Saturday, March 5, 2011

Today we saw our 130th species for our 2011 British List, a Whimbrel. Bardsey is rather unusual in having a few Whimbrel which over-winter each year. They seem to loosely associate with the flock of twenty or so Curlew which also over-winter in the area. Typically Whimbrel leave their breeding grounds in Northern Europe and pass through the UK from July until October, heading for their African wintering grounds. They then return to our shores from about late March onwards as they head for their tundra nesting sites. In Britain they breed in Shetland and occasionally on more southerly Scottish islands. It was quite a surprise therefore when a pair bred on the Gwylan Islands, just across the Sound from Bardsey. Especially as they chose to nest in the middle of a Great Black-backed Gull colony. Rather surprisingly they were successful and fledged two young in 2000.

One of our over-wintering Whimbrel Numenius phaeopus phaeopus © Richard Brown

The last Whimbrel we saw was just a few weeks ago in Costa Rica.  However, it was of a different race, Hudsonian Whimbrel Numenius phaeopus hudsonicus. Superficially it looks very similar to today’s Whimbrel Numenius phaeopus phaeopus, the main difference being rump colour, brown in the Hudsonian and white in ours.  While their ranges don’t over-lap (Hudsonians being restricted to the Americas), vagrant Hudsonian Whimbrels have been recorded on a handful of occasions in the UK. With this in mind, we inspect the rumps of Whimbrels on Bardsey very  closely!

Hudsonian Whimbrel Numenius phaeopus hudsonicus © Richard Brown

Part of the daily census is to record which colour-ringed Chough are present on the island. The majority of our birds sport rings of coloured plastic, these being added either on the island or elsewhere in North Wales. Colour ringing is an important tool for monitoring Chough populations, which are restricted in the UK to Wales and Cornwall. The rings allow individuals to be recognised in the field without having to disturb the birds. Sightings of colour-ringed birds have given us much insight into their movements. For example, we now know that in North Wales adult Chough escort their young to Snowdonia, where they deposit them in large non-breeding flocks. The adults then return to their breeding areas whilst the large flock of non-breeders roams widely. 

A few of the Chough currently feeding on Bardsey. The front three are ringed with unique colour combinations so we can monitor their movements on the island and across Wales. © Richard Brown

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