The Barra Sparra

Ian Thompson, Yvonne Benting and Bill Neill write:

We have been colour ringing House Sparrows here in Askernish, South Uist as part of the BTO’s RAS scheme for the past seven years. Because House Sparrows have a reputation as being difficult to catch and retrap, the use of colour rings was a conscious decision on our part. This enabled us to identify the birds individually in the field, but more importantly, it allowed our neighbour to participate in the project by recording the birds that visited his garden.

Female House Sparrow. Photo by Ian Thompson

While the House Sparrow RAS season runs from April – August, we observe and record our birds all year round. Again, the use of colour rings has allowed us an insight into their movements around our islands and this has surprised us as to how far ranging they can be. We now receive regular updates from several observers around the islands, and the birds have been recorded as far north as Balranald, North Uist (46 km) and as far south as South Glendale, South Uist (11 km).

To date, all these movements have been within what is known as “the long islands”, which are all joined by causeways, and none have yet travelled over water. With two birders having recently moved to the Isle of Barra, we began hoping that one of our birds might turn up there.

Recently we had been seeing three unringed birds (two male, one female) amongst our regulars and favourable weather gave us the opportunity to try to trap them. Over a period of two weeks, we trapped and ringed 12 new birds (seven female, five male) and we still had four unringed birds (two male two female).

But, amongst the 12 was a bird we hadn't originally ringed (control)!

After a few enquiries, we found that the bird had been ringed by Mark Oksien earlier this year on 18 September at Garrygall, Barra (see map below). Not only has this bird moved 26 km, this is the first time we have recorded a House Sparrow crossing water to other islands. After such a long wait, this was not the way it was meant to happen. We expected that it would be one of our colour ringed birds turning up in Barra, not the other way round.

As Bruce Taylor, one of the Barra birders commented  “the way Calmac has operated of late, we can rule out ship assistance”.

This House Sparrow has since become known as the “Barra Sparra”.

Note:- None of the 12 Sparrows that were ringed have been seen since.

We had news yesterday (27 Nov 2017) of another sparrow making the reverse trip! A bird I ringed on 7 Nov 2017 (O54) turned up in Bruce Taylor’s garden yesterday (one of the birders on Barra) at Brevig, Barra. It would seem that we have quite a movement of sparrows here in this bout of hard weather.

House Sparrow O54. Photo by Bruce Taylor

Information and regular updates on our project and sightings of our birds can be found on the Outer Hebrides Birds website or by following this link.

RAS: Renewing Acquaintances in Spring

For almost 20 years, the Retrapping Adults for Survival (RAS) scheme has used standardised bird ringing as a tool to monitor adult survival rates of species not frequently caught at Constant Effort Sites. The results are used to generate annual survival estimates which help us to understand more about the contribution changes in the probability of mortality make to population trends recorded by surveys such as the BTO/JNCC/RSPB Breeding Bird Survey (BBS). Birds are generally faithful to breeding sites between years, so RAS methodology aims to re-encounter as high a proportion of returning adults as possible each year; for some species, this task can be made significantly easier by fitting colour-marks, allowing birds to be individually identified without capture. 

The initial uptake for RAS was fantastic, with 75 datasets received in 1998. Since then, the number of projects has risen steadily and in 2015, a tremendous 190 datasets were received. We now have over 200 active projects studying 59 different species. 60% of projects focus on one of the 24 target species, as outlined in the Demographic Targeting Strategy, with a further 11% of projects targeting seabirds (which don’t yet feature in the target species list).

The most frequently studied species are still House Sparrow and Pied Flycatcher, which are the focus of 23 projects each. In third place is Sand Martin, which is studied by 15 RAS ringers, often at artificial banks such as the one at Rutland Water which enable breeding success to be monitored concurrently. Following closely behind is Starling (14 projects), a species that has become increasingly popular in recent years. Prior to 2013, there were only two RAS projects on this red-listed species so the additional data now being produced are very welcome! Not quite making double figures are Dipper and Reed Warbler, which are the species of choice for nine RAS ringers each. Perhaps surprisingly, there are still fewer RAS projects than we might expect on some generally well-ringed species, such as Swallow and Tree Sparrow (six projects each) – we would love to hear from anyone interested in taking up the challenge of a RAS on these species.

This colour-ringed Starling is part of a RAS population in Lancashire. Photo by Peter Alker.

The fruits of RAS ringers’ labours have just been published. The full suite of national RAS results for 2015 is now available and includes a trend for Tawny Owl, which we have been able to produce for the first time following the submission of some valuable historical data. RAS works particularly well for longer-lived species, such as owls and seabirds. A number of ringers with existing, long-term ringing projects have recently registered for RAS, instantly enabling us to produce survival trends for their studies.

A trend for Tawny Owl is available for the first time. Photo by Ruth Walker.

 

RAS survival trends for 12 species (Little Owl, Jackdaw, Sand Martin, Swallow, House Martin, Dipper, Pied Flycatcher, Stonechat, Wheatear, House Sparrow, Linnet and Siskin) are also included in the annually produced BirdTrends report, which provides a range of information about population trends and their potential drivers for over 100 breeding bird species.

We are very grateful to all our fabulous RAS ringers who put so much time and effort into generating this incredibly valuable data. Anybody considering starting a RAS or wondering whether a current project could be suitable for RAS is encouraged to contact the RAS organiser.

August recoveries update

"I found a bird's leg in my sock!"

Over the years there have been some odd finding places for bird rings, including at the bottom of the North Sea, a Red Kite in the engine of a plane and a Mute Swan killed by a Lion at Chester Zoo. This month's winner is quoted, "I put my sock on this morning and felt something sharp dig into my foot. Upon further inspection, and to my disbelief, I found a tiny metal ring attached to a dismembered birds leg!". We are waiting for the ringing details on this one, but the leg was small, perhaps Wren or Goldcrest sized.

With the start of the shooting season, reports of ringed wildfowl are increasing. Last month we had 2 interesting reports of Pochard that were shot in Samarskaya Oblast, Russia (3287km) and Shaturskiy Rayon (2600km), Russia, after being ringed at Welney WWT, Norfolk in 2007 and 2008 (yellow pins).

Passerines played their part last month with Common Redpoll L656176 (blue pin) being ringed by Spurn Bird Observatory on the 16th of October 2010 to be then controlled by a ringer in Finnvik, Tromso, Norway on 5th August 2011 (2035km in 293 days).

View August update in a larger map

We don't normally get many reports of dogs attacking birds (apart from the odd swan) but House Sparrow TS36895 was very unlucky to be killed by a Jack Russell while flying past a bird table! Cats are the normal cause of death in gardens, partly because they frequently bring the ringed bird to the owner for reporting. Out of the 32 'caused by predator' reports during August, 22 of these were from cats, with the next highest being five deaths from birds of prey.