Lower Derwent Valley National Nature Reserve: 15/01/14

Welcome to the LDV NNR ringing blog, this blog is designed to share the experiences, findings and tales from a group of dedicated ringers. We specialise in conservation orientated research projects, largely focusing on wildfowl, waders, owls and birds of conservation concern, in and around the Vale of York NNR's.

NB - Whilst the purpose of this blog was initially designed to cover our nationally important wildfowl ringing activities, it now also features wildlife and work posts, explaining how we manage the NNR for both wildlife and people.

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Friday, 17 January 2014

15/01/14 - Big! Bright! Boring? Think again!

A small whoosh-net catch at Bank Island last week produced six Mallard, two Teal and a Moorhen. Two of the Mallard were notable in being very large and extremely bright and well marked individuals – with wing lengths of 279 and 280mm. These are at the larger end of the wing lengths recorded with Mallards (typically in the range 255-270) and so it was wondered if these might be non-British birds.... Previously we have caught a few similar sized birds to these each winter, typically in March, when the exceptionally bright and large birds have usually had wing lengths exceeding 290mm. The rather large birds caught this week coincided with a large arrival of wintering waterfowl which has seen numbers of Wigeon and Teal jump by several thousand.

Male Mallard - Bank Island - 08/01/14

The issue of what represents a ‘wild’ and winter migrant Mallard is an interesting one. Following a run of milder winters over the last decade or two, our last recovery of a Mallard ringed in the Lower Derwent Valley NNR and recovered abroad was in 2007 (with a previous nine prior to that time). It would appear that the number of Mallards moving into the UK and the LDV from further north and east have decreased in recent times, which is in common with other species ‘short-stopping’ in Europe. It was therefore interesting to hear about a bird we ringed in the cold weather period in the winter of 2012 that had been recovered in the Netherlands during 2013. Wintering birds ringed in the valley have now been recovered in the Netherlands, France and Denmark whilst ducklings ringed here have been recovered in both Germany and France. Young birds ringed in the breeding season in Norway, Finland and Sweden have all been found here whilst an unusual record concerns an adult male that was ringed at Wheldrake in moult during June 1997 and was shot in the subsequent winter in Denmark. So clearly even the humble Mallard which often gets overlooked may be more worthy of our attention...

The flood water which has started to appear gradually on Bank Island and Wheldrake Ings over the course of the last week has brought in thousands of wintering ducks, a count across Wheldrake last week produced 6300 Wigeon, 3150 Teal, 324 Mallard, 87 Pintail, 5 Pochard, 13 Tufted Duck, 9 Shelduck, 9 Shoveler, 6 Gadwall and 1 Goldeneye. Total counts for the valley included 8200 Wigeon and 6000 Teal, the Wigeon count in particular being lower than expected in comparison with recent winters when a peak of 14-15,000 birds have been recorded.

The lack of standing deep water has suppressed the numbers of diving duck, a mere 13 Tufted Duck are present at the moment compared to the record breaking 700+ recorded at this time last year in the extensive floods. However, with more rain forecast, further flooding is likely and surely some colder weather is due to arrive from the east at some point, and so there is time yet to see numbers increase.