27 May 2016

Elderly Shag strengthens our position in Europe!

Jim Lennon from the Shiants Auk Ringing Group writes:

Ringing seabirds can be mucky and challenging work, especially when you’re ducking under a rock to reach a Shag chick, while keeping an eye out for its protective parents (often the croaking male). However, this is soon forgotten when you receive news of one of them nearly 31 years later!



Shag chick 1227282 was one of a brood of three ringed on the Shiants Isles, Western Isles, on 30 June 1985 by Ms Sam Powell, a trainee ringer from South Wales working with the Shiants Auk Ringing Group. A total of 725 pulli from 377 broods was ringed on the Shiants that year.  Most of the subsequent recoveries were of birds that perished within the first 12 months, a few survived for four or five years and an exceptional bird was found dead after nine years.

But 1227282 outlived them all by a country mile.  For the next 30 years following ringing, it most likely spent its life breeding on the Shiants and in the waters of West Scotland, but we’ll never know for sure as it was never heard of again until John Taynton, a RSPB worker on the Shiants, found it freshly dead on 26 April 2016 i.e. a life span of 30 years 302 days.

video

According to the BTO’s latest longevity list (2014), this makes the Shiants bird the oldest ringed Shag in Britain & Ireland, and also in Europe (see Euring), raising the record by nearly a year.

Note:
The Euring information is not updated as regularly as the BTOs longevity lists because it needs to access all the data from all the Euring ringing schemes and this can take some time.  It currently indicates that a 34 yr old bird from the Shiants is Europe's oldest  Puffin but two just shy of 36 years old and one almost 37 years old, are listed on the BTO longevity records site.

16 May 2016

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.