Many aspects of Turkey Vulture migration are poorly understood. Vultures of
the far west mostly go to southern Central and South America for the winter but
better studies are needed to understand the variations between different
populations. Most of the evidence suggests that they do not feed during their
migration through Central America although some evidence shows birds apparently
feed while still over North America. However, these reports are mostly for
eastern birds, and our vultures, making the long trek across Central America
may be different in behavior. They certainly fly a longer distance in migration
than vultures of the east. The Turkey Vultures in Central America are largely
resident and by flying over them our vultures avoid any competition. A few
observations show vultures arriving to wintering areas in poor condition and
seeking food upon arrival. Studies of captive vultures have shown that they can
survive many days while fasting. It has been difficult to determine how many
miles vultures may travel in a day or how long the flight southward actually
takes. Vultures defecate on their legs which means that they can’t be banded or
the buildup of feces causes problems. Without banding individuals it is hard to
determine the movements of individual birds. Visual observations of migrating
vultures have their own difficulties. They often fly so high as to be unseen.
Over the canal zone they often fly in mixed flocks with other raptors, but they
tend to be ignored by counters who are focused on particular hawk species
instead.
Dan Gleason
Owner, Wild Birds Unlimited of Eugene
Ornithology Instructor, retired, University of Oregon
dan-gleason@xxxxxxxxxxx
(Please forgive my typos. I beat leukemia but the intense chemo was very, very
hard on my eyes.)
On Sep 2, 2021, at 11:02 AM, Robert O'Brien <baro@xxxxxxx> wrote:
But, what do they eat? Sheep kills by coyotes in the Willamette Valley are a
potential source as are still-born or weak lambs.
But how many vultures can those feed? Ranchers likely won't tolerate large
numbers of kills. I've seen them walking through
recently mowed fields, apparently looking for small rodents killed by the
mower. But how much food can that provide?
There is a roost somewhere near me so that I have anywhere from 2 to 20
vultures soaring around a cliff every afternoon
in season. None in winter so far. What are these guys/gals eating?
Do OBOLers have experience with feeding TVs? Clearly they are eating
something.
Bob OBrien Carver OR
PS I once saw a Turkey in Ft. McMurray Alberta, pretty far north. But eBird
shows several records for the Prudhoe Bay area!
At least up there they would find wolf or bear kills.
On Thu, Sep 2, 2021 at 1:50 AM larspernorgren <larspernorgren@xxxxxxxxx>
wrote:
Turkey Vultures in Saskatchewan, their northernmost breeding ground
anywhere, winter in Venezuela. This knowledge is the result of a
banding/marking program similar to the Redtails at PDX. I've noted large
numbers of TVs in Sonoma County in early January. There has long been a
wintering flock just south of Fern Ridge Reservoir. Many teams in the
western portion of the Eugene CBC report them. But it's interesting that
they seem to seldom if ever frequent the rest of the circle in the colder
part of the year. Now there's a wintering population in the Coquille Valley
which gives the impression that it's growing in numbers. I imagine these
groups each have a fairly well defined summer range, distinct from other TV
cohorts.
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------
From: Robert O'Brien <baro@xxxxxxx>
Date: 9/1/21 9:41 PM (GMT-08:00)
To: Kevin Smith <kevinsmithnaturephotos@xxxxxxxxx>
Cc: OBOL <obol@xxxxxxxxxxxxx>
Subject: [obol] Re: TV's on the move
Actually, as to their destination, a few years ago I read of a banding study
that found (southern?) Oregon TVs wintered mostly in central Baja and the
adjacent mainland across the gulf. I might be able to find the article if
anyone was interested.. Bob OBrien Carver OR
On Wed, Sep 1, 2021 at 6:42 PM Kevin Smith
<kevinsmithnaturephotos@xxxxxxxxx> wrote:
Going on 7PM today and the Turkey Vultures are on the move south! Twelve
of them are headed for a night roost here at Crooked River Ranch. It will
be interesting to see just how many will congregate to make the trip. We
have had as many as 27 trying to find space on the cell tower behind our
house to all fit in one place. But wait! There's more. Well there WERE
more, Thirty-Two in the poplar trees at Ogden Wayside. That's when we
found that the carrying capacity of poplar limbs was only THREE birds at
once. We went and watched them circle in and land. CRACK! One limb
breaks and falls to the ground. crack, again. Another limb sends three
Turkey Vultures away to circle once, twice more before finding a roost for
the night. Their long trip south to Texas, Mexico, central America and yet
farther . Across Panama canal to Columbia and who know where. Hope they
make it back next spring to circle, circle, circle to finally pick up the
'leavings' of our un-thinking automobile drivers in a hurry to get
somewhere. Sixty miles per hour in a thirty-five mile per hour zone is
nothing for them. Don't worry. Nobody will turn them in. Run down that
young spotted fawn. The vultures will come and clean it all up.
Hope we DO see them return next spring.
Kevin Smith
--
Nature is my Religion. Wildlife has never said "Don't take a photo of me
while I'm laughing"
--
Nature is my Religion. Wildlife has never said "Don't take a photo of me
while I'm laughing"
