Extraordinary Siberian vagrant – a first record of Baikal Teal in Arizona
Initial Discovery and Documentation
During late November 2010 I made frequent trips to the Gilbert Water Ranch, a suburban Phoenix riparian preserve, where I noted dabbling duck numbers were dramatically increasing. Male ducks were in fine looking alternate plumage and it was enjoyable birding. In particular there were now hundreds of Northern Pintail and Green-winged Teal, perhaps seasonal maxima, concentrated at the shallow water ponds that provided excellent feeding conditions for dabbling duck species. On 02 December 2010 I arrived at the preserve parking area on Guadalupe Avenue and immediately noticed the cacophony of chattering and trilling of the many duck actively feeding on pond 1. Keeping to my usual pattern, I headed first to this pond on a clockwise loop of the preserve. Small flights of duck, settling in quickly on cupped wings, continued to join the frenzied late afternoon feeding activity as I walked over. Little did I know that this would be the first and last stop of the afternoon!
I began looking through the ducks on pond 1 with my Nikon ED50 field scope and 27x wide angle eyepiece lens. Almost immediately, at about 4:15 pm, I came across a smaller duck resting among a group of the much larger sized Northern Pintail. The bird was facing straight at me, standing in shallow water up to its belly, but with its head turned around and tucked under a wing. I estimated it was larger than Green-winged Teal but perhaps smaller than American Wigeon. I noted the purplish-suffused chest coloration with fine dark spots and, with its head turned away, a prominent white V-shaped line dropped down the back of the head outlining the grayish crown. The chest coloration and markings were not good for Blue-winged Teal and it seemed a little larger than this species. In my mind I had one good candidate of the possible identification but this seemed absurdly improbable. A moment later the duck lifted up its head and, to my utter amazement revealed its identity. In late afternoon sunlight I was looking at the unmistakable striking green and buttery-yellow facial pattern, with black tear-line joining eye and rear chin, of a male Baikal Teal Anas formosa!
My first thought was what if it flies off right now and is never seen again! Regretting not being photographically better equipped, I proceeded to document my discovery using my Apple iPhone 3 camera and Nikon ED50 fieldscope (“phonescoping”). I managed to obtain several photographs that clearly evidenced the face pattern of the male Baikal Teal and its relative size among other duck species. Once I was satisfied with my documentary photographs I hurriedly sent out a brief email report of the observation to members of the AZ-NM Listserv, at about 4:24 pm, hoping to alert other birders and photographers to the presence of this charismatic Siberian vagrant. I am originally from England and know well the legendary status of Baikal Teal vagrancy. I could scarcely believe my good fortune to discover this bird species here in the desert of Phoenix, Arizona.
The male Baikal Teal continued actively foraging for some time in the shallow water and at one point I was afraid it might be lost as it dashed among its many congeners. It appeared to be strongly associated with a group of Northern Pintail that were beginning to roost in the southwest section of pond 1. I noted other plumage characters including white belly, buffy-brown edges to some flank and upper-part feathers, medium length chestnut-edged ornamental scapulars, and a small vertical white breast bar that was visible only on the right side. The striking green and yellow head pattern, with finer black and white markings, was textured in appearance perhaps due to the recent molt. The bill color was dark bluish-grey with blacker edges. The iris was dark reddish-brown and on occasion when closed the eyelids showed pale whitish coloration. After about twenty minutes foraging it again stopped in very shallow water and tucked its head under one wing.
After what seemed like a very long wait, and with rapidly fading light, I was relieved to hear footsteps running along the footpath behind me as other birders arrived at about 4:45 pm including photographer Brendon Grice. Excellent photographs were obtained just as the bird finally went to roost for the evening on pond 1 at the exact spot I had discovered it.
Distribution and Conservation Status
The Baikal Teal is an Asian duck species and was once found breeding widely across eastern Siberia but is now found only in the eastern part of this original range. Today breeding is known from the Yenisey Valley (85 °E) eastwards to Cape Schmidt on the Chukotka peninsula, the western Ana’dyr basin, northern Kamchatka and the Sea of Okhotsk coast. The main breeding concentrations are localized on river basins over this enormous range. During migration Baikal Teal can be found in the Russian Far East, Mongolia, Japan, North Korea, South Korea and northern China. Wintering in massive congregations this species appears to have consolidated in recent decades at a small number of locations in South Korea with much lesser numbers in eastern China and Japan, while it is a rare winter visitor to Taiwan and Hong Kong.
Once considered one of the commonest duck species in northeast Asia, the abundant Baikal Teal was a key game bird species in Siberia where populations were estimated at several million. In the second half of the twentieth century however, the species suffered a steep decline to possibly as few as 50,000 birds, with apparently the 1960s suffering the sharpest decline. Major contributing factors included unsustainable hunting pressure, particularly in Japan where enormous numbers were killed for the food market, and perhaps the effects of the widespread use of toxic agricultural pesticides. Baikal Teal were essentially wiped out as a wintering species in Japan numbering only a few thousands in surveys.
More recently however, population surveys have shown a remarkable increase in wintering populations in South Korea. Whether this is due to increasing breeding success or discovery of previously undocumented birds has not been established. Population surveys in South Korea in January 1999 found 200,000 birds, and in November 2003 there were as many as 250,000 at Seosan lake complex and 400,000 at Geocheonnam lake, Haenam as well as more at other sites. A simultaneous survey in 2004 of wintering birds found at least 650,000 Baikal Teal in South Korea. During this period fewer than 10,000 birds wintered in Japan and China which suggests South Korea is now the main wintering location for Baikal Teal. Census data from 2009 showed that Baikal teal is the most abundant waterfowl in South Korea with more than one million wintering individuals. This remarkable history, the collapse followed by growth of the Baikal Teal population, is considered the most dramatic change in any waterfowl species numbers in the last 50 years.
