Thursday 10 September 2009

The Early Autumn 2009 invasion of GLOSSY IBISES from SW Spain




























Plates 1-2 Glossy Ibis at Chew Valley Lake, Avon (Gary Thoburn) and Plates 3-8 at Pembrey Harbour, Carmarthenshire (Peter Morgans)

Well, yet another example of post-breeding dispersal of a species breeding in Iberia. We have seen a similar pattern emerge with Little Egret, Great White Egret, Cattle Egret, White-headed Duck, Marbled Duck, Pied Avocet and Yellow-legged Gull in the past decade and now in September 2009, the same seems to be happening with GLOSSY IBIS (Plegadis falcinellus).

It was just two years ago (2007) that a record-breaking 29 birds made it to the UK, including a staggering 17 summer-plumaged adults that overshot the Mediterranean Basin and appeared. firstly in Cornwall, and then at Frampton-on-Severn and Slimbridge 100 Acre Lake (Gloucs) from 20 April to 15 May. A colour-ringed juvenile in North Lincolnshire in early 2008 confirmed the origin of these wayward flocks - Coto Donana Reserve in SW Spain - reflecting the exceptional rise and success of this species in that area.

On 1 September, a flock of 12 GLOSSY IBISES flew east over Killag (County Wexford, IRELAND), of which four were colour-ringed.

Two days later, on 3 September, a single juvenile appeared at Coedbach Marsh at Kidwelly (Carmarthenshire). It was highly mobile but was still present in the evening, favouring the floods at Glan Rhyd at SN 433 061.

Next morning (4 September), a staggering flock of 25 birds was seen, favouring grass fields in Pembrey Harbour (Carmarthenshire). Fifteen soon flew off leaving just 10 birds probing the flooded meadow directly opposite the Shoreline Caravan Park. These ten birds took this area to their liking and remained in the field for the rest of the day, often showing down to just 20 yards at times. The entire flock consisted of immature birds, most likely birds fledged this summer. News soon circulated through the information services of how well they were showing and the flock became an instant attraction with all budding photographers, the results being stunning (see selection of images above).

All ten birds remained at the old harbour (at SN 437 003) until Sunday 6 September. That day, whilst observing the flock down to a matter of just feet, I took down the details of the rings, with white rings inscribed 'MVP', 'HH4' and 'MR3' and another with a slight yellowish wash marked 'NJF'. After informing Alan Davies (Birdline Wales) of the details, Barry Stewart traced all of the birds back to the very same breeding colony in the Coto Donana (Spain) from where the 2008 Lincolnshire bird originated.

On 5 September, 8 juveniles were again noted in Forgotten Corner at Tacumshin Lakes (Co. Wexford), whilst in addition to the Welsh ten, a further flock of 7 flew west over Canvey Island (Essex) at 1245.

It then transpired that a single juvenile had flown SW from St Nicholas at Wade towards Chislet Marshes (Kent) on 4 September. This bird was relocated at Stodmarsh NNR on 6 September, where it remained somewhat elusively in the long grass terrain of the marshy pools overlooked by the reserve's Marsh Hide. It continued to show until at least 10 September.

What was almost certainly the same single juvenile flew east out of Glamorgan on 6 September and was later relocated at Chew Valley Lake (Avon), showing initially from the Stratford Hide on 6-7 (where it roosted overnight in a tree on Denny Island) before moving to Herriott's Bridge, where it fed on the mud.

Those seven birds seen in flight over Essex on 5 September flew north towards Sutton Gault on the Ouse Washes (Cambs) on 7 September.

Suffolk then took part in the influx with a juvenile in cattle fields at Hen Reedbed SWT reserve mid-evening on 8 September (after flying west along the Blyth Estuary) with what was possibly the same bird showing well at Boyton Marshes on the Flashes Pool on 10 September. Two additional birds flew north over Minsmere RSPB reserve late afternoon on 10 September and appeared to land on Dingle Marshes at Walberswick.

So, the story so far - a bare minimum of 25 individuals involved, but most likely many more and part of a widespread post-breeding dispersal north. All appear to be juvenile or first-year birds.