Sand martins on the 4th of July

 A team of six did our second mist netting session in front of the sand martin bank on Friday and followed that with some sand martin nestling ringing to complete our mornings ringing.  It meant an early start, with the nets up at 5 am.  We walk the nets, already set, into place in front of the bank, and as we move in birds leaving their nest holes are caught whilst we are on the move.  We were more efficient in getting the nets out this time compared to last, but as always we learnt new lessons for next time.

The team of six looking cheerful despite the early start!

The catch was very good. We limit ourselves to an hour to minimise the disturbance to the colony.  We are planning to continue this at approximately two week intervals, with this being the second catch.  We caught 83 birds.  One of these was a sedge warbler, only the second one for the year so far.  Of the remaining 82 only 6 were birds that hatched this year.  I have read reports from other colonies of first year birds roosting in the colony, but this does not seem to happen much here.  There are reports from local birders of sand martins roosting in reed beds near the tramway line so this may well include our first year birds.  All six were already ringed. 

 

First year bird showing characteristic paler fringes fringes to feathers.

28 of the 76 adult birds caught were retraps, 27 of them were birds we had ringed previously this year.  The 28th was our third French ringed bird.  

French ringed sand martins.  Just as attractive as all the others.

 We will post details of these three encounters when we have the details for this third bird.  This left 48 new adult birds, so adding 49 to the total of breeding adults encountered this season.

The nets just before we finished.

Having packed up from our mist netting session we turned out attention to nestlings.  It is very busy at the moment behind the bank with many pairs bringing up their second broods with the earlier second broods really coming to the ringing stage over the next week or so.  We dealt with 8 broods of youngsters ringing a further 34 chicks.  

Overall an extremely productive morning!

Mist netting & Sand Martin Cliff

This post will cover another 3 sessions.....

On Sunday 22/6/25 a team of 4 put up 4 nets in the reed bed in front of the Discovery Hut. We caught 23 birds, including a Reed Warbler originally ringed as an adult on 9/5/19, making it at least 6 years old. The typical life expectancy is 2 years, but it still has a long way to go to reach the oldest known bird of 12 years, 11 months & 21 days. 

The Team

Adult Sand Martin

	Ringed	Re-trapped
Blackcap	1
Cetti’s Warbler		1 (9/1/25)
Chiffchaff	3
Reed Warbler	15	1 (9/5/19)
Robin	1
Sand Martin	1
	21	2

Once the mist nets went quiet, we moved on to ring 5 broods of youngsters in the Sand Martin cliff, where Doug had already spent the morning surveying the nests with an endoscope. 

Endoscoping the young Sand Martins

On Sunday 29/6/25, another session took place at the back of the Sand Martin cliff. It was a busy session with 13 nest boxes being checked, and 11 broods ringed, the remaining 2 broods being too small to ring. We then checked out the condition of the Abberton duck trap which had been removed from the scrape behind the Discovery Hut whilst it was dredged. The trap requires some attention, but hopefully it will be back in operation soon.

Assessing the 'flat-packed' Abberton duck trap....modifications are needed as the water is now deeper.

Today, a team of 5 set 5 nets mainly around the feeder area, but with one in the reed bed to the rear of the Discovery Hut. It was an excellent session with 39 birds of 13 species being caught, mostly youngsters. We caught 5 Sand Martins, including an un-ringned juvenile....I wonder how it escaped our attentions in the cliff!

A  young Song Thrush....we caught 3

The wing of a young Song Thrush

Comparison of Reed Warbler wings: pristine juvenile top, worn adult below

1st Sedge Warbler of the year...a juvenile as shown by the spotty 'necklace'

Pristine wing of the juvenile Sedge Warbler

Juvenile Greenfinch

Wing of the Greenfinch. The thickness of the yellow on the primaries indicates that it's a male.

	Ringed	Re-trapped
Blackbird	1
Blackcap	4
Blue Tit	1
Cettis’ Warbler	1
Chiffchaff	3
Great Tit	1
Greenfinch	1
Reed Warbler	10	2 (17/6/25 x 2)
Robin	1
Sand Martin	4	1 (19/6/25)
Sedge Warbler	1
Song Thrush	3
Wren	3	1
	34	4