13 January 2015

2015 nesting season underway by New Year!

Dave Leech writes:

For many BTO nest recorders, particularly those monitoring Barn Owl repeat breeding attempts well into the late autumn, it feels like the 2014 breeding season has only just drawn to a close. However, the respite is brief – while we seek shelter from the biting winter gales, the avian community is gearing up for the coming spring.

The Met Office have recently announced that 2014 was the warmest year on record in the UK and this winter has certainly been mild if, as most bird ringers will point out, a tad windy. Mild weather at the start of the year can certainly stimulate opportunistic singing, and I’ve already heard Great Tit, Wren and Dunnock in song within walking distance of my house in southwest Norfolk; nest recorder Mark Lawrence has been listening to the reedy warbling of the latter since early December on his patch in Devon.

Dunnock singing - Liz Cutting

While the nestling diet of these birds is not necessarily conducive to early breeding, species able to take advantage of soil invertebrates are less limited by food availability and may breed opportunistically at the end of winter, particularly around human habitation where temperatures are artificially raised and bird feeders provide additional sustenance. Nest recorder Mark Lucas has already reported his first clutch of Robin eggs in North Yorkshire via Twitter, found on the 9th January, beating the earliest record submitted to the BTO Nest Record Scheme by a fortnight. A pair of Mistle Thrush breeding in a Glasgow park were also flagged up on Twitter, the young having fledged in the last week.

Mistle Thrush nest - Herbert and Howells

Some birds couldn’t even wait for the New Year to start the 2015 season. RSPB warden Doug Radford was told of a Moorhen on eggs in Cambridgeshire in mid-December which had hatched by Christmas, and we’ve also received reports of Grey Heron laying at the start of the month. Not to be outdone, the BTO’s own Nick Moran stumbled across a brood of small Mallard ducklings on the 12th December at our reserve in Norfolk.

Mallard with ducklings - John Harding

While these examples demonstrate birds ability to respond to windows of opportunity, they are all anomalies. The data collected by BTO volunteers for the Nest Record Scheme over the past 75 years tells us that the main Robin breeding season kicks off towards the end of March, while most Moorhens start to lay from the beginning of April onwards.  Grey Herons are early breeders (Table 1), but laying doesn’t typically start until mid-February, with Raven generally the next species to follow in any number, then Tawny Owl, Collared Dove and Magpie at the very beginning of March.

BTO data have played a key role in demonstrating the advance in avian laying dates in response to the warming climate, as summarised in the recent BirdTrends report, and it is vital to ensure that this monitoring is ongoing. So, if you’re looking for a New Year’s resolution that furthers your knowledge while also giving something back to the conservation effort, why not make 2015 your first year as a nest recorder?

Table 1. Top 10 earliest UK breeders as calculated using Nest Record Scheme data for the period 2000-2009. Dates shown are the fifth percentile of the laying date distribution. Note that some early breeding species (e.g. Long-eared Owl, Crossbill) are excluded due to very small sample sizes.

06 January 2015

Fall-ing for Woodcock

On a very cold and snowy morning early in the New Year Rachael and I joined Tony Cross, one of the founding members of the Woodcock Network, on one of his many nocturnal winter forays into the hills of Shropshire and Mid-Wales. Formed in 2008 to increase the study of this elusive but surprisingly numerous nocturnal wader, the Woodcock Network has managed to increase the annual total of Woodcock ringed in the UK from just 80 in 2007 to over 1,377 in 2013. This has been achieved by encouraging a growing number of ringers to give the ‘dazzle and net’ technique a go. Those who have done so have quickly discovered that this under-researched species offers rich rewards for anyone prepared to brave the wet and windy nights of winter. Mid Wales ringers alone ringed exactly 500 Woodcock in 2014 and Tony recently had a record catch of 27 Woodcock in one night.

Woodcock - Tony Cross

As it turns out we chose quite a memorable occasion to tag along. The first bird we caught, and Tony’s first bird handled in 2015, was the Network’s first ever control of a foreign ringed Woodcock, - originally ringed in Latvia on 27/10/2012 at Pape, Rucava 56'10N 21 01E (see Tony's blog) 1,600km away. Most foreign ring recoveries we process are from birds that have been shot but with a growing number of ringers now focusing on Woodcock in France, Russia, Italy and Spain the chances of capturing a foreign-ringed bird is set to increase each year.  Woodcock ringers in the UK have also enjoyed a regular stream of recoveries from far-flung locations such as Ireland, Spain, France, Holland, Germany, Norway, Denmark, Sweden, Finland and Russia.

The Latvian ringed Woodcock

Since being trained to ring Woodcock by Tony in 2008, Owen Williams, director of the Network, has concentrated his ringing efforts on a site near Aberystwyth in West Wales on which he has caught over 700 Woodcock. This has revealed some fascinating details on wintering site fidelity. For example in the winter of 2012/13 out of 85 adults caught on the site an amazing 47% were birds he had ringed in previous winters. Not bad considering that there are no resident Woodcock in this part of the country!

