Hi -
The Long Island goldfinches persisted for at least 75 years but died out I
think in the 1970s or 1980s. Like Vancouver's Mynah colony, Florida has had
several introduced birds build up substantial populations, then later crash and
die out. These have included Black Francolins, Budgies, and Blue-Gray Tanagers.
When I left Florida 22 years ago, the Red-whiskered Bulbul and Spot-breasted
Oriole populations were declining, but both apparently are still present.
The Smooth-billed Ani is a more interesting example: it was not introduced, but
colonized from the West Indies in the 1930s, and by the time I moved to Florida
in 1977 was widespread but uncommon in the bottom third of the Florida
peninsula. Throughout, there was continuing evidence of new arrivals - for
example on three occasions I saw Anis at the Dry Tortugas in the 1970s and
1980s. The population crashed in the 1990s, and by the time I left in 1998, I
was unaware of any persisting breeding colonies. I think now they are known as
occasional strays from the West Indies.
The Budgie population built up to many thousand birds in the 1970s, occupying
the Gulf Coast from south of Sarasota up to Tarpon Springs or so. In 1981 I saw
a flock in Pinellas County of over 400 birds. This population crashed in the
1980s, and it appears the disappearance proceeded from south to north, with
birds disappearing from the Sarasota area first, and the last survivors hanging
on at the north end of the range. IMO the nature of the crash and the
geographic progression are suggestive of an infectious pathogen, perhaps coming
from one of the numerous other parrot species loose in Florida.
When one of these apparently-established populations dies out we are left with
the question of whether they were really established but succumbed to an
environmental change, or whether the decision that they were established in the
first place was overly optimistic. I prefer the former explanation in most
cases, because most of these populations are occupying urban or otherwise
highly modified environments, and our modifications have continued apace. When
I was growing up outside Eugene (1950s and early 1960s) we considered Bobwhites
to be established residents of the area, but by the 1970s they were gone.
During that time the area did not become more urbanized, but the nature of
agriculture changed greatly, from annual row crops, grains, and orchards, to
mainly grass seed crops.
Another possible explanation for the population crashes of Bobwhites in the
Willamette Valley, the great decline in pheasant populations in Oregon, and the
crash of the Budgies in Florida, is genetic problems associated with new
introductions. "China" Pheasants were introduced into the Willamette Valley in
the late 19th century and did pretty well until the 1960s, when ODFW's
predecessor, the Oregon Game Commission, spent much effort and federal money on
trying to bring in other subspecies of pheasants with genetics supposedly
better pre-adapted to Oregon. In the early 1970s they were mainly raising
"Mongolian" Pheasants, and when I returned to Oregon in 1998, "Sichuan"
Pheasants were the breed of choice. The numbers of naturally reproducing
pheasants crashed during all of this "improvement" and the range of vigorously
reproducing populations has declined greatly. Bobwhite populations over much of
the species range in the US have collapsed coincident with the development of a
mail-order industry for quail eggs and chicks, and ubiquitous releases of
farm-raised birds. Here in North Carolina I am seeing probably 30-50 Wild
Turkeys for every Bobwhite I see or hear.
The Florida Budgie population, of course continued to be augmented by
continuing escapes of pet birds, and by the 1970s, the birds in the pet trade
were quite different from the birds sold a few decades earlier. The "new and
improved" ones were a bit larger, I think laid larger clutches, and in
captivity had much shorter lifespans (3-5 years vs 12-18). It seems very
possible in all three cases that the continued introductions did real harm to
the previously adequately-adapted gene pools.
Wayne
From: "baro@xxxxxxx" <baro@xxxxxxx>
To: "Jeff Gilligan" <jeffgilligan10@xxxxxxxxx>
Cc: "Paul T. Sullivan" <paultsullivan@xxxxxxxxxxxx>, "obol"
<obol@xxxxxxxxxxxxx>
Sent: Wednesday, March 18, 2020 2:07:50 PM
Subject: [obol] Re: eBird reports of European Goldfinches in USA
Now we're talkin' ancient history. I just pulled out my 2nd edition 47th
printing Field Guide to the birds by Rodger Tory Peterson. Copyright 1947. The
second revised and enlarged Edition. In those olden times European Goldfinch
was Illustrated along with the other American species. It had been introduced
very early on into New York State.
Here's what it says " naturalized in Bermuda small colonies established on
South East Long Island"
That is back in the time of introducing a variety of European birds into
America and this one was successfully introduced for a fairly long time into
the New York area. But to the extent that modern field guides do not even list
it, it apparently eventually died out there.
This parallels in a way the introduction of Crested Myna into the Vancouver
area in Canada. Some years ago I had the Good Fortune to see the last pair
before they went extinct in North America. It had been an ABA countable species
there for decades
Now European Goldfinch had a good run in New York who's ecology is not all that
different from Oregon. About the same latitude, same annual amount of rain,
although not spread out as much as Oregon. Etc.
Along with mandarin duck I'd say it's chances of being established in Oregon
are fair to poor
Bob O'Brien Carver Oregon
On Wednesday, March 18, 2020, Jeff Gilligan < [ mailto:jeffgilligan10@xxxxxxxxx ;
| jeffgilligan10@xxxxxxxxx ] > wrote:
A question about how Eurasian Goldfinch might fit into our ecosystem if it
expands its presence in North America. I have seen them in Europe in several
countries but don’t recall if they were generally in the types habitats where
American Goldfinches nest. Visiting an aunt and cousins in suburban Pittsburg
the past two summers, I was surprised by how the American Goldfinches there
were in habitats with large trees, though not dense forests, while ours are
mainly in brushy edges to grassy open places, or emergent low brush and trees
during nesting season. In my experience, in winter they often are in large seed
producing trees in Portland, but never nest in such areas. My impression of the
eastern American Goldfinches is that they use the habitat in summer that I
think is typical of Lesser Goldfinches in the Portland area. Maybe they also
use habitats in summer similar what they use in Oregon, but the Pittsburg area
has little of such habitat. I never considered the matter when I have seen
Eurasian Goldfinches in Europe. Does anyone have an opinion about this?
Jeff Gilligan
BQ_BEGIN
On Mar 18, 2020, at 10:13 AM, Paul Sullivan < [
mailto:paultsullivan@xxxxxxxxxxxx ;| paultsullivan@xxxxxxxxxxxx ] > wrote:
The presence of European Goldfinches in Wisconsin led me to look at the eBird
map for the species. [ https://ebird.org/species/eurgol ;|
https://ebird.org/species/eurgol ] ;
There is a concentration of the species in northern Illinois and Wisconsin,
plus Detroit and New York, with scattered sightings from Virginia to New
Hampshire. One possible sighting west of the Mississippi south of St. Louis,
and many in California, especially the Bay Area.
Paul Sullivan
From: Paul Sullivan [ [ mailto:paultsullivan@xxxxxxxxxxxx ;|
mailto:paultsullivan@xxxxxxxxxxxx ] ] ;
Sent: Tuesday, March 17, 2020 8:47 PM
BQ_END
