[mou] FW: Wood Lake Warblers and some Oriole questions

[Alt, Mark]

I am much better informed after a discussion with Tony Hertzel,
corroborated by clarifying comments supplied by Bruce Fall (attached
below). I agree it must have been a "bright" female Baltimore Oriole
with a dark face, a darkly washed breast, with a dull buffy orange
rather than yellowish on her belly and underparts. Wing bars were not
noticed. The written record shows that males rarely assist in nest
making. Watching this Oriole peel the bark off of the Grapevine was
wonderful. Look for this behavior; it seems the Orioles are setting up
housekeeping right now. This one is working up high in one of the giant
cottonwoods right by the dead end the path takes towards the pond near
the visitor center in Wood Lake in Richfield, Hennepin County. Set out
long fibers for them at your house. I now have another reason to plant
and maintain wild grape in a forest plot, I have always loved them. The
first Bay-breasted Warbler I ever saw was perched horizontally on a
vertically growing grape vine, parrot-like, back in the woods of Western
Pennsylvania. On walks with my grandfather, he would cut a vine, then
cut it again 4 feet above, holding it aloft to let me drink the clear
sweet liquid that ran out as if it were a hose. I don't cut grape vines
any more, but I remember it being good stuff. Watching an Oriole for ten
minutes today sure changed the way it played out. Pick the nearest bird
and watch it and figure out what you are seeing it do. The worst you can
do is be wrong, as I was today. God's grace is shown to us in little
children and birds.
Here's some information on this from the Birds of North America=20
(online) for Baltimore Oriole:

"Construction process

Generally female is sole builder; male may occasionally bring material=20
for nest and inspect nest during construction (Bent 1958, Wedgwood=20
1989, Sealy and Neudorf 1995, NJF). A few records of males building=20
nests (Bent 1958, Audubon 1967), although these may have involved=20
females that were very similar to adult males (NJF; see Distinguishing=20
characteristics, above)."

If your bird is a dark-headed and bright female, you should be able to=20
see the male as he follows her about during nest building.




Bruce

>
> Mark,
>
> In response to your questions on MOU-net regarding oriole
nest-building
> behavior, the answer to the first question is that males generally
> don't contribute anything to nest building (although they closely
guard
> their mate during the process), as is typical for most passerines. My
> guess is that the bird you thought was a male (you noted it was "dimly
> plumaged") may have been a dark-headed and bright female--some females
> (probably age related) can appear rather male-like with considerable
> black on the head, especially the throat. I saw such a female nest
> building at the Old Cedar Ave. Bridge on yesterday (Sunday) morning;
> the nest was about half finished. Her mate was nearby.
>
>
>
> Bruce A. Fall
> General Biology Program
> 3-104 Molecular and Cellular Biology
> 420 Washington Ave., SE
> University of Minnesota, Minneapolis, MN 55455
> phone 612-625-4391, fax 612-626-7823
>
>
>
>