21/06 Thatcham Marsh LNR

Location: Thatcham Marsh LNR CES Visit 2026.06

Session:     21/06/2026 07:30 to 11:00hrs

Present:      JHW, IW, RAD, JL..

Weather:    Sunny very hot calm

Nets: 192M reed bed ride + 2 12M separate rides set in scrub (site B) up from 06:30 to 10:30hrs.

Lures    (none):

The noisy juvenile Great Spotted Woodpecker (RAD)

Notes: A Great Spotted Woodpecker capture is always noisy as the birds protests and fights back often inflicting injury on those not quick enough to avoid its beak when handling the bird. So far since we begain the CES in 1993 we have ringed 36 from the reed bed nets usually they are dispersing after breeding as the juvenile photo’d above. We are halfway through the season on visit CES 6 of 12 scheduled visits for 2026. Cetti's Warbler seem to have had a good breeding outcome. Reed and Sedge Warbler numbers still seem low, although this isn’t backed up by last years matching visit. Now that we are halfway through the season a look at visits 1 to 6 for Reed Warbler and Sedge Warbler shows that the formers total is towards the high side of visits since 2021 while the latter remain around the normal for the last 10 years – the exception being 2024. The data for the CES uses just the totals from Reed Bed nets 1A and 2A, those birds from the B site scrub nets are excluding to maintain consistency as the use of B site is irregular. The totals in the tables below include B site birds. We were glad to complete the session and take the nets down at 10:30hrs as the temperature was becoming uncomfortably high for both us and more importantly the birds.

Recaptures: (11)

Cettis Warbler ringed: 21/06/2025, 28/09/2025, 26/04/2026

Sedge Warbler ringed 10/05/2026

Reed Warbler ringed: 23/06/2024, 10/05/2026x2, 02/08/2025, 02/05/2026, , 31/05/2026

Wren ringed: 15/10/2023

Sightings: No Cuckoos heard this week; its around this time their return migration begins. Pochard still with ducklings on the nearby pit. A few swift over high up but no hirundines seen. The Water Rails was heard to call; they have been silent for the last visit or two. A juvenile male sparrowhawk did a low run across the reed bed net ride just after nets down unfortunately. At the same time a Coal Tit was singing from the trees at the north end of the ride; not a regularly detected species around the reed bed. The only pair of Reed Buntings with a territory near our ride was unusually vocal during the session. Lots of insect activity over the grassland and along the ride, mostly Marbled Whites. In the long grass near the ringing station what was probably a vole or shrew was active – grass stems moving as it pushed its way through the foliage.