A superciliaris at sunset
A rare wagtail hybrid was the last thing Seán Ronayne expected during an evening sound-recording session at Cahore Marsh.
ON the evening of 27 April I popped into Cahore Marsh, Co Wexford. Following Cian Cardiff’s and Stephen King’s directions, I parked up at the base of an impressive dune system. I made my way towards a track when a series of close calls engaged my brain and instantly gave me a rush: Yellow Wagtail – a
scarce migrant in Ireland and a species I was hoping to sound-record here. I looked up and saw three flashes of gorse yellow as the birds perched directly over my head on some electricity poles.
I lifted my binoculars to have a look. The birds then landed right next to a pair of Little Ringed Plovers; the first was a Blue-headed Wagtail – fantastic! The next, which I picked up some 10 m away, was a British flava. This is the expected subspecies in Ireland, although it’s always a good bird to find. I continued scanning until I found the third bird and instantly felt my binoculars tremble: this one had a jet-black head!
My feeling of calm went out the window and I seemed to lose all sense. I took a deep breath and fired off some shots of the bird and that was it – all three birds flew up, circled around a few times and headed north. I didn’t get much time to study them or take much in. Thoughts of feldegg
came to mind. I skimmed through my photos and zoomed in – it definitely had a jet-black head, but I noticed some white behind the eye. It was then that deep down inside, I knew that this bird probably wasn’t a pure feldegg,
even though I really wanted it to be one.
I made some overly excited phone calls to Cian, Stephen and Harry Hussey and Killian Mullarney, who expressed the same thoughts. Regardless of what it was, the bird was a stunner and a rare beast indeed. I hung around for about an hour, but the birds never returned and darkness began to fall.
That night I assessed the photos further and thoughts of this bird being a feldegg × flava intergrade (‘superciliaris’) became more insistent. Calls were sent to both Stanislas Wroza and Magnus Robb and the conclusion was that all calls recorded conformed to a north-western taxa (flava/flavissima/thunbergi).
This could mean three things: either the black-headed bird didn’t call, it didn’t give its typical call or it calls like its non-feldegg parent (presumably a flava).
I visited the following day and, on arriving at the wagtail spot, I got a shock – the bird was right in front of me! I reached for my camera and began to fire off some shots, before switching to soundrecording. The bird was emitting a series of lazy song-like notes for some time before it eventually flew, giving a single clear flight call.
With a combination of prolonged good views and a new set of closer recordings and photos, the identification became clearer, allowing several features to be seen which were not visible in the brief, more distant views of the day before.
Initial impressions of the white on the first day were of a blotch behind the eyes, but in actual fact, at close quarters, it looked more like a distinct supercilium with some areas disjointed, particularly to the front of the eye. Feldegg doesn’t show such a feature, but flava does. A rather prominent white lower eyering is also evident – another flava feature.
Also, there is a trace of a white submoustachial stripe and various other white flecks and patches, including under the bill, again at odds with pure feldegg. The black on the nape on classic feldegg is usually rather extensive and in this bird that isn’t the case.
I obtained several close recordings of this bird, with no other birds present to cause confusion. Having spoken to various people who have experience with the different subspecific vocalisations, as well as listening to several online, the calls on the second day did not sound raspy and seemed flat (at least to my learning ear), conforming to a north-western-type vocalisation. Just to be sure, the recordings were sent to Stanislas and Magnus who concurred with the above sentiments.
With all this taken into account I think it leaves little doubt that this bird is not a ‘pure’ feldegg and is almost certainly a ‘superciliaris’. I’d like to think it has more feldegg than flava, though, as many of the superciliaris online have a really prominent supercilium. ■