[Mnbird] ecological trap

[Raymond Faber]

Robert Jessen's post about a red-tail taking a duckling reminds me of an
experience I had in 2019.  We were banding herring gulls on Big Sister
Island in upper Green Bay, Lake Michigan and I had just finished telling my
two student assistants that the gulls presented an ecological trap for
ducks nesting on the islands.  The gulls are very aggressive (we wear hard
hats!) and thus protect nesting waterfowl from predators, but I had never
seen ducklings--they are apparently attacked by gulls upon leaving the
nest.  And then one of the students yelled that there were ducklings in a
nest.  Thereupon the red-breasted merganser ducklings ran from the nest,
entered the water, and were immediately attacked by gulls.  We watched as,
one by one, all of the ducklings were carried off.  The students were
appalled, but another lesson was learned.

Ray Faber

-- 
Raymond A. Faber, Ph.D.
Professor of Biology
Saint Mary's University of Minnesota
700 Terrace Heights #1524
Winona MN 55987

Telephone: 507-457-1540
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