30/01/19 - Wildfowl ringing

We've been enjoying some great success in catching Teal to ring over the last two months. There are around 5500 in the valley at the moment, and since the first catch on the 30^th November last year, we’ve caught and ringed over 1000 taking the total number ringed in the valley to over 4650 (around 4% of those ringed in the UK). 

This has generated a number of recoveries with Teal ringed in the valley being reported from Sweden, Finland, Norway, Russia, the Netherlands, France and Portugal, but there has also been some interesting re-traps from within the valley. Three birds caught at Bank Island last week had all been caught and ringed together in the same catch, at Bank Island, almost exactly four years earlier, leaving us wondering if they had stayed together and just how many air miles they might have clocked up since we initially encountered them. It has also revealed the degree and turnover of Teal using the valley – our peak count has recently been reaching around 10,000 but just how many individuals pass through the reserve over the year? Two birds ringed on 18^th November last year had already made it to the Manchester area and southern France by the New Year, whilst another, ringed on 12^th December was found in Lampeter, Wales, just 10 days later. Many thanks to our staff and volunteers for putting all the extra hours in recently to carry out these catches which are largely at dawn or dusk.

The eloquent looking Pintail is one of our favourite ducks seen on the reserve at this time of year – with numbers currently continuing to increase with over 250 now present throughout the reserve.  We’ve caught and ringed 18 so far this year in and amongst our cannon net catches of Teal and Wigeon, as part of our long running studies with the BTO and WWT. We’ve also received two interesting ringing recoveries back from birds ringed in the valley in previous winters - both were ringed at Bank Island in January 2017 with the first being found at Baie d’authie, Fort-Mahon-Plage, Somme, France, 440km to the south last November. The other was found at Wexford Harbour in Ireland, some 400km west of the valley last December. It’s interesting to know where our birds have been, but it’s also useful in looking at how and when birds use the site in terms of understanding large landscape scale movements.

Mallards are a widespread and familiar species across our urban and rural landscapes, with the feeding of bread to local populations perhaps being the first engagement we had with birds and the natural environment. Although the UK breeding population (estimated between 61,000-146,000 pairs) has been increasing since the 1960’s - although also assisted by the vast numbers released by shooting parties, wintering numbers of c700,000 individuals have shown a decline since the late 1980’s. This is thought to be linked to a decrease in birds coming from Europe in a response to milder winters. 

The Lower Derwent Valley NNR remains a key site in the UK for wintering birds, with up to 3000 present most winters. Recently we were pleased to catch and ring a sample of over 40 Mallards, which also saw us pass a milestone of the 5000th individual to be ringed on the reserve over the last 30 years. Our ringing recoveries have shown birds moving to and from Norway, Finland, Sweden, the Netherlands, Germany and France, although the number of continental birds has reduced over recent years in line with the national trends. It is important that the monitoring of this species, and all species continues, with this work helping to shape future conservation strategies.