Wednesday, June 15, 2011

On Monday we decided to take a brief break from traversing the steep and rocky East Side for seabirds and made the most of the warm, sunny weather by beginning the annual Swallow monitoring on the island. 

Creeping around in barns and old pig sties was worth it with 19 pairs recorded in total. Of those 19 two had lined nests but not yet laid, leaving a count of 34 eggs and 27+ young from the remaining 17 pairs. Upon arriving back from their South African wintering grounds, Swallows make repairs to old nests, before lining them with straw, feathers and wool in which to lay their eggs (above). Most of the chicks we recorded were just hatched and therefore too small to ring (middle), but one pair at the farm must have started earlier than the rest and four suitably sized chicks were ringed (bottom). The ringing of chicks has shown that most British Swallows set up territories within 30km of where they themselves hatched. (c) Richard Brown

Oystercatcher chicks have started to hatch all over the island. The parent bird's alarm calls cause the chicks to crouch low to the ground, under or near vegetation. Some are easier to find than others and we couldn't help but wonder if this one thought that it was well hidden because it had its head covered. (c) Richard Brown

A visit to Seal Cave, our largest Razorbill colony, proved fruitful with about 80 birds ringed. Productivity seems to be acceptable but at least one pair of Herring Gulls are specialising in taking the helpless chicks. The breeding season has been quite protracted this year with many adults still incubating eggs, several recently hatched young (such as the one above), but also many chicks which have already fledged (at about 18 days old). (c) Richard Brown

A Collared Dove taken in the Cristin Heligoland became the 69th species to be ringed this year. Despite the daily occurrence of flocks numbering up to ten individuals at the moment, this species continues to prove very difficult to catch. Indeed this was only the 51st to be ringed in the 58 year history of the Obs. These wandering birds, of which the majority are birds which have fledged this year, are most likely visitors from the farms of the nearby mainland where they are numerous. Collared Doves can breed in the year in which they hatch, so these fledged young, already moulting their wings and body feathers so that they are indistinguishable from older birds, may be nesting soon. Collared Doves have only nested once on Bardsey, an attempt which soon failed. (c) Richard Brown

Giselle found this July Belle whilst we were searching for Oystercatcher chicks among the Gorse of the South End, which was not much of a surprise as Gorse is the larval foodplant. More of a surprise is that it is only the second Bardsey record since 1999. (c) Giselle Eagle

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