29 October 2015

The Goldrush: update

After the big influx that we reported previously on the Demog Blog, and on our very own BTO Bird Migration Blog, things have calmed down somewhat after the initial rush (see BirdTrack chart below). For our ringers however, it's time to start inputting all that data scrupulously collected including age, sex, date, time, location, wing length, weight and fat and muscle scores. 

Goldcrest reporting rate by BirdTrack

Once the BTO receives the data, they will be loaded and the ringer/finder should receive the details about these birds within a few days (as long as the original ringer has submitted the ringing data). If it's a foreign-ringed Goldcrest, the BTO will contact these schemes and exchange information. Just this morning we received a file from Daphne Watson from the Isle of Wight who caught a Belgian ringed Goldcrest and the details arrived with the Belgian Ringing Scheme only 3 hours later (isn't technology brilliant!). They send us the ringing details and we then pass the information onto Daphne.

Unusually pale Goldcrest lacking it's dark pigments taken by Euan Ferguson and Carmen Azahara

Pale Goldcrest compared to a more usual one, taken by Euan Ferguson and Carmen Azahara

Below is a map of the origins of all the Goldcrests ringed abroad that have been caught in Britain & Ireland within the last couple of weeks! There are bound to be a few more and they will arrive in due course, ready for the Online ringing report to be published next year.

Some of the origins of these Goldcrests are very notable, as we have only received a handful of reports from these locations in the last 106 years (it also takes a lot of Goldcrests to get a handful). For example this was the 15th Belgium-ringed, the eighth Polish-ringed and sixth Lithuanian-ringed Goldcrests reported here. Click on the red point to find out how many reports of Goldcrests there have been from each county.

22 October 2015

Getting collared by a goose

Geese are one a special group of birds that can divide people's opinion in the same way that city pigeons or urban gulls can. Many assume that geese stay in the same place year after year, especially the ones that are fed in parks and urban areas. No one really knows for sure however and ringing is uniquely set up to be able to find this out.

Canada Geese taken by John Harding

One particular issue people have is that when geese moult during June or July, they drop all their flight feathers simultaneously and become flightless. Due to the fear of predation they remain very close to bodies of water for the month or so while they regrow their feathers. Geese can cause serious habitat degradation in certain locations like the reed beds at Hickling Board, Norfolk (.pdf) and understanding more about the reasons behind this can improve the situation for geese and people.

On our BTO Nunnery Lakes reserve, Thetford, Norfolk we have several fishing lakes and the geese usually choose the lake that has fencing around it. The downside of this decision is that the geese quickly eat all the accessible food and they have to be moved out onto another lake. During this process the geese are ringed, and in 2012 our ringers started to add uniquely coded plastic neck collars to Greylag and Canada Geese as part of the Hickling Broad project.

Canada Goose AEL - taken by Neil Calbrade

Neck collars are a safe marking method for large geese and have been used widely in previous studies on species such as the migratory Pink-footed Goose and White-fronted Goose, allowing individuals to be identified when on water as well as on land. This is particularly important if you are investigating moulting birds, where seeing their legs are an issue. Due to the size of the goose's head the collars actually have quite a lot of room inside to move around.

Greylag FHA bringing up the next generation - taken by Janet Foster

Since 2012, we have had a fantastic response from BTO staff, volunteers and members of the public who have submitted sightings of any geese with neck collars to www.ring.ac, specifying the species, combination on the colour ring, location (ideally with a grid reference) and the date.

The map below shows the sightings that we received between summer 2012 to summer 2014 away from the reserve itself. As you can see they did indeed go into town but also they explored the surrounding waterways and lakes.

What is amazing however, is after the summer of 2014 the geese were spotted much further away from the BTO reserve, see map below. The reason for this are under investigation and some individuals regularly return to the BTO after making these 'unusual' movements. Being able to identify each individual on the water should help us answer some interesting questions like 'do geese moult in the same place every year', 'do they winter in the same locations' and 'why do they move'.

