CV birders,

It should be pointed out the the data presented by Don are publicly
available through the International Species Information System at
www.isis.org (click on Species Holdings and work your way through from
there). I am grateful to Steve Holzman for originally directing me to
this site, which also gives info on all the collections in question.

ISIS receives data from many public collections worldwide, but not all
of them, and from no private collections. I asked Roger Wilkinson
(Curator of Birds at Chester Zoo, UK, and expert consultant to the
British RC) about this further. He estimated that private collections
would very likely hold at least double the ISIS total (which for
Demoiselle Crane is 103) and possibly many more. So I would suggest that
200 is a minimum estimate. I am currently researching the American
Federation of Avicultures' Exotic Bird Registry (i.e. private
collections) to see what, if anything, that reveals. Alan Knox, formerly
of the British RC, was of the opinion that globally "they aren't at all
rare in collections which have large birds."

I have researched the ISIS data further. Given that we will almost
certainly never have accurate data for private holdings, I tried to
examine the ISIS figures as an index of a species relative abundance in
captivity. (I appreciate that there several flaws with this approach;
discussion of these is beyond the scope of this posting, but I'd be
happy to answer queries privately.) Here are the ISIS numbers for North
America for a variety of species:

Demoiselle Crane (Anthropoides virgo) 103
Common Crane (Grus grus) 13
Hooded Crane (Grus monacha) 33
White-naped Crane (Grus vipio) 66
Red-crowned Crane (Grus japonensis) 67
Red-breasted Goose (Branta ruficollis) 128
Bar-headed Goose (Anser indicus) 157
Emporer Goose (Anser canagicus) 44
Kittlitz's Plover (Charadrius pecuarius)4
Greater Sand-plover (Charadrius lesch.) 0
Siberian Accentor (Prunella montanella) 0
Great Tit (Parus major) 5
Blue Rock Thrush (Monticola solitarius) 0
Swallow-tailed Gull (Creagrus furcatus) 0

It was surprising to me that Demoiselle Crane is nearly as common as
Red-breasted Goose in the North American ISIS-reporting collections. The
latter has occurred on several occasions in the US in a number of states
including California, but is widely assumed, rightly or wrongly, to be
escaped (AOU Check-list 1998). It may be incongruous to assume
Red-breasted Geese are escapes while maintaining Demoiselle Crane is a
genuine vagrant, given their similar frequency in captivity.

Common Crane is generally assumed to be a genuine vagrant to North
America. It is therefore interesting that it is about eight times
scarcer in captivity than Demoiselle. Only Sandhill Crane is more common
in captivity in North America than Demoiselle according to ISIS.

Anyway, I would recommend anyone with a serious interest in this issue
looks at these data on the ISIS website. For example, I was most
surprised to find that there were no Blue Rock Thrushes in these
collections in North America. This species is common in captivity in
Europe and Asia (pers. obs.), and may be so in private collections in
North America also. This is significant because there are recent reports
for Unalaska Island and British Columbia (not mentioned in the AOU
Check-list 1998). This species is a good candidate for vagrancy to North
America, and its apparent rarity in captivity may add some support to
these reports as genuine vagrants.

It should be clarified that the absence of bands, atypical plumage or
bare parts abrasion, or abnormal flight, unfortunately mean very little.
These are characters that, if present, would be suggestive of a captive
origin. However, when absent, these characters do not imply that the
bird is wild. In my experience, captive birds, especially those in
private collections, are often unbanded, in excellent plumage condition,
and fly just as well as any wild bird. Based upon what I could ascertain
from USDA websites, the only captive birds for which a USDA approved
band is compulsory are "hookbilled" birds (i.e. diurnal raptors and
owls). Suggestions that a bird can easily make a flight from one field
to another add no significant support to a putative wild origin, to
which the muscle mass study reported by Don attests.

Although Demoiselle Crane is certainly a candidate for vagrancy from the
Eastern Palearctic, my research suggests it does not fit a classic
profile. For example, I've been fortunate to consult at length my good
friend Geoff Carey, former chair of the Hong Kong RC, who has studied
crane migration in China for 15 years. Here are a few of his comments,
with my clarifications in brackets:

"I can't find anything in my Chinese literature, books or journals, that
refers to vagrancy or extralimital records [in China]. I feel that for a
bird as large and as obvious as this, even China would be expected to
have some extralimital records if such occurrences were numerous. As you
probably know, it has occurred in Japan as a vagrant, but I don't know
how many times." [approx 15 records prior to 1991 (Brazil 1991, The
Birds of Japan), plus a couple since (pers. obs.)]

