Bearded Tit © Ray Scally
Bearded Tits continue their association with reedbeds all year round. They switch from their insectivorous summer diet to seed-eating during winter, with changes to their digestive system – elongation of the gut – to cope (Bibby 1981). Continuing their dependence on phragmites, this is their favourite seed, but they also eat other grasses and sedges such as nettles and willow-herbs. During this winter Atlas period, birds were seen, and heard ‘pinging’, in Neston Reedbed during winter 2004/ 05, and in the same habitat at Woolston in 2006/ 07. At Neston there were four birds on 27 November 2004 and one, two or three birds reported on other dates through the whole winter period; at Woolston four birds arrived in mid-October 2006 but after a few days, none was found again until two were present on 18 February 2007.
There have been few wintering records of the species in Cheshire and Wirral. In 1965/ 66 there was substantial immigration to Britain and a few reached the county: one caught at Bidston Moss in February 1966 wore a ring from the Netherlands. From 1971 to 1975 a few birds were also reported in the county, mostly in October, but odd ones during winter. Since then, their scarcity is shown by the few records in Cheshire and Wirral Bird Reports, the only birds in winter being a male at Rostherne on 29 and 30 November 1977, one or two at Neston Reedbed for ten weeks over winter 1992/ 93 and two at Arpley Tip (SJ58T) on 4 February 2001.
Bell (1967) described the birds in 1965/ 66 as the first authenticated records for the county, discounting Coward’s (1910) listing of two pairs shot during the 19th century; Coward himself questioned the records, but largely because ‘the Bearded Titmouse is a species that rarely wanders from its usual haunts’, a statement that is now known to be spectacularly wrong.
One of the features of Bearded Tit ecology is their irruptions. In some autumns at some sites, birds gather and rise high above the reeds, perhaps dropping into a new part of the same reedbed, and on occasion leaving the site and flying long distances. During these movements they tend to travel in pairs: a male and female caught just outside our county boundary at Shotton, Flintshire, by Merseyside Ringing Group in October 1965, bore consecutively numbered Dutch rings. There has been much discussion what drives these irruptions. The species’ extreme output of young can lead to high autumn populations, perhaps putting pressure on food resources and forcing them to move in search of reed seeds. But Bearded Tits showed this behaviour every year since they colonised Leighton Moss, regardless of population or seed availability (Wilson 1993). It is not just one-way traffic: some irrupting birds have returned to the continent, including birds ringed in Flintshire in the 1970s subsequently caught in Germany and the Netherlands.
Numbers may be substantially reduced in severe winters, when reed seeds can become glazed with frost or hidden under snow. The breeding population of Leighton Moss fell following hard winters in 1978/ 79, 1981/ 82 and 1985/ 86 to 1987/ 88, and crashed from 65 pairs in 2000 to 7 pairs in 2001 after high water levels in late 2000 had submerged the reed litter, their favoured feeding site, followed by midwinter snowfall (White et al 2008).
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