Red-rumped Swallow a bird new to Frodsham Marsh
29th August 2012.
WEATHER: Sunny with heavy showers following a more prolonged period of heavy rain earlier in the day. Wind moderate to fresh south-westerly easing to moderate.
I arrived at Frodsham Marsh at around 5pm and spent 30 mins or so scanning No 6 Tank from the top causeway that runs along the north side of the tank. The earlier heavy downpours had attracted many Teal and a flock of Ringed Plovers to the shallows in the centre of the tank and I noticed the recently resident 4 Ruddy Shelducks feeding on the mudflats further in from the shore. There was a steady stream of hirundines moving west over No 6 Tank with more (mainly Barn Swallows) feeding over the adjacent No 5 Tank. Looking at the Ruddy Shelducks once more, I noticed that the rain had created a number of small pools towards the south-west corner of the tank, close to where the main pipe deposits dredgings onto the tank from the Ship Canal. Rather than returning back along the causeway, I decided to drive to the south-west corner to check out these pools. Looking over the embankment there, I found an interesting mixed flock of Pied, White and Yellow Wagtails and a couple of Greenshank. There were also more hirundines, but here their progress west was more leisurely than on the north side, as many were taking advantage of the shelter and presumably good feeding provided by the south embankment.
A small flock of mixed Barn Swallows and House Martins were feeding above the south-west corner and I was quickly attracted to one individual in particular. This was clearly a swallow rather than a martin, being larger and with a flight action like a juvenile Barn Swallow with wing-beats appearing more rushed compared with the suppleness of an adult in its pursuit of insects but not as flickering as on a martin. It was with about 4 Barn Swallows feeding at a height of about 30 metres above me and at a slightly lower elevation than the House Martins, however it was clearly not a Barn Swallow. From below a dark vent and pale throat with no hint of a breast band drew immediate attention. The underparts were off-white and appeared a little duskier compared to the Barn Swallows, though I could not detect any obvious streaking. The tail streamers were longer than on the House Martins but seemed no longer than on a juvenile Barn Swallow nearby. By this time I recognised I might be onto something interesting but I had still not seen anything of the upperparts. Thankfully the bird banked twice in excellent light and I was able to clearly see a pale rump, showing a peachy-white tinge where the rump patch joined the dark blue back but otherwise being whitish, plus a pale collar. The rest of the upperparts were similar in colouration to a juvenile Barn Swallow, lacking the typical gloss shown by an adult. Now I was sure it was a Red-rumped Swallow.
I watched the bird for another minute before it began to drift off west along the south embankment of No 4 Tank in advance of another rain shower. I contacted Mark Payne and Paul Brewster to put the news out. Mark was in the area and soon arrived, later followed by Frank Duff. By now large numbers of hirundines had begun to gather over the south embankment of No 6 Tank as the wind began to lessen and the latest shower moved on but unfortunately, and to my knowledge at least, the bird was not seen again. No photographs were taken and the bird was not heard to call.
I believe the Red-rumped Swallow was a juvenile given the length of the tail streamers, lack of any glossy sheen on the upperparts and paleness of the rump and collar, neither of which showed any marked rusty tinge.
N.B. I have experience of seeing Red-rumped Swallows in the Mediterranean region, Central Asia and the Indian sub-continent.