Yellow-bellied Flycatcher, Philadelphia Vireo, Marsh Wren, and American
• The observing platform at Julian Wetlands is
out. The labor source that was planned on didn’t pan out.
• 28 Oct.: Don Dearborn will be our next
• 4 Oct.: Bird Club will have a table at
Clearwater Conservancy’s annual Spring Creek Day at Millbrook Marsh.
• 13 Oct. The Big Sit… We have two local
circles. Trudy and Dave Kyler have one at the hawk watch on Stone
Mountain, and Diane Bierly and Bob Snyder have one at the beach at Bald
Sara Parbian, a graduate student at Penn State, spoke on “Snails for
Dinner? Effects of Calcium Availability on Forest
Songbirds.” While large birds are able to store calcium in their
long leg bones, small birds cannot. They must supplement their
calcium intake in order to produce strong egg shells, and the extra
calcium must be consumed roughly 8 hours prior to laying the
eggs. This is a problem for forest birds, since PA forests tend
to be poor in calcium to begin with, and is exacerbated by the fact
that PA has some of the most acidic rains anywhere in the U.S.
In her 5-year study two forest tracts were “seeded” with crushed
dolomitic limestone and two were left as controls. The species of
interest was the Ovenbird. She hypothesized that perhaps the
Ovenbirds were consuming snails as a calcium source. During the
course of the study, she found that the number of snails in the treated
areas increased 10 fold. She also found that while the territory
size remained the same, the number of Ovenbird territories in the
treated blocks also increased.
However, there isn’t much documentation on the actual consumption of
snails by birds in the U.S. She also set out several feeder
stations baited with snails and mealworms and monitored them with
motion-sensing cameras. Although many species visited the
feeders, only the Brown-headed Cowbird was actually caught in the act
of eating snail shells. Cowbirds require large amounts of calcium
because of their egg-laying behavior and readily consume snail shells.
Minutes taken by Nan Butkovich, Secretary