I am glad to see an informed discussion about the apparent decline in Bonaparte's Gulls both in western and coastal New York State. Birding forms tend to focus on the positive such as new sightings, influxes, and weather-related events, with much less attention given to species that might be disappearing before our eyes. The human brain is not very good at accessing the absence of something and birding record systems are seemingly not much better either.
Aside from Bonaparte's Gull, I have wondered about the status of America Golden-Plover in the state. In the past several years I've noted few if any reports of larger flocks that would draw birders to sod fields and other grassy habitats in the fall, especially in eastern Long Island. In recent years only a scattering of Golden-Plovers have been reported in the fall (principally from late August to late October), rarely more than two together. Many people may have successfully ticked their 'year bird' and not given much more thought to it but the reality is that we probably are all ticking the SAME few birds. Looking at the tallies for some of the hotspots for southbound plovers it was not long ago that flocks of 60-100+ were frequent in and around Riverhead (Suffolk NY). 2016 seems to have been the last good season (many reports of 60+), with 2012 and 2013 similarly featuring some larger flocks (counts of 102, 105, etc). Is something going on? Is the apparent decline in birds staging on eastern Long Island echoed elsewhere? American Golden-Plover is an arctic and subarctic tundra nesting species that makes a long oceanic flight (a minimum of 2,400 miles nonstop) to wintering grounds in the Pampas and Campos regions of southern South America. It is possible that weather conditions have allowed birds to launch from further north and simply bypass our area. Scrutiny of trends in the Canadian Maritime Provinces and New England or the Mississippi/Missouri/Ohio flyway (if the southbound route has shifted towards the center of the continent) might shed light on this. Changes in pesticide use might also render the Long Island sod fields less attractive such that birds arriving at night leave soon after. It's worth noting that aside from a possible shift in the migration route, many high latitude breeding species undergo cycles of abundance that reflect cycles in breeding success - these may relate to lemming cycles, late snowmelt, and so on. It could be we are in the trough of one of these cycles. Careful monitoring of the relative numbers of juveniles/1st basic and adults (estimating the ratio from year to year) can give warnings of these changes. This could also be done fairly easily with Bonaparte's Gulls because these two age classes are easy to distinguish. Unfortunately, relatively few birders keep notes on these things and again there's no simple way that I can find to recover such information from eBird or other record collections. Maybe folks on this list will have insight into how best to use the available data in this regard. All food for thought. Don't get me started on Upland Sandpiper...... -- Angus Wilson New York City -- 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://www.mail-archive.com/nysbirds-l@cornell.edu/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/ --