The conservation status of Baikal Teal has altered following this dramatic population turnaround. In 2001 the Baikal Teal was listed with a status Vulnerable amid strong concerns for the declining population trend and habitat destruction in their wintering grounds. However by June 2011, estimates of population size had increased to more than one million individuals and it is now listed as a species of Least Concern (LC) with an increasing population trend.
The small number of massive wintering congregations in southeast South Korea has raised some conservation concerns. There are significant risks from disease outbreaks, winter roost sites are not formally protected, and potential changes in local agriculture could be catastrophic since the species is largely reliant on rice grain left behind in post-harvested fields. In an agreement with local South Korean government, rice farmers leave 10% of rice harvest in fields for the wintering Baikal Teal. Recent surveys confirmed the recovery in the eastern Russian breeding population but there is little evidence for recovery in the western part of its original range.
Vagrancy in North America
Baikal Teal is categorized as a Code-4 casual species in the ABA Checklist area. The code-4 casual status denotes a species recorded less than once annually but with greater than six total records including three or more in the last 30 years. The species has been recorded most frequently in Alaska and the western Pacific Coast states. There are more than twenty records from Alaska, some involving multiple individuals. Outside Alaska there are ten records from British Columbia, Washington, Oregon, and California. These records, comprised mostly of male individuals shot by hunters, are considered to be naturally occurring vagrants. There are also scattered records from Colorado, Ontario, Oklahoma, Louisiana, North Carolina and Ohio but these are regarded with uncertain provenance due to potential captive origins. Baikal Teal is a desirable species in aviculture although there appears to have been significant reductions in its occurrence due to importation restrictions and difficult breeding requirements. The species has also been recorded on one occasion in Hawaii.
Baikal Teal has never been recorded in Arizona prior to this discovery. However the species has been recorded seven times in California including southern counties bordering Arizona. A well documented individual, in fact the first living Baikal Teal seen by birders in California after four records that were shot by hunters, was discovered on 10th December 2005 near Lompoc in Santa Barbara County. Those shot by hunters in California were obtained in the counties of Lassen (27 Nov 1974), Butte (4 Jan 1975), Riverside (12 Jan 1974), and Imperial (29 Dec 1946). The hunter shot individual from Calipatria, Imperial County, California on 29 December 1946 represents the geographically closest record to Arizona and was about 200 miles from Phoenix.
Evidence of Vagrancy
Potential records of natural vagrancy in many duck species are compromised by their widespread occurrence in captivity. It is sensible therefore to examine the evidence for and against a natural origin on a case-by-case basis. Elements such as date of occurrence that might reveal a pattern of vagrancy, age of the individual, plumage molt and wear, evidence of physical alterations that might be found in aviculture collections and behavior can tell us a lot about individual records.
Since many birders, including myself, visit the Gilbert Water Ranch on a frequent basis it seems unlikely that such a striking looking species would remain undiscovered for long. Its discovery, on 02 December 2010, fits well in a pattern of accepted natural vagrancy records for Baikal Teal from western North America with a concentration of records in winter months, particularly December.
Excellent photography, literally from head-to-toe, revealed many detailed physical features about the bird. Feathers appear in very good condition on this bird without missing parts or damaged ends. It appeared to have undergone an almost complete pre-alternate molt with only some juvenile plumage showing on the flanks and back areas. This early winter late transitional molt condition matched expectations for this species at this time of year. Evidence of juvenile plumage indicated it was a hatch year bird.
Ducks from collections often have one or both hallux (hind toes) removed as a mark of captive breeding. This individual showed complete hind toes on both legs and in addition the bird carried no bands.
In a recent scientific approach to testing hypotheses of vagrant duck origins, stable hydrogen isotope ratios were measured in different generations of feather taken from a Baikal Teal shot by a hunter in Denmark. Results of this study indicated that only the new feathers, molted on the wintering ground, matched the stable isotope ratios found in coastal bird species in Scandinavia. In contrast, the stable hydrogen isotope ratios from feathers developed during the first complete molt on the breeding ground were significantly different and only matched ratios known from extreme continental boreal forest and tundra regions. This evidence indicates Baikal Teal has the potential for long distance vagrancy from its breeding grounds in Siberia.
During much of the time the bird was present at the Water Ranch it strongly associated with the numerous Northern Pintail, a species which had seen a surge in numbers at Gilbert Water Ranch in the days preceding its discovery (G. Nunn, personal observation). It seems possible that it arrived with this late surge in numbers of Northern Pintail.
Finally the bird exhibited what I would call normal skittish behavior like its congeners. This included, on at least one occasion, predator avoidance in response to the sudden appearance of a Cooper’s Hawk that flew across pond 1 at low height (G. Nunn, personal observation). The Baikal Teal immediately flushed from the pond, along with many other duck, and was gone in the blink of an eye. Put together the different lines of evidence strongly suggest a case of natural vagrancy.
It was fortunate for many observers, and photographers, that the Baikal Teal stayed at the Gilbert Water Ranch for just over a week after the original sighting, being last seen on December 10th, 2010.
Conclusions
Comprehensive population surveys in its South Korean wintering range indicate that Baikal Teal has undergone a significant population increase over the past several decades with more than one million birds accounted for. It seems reasonable that natural vagrancy has increased accordingly and the species should be considered when watching waterfowl in North America. Based on the pattern of accepted records in western North America the species should be looked for in migrant ducks arriving in the region in the winter months, in particular December.
On October 6th 2011 the Arizona Bird Committee announced acceptance of this record, with an 8-0 vote, as a naturally occurring vagrant, the first Baikal Teal to be found in Arizona.