Sunday 29 August 2021

Late Summer - some results and thoughts.

Some notes from our activities over the last few weeks...

Reed Warblers

The number of Reed Warblers re-encountered for the 8th year of our RAS project is looking as expected with 42 birds from previous years.

We seem to be finding more females with brood patch 5 and in body moult ?  Have we no late nesting attempts ? Certainly many juveniles of several species including Reed Warblers have been caught with poor feather growth this season. Many examples of tail and wing feathers with fault bars. The example below is a Great Tit with a marked fault bar.

Sedge Warblers

Sedge Warbler ATP3573

Ringed Icklesham, Sussex 13/08/2021 by Rye Bay Ringing Group
Re -encountered Teifi Marshes, Ceredigion 19/08/2021 6 days 389 km West 

The movement above adds interest to the origins of our Sedge Warblers. We have thoughts that the reason we rarely find a control from further north is that a large proportion of our Sedge Warblers are passage birds from breeding areas of Ireland where few birds are ringed. The bird above maybe an arrival in the south east now heading west - or just a wandering juvenile...


Much lower numbers seen than previous years. Maybe the Swallows are using Maize fields down towards the estuary to feed over and roost. The largest roosts seen so far this season is only c250 birds and very few Sand Martins seen.

A breeding male with a nest in a garage 3kms away was caught in the roost, subsequently seen again at the nest 2 days later and now has another brood. We have not recorded this behaviour before and we assume the adult was on a feeding visit to the reedbed.

Reed Buntings

The number of Reed Buntings re-encountered for the 11th year of our RAS project is looking above average with 42 birds from previous years. Many of these are re-sightings of colour ringed birds with the majority of these sightings from our feeder near our Mallard Pond trapping area or from random feeding by Reserve visitors regularly leaving wild bird food in the car park.

Garden CES

The 2nd season has now been completed. 364 encounters of 20 species, 510 last year also 20 species with same nets and session length. The gut feeling was a decline in juveniles and this is backed up by the data and the graph clearly shows the smaller number of juveniles of selected species.

It will be interesting to see the BTO analysis of this season across all of the garden CES sites.

Storm Petrels

Only 3 Storm Petrels were ringed by the Group in 2020 but one of those has been re-encountered this month in Anglesey.

Storm Petrel 2720334

Ringed Mwnt, Ceredigion 17/07/2020

Re-encountered Point Lynas, Amlwch, Anglesey 03/08/2021 382 days 145km N

Into the autumn at our old CES site by the river and  Pentood Marsh nets. A mixture of reed bed, scrub with a lot of bramble that is fruiting well. Over the coming weeks these sites will become our focus as the numbers of acros fall, Chifchaff and Blackcaps will make up the bulk of the captures with a few species of an autumnal flavour...

Rich D & Wendy J

Sunday 1 August 2021

Juvenile Acrocephalus Numbers

The following table summarises the number of juvenile Acrocephalus warblers ringed on the Teifi Marshes up to the end of July for each of the last eight years.

RW = Reed Warbler
SW = Sedge Warbler
effort = ringing sessions, i.e. a combination of the number of days and different sites at which ringing took place.
RW/e and SW/e indicate the number of new juvenile birds ringed per session, rounded to the nearest whole bird!

RW SW effort RW/e SW/e
2014 131 98 26 5 4
2015 89 53 17 5 3
2016 82 67 22 4 3
2017 84 120 21 4 6
2018 99 132 28 4 5
2019 30 46 18 2 3
2020 57 64 20 3 3
2021 48 58 14 3 4


The numbers will be a function of both the number of breeding pairs present and of their breeding success.