14th July

This time last year we were probably moaning about the effects of the summer-long drought on our stewardship crops, but today they were in danger of being washed out of the ground, blown over or suffering salt-burn such was the ferocity of the gale and rain that arrived courtesy of an unseasonable depression sweeping through. For the most part sea-watching was utterly unrewarding, with just 22 Manx Shearwaters, 17 Common Scoter and a Balearic Shearwater through off the Bill, although the continuing Yellow-legged Gulls did provide constant entertainment there - numbers were again hard to assess, but examples of up to 12 settled together at times in the fields and 15 through west off the Bill in an hour during the evening suggested that 30 was likely to have been an underestimate. Overhead at the Bill, many dozens of Swifts were apparent at times during the spells of lighter rain but there was no clear evidence that they were moving rather than just circulating while being undecided about quite to escape the grim conditions. Elsewhere, 24 Dunlin, 2 Redshank, 2 Sandwich Terns and a Common Sandpiper were at Ferrybridge.

At the Bill it was another day of Yellow-legged Gulls © Martin Cade:

At Ferrybridge the Little Terns have been fortunate to escape the contagion that's swept through the other Dorset tern colonies and are now fledging in good numbers...

...whilst wader numbers finally picked up a little and included this Common Sandpiper...

...and these two Redshanks (that provide a nice comparison of juvenile vs adult at this time of year after we happened to write about this the other day) © Pete Saunders:

And now onto some pretty exciting news from the island, this being that Cirl Bunting has bred successfully at the Bill - seemingly the first successful breeding in Dorset since 1971 and the first ever breeding record at Portland. In view of events earlier in the year when it was common knowledge that at least two males and a female were present, this probably won't come as a great surprise but actually working out what's been going on and eventually proving a successful outcome has been far from straightforward © Martin Cade:

The timeline of events goes like this: 

7th April a singing male arrives at the Bill and appears to take up territory, ranging widely for the next few days; 

15th April a second singing male arrives but appears not to remain; 

25th April the first male and a female trapped and ringed at the Obs and continue to be seen together during subsequent days with the male singing frequently; 

10th May a second female trapped and ringed at Culverwell, with sporadic sightings of a pair for the rest of the month but very little song heard and the birds generally very furtive; 

5th June the male starts singing more or less continually, mainly at the Obs garden, and continues to do this for several days but thereafter goes quiet and no further sightings of either it or a female; 

27th June the male and second female retrapped and found to be in breeding condition (the male with a strong cloacal protuberance and the female with a conspicuous brood patch); 

9th July the male seen feeding a recently fledged juvenile © James Phillips:

Our interpretation of events, which may be entirely wide of the mark, is that an initial breeding attempt involving the long-staying male and first female failed on or about 4th June and the male then struck up with the second female which was still about but hadn't been noticed. Out of interest, with the exception of periods when the male has been singing, it's been remarkable how unobtrusive these birds have been: although we've tended to give the 'action' a wide berth and most our meaningful encounters from the point of view of understanding the situation have been via the serendipitous handling of the birds during the course of our normal ringing operations, we've never really had a clear idea of where the nest site(s) have been and the many visiting birders to the Bill have had almost no random encounters with the birds since late April - there must be a good chance that breeding attempts in less well-watched parts of the Dorset coast could easily escape attention if a singing male hadn't been noticed early in the attempt.

On an altogether more esoteric note, before this event unfolded we didn't know Cirl Bunting at all well and were surprised when listening to the male how readily it switched between two obviously different versions of the rattling song - if you've watched the video above you'll have heard it do just this but here it is again with two 'ordinary' rattles followed by two slightly slower and lower-pitched rattles. On looking this up in BWP it turns out to be perfectly well documented, albeit without any explanation as to why this 'song-switching' might occur:

 When the Cirl Buntings first turned up we also found ourselves struggling to remember how you told their song from that of Lesser Whitethroat, which in turn reminded us of being in Russia years ago listening to and sound recording Arctic Warblers and thinking how similar they sounded to both these more routine singers. The differences are relatively subtle and relate to the speed of the rattle and its pitch, with both Lesser Whitethroat and Arctic Warbler also throwing in further helpful clues - the former usually precedes the rattle with a bit of a rambling warble, whereas the latter usually chucks in one or more of its characteristic 'zik' call-notes before each rattle. Here are two rattles each of Cirl Bunting, Lesser Whitethroat and Arctic Warbler, together with a sonogram comparison of the individual rattles: