With some potentially serious negatives against it, what is ostensibly the first Bufflehead for Northants is likely to be an escape … or is it?
Late this morning, Terry O’dell discovered what later proved to be an adult female Bufflehead on the south side of the main barrage lake at Clifford Hill Gravel Pits. It was still present this afternoon, during which I managed to obtain some rather poor quality, wind-shaken, digiscoped video.
There have been two individuals deemed escapes reported recently: a yellow-ringed bird in Norfolk in April and a (presumed) metal-ringed bird in West Yorkshire last month. The Clifford Hill bird is metal-ringed on its right leg and, along with its having appeared in June, the odds are rightly stacked against it being a wild individual. Or are they?
Bedfordshire, 29th October 2015
Here are a few facts resulting from my research into the escape likelihood of the one in Bedfordshire in October 2015. I’d spent some considerable time looking at the Bedfordshire Bufflehead ring and doing some research.
I have a contact who produces a lot of video material for the BBC and I sent him some footage to see if he could freeze the ring on my video of that bird better than I could. He tried but couldn’t. The characters on the ring appeared to occupy a good 50% of the depth of the ring and appear just as a dark area. Any smaller characters above or below, if they exist, are invisible. The format could match one or two of the smaller rings in the image attached, lifted from http://www.duckbands.com/ an American site.
I also spoke to James Lees at length about it. His view from a ringing perspective was that it was more likely to have been ringed in the wild than in captivity because most collections use plastic rings, not metal, and he believes that Slimbridge is the only collection (he knows of) which uses metal rings (same format as BTO rings) for individual ID because their collection is extensive and because they move birds around to other collections to breed and keep the gene pool healthy. He also pointed out that American-ringed ducks have been seen in the UK before and that they once had a ringed Ring-necked Duck visit from the states and it ultimately found its way back across the Atlantic, and was seen again in Newfoundland after leaving Slimbridge. All this I guess we know …
So, what we have for the pro-wild camp is:
- Metal ring, indicating higher likelihood of wild than captive origin
- Ring format could match that of Nearctic-ringed bird
- 22.5 thousand Buffleheads ringed in Nearctic between 1951 & 2011
- Buffleheads can live for 18 years (OK if it’s an adult drake coming out of eclipse)
- October is the peak migration month for Bufflehead in the USA
- The bird stayed for one day only and, so far, has not been reported anywhere else
- No birds missing from local collections (but doesn’t rule out an escape from further afield)
And for the pro-escape camp:
- It had a ring of any type
That’s my analysis concluded. Read into it what you will but unless it’s seen to haul itself out on to the bank or an island, where the ring can be properly seen, we’ll never know for sure.