Most records received by the committee are processed within a year and published in its annual report in "British Birds". Some records prove problematic, and for some species, it has taken the committee many years to come to a decision. This has particularly been the case where the species or subspecies in question was new to Britain—examples include northern harrier (Britain's first, in Scilly in 1982, accepted in 2007), long-toed stint (Britain's first, in Cornwall in 1970, accepted in 1994), least tern (Britain's first, and to date only record, accepted in 2005, after first occurring in 1983), black lark (Britain's first, from Spurn, Yorkshire in 1984, accepted in 2004 after a second set of notes came to light), Sykes's warbler (the first three records, from 1959, 1977, and 1993, accepted in 2003), Iberian chiffchaff (the first two records, from 1972 and 1992, accepted in 2000), and Hume's leaf warbler (the first 27 records, the earliest from 1966, accepted in 1998). Occasionally, decisions have been delayed due to non-ornithological factors, such as the loss by the Royal Mail of a file on Britain's first lesser short-toed lark.