"It would appear that movements from the breeding grounds are probably
along a well-defined and relatively narrow band to the southwest. Even
at somewhere like Beidaihe [a famous migration site on the NE Chinese
coast where Geoff and I have worked], Demoiselle Crane is rare. It
appears that birds breeding in the most northeasterly parts of China are
either very low in numbers and/or move directly west, keeping the
grassland areas of north China, before shifting southwest."

[On localities where Sandhills and Demoiselles might meet:] "The only
likely locality would be in migratory flocks over Beidaihe, or on
wintering grounds at Po Yang. However, there are only 2 records of
Sandhill at Beidaihe, and no records of Demoiselle, as far as I know,
from Po Yang." [Po Yang is a famous crane wintering area in the Yangtze
Valley in SE China that Geoff and I have visited.]

[On possible vagrancy to the US:] "Overshoot in spring is presumably
possible, despite the distance from northeast China to western North
America. A line drawn from wintering grounds in India through northeast
China would aim for western Alaska (just!). Quite an amazing record, if
of natural occurrence!"

Personally I was most surprised to discover that Demoiselle Crane was so
rare at Beidaihe, and its apparent rarity in the north-east of its range
may be quite significant. Although research by myself and others is
ongoing, and although I was initially pretty high on this record as a
vagrant, my feeling now is that the escape probability almost certainly
exceeds the likelihood of genuine vagrancy. As Alan Knox concluded, "as
you know, it only takes one over the wire to be a problem!"

Cheers, Jon.



creagrus@... wrote:
>
> Thanks to a phone discussion with Tori Kaldenberg at the International
> Crane Foundation in Wisconsin, I have obtained a preliminary list of
> Demoiselle Cranes in captivity in North America as of June 2001 that
> are in zoos or other semi-public hands. We did not recognize all the
> names but I present the fairly complete preliminary listing below.
> She considers this species to be "fairly common" in captivity in zoos,
> and "one of the more common cranes" in captivity in private hands.
> Alas, there is no listing of Demoiselle Cranes in private hands. She
> believes that the number held privately may be less than the number
> held by zoos, but it could be more. It is not possible to trace all
> the private holdings in the U.S. and Canada.
> As to zoos and other public or semi-public holdings, as of 6/30/01
> there were 48 males, 45 females, and 10 of unknown sex, for a total of
> 103 in this type of holding. If was assume about the same number in
> private hands (likely a fair assumption), there are in the
> neighborhood of 200 in captivity in North America.
> Here is a partial listing that I was able to take down over the
> phone: Montgomery Alabama (1); Omaha NE (4), Prospect UT (2), San
> Diego Wild Animal Park (2), St. Paul MN (2), Tracy Aviary UT (2), New
> York Bronx (2), Petersboro (2), Redwood (state?) (1), Seattle WA (2),
> West Orange (state?) (4), Nat'l Zoo in Washington, D.C. (2), Pittsburg
> (PA?) (1), San Antonio TX (2), Sedgwick Co. Zoo KS (2), Toledo OH (2),
> Wild World (state?) (2), Oklahoma OK (2), Pittsburg (CA?) (2), San
> Diego Zoo (2), St. Louis MO (2), Toronto (3), Winnipeg (3).
> Note the wide dispersal and distribution with holdings that
> are rather evently scattered across the U.S. and Canada without
> significant concentrations in any particular region. We don't know if
> the same is true for private holdings.
> Ms. Kaldenberg opined that "likely a strong majority" of zoo birds
> would be banded, but there is no requirement that any of these cranes
> be banded. She did not know what the likelihood of banding was for
> private holdings of cranes. There is also no requirement that
> privately-held cranes be banded.
> As to the issue of the ability to fly, she mentioned a recent
> project to re-establish a population of Whooping Cranes in Florida
> among wintering Sandhills which involved weekly flights of the
> imprinted Whooping Cranes with an ultralight glider. The muscle mass
> of these regularly-flown birds was compared to that of captive birds
> which were not flown. The surprising preliminary results are that
> there is not much difference in muscle mass between the two sets of
> cranes.
>
> Cheers,
> Don Roberson