Alderney Bird Observatory seabird and shorebird ringing return for 2020
PART 2. Shorebirds & Terns
By ABO Warden & Alderney Island Bird Recorder John Horton
Fewer seabird ringing trips to the offshore colonies did present the opportunity to channel resources at the breeding shorebirds, especially those within the ABO dedicated census area. Ringed Plovers bred successfully both inside and outside the RAMSAR site, four chicks were ringed at Platte Saline beach on 22 June.
Ringed Plover chick – north west coast
Our field observations noted successful breeding of this species at three other sites. Excitingly, images taken in the field showed that one breeding bird (ring on left leg) was ringed as a chick here in 2019. Our ringing efforts provided the first evidence confirming the retention of individuals hatched on Alderney.
Ringed Plover NE coast.
We had by far our best year monitoring Oystercatcher chicks, ringing 13 birds within the dedicated ABO daily census recording area. Further breeding pairs were located around the remainder of our coastline totting up an impressive 22 pairs on mainland Alderney. It is likely that the number of breeding pairs is in excess of 30 including the offshore islets. Several Oystercatcher nest sites were inaccessible, or chicks could not be located during the window of opportunity to ring them.
Oystercatcher chick NE coast.
A gregarious nester, the fortunes of the Common Tern colony continue to ebb and flow. The ABO continued to work with the States of Alderney and Alderney Wildlife Trust to bring about the return of this species as a regular breeding bird on Alderney’s north east coast. The programme of eradicating rats at the Terns favoured breeding location managed by the ABO in 2016 went on to witness the breeding and successful fledging of Common Terns in Alderney in 2018, this after an absence of many years. It remains one of our most rewarding projects and notable successes.
In 2020 the colony moved to utilise Fort Houmet Herbe. This location is tidal, and the Fort privately owned. Frustratingly, this meant we were unable to determine numbers of nests accurately or ring any tern chicks this year. On the plus side the forces of nature rendered the fort tidally marooned each day greatly reducing the potential of disturbance.
Field observations were obtained from the adjacent footpath from where we were able to record eight chicks. Several other adults carrying fish were observed regularly dropping into the fort apparently to feed chicks out of our view. A high count of 36 adult birds were present at the colony at the peak of the breeding season and at least 12 birds successfully fledged. Having had a relatively good breeding season it will be extremely interesting to see if the Terns choose the same location in 2021.
The first of this spring ‘prospecting’ Common Terns (left hand bird wearing a ring) settling on Fort Les Hommeaux Florains 18th May.
There is little doubt that the banning of dogs and horses on almost all of Alderney’s beaches between June and September annually has an incredibly positive impact on the breeding success of our shorebirds during this most critical period. We were delighted to complete our most comprehensive study of the coastal breeding birds within the census area monitoring 10 species this year. Details of this study will be available in our 2020 annual report.
Having developed close ties with the wildlife and ornithological organisations of our neighbouring Bailiwick Islands (and Isle of Man) I am aware that they would like to emulate our progress in minimising disturbance to nesting shorebirds.