Blue Tit photographed at Bas Capelles [BAS] on 4/10/2021 Photo: © Rod Ferbrache (visit site)

Neither Dobson and Smith found the Blue Tit common in Guernsey. Smith described it as 'by no means numerous' and Dobson found it 'distinctly uncommon' in the spring of 1946. It was also scarce in Sark and Alderney. E.D. Marquand spent four years in Alderney at the turn of the century and did not see a single bird. The reasons for its scarcity are unknown but the lack of mature woodland in the Bailiwick at this time may have been an important factor.

Blue Tits are now a common resident in Guernsey, Herm and Jethou, Sark and Alderney. During the 1989-91 GBBS, Blue Tits were found breeding in all 26 squares. Outside the breeding season, birds concentrate around gardens and ringing has shown over 100 individuals can regularly visit one site over the course of a winter.

Passage of Blue Tits through the islands is hard to prove. One bird, ringed at the Dell Nursery on 7 September 1988, was recovered at St Alban's Head, Dorset on 25 October in the same year. There are also several Guernsey/Sark and Jersey/Guernsey movements and birds have been seen on offshore islands such as Burhou where they would not normally be resident. These observations could either be indivative of true migration or just post-juvenile dispersal but it does show that birds do move away from the islands.

Blue Tits are associated with large irruptions. A large tit irruption took place in 1957 and the population in Guernsey was increased 'about ten times' in the first few weeks of October. Numbers gradually fell away during the winter. No large tit irruptions have been observed recently although passage has been noted in several years including 1983.