Late July Sand Martin roosts

Peter and Alan J resumed regular roost visits after a short pause, which are receiving regular disruption from the local Hobbies. On Friday 12th, the catch was 36, made up of Sand Martin 29, Cettis Warbler 1, Reed Warbler 3, Starling 2, and a Hobby 1 (2nd year male).

The local Hobby pair have been very interested in the roosts this year!

On Wednesday 16th, the catch was 33 + (1), made up of Sand Martin 12, Chiffchaff 8, Reed Warbler 1 + (1), Garden Warbler 1, and Long-tailed Tit 11. Another Hobby (size suggested a female) flew into the net but escaped before it could be caught. Peter was 3/4 of the way to it at the time it got out!

On Tuesday 23rd, the roost had built to a decent c1,500+ birds, which settled just west of the jetty (viewed with the thermal). It was a tad breezy and the catch of 17 was made up of Sand Martin 15, and Chiffchaff 2. The Hobby came in at dusk, causing all the Sand Martin to gain height before diving straight back into the reeds.

Another attempt on Friday 26th (in better conditions) produced 63 + (1) - made up of Sand Martin 61 + (2), Chiffchaff 1, and Reed Warbler 1 + (1). Two Hobby were present but they were not as persistent as earlier in the month. When the Hobby turned up the Martins flew very high again (only visible with the thermal), before swooping down straight into the net lane to roost on either side of the jetty. Most entering slightly too high for the nets but still a decent catch. The age mix was interesting with 45 + (2) adults, and 16 first years. Still 1500+ roosting.

The last roost visit for July was on Tuesday 30th, but numbers had reduced, and only 7 birds were caught - Sand Martin 3, Swallow 3, and Chiffchaff 1.

The roosts this year have been beset by the weather, the wind just hasn't been dropping enough at dusk and there have been comparatively very few suitable nights to attempt a roost. The presence of various predators has been noted on every visit, which would logically also impact the success rate of the roost catches, however further work would need to be done on this, as the picture isn't as clear as it would seem, with the Hobby for example seen chasing birds straight into the net on a handful of occasions over the last 5 years. 

A total of 368 birds were ringed in July (across all projects) and our YTD becomes 844.