Greetings All
The Pink-footed Goose (and friends, about 30 Canadas and 5-10 Richardson's Cacklings) spent nearly the entire day in the large pond adjacent to Idaho Creek Wildlife Area. The bird was typically best seen from along Weld County Road 7, and though our cars were sticking a wee bit into the street, no one came to shoo us off; indeed several locals came by for interested and friendly chats. The wild vs non-wild question is unknowable. No bands, hind-toes intact. So, at least no slam dunk signs of prior captivity. Washington State had two adults appear on its outer coast in December 2003. I was part of the WBRC when we reviewed the birds. Many of us felt the odds of the birds being wild were high, but decided to hold off on accepting the species onto the state list -- waiting to see if a pattern developed Why did we think the birds had a goodly chance of being wild. 1) Wild population was quickly increasing and had spread to Greenland 2) We enlisted the aid of some of the country's most respected aviculturalists (and avian curator at the Seattle zoo), and found only one aviculturalist that kept this PF Goose (I can't remember where - but in Canada, 4 birds total, all well ensconced at the time). Don't know why this species is rare in captivity in North America but it is. This is in contrast to Barnacle Goose, which is not rare in captivity. 3) We looked at the migration path of Iceland breeding birds to nw Europe (the species' usual wintering ground). Turn that around 180 degrees (a common misorientation pattern in vagrant birds), travel the same distance, and that puts the birds in central Saskatchewan (as I recall). Continue that same direction... and you are on the Washington coast. Hook up with other geese in Saskatchewan, and you might find yourself in CO. Also, I think if you change the breeding location (Iceland vs Greenland), that 180 degree error might land the bird in CO. Sadly, the eBird reviewers for WA decided to be very conservative and did not put those well documented birds on eBird, which makes research into these matters more challenging. There were, interestingly, another 2 PF Geese on southern Vancouver Island, BC (not far from the 2003 WA birds) during the 2016-2017 winter. Same pair??? There are no other accepted PF Geese on eBird west of NY and PA. Below are stats on the population increase of PF Goose. Taxa with rapidly increasing populations are far more prone to vagrancy, explaining why Aleutian Cackling Geese have been found as vagrants far more than minima Cackling Geese over the last decade, despite relatively similar populations and migration distance. I hope this provides some illumination if not 100% conclusions Steve https://monitoring.wwt.org.uk/our-work/goose-swan-monitoring-programme/species-accounts/pink-footed-goose/ 2017 515,852 17.1 1.85 2016 481,341 18.8 1.75 2015 536,871 18.8 1.89 2014 393,170 19.4 2.01 2013 372,074 17.3 2.16 2012 359,175 21.1 2.30 2011 260,325 8.5 1.77 2010 297,798 19.9 2.32 2009 364,212 17.3 1.87 2008 351,188 22.9 2.08 2007 284,405 20.0 2.27 2006 230,123 19.3 2.20 2005 302,774 18.1 1.7 2004 276,644 19.4 2.1 2003 280,998 19.0 2.19 -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/1679fe62676-1ec0-2305%40webjas-vab144.srv.aolmail.net. For more options, visit https://groups.google.com/d/optout.
