26 February 2016

What happened to all the Jays?

Around the UK, Jays haven’t needed to dip into their large cache of acorns much this winter, with the weather being so mild. They will top up their diet with invertebrates and any other meaty treats they can get. This search can lead them to gardens during cold periods and some of these gardens are occupied by BTO ringers.

Jay taken by John Flowerday

Last year our BTO ringers ringed 506 Jays in the Britain & Ireland (c700 is the five year average) and as Jays can live to a maximum of 16 years old, there are a good number of ringed Jays in the wild population. Being very clever birds, they can provide a challenge to ringers to catch them but once caught they deserve respect as they are incredibly powerful birds with very sharp claws and beaks. Once in the ringers hands the birds are ringed, aged, and several measurements taken to record the condition the bird and if any moult or breeding is occurring.

Jay taken by Lee Barber

Thankfully 89% of the reports of ringed Jays come from our ringers by re-catching them, months or even years later. This information is vital to understanding the movements, behaviour and survival of this beautiful bird. Ringed Jays are also found by non-ringers, which usually report them through www.ring.ac website.

Most of these birds are just found dead with no cause of death given, however a large proportion are legally shot/trapped with the aim of reducing their impact on other species nesting attempts. The Jay is not without its own predators however, as 6% of ringed birds reported to the BTO have been taken by a predator. Even the Peregrine is a little partial to the odd Jay as a recent BTO Demog Blog post can testify.

17 February 2016

Making a home for my ‘tweet’ Valentine

Hazel Evans, Nest Box Challenge Organiser writes:

There is still a chill in the air, but at last the days are getting longer and it’s time to think about where our local birds will be nesting this year. Valentine’s Day sees the start of BTO and Jacobi Jayne’s annual ‘National Nest Box Week’. The aim of the week is to encourage and promote the putting up of nest boxes in your local area.

There are numerous reasons why I advocate nest boxes and it can be as easy as you like to take part. The simplest thing you can do is to go to your local garden centre and purchase a suitable Nest Box and put it up in your local area. This may be your garden, but if you are looking further afield, a local park or woodland is also great (as long as you have the land owner's permission). As old trees fall or are cut down, houses are better insulated and gaps under the eaves are sealed, there are fewer natural cavities available for nesting birds so providing artificial nesting locations is extremely valuable.

Robin in an open fronted nest box. Photo by John Cranfield

Once you’ve put up your nest box - or filled your local park with them - monitoring is where the real conservation value lies. Nest boxes give us the opportunity to easily collect data on the breeding success of cavity nesting birds; the same data can require a little more time and skill to collect from natural nest sites. As long as the NRS Code of Conduct is adhered to, we can safely record the progress of nesting attempts by looking inside next boxes to count the number of eggs and chicks and submitting data to the Nest Record Scheme (NRS). There is a very large body of research showing that the contents can be examined without any negative impacts on the outcome of the breeding attempt.

NRS participants monitor nests by inspecting them at intervals and recording the number of eggs laid, the number of chicks hatched and whether chicks fledge successfully. This information is used by the BTO to study the breeding performance of wild birds to help identify when reduced productivity might be causing population declines. People can be concerned about opening up a nest box and checking the contents, but done in the correct way the value of the data collected is huge.

Blue Tit chicks. Photo by Simon Thurgood

By far the most common inhabitants of garden nest boxes are Blue Tits and Great Tits. They have adapted so well to living in our man-made constructions that we receive thousands of nest records for these species every year. These records provide such good national coverage that it is possible to explore the degree to which birds' responses to changes in the environment vary between regions and habitats.

At the other end of the spectrum are Treecreepers, which have so far not adapted to using nest boxes. A nest recorder recently developed a design which mimics the thin, natural cavities preferred by Treecreepers. If you would like to have a go at making one of these boxes then please do let the Nest Record Scheme know whether the box is used or not. If it is used then you can also submit a nest record.

Treecreeper. Photo by John Bowers

A huge variety of nest boxes are available to either buy or to make and you can find information to help you choose an appropriate box on the National Nest Box Week website. When choosing a box it is important to make sure the lid can be lifted or removed to allow you to monitor the contents (or that you can appropriately modify it) and that it is well constructed from a thick enough (and appropriate) material to protect a clutch of very small, very vulnerable chicks! Building a box can also be very rewarding and save a lot of money.

Nest boxes can of course be put up at any time of year but winter is ideal as it provides time for prospecting birds to find the site before the breeding season. Once used, it is a great idea to clean out old nests the following winter to allow for a fresh start in the spring. To comply with legislation, nests can only be cleaned out between 1 August and 31 January.

05 February 2016

Something for Saturday? Second ever ringed Green-winged Teal sighted in Suffolk!

With the wildfowl shooting season either finished or nearly finished (depending on location), our recovery rate of ducks and geese is about to reduce substantially. Birders and ringers, however, will continue to provide much needed data on distribution, longevity and movements.

Green-winged Teal, a scarce visitor to Britain & Ireland from North America, is a good bird to record on your BirdTrack list when out birding. Some individuals will have escaped from captivity, which complicates the situation some what, but that deserves a whole post in itself.

BirdGuides are currently reporting a very interesting Green-winged Teal at Blythburgh, Suffolk which, importantly for the BTO Recoveries Team, is wearing a nasal saddle, and thus has a known history!

Green-winged Teal taken by Barry Yates

The nasal saddle works by only covering the top of the upper mandible, thereby not interfering with feeding or other behaviour. Even though we don't use nasal saddles as part of the BTO Ringing Scheme, this marking method is used to great effect in Portugal, as a previous report of a Lesser Scaup on the Demog Blog shows.

Green-winged Teal taken by Barry Yates

The origin of this bird is unknown. It may have escaped from a European collection or it may be a genuine vagrant. We do know however that it was ringed as a juvenile male at São Jacinto Dunes Nature Reserve, Aveiro, Portugal (40º41’N 08º44’W) on 21/01/2015. Since then it has stayed in the area until at least 10/02/2015 when it was next reported and photographed in Suffolk on 01/02/2016 and is still being reported at time of writing.

There have only been two British or Irish ringed Green-winged Teal in the 107 years of our Ringing Scheme (in 2001 and 2003) and in that time we've only had one report of a foreign-ringed Green-winged Teal being found in Britain & Ireland, which was shot on the Isle of Scilly in 1971. Hopefully the Suffolk bird will continue to be reported to us and our Portuguese colleagues on its journey.

For more information on the work done by our Portuguese colleagues, check out their website, www.pt-ducks.com and if you see this bird feel free to report it to BirdGuides and to us via www.ring.ac (using the ring number J15195 and scheme of Lisbon).