fast ferry and pelagics

------------------------------

Date: Fri, 2 Oct 2009 11:37:26 -0500 (CDT)
From: John H Idzikowski <idzikoj@uwm.edu>
Subject: [wisb] Re: fast ferry and pelagics?

The idea of Lake Michigan having some sort of undiscovered pelagic
assemblage of birds way out 30 miles from shore is not new, but the
parallels to oceanic pelagic birding are only superficial. Oceanic
pelagics are concentrated and targeted mostly by occurrences in
specific areas defined by a food source present due to currents and
upwellings because of local benthic canyons and dropoffs. The depths
of Lake Michigan way out from shore are far too deep for most divers
and with the decline of its main prey exploited during migration,
Long-tailed ducks, a deep diver, have declined in migration so we are
left with the mostly migrant group of birds in more shallow water
along the shore. The most productive trips have been those in small
boats that parallel the shore in September- Novemeber that are about
1-3 miles out where divers and phalaropes will be found.

Suppose you had 500 jaegers- our only truly pelagic migrant?
(kittiwake?) -on Lake Michigan evenly spread out- that's probably way
too many to expect in fall, but that would be one jaeger per 45 sq
miles- you'd be lucky to get one on any ferry trip. On the ocean of
course they are often attracted to the feeding community defined by a
food source and are therefore more concentrated. Even on Lake
Michigan I think that they still stay within 10 miles of shore. Most
are carried to the Michigan side of the Lake because of the
prevailing winds in fall and some concentrate on the south end- i.e.
Miller Beach. The best way to get jaegers on Lake Michigan's west
shore is to sit along the shore late in the evening from Sept 15- Oct
15 (but I have also had Poms as late as December) and watch a gull
loafing area such as the breakwater right near the Lake Express Ferry
in Milwaukee or a similar spot elsewhere, especially on E or NE
winds. They may come in to shore late in the evening and
often will attack some gulls before dark. .

There are some benthic features that have defined feeding areas for
divers near shore- if you have been around for awhile you remember
Loon Bluff in Ozaukee Co- where we found many divers and sometimes
jaegers and kittiwakes attracted to these concentrations. It turned
out that there is a sort of a shallow benthic plauteau near the Bluff
that due to adequate sunlight penetration creates a local food
supply. This property was added to a federal list for consideration
of acquisition in the late 70's, but it was sold to a private party.
At the north end of Virmond Park just south of Loon Bluff there is a
shipwreck and you might have noted the concentration of divers at
this spot when you searched for the Barrow's Goldeneye that wintered
near shore for many years. I imagine that this wreck is covered with
Zebra and Quagga mussels.

John Idzikowski,
Milwaukee