Spring 2021 saw the relaunch of the Cornwall Swift Breeding Survey which was postponed from 2020 when, due to Covid-19, it was not feasible to ask people to go out surveying Swifts.
The BTO and Cornwall Birds advertised 60 tetrads (2x2km squares) to be searched for evidence of breeding Swifts. These were areas where ‘Confirmed Breeding’ (20 tetrads) and ‘Probable breeding’ (40 tetrads) were recorded in the CBWPS Atlas 2001-2009 as illustrated in the map below. The map also shows the 140 tetrads where ‘Possible Breeding’ was recorded and 302 of the smallest dots where birds were recorded as being present.
In the 2001-2009 Atlas the 20 squares proven for Swift breeding were as follows: St Just, St Buryan, Newlyn, St Ives, Helston east, Fal south, Fal east, Truro west, Truro, Gear Sands, St Newlyn east, Quintrell Downs, Tregatillian, Mevagissey, Tregooden, Trebarwith Strand, Delabole, Camelford, St Dominick and Calstock
The 2021 survey methodology was drawn from the Swift Conservation website and consisted of two visits either between dawn up to two hours later, or between the last two hours before dusk looking for low flying parties of screaming birds. If birds matching these criteria were found, the area was then to be searched for nests.
At the time of this survey, beginning in the summer of 2021, the Swift carried a Conservation Status of Amber. Unfortunately, six months later, after a decline of 58% in the last 25 years, the Swift was added to the Red List. The picture in Cornwall appears to be similar. From the tetrads that were surveyed, only 11 reports came back with positive results which are listed below. From these 11 squares only three areas continue to have proven Swift breeding from the last Atlas. These were Helston, Falmouth and Calstock although three areas were confirmed for breeding that were only listed as Probable during 2001-2009. These were: Crowlas, Porthleven and Trewen Fm (Bodmin Moor).
2021 Survey Results
St Buryan: Swifts were reported arriving and breeding was suspected but the exact location wasn’t identified.
Crowlas: The furthest west for Confirmed Breeding where the Methodist church had a party of eight screaming birds with a minimum of 6 nests reported. This sets the tone for the rest of the report in that the buildings being used were mainly pre-1919.
Helston: Two tetrads were covered with three nests reported again in buildings of pre-1919 build.
Porthleven: Nine screaming birds were found and a single nest positively identified at one site and near the Methodist church a further six screaming birds were found but no nests. Both sites were pre-1919 buildings.
Falmouth: Two tetrads with one producing a good number of nest sites i.e. boxes and holes under eaves and a detailed report from the observer. What is also encouraging was an area of new builds found to be containing 18 Swift bricks. Unfortunately none were found to be occupied but even the presence of these bricks is a positive step forward to the conservation of Swifts.
Truro: Two tetrads were covered, however the results were different. No nests were reported in Truro, just parties of six and four screaming birds around buildings of pre-1919 origin.
Trewen Fm, Bodmin Moor: The observer reported that eight birds had been present but no nesting activity was found.
St Germans: two sites were positively identified in and around St Germans with a minimum of five nests but in reality probably more. Access restrictions prevent a full count from being undertaken. A third site potentially holds them but could not be investigated fully due to potential negative conflicts with the recreational users of the site, evidenced from past history.
Calstock: Up to eight birds seen with two entering under the eaves in a pre-1919 building.
From the records received Swifts clearly have a liking for older buildings, but renovation and demolition are making these nesting sites increasingly scarce. Under the eaves is certainly the preferred site for nest boxes which can and may be occupied. Sometimes the additional playing of Swift calls on MP3 players can yield positive results.
Outside of the advertised survey areas, evidence of Swifts breeding was as follows:
Old de Lank Farmhouse: A long standing association with Swifts was reported. At the time of checking at least 20 birds were present.
Liskeard: Breeding was not proven but 17+ birds were observed low flying around Aldi Supermarket.
Castle Dewey, Warleggan: Suspected breeding with up to eight birds present.
In addition some observers submitted records using the Swift Mapper App which can be found at https://www.swiftmapper.org.uk. Through the Swift Mapper website we also know that in 2021, Swifts bred in St Just, Penzance, Redruth, Carnon Downs, Truro, Gloweth, Par, Newquay, St Eval (young seen), St Kew, Kilkhampton, Fowey, Looe, St Germans and Torpoint.
If we take a closer look at Swift Mapper for Cornwall from 2010 to the present day we can see that the Falmouth – Truro area appears to be the best area for Swifts, at least for reporting breeding Swifts. Whilst the number on the Tamar looks high, the majority of these are in Devon. 153 occupied nests have been recorded on Swift Mapper in total which, when you consider the number of screaming parties that have been recorded, isn’t many. Is this because people are happy to record their sightings of screaming birds but are unable to search afterwards for that highest level of breeding status – finding the nests.
The BTO Community also uploaded 386 records of Swifts onto BirdTrack from 55 10km squares. The earliest records in 2021 were both courtesy of BirdGuides at Porthgwarra and Penryn on the 22nd April and the latest record was on 9th Sept at Stithians. The highest count on BirdTrack was of a feeding flock of approximately 60 birds at Nanjizal on 8th June. The map shows the Reporting Rate for Swift in Cornwall during 2021 (Green line) and for comparison the historical average (no words needed). One confirmed breeding record on BirdTrack was of 12 birds screaming over Wadebridge before entering nest sites.
The Wider Picture
Information about Swifts, their migration and other challenges continues to come to light. In 2010 the BTO began a six year program of fitting GPS tags to Swifts. The map below shows the migration of bird A320 from the tagging point in Fowlmere, Cambridgeshire to central and east Africa. A320 threw up three surprise pieces of information that demonstrate that Swifts cover the whole of the known wintering range rather than a specific area. Autumn migration takes it through countries that make up the Atlantic seaboard of northern Africa and finally there is an important spring fuelling stop in the skies above Liberia. Previously it was thought that, because they feed on the wing, Swifts simply make their way more slowly, but directly, feeding as they go, without the need for extended stop overs. This is completely new information and pinpoints a focal area for future research.
The Swift also lives up to its name with one tagged bird having fed up in Liberia for 15 days then returned from West Africa to the UK covering the 5,000km journey in just five days. A similar program of tagging exists in Beijing where their birds also winter in Africa.
There is no doubt that the Swift is in trouble. Many regions have set up their own Swift Action Plans and in Cornwall the BTO and Cornwall Birds have made a start. Rome wasn’t built in a day and it takes time and effort to motivate people. However, if we don’t act, how long has the Swift got left as a breeding species in Cornwall? We need to get more people involved in 2022 so if you’ve got a few hours to spare please get surveying.
In compiling this report I would like to thank those people who volunteered, those who have uploaded records onto BirdTrack and Swift Mapper and to Bruce Taggart for commenting on the draft.
The Swift is a truly remarkable bird so in the next edition of Palores we’ll take a closer look at the ecology of the Swift and at some nest box designs you could make at home for your house or any suitable area you happen to know of.
Simon Taylor is the BTO Regional Representative for Cornwall