Great video of Eurasian Woodcock feeding

Check out this fantastic video of a Eurasian Woodcock feeding in Norway:

Feeding Woodcock from Frode Falkenberg on Vimeo.

Why so quiet?

Many regular viewers of Woodcock Watch may have noticed a recent lack of activity from the tagged birds. This is in contrast to observations from the field – many sponsors have written to us to say that the woodcock seem to be reappearing in the UK now. So why is there so little movement?

We believe that the problem relates to the tags’ batteries. The tags are solar-powered and need to be recharged by the sun. It is possible that during the bird’s moult, due to a change in the woodcocks’ behaviour, the tags were not receiving sufficient sunlight and have run completely flat. To fully recharge a battery from flat will take about 4 hours of bright sunlight. It may be that the tags are not receiving this. Day length is short and sunlight intensity low in the northern locations where the birds have spent the autumn, not to mention the fact that the birds are often hidden during the day.

Those who followed Woodcock Watch last year will remember the same issues in our first autumn. However, this year’s results have been noticeably better and the tags have returned far more data. Crugith and Lanyon for instance have transmitted useful results through the majority of their autumn migration and we hope that more such data is on its way.

It is more than likely that some of the birds have died. Crousa, who we have not heard from since May, and Elissa, who has not sent data since June, are probably no longer alive. Annual survival rates are around 60% for woodcock - that is to say that around 40% of the adult population do not survive from one year to the next. Lifespan does not typically exceed 4 years. It is perfectly natural that we lose a few of our woodcock over the course of a year.

But for birds like St Patrick, Skittle, Amy and Rebecca, who last transmitted in August or September, there is still hope. It is possible that their tags will receive the sunlight they require in the coming weeks and will then begin transmitting data again. We observed this pattern in 2012 with several individuals sending winter locations after an autumn quiet period. It is possible that some of these birds, when we next here from them, will be back here in the UK.

Help us tag and monitor a woodcock

We've teamed up with Crowdfunder.co.uk to try and raise £3,500 by the end of the year to cover the cost of buying, fitting a satellite tag and monitoring one woodcock on its epic migration.

How Crowdfunder works

No donation is too small and we are offering rewards for those who pledge £5 or more. Your donation payment is only actually taken if we hit our target of £3,500 by the end of the year.

You can view our appeal page at www.crowdfunder.co.uk/woodcock/

New location data for Crugith and Lanyon

Crugith and Lanyon continue to set the pace for the return to the UK. Crugith is currently in Berkatal in central Germany:

Lanyon meanwhile is hot on Crugith's heels and is currently in Pierkunowo, Poland:

Look what else we came across on Tuesday night

Whilst we were out on Tuesday night we managed to catch and tag three of the six woodcock we saw. Numbers are low at the moment but we're expecting more migrants to return shortly.

In addition to the three woodcock we also came across a golden plover. Our research assistant Chris is currently training towards a general ringing permit so the experience of ringing a new species was a real bonus.

Our first woodcock of the winter

Our first woodcock of the winter, ringed and ready for release at 10.30pm on Tuesday 5th November.

Geolocators vs Satellite Tags

Since 2012, the GWCT Wetlands team has tagged 24 woodcock with satellite transmitters. The movements of these birds have been transmitted back to us in near real time, and as well as a large amount of valuable data, they have provided a great deal of interest to the thousands who have viewed their migrations on the Woodcock Watch website.

But these few satellite-tagged stars of the show are only a small proportion of the woodcock caught and tagged. Though they may provide an exciting and easily-accessible insight into the movements of our birds, there is no escaping the fact that satellite tags are expensive, costing around £3000 each. It’s with this in mind that we have looked at alternative methods of gaining data on woodcock migration routes, and found one, in the form of the geolocator.

Geolocators are tags that are even smaller and lighter than satellite transmitters. They are also a fraction of the cost - we can buy around twenty geolocators for the price of a single satellite tag. They work by logging light levels, from which time of sunrise, sunset and day length can be determined.

These data can be used to calculate an approximate longitude and latitude for the bird twice a day. Geolocators are accurate to 60-150 km and whilst this is far less accurate than a satellite tag, it is an acceptable margin of error for a bird that may migrate 2000–7000 km.
Geolocators do present one difficulty however. The tags store information on the birds’ whereabouts but do not transmit it – the tags must be retrieved and the data downloaded. The chance of recapturing the same woodcock from one year to the next – considering the several thousand miles it may have travelled in the meantime – probably seems like finding a needle in a haystack.

Amazingly, however, it is possible, and this is thanks to the fact that woodcock tend to be very site faithful. Woodcock will return to the same wintering sites year on year and on some occasions even the same field. We have deliberately deployed these geolocators at sites where we have previous knowledge of site fidelity from ringing and are able invest time in recapture efforts each winter.

As well as recapturing live birds, we have also had several tags returned to us by those that have shot woodcock wearing them. It is with this in mind that we share the following information so that those who shoot woodcock are able to recognise the tags and return them to us.

• The tags are very small, approximately 8 x 20 mm.
• The tags may be almost entirely covered in feathers as they sit flat on the back. The light sensor should be visible, protruding from the feathers on a small stalk about 20 mm long. It is possible that this stalk could break off but the tag itself may still contain useful data so please check beneath the feathers.
• The tags are mounted to the lower back and held using leg loop harnesses. These pass under both legs and hold the tag above the preen gland and between the wings in an area that does not impede preening or flight. A tag can be easily removed by stretching the elasticated loops back over the legs.
• The tags have been deployed in small numbers in Norfolk and in north-east Scotland. Tags have been deployed in large numbers in Cornwall, and, with the help of the Woodcock Network, in Mid-Wales. People who shoot in these areas are far more likely to encounter geolocators.

To date, just over 100 geolocators have been deployed since 2010 and 18 recovered. People who recover a geolocator can return it to Andrew Hoodless, GWCT, Burgate Manor,
Fordingbridge, Hampshire, SP6 1EF or email: woodcock@gwct.org.uk for more information.
Both geolocators and satellite tags are valuable tools in monitoring woodcock migration, each with their own benefits and disadvantages. Whilst satellite tags are able to provide us with very accurate and easily-accessed data, the geolocators are a cheaper way to increase sample size. The success of our geolocator study hinges on achieving reasonable return rates and every tag that we are able to recover will make a big difference.

Crugith leading the charge home

It looks like Crugith may be the first of our woodcock to make it back to the UK. She's continuing west and has just crossed over into Germany from Poland.

First data from Woody II since August

We've received some new data from Woody II, the first update since August. She's making her way back and is currently approaching Moscow.