37 Blacktail Godwits on Bowling Green Marsh yesterday 6 in Summer plumage. The majority of the over wintering birds head for their breeding grounds in and around Iceland. We think juveniles stay on the estuary but are the Summer plumage birds returning birds? Also a couple of Teal, an odd Widgeon on the Marsh and a summer plumage female Long-tailed Duck has turned up on the Estuary, are these juveniles to?
It's possible that the breeding plumaged godwits are still on their way north, despite the late date. Northward wader migration continues well into June because feeding opportunities tend to be better in more temperate climates in late May/early June and they don't want to arrive on their breeding grounds before they have thawed.
It is also possible that these are returning birds that have attempted to breed and failed (because of the short breeding season available in the arctic, second breeding attempts are not often made to replace lost clutches or lost young).
Or, they might be individuals that, for whatever reason, didn't attempt the journey north (perhaps as a result of illness, or because of immaturity).
At this time of year it is practically impossible to know whether waders are coming or going!
The ones that aren't in breeding plumage are probably more likely to be immature individuals, and although they may have travelled north they wouldn't have any reason to hang around if they didn't pair up.
Teal and Wigeon could possibly be attempting to breed at the site, or could be non breeding birds (whether immature or not) that have chosen to remain for the summer. The Long-tailed Duck will be a non breeding bird, but not necessarily immature.
All make good sense Roy thanks for your time replying...