I agree strongly with John and Angus. The consequences for the eBird Hot 100 are at most not very important and at least potentially amusing. I thought everybody knew they were supposed to keep track of their own lists, rather than to trust in the algorithms of strangers!
More specifically, regarding European Goldfinches in the New York City area now, the numbers of birds present and the area occupied are large enough to suggest establishment. Perhaps not everybody is aware that this species established breeding populations on western Long Island for decades. It is even conceivable that these were never completely extirpated, and that today's birds derive at least in part from those naturalized populations (but they are certainly at least partly derived from recent escapes, as proven by the presence of plastic leg bands on some). The best argument against the hypothesis of demographic continuity between the period of establishment and the current resurgence in reported abundance is that very few or none were reported for several decades. But this is at best a weak argument from negative data that are known to be systematically biased against reporting. Monk Parakeets provide a parallel example that is very instructive. This species established breeding populations in the New York City/Long Island region that were fairly large and widespread by the early 1970s. These were subjected to eradication programs during the mid-1970s, and perceptions shifted to the extent that NYSARC acted (overly boldly in my opinion) to remove the species from the official New York State Checklist in 1982. Reports almost ceased during this period, but we know in this case that the gap in documented occurrence was an error arising from two sources: because backyard birders who liked the parakeets concealed their presence to protect them from destruction; but also because the remaining birds were perceived as "not countable" by competitive birders. Today's thread illustrates that under-reporting of "not countable" species has persisted in birding culture, to the detriment of our ability to infer the actual statuses of non-native species. Shai Mitra Bay Shore ________________________________________ From: bounce-122144147-11143...@list.cornell.edu [bounce-122144147-11143...@list.cornell.edu] on behalf of John Laver [eart...@gmail.com] Sent: Tuesday, December 19, 2017 2:20 PM To: Angus Wilson Cc: NYSBIRDS-L@cornell.edu Subject: Re: [nysbirds-l] Governors Island: European Goldfinch Flock (18-Dec) "Personally, I think tracking these potential colonizers is important and interesting. Simply invalidating them or discouraging reporting isn't a good solution." Agreed, particularly as range flux is likely to accelerate in ways we'll need to observe and measure as climate changes take hold. We need to think about the Big Picture. John Laver Manhattan On Tue, Dec 19, 2017 at 1:50 PM, Angus Wilson <oceanwander...@gmail.com<mailto:oceanwander...@gmail.com>> wrote: For European Goldfinch I suspect 'domesticated' isn't an option. Same for other known or presumed escapes or deliberate releases that occur with regularity in NYS (e.g. Chukar and various non-domesticated waterfowl). Personally, I think tracking these potential colonizers is important and interesting. Simply invalidating them or discouraging reporting isn't a good solution. Issues with list purity can be a separate conversation, decoupled from the scientific uses of this information. Angus Wilson New York City, NY -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME.htm http://www.NortheastBirding.com/NYSbirdsRULES.htm http://www.NortheastBirding.com/NYSbirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://firstname.lastname@example.org/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L 3) http://birding.aba.org/maillist/NY01 Please submit your observations to eBird: http://ebird.org/content/ebird/ --