This summer the ABO were again able deliver the annual seabird ringing program. The only significant change was to use Dave Venn and his boat ‘Avanti’ to take our research teams and equipment to and from the various island throughout the seabird ringing season. The ABO would like to thank Dave for his excellent work transporting and landing us all safely on several occasions. Alderney tides can be challenging and a local experienced expert seaman is an entirely essential ingredient for these trips.
Storm Petrels have been ringed on Burhou island off Alderney island in the Channel Isles since 1962. This recording effort has historically been completed by the Channel Island Bird Ringing Scheme (CIBRS) members who’s bird ringers have been until the launch of the ABO in 2016 had come extensively from Guernsey. In recent years some of Alderneys islets have become part of the national RAMSAR scheme recognising the importance of Burhou in terms of its conservation and especially its various nesting seabird colonies. Since the ABO took the helm of the seabird ringing effort we have sort to standardise the work undertaken, consistency in the ringing methods and strategy produces annual data that allows us to more acurately understand and estimate the size of the breeding population of our Petrel colony along with insights into the fluctuations in the fortunes of this species over periods of years.
Burhou Island NW of Alderney
There is opportunity to land a bird ringing team of up to nine researchers. The ABO progress and experience has enabled us to include not only Channel Ilsands ringers but also to UK ringers for these trips, 4 UK based bird ringers joined us for this years group. We spend 2 nights on Burhou island on which there is an adequate stone hut with gas cooking facilities and bunks for sleeping, though tents are an option so long as they are within the walled garden area surrounding the hut ( and with permission from the Alderney harbour master). Getting to Burhou, 1.4 miles NW of Alderney, involves a 10-15 minute boat journey on a fishing charter vessel, from this we transfer a couple at a time to a smaller rib-type dinghy boat taking us and our equipment to shore.
First job is to move the equipment the short walk to the Burhou hut, then its on to set up the nets at the SE corner of the island. Here specified locations for net rides have been established. This years team soon had everything ready for our return in a couple of hours to open the nets at dusk. As we set up the nets and ringing base we were treated to great views of a Large Tortoiseshell butterfly. Two 18m nets can keep an experienced team of ringers busy for several hours, so it is important to keep the nets separate so that one or both can be closed should the numbers of birds exceed the capability of the team.
Setting up the nets soon after landing on Burhou island, in the background the SW corner of Alderney and Les Etacs Gannet colony
We do not deploy tapes of any kind, as darkness falls the birds are soon active and abundant. Walky-talky radios are deployed between the ringers and the ringing base to ensure resources are best deployed. Close attention is paid to the birds (and bird ringers) ensuring welfare and safety is maintained throughout. As with most forms of bird ringing, weather conditions play a major role, the nets are in fairly exposed positions so wind speeds need to be fairly low combined with no rain. Sophisticated weather apps now allow us to observe weather patterns in advance of the ringing sessions and this year conditions for our first night looked very promising against a potential second night predicting much stronger winds. In consideration of disturbance to the colony, the 2nd nights effort should it go ahead would take us to the NW corner of the island.
After a meal back at the hut we headed out and opened the nets as the light began to fall away at 9.40pm. Whilst our group waited in anticipation of the privilege of working with these wonderful little birds sometimes referred to as the Swallows of the sea, we were treated to a magnificent fly-by from a pair of Peregrines and their recently fledged chick.
Our first customer in the nets was a Rock Pipit. Burhou has a very strong breeding population of Rock Pipits, there is excellent potential here to obtain some important baseline data on this little studied species, something we hope to progress with next year. Soon after 10pm the Petrels were active and the team worked diligently through into the early hours packing up the nets towards 4am. Conditions had remained favourable and a combination of tired and exhilarated ringers/researchers returned to the hut to sleep having processed over 360 individual Storm Petrels.
Most of the team had surfaced by early afternoon and we then turned our attention to building on the work completed July this year; the annual program of colour ringing the Lesser black-backed Gull colony. The primary work on these Gulls is undertaken annually around the 9th July and we had completed this task this year returning 144 new ringed birds. This 2nd effort effectively mops up birds too young to be ringed during the earlier visit along with those that had been overlooked. As the afternoon temperature dropped we moved through the colony that consisted mainly of well grown fledged and flying 2019 hatch birds. We still managed to colour ring another 20 Lesser black backed Gulls along with 2 Great black backed and 1 Herring Gull.
The forecast early evening was of increasing winds and the decision was made to pull the team off the island ahead of the inclement weather, and head back to the bird observatory.
Despite our program being cut short the nominate site for data gathering was amply covered. We processed 360 birds during a single session and this included an impressive 8 foreign controls (birds originally ringed in a country other than Alderney) usually we see several French ringed birds but this time around all were UK ringed birds. The histories of these 8 individuals have been extremely interesting. 6 of the birds were ringed along the SW coast of the UK between Portland Bill Dorset and Porthgwara Corwall, but one bird was originally ringed as pullus (a chick in the nest) in the nest on Lundy island. A further bird was originally ringed in NE England in Tyne & Wear. We had over 20 local retraps that included a bird first ringed on Burhou in July 2000!
Further data and information and will be available to ABO members in the ABO annual report.
Above (left) Sexing of Storm Petrel looking at the extent of the white feathering on the underwing, and (right) ageing looking at feather wear & primary feather shape.
These unusual and exciting annual research trips are open to UK ringers, whilst experienced ringers are required for these teams the door is also open to one or two Trainee ringers each year. If you are interested in joining us for the 2020 seabird season contact John Horton the ABO Warden on TEL 07815 549191 or email abo.warden@outlook.com
Thanks to this years Burhou team who did a sterling and professional job gathering the data and to Carl Hunter Roach for providing photos included here.