UPDATE: In my original post I stated that I believed the American Bittern was an adult but subsequently, there was discussion on the Irish Bird Network (IBN**)  on the aging of this bird. In these, Killian Mullarney, one of the authors of the Collins Bird Guide clearly showed that it was a juvenile. Killian generously allowed me allowed me to reproduce the text of his posts to IBN at the end of this post. 

ORIGINAL POST

I was at my desk at lunchtime on Wednesday, when a tweet came through from Cork Bird News about a bittern at Castlefreke near Rosscarbery in west Cork.  The Eurasian Bittern, a secretive heron of reed beds, is a sporadic visitor to Ireland and a former breeder - but I  wondered if the Castlefreke bird could be the far rarer American Bittern following the recent westerly winds. However, I had a job to finish so I switched back to that until 3pm when another tweet announced that it was an American Bittern and it was giving stunning views! WTF OMG MEGA!!!

Irish birders have never connected with this species because most of the 22 previous records were shot or found dead in the 19^th century. There have been only four records from the birding era of last 60 years or so - the most recent was one killed by a dog in Co. Wexford in 1990 - and you can't tick dead birds! So now the pressure was on to get the job finished and to prepare for an unscheduled day off. Firstly a quick check of the weather forecast for Thursday – mild, with gentle breezes and partly cloudy – an excellent late November day. In contrast, the forecast for the following days was cold, wet and windy. So the weather was reinforcing the first law of twitching - go ASAP! You never know how long - or short! - a rarity will stay!! Next Google maps – and it was pretty much as I expected - a round trip of 650km and seven hours driving without stops (the 4.5 hours one way shown on the map includes going into towns so that the map shows their names). At least dawn wasn’t until about 8am. so, compared to summer twitches, it would be a relatively late 4.45am start! A quick round of calls and texts made it clear that all the usual Dublin suspects were going, including Victor, Sniper, and two of my regular crew, Rooster & Dipper.  The urgency was heightened by the knowledge that  the Cork lads were already ogling it as I was getting my act together!

Shankill-Castlefreke-Google-Maps

Brrr, brrr brrr – jaysus, what effin time is it? . . . yaaaaaawn! Oh yes, it's a twitch day. Up, dressed, don’t forget the sambos, keep the dog from waking the whole house as the lads knock on the door, get  three of us and  gear into the car and out onto the M50 for the long run down the Naas dual carriageway and then on through the darkness and drizzle along  the M7 and the M8. At least we didn't have to drive through all the towns and villages of twenty five years ago:- Naas, Newbridge, Kildare, Monasterevin, Ballybrittas, Portlaoise, Abbeyleix, Durrow, Cullahill, Johnstown, Urlingford, Littleton, Horse & Jockey, Cashel, New Inn, Cahir, Skeenarinkey, Kilbeheny, Mitchelstown, Fermoy, Rathcormac, Watergrasshill , and finally Glanmire before we arrive in de reel capital!  Nowadays it’s a steady 120kph to burn up the quiet early morning motorway in two and half hours until we hit the rush hour tail back at the Jack Lynch tunnel.

A quick call to Vic as we wait at the first traffic lights of the day – he’s already in Castlefreke but the bird hasn’t shown yet. For us, it's another 50 minutes around the South Ring and out the N71 to West Cork via  Inishannon, Bandon and Clonakilty before we arrive just after half eight as the morning brightens up and the bird has just been found. Cue, a huge sigh of relief as we’re now pretty certain of not dipping, i.e. missing the bird.

Shortly after we got the car parked, we got our first moderately good views as it hunted around a small lake – newly developed as part of the reconstruction of Castlefreke Castle – a project with it's own story! It looks like it will be West Cork’s answer to Downton Abbey when it’s finished. Anyway, we watched the Bittern intermittently as it regularly came out of the reeds and flew occasionally – happily the American version is much less skulking than the Eurasian Bittern.  While it was hidden we had time to catch up with other happy twitchers at the scene - and chat to the locals who were wondering what on earth was going on!

American Bittern © John Coveney2015 (3 of 3)  Sometimes, it just poked its head out – pretending to be a reed??

American Bittern © John Coveney2015 (1 of 3)

Eventually, however, it came really close giving superb views during a sunny spell - so it was very definitely ticked!  This shot clearly shows the distinguishing features – the dark culmen (top) on the bill, the brownish black crown (black on a Bittern), the long dark moustachial stripe (much shorter on a Bittern). The strength of this stripe also indicates it's an adult * - see the Update Below

American Bittern © John Coveney2015 (2 of 3)

After views like that, it was time to break out the sambos in the mild afternoon sunshine and get ready to re-run all those kilometres back home to Shankill  in time for dinner.

Many thanks to  Lynne and Ted de Beer and Peter Wolstenholme for finding this bird and getting the news out; and to Joe Hobbs for details of previous records. Check out excellent video footage from Michael O'Keefe here and here - you have to watch the first one for a while to realize its actually a video!

* UPDATE

On 11 December on IBN, I asked Killian to explain why the American Bittern was a juvenile and he responded as follows:-

Hi John,

The excellent quality of the several of the flight photographs of the Castlefreke American Bittern reveal that it has rather prominently pale-tipped primary coverts, indicative of juvenile plumage. Perhaps more importantly, the primaries and secondaries all appear to be of the same generation (again indicative of juvenile) with no suggestion of any subtle moult contrast between different generations of flight feathers that would be expected in an older bird, particularly at the juncture of the primaries and secondaries. The most in-depth reference to the subject on my shelves is Peter Pyle's Identification Guide to North American Birds (part 2) which discusses these and some additional ageing features in more detail.

Killian

I replied as follows:-
Killian,

Thanks for that. These features you mention are clearly visible on e.g. Aidan Kelly's shot on Surfbirds [my own previously unpublished and not very good flight shot is below]. The darkness of the moustachial is more prominent than I would expect on a juvenile from looking at the Collins Bird Guide. Would this be due to moult or variability do you think?

John C

001-American-Bittern-©-John-Coveney

. . . and he replied as follows:-

"Hi John,

The opportunity I had to examine the fresh corpse of the 1990 American Bittern at Killag, Wexford  helped me understand how much the prominence of the dark neck-stripe (I think this is a better term than 'moustachial', though perhaps 'malar stripe' is technically more correct) in this species depends on how the feathering of the adjacent tracts is laying. A lot of the time, it seems, the dark stripe is largely concealed by overlaying side-of-neck and foreneck feathering, but it may become more prominent in an instant if the bird's activity changes, as happens when display commences, or a bird takes flight. For this reason, the strength and colour of the neck-stripe is perhaps not such a straightforward means of ageing American Bittern as is commonly suggested. The other thing to bear in mind is that juvenile American Bitterns apparently undergo an extensive moult of head, neck and body feathers between July and November of their first year, after which these parts of the birds' plumage are said to be very similar to or identical to adult plumage. I say 'apparently' because I have not studied this matter in any great detail and I have occasionally struggled to figure out what is going on when looking at online photos. This is why I consider the condition of the larger wing feathers and the presence/absence of moult contrast to be a more reliable means of ageing autumn birds than some of the other features available.

For anyone who has an interest in following up on this subject there is a great series of shots of a very young juvenile American Bittern from Ron Clifford here and and an even more instructive series from Dan Streiffert here, the first of which demonstrate just how prominent the dark neck-stripe can be on a displaying bird

Killian

Finally for lots more excellent shots of this birds, check out Irish Birding and search for American Bittern; see David Monticelli's excellent series here, and perhaps for the the best shot of all, check out this one by Richard Mills.

** You can also subscribe to IBN to see these discussions in their original context - it’s free.