Gabriel Willow has touched on an annual puzzle for those who worry about such things, namely the question of provenance: is it a natural vagrant or a wandering escape? This of course should not detract from the enjoyment of seeing and reporting these attractive birds, which I encourage everyone to do, hence the separate subject line.
For waterfowl like Barnacle Goose, there is no simple answer because it is clear both scenarios apply and often one has to make a judgement call on which seems most likely. Clearly wild Barnacles _ DO _ make it to New York. This is reflected in the acceptance of the majority of recent reports submitted for review, a treatment shared by several neighboring states. There are several factors that go into this. First there is a well-defined seasonal pattern of occurrence in the Northeast, consistent with birds coming down the west (rather than east) coast of the North Atlantic from their summer nesting grounds in the high-arctic, second there has been a steady growth in wild populations due to increased protection on both breeding and wintering grounds and third, the impact of climate change on the ecology of the high arctic. These correlates are bolstered by a handful of band recoveries (compelling evidence), including photographed in the Bronx in late November 2010 that had originally been banded in Scotland (NYSARC 2010-82-A/C). So far, so good. The fly in the ointment, however, is that Barnacles are also quite popular with waterfowl collectors; they are a very handsome species and undemanding in terms of upkeep. Regrettably, not all collectors mark their birds appropriately hence it is sometimes difficult to tell whether a bird is an escape (or even a deliberate release). A quick search of the internet will turn up birds for sale in NY State or nearby. Examples of free flying ex-captive Barnacles, including one or two family groups, are known and have been shown to range widely. Sometimes it is known where they come from, other times it is not. For instance in 2009 a Barnacle Goose was discovered on the Olcott Piers (Niagara Co.) in late September - already goose migration season in western NY - and turned out to be banded. Bill Watson managed to read the band and discovered (presumably to his dismay) that it was an escape from a private aviary in Delevan, New York, about 60 miles south of Olcott (see NYSARC 2009-60-A). Drat! Along similar lines, Barnacles are sometimes found in the northeast during the summer. These cases are less clear cut but are more suggestive of escapes perhaps than of natural vagrants. Wild Barnacle Geese generally have a strong migratory urge and should be further north at this time of year. One recent example of a summer bird is an unbanded individual that found in Alexandria Bay, Jefferson Co in July 2011 (NYSARC 2011-97-A). This is a fascinating topic and for those wishing to delve deeper I would recommend reading the discussions that accompany reports submitted to NYSARC published in the Committee's annual reports. A good place to start is with the 2010 birds, including the individual mentioned above that was banded as a wild bird in Scotland: http://www.nybirds.org/NYSARC/Reports/NYSARC2010.html >From there one might want to read the Barnacle Goose entry in the 2006 Annual Report, which marked a significant switch in NYSARC's thinking based on the mounting evidence for natural occurrence: http://www.nybirds.org/NYSARC/Reports/NYSARC2006.html A full compendium of documented sightings received by NYSARC, with links to the relevant Annual Reports reports is here: http://www.nybirds.org/NYSARC/HistData/BRNG.htm Providing reports on _ ALL _ Barnacle Goose sightings to eBird and NYSARC regardless of season, adds to the dataset and helps inform our collective decisions. Cheers, Angus Wilson Chair, New York State Avian Records Committee (NYSARC) New York State Ornithological Association (NYSOA) -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birdingonthe.net/mailinglists/NYSB.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
