Species Up­date

It’s pos­i­tive news for the Bearded Tit, whose num­bers look set to in­crease over the com­ing years, says Kate

Bird Watching (UK) - - Contents - KATE RISELY’S Kate Risely is the Bri­tish Trust for Or­