If you do see a neck collared goose, please report it via www.ring.ac and you will receive information on the movements of that particular goose and at the same time increase our understanding of these birds.

13 October 2015

The Goldrush

With all the excitement of the Yellow-browed Warbler influx at the moment, from Shetland to Cornwall, it could be easy to overlook the fact that Goldcrest is also doing very well (see the reporting rates on BirdTrack below). Weighing about 6g, this tiny bird was thought to ride on the backs of Woodcock to our shores (as they arrived at a similar time to Goldcrest) from Scandinavia and the Continent because they wouldn't be able to make it on their own; hence the old name of 'Woodcock pilot'. We now know this is not the case and they can make these massive migrations all on their own.

Ringers all over the country have been catching large numbers of Goldcrest with 150 ringed at Landguard Bird Observatory and 485 ringed at Spurn Bird Observatory over the last three days. This would be a small fraction of the number of birds actually moving through, as the 1,000+ estimate at Gibraltar Bird Observatory on one day can testify.

We have heard that a few have been caught wearing rings from different countries, for example the Mid Lincs Ringing Group caught a Goldcrest ringed in Denmark and a Polish-ringed bird was caught by Tees Ringing Group and Sandwich Bay Bird Observatory caught a Dutch and Latvian ringed Goldcrest. Mike Marsh and his team from Orfordness Nature Reserve managed to catch 109 Goldcrest last Sunday (11 Oct) and one of them was ringed on 6 October at Falsterbo Ringing Station, Sweden! Amazingly, the ring number was TM3052, which, if you put this as a grid reference on an OS 1km map, is only 15km from where the bird was caught. We don't believe this Goldcrest was pre-programmed to go here!

Goldcrest from Sweden. Image of ring taken by several photos of ring merged. By Dave Crawshaw

There are bound to have been more foreign Goldcrest captures over the past few days so feel free to share your stories below in the comments box.

01 October 2015

Phylosc's, Acro's and lovely lady Sylvia

Adam Homer writes:

The numbers of warblers ringed at Stanford Reservoir, Northants has increased significantly over the last 5 years. An annual habitat management plan allows us to control tall scrub which then allows low scrub and vegetation such as Brambles, Hawthorn, Sedge and Phragmites to regenerate. This as we all know is very important habitat for breeding birds such as warblers.

A site that is as far inland from any coastal observatory that you could get, Stanford Ringing Group prides itself on the numbers of warblers caught annually. Over 3,600 warblers were ringed in 2014 and already this year we have ringed nearly 3,800 and we still have October to catch a few more Blackcap and Chiffchaff.

With all these warblers ringed and eventually setting off on their migration we do receive a few reports of birds controlled (caught by another ringer >5km from ringing site) and we occasionally control birds ringed at other sites. Every spring we also retrap some of our returning warblers and to me that is what bird ringing is all about. That a small bird such as a Garden Warbler or Willow Warbler can fly a round trip of 3,000 miles and return to the site it has been breeding at for 10 years in a row is amazing!

Garden Warbler taken by Lee Barber (tail obscured)

One of these record-breakers was once again retrapped this year. It was a Garden Warbler that was ringed as an adult female on 2 July 2005. She then disappeared for two years, returning in 2008 and retrapped every year since. I was on holiday when she returned this year and was caught during two of our CES sessions. On 8 August she became the longest known BTO-ringed Garden Warbler at 10yrs and 37 days, breaking the longevity record for this species by 7 days*.













Garden Warbler












Lesser Whitethroat












Sedge Warbler






Grasshopper Warbler






Reed Warbler






Willow Warbler













As you can see from the table above, the numbers of warblers, particularly Blackcap and Chiffchaff, have increased significantly with Garden Warbler and Lesser Whitethroat also showing a positive upward trend.

*Eds - The longevity records will be updated when all the 2015 data has been sent to the Ringing Scheme and fully processed. This longevity record will then replace the previous longevity record... unless another ringer catches an older bird or Stanford Ringing Group catch this Garden Warbler again a few days older.