Typical Woodcock habitat found in Mid Wales

The Woodcock Network works closely with Andrew Hoodless of the Game and Wildlife Conservation Trust (GWCT), an organization that has researched Woodcock for many years. The biometric data, counts and observations, which are shared with GWCT, have made a significant contribution to learning more about this species. The Network has also funded a number of geolocators to add to those being fitted to Woodcock by GWCT as part of a project to research their migration.

As the Woodcock is a quarry species shot in the UK it is vitally important that the results of this research are communicated effectively to shooters in order to encourage sustainable hunting. Both the Woodcock Network and GWCT, who are part funded by the shooting community, do this through articles in the shooting press and at numerous talks around the country.

Anyone wishing to know more about how to get involved in Woodcock ringing should contact Owen on 01974 272654 or Tony on 01597 824389.

Thanks to Owen and Tony for all of the information in this post.

24 December 2014

Merry Christmas from the Demography Team

As we move closer to Christmas, many bird ringers will still be out collecting valuable data on our bird populations across a range of habitats, from gardens, woods and farms to salt marshes and estuaries. Winter ringing tells us a lot about the survival and movements of birds in response to weather and can also be used to assess the breeding success of birds that nest outside the UK, such as wildfowl and waders. We've received information about just over 763,000 ringed in Britain & Ireland during 2014, which is 55,000 more than this time last year, and expect many more records to arrive over the next few weeks.

Coal Tit - Lee Barber

This period of the year is a little quieter for nest recorders, although those out monitoring Barn Owl second broods will have only just laid their ladders down after an incredibly prolific season. With temperatures above average for the time of year, however, it's always a good idea to keep an eye out for signs of opportunistic nesting behaviour, particularly in gardens and around towns where the climate tends to be warmer and many homeowners are providing extra food. Data from this summer are still flooding into the Nest Record Scheme thanks to the amazing efforts of our volunteers, and we've received over 36,000 nest histories so far, over 2,000 more than at this stage last year. As with the results generated by ringers, this information will be used to improve our understanding of the role that survival and breeding success play in driving population trends.

BTO Blue Tits - Sue Lawrence

On behalf of the birds and the BTO, we would like to thank all our ringers and nest recorders for their support and hard work during the year, and all readers of this blog for your interest in, and support of, these vital surveys. If you're not yet involved and fancy making bird surveying one of your resolutions for 2015, why not have a look on our survey pages to find an option that suits you?

Merry Christmas and a Happy New Year from all of us at BTO HQ!

18 December 2014

Yellow legs and Black heads in Switzerland

We recently received a partial ring-read of a Black-headed Gull in Switzerland which did look to be a BTO-ringed bird, so definitely one worth chasing up! A few emails later and a week after first seeing the bird at Morges, Franck Lehmans was able to read the ring again and get the full number (EX70855); a bird ringed as an adult at Pitsea Landfill Site in October 2012.

This is only the second report of a British-ringed Black-headed Gull in Switzerland, following a bird ringed as a chick in Essex in 1999 and seen in December that year. The map below shows all movements of Black-headed Gulls to/from Britain & Ireland, from the Online Ringing Report.

Franck has a bit of a track record finding North Thames Gull Group birds: in April/May 2014 he reported a Yellow-legged Gull (Orange YY5T) originally ringed at Rainham Tip in February 2014. This bird also has an interesting history, being seen just five days after ringing in France, before moving on to Switzerland.

Wanderings of Orange YY5T
To top the story, in the same week that Franck was watching the Pitsea Black-headed Gull in Switzerland, the Yellow-legged Gull he'd seen in the spring was back at Pitsea, photographed by Richard Bonser (check out his excellent blog here)!

Orange YY5T at Pitsea Landfill on 29th November (c) Richard Bonser
Many thanks to North Thames Gull Group for sending on the details of these birds and for letting us use the map from their excellent website.

15 December 2014

Migration Mapping Tool

There has been a lot of discussion recently around the value of bird ringing. Ringing collects data on survival, productivity and abundance and this information helps scientists understand species declines, allowing them to prioritise conservation efforts. While the scientific benefits of ringing are relatively easy to see, the more practical applications of ringing are sometimes less obvious.

In November 2014, Highly Pathogenic Avian Influenza (HPAI) H5N8 was confirmed on a farm in Yorkshire. Guidance was updated on the BTO website and includes information about how to report any unusual mortality in wild bird populations.

Common Teal, one of the species analysed by the Migration Mapping Tool.
Photograph by Edmund Fellowes
During the previous outbreak in 2007, movement data collected over the last 100 years from birds ringed across Europe were collated by EURING to produce the Migration Mapping Tool. This maps migration routes in time and space for 21 species of water-bird. The tool was developed to assess the potential risk of AI being moved by wild birds; of course, other possible mechanisms of movement also have to be considered. It provides a summary of bird movements between different areas in Europe and at different times and demonstrates how useful data from bird ringing can be in a wider context. As well as being a valuable tool in the assessment of possible risk from the movement of AI, the Migration Mapping Tool is a fascinating resource for learning more about migration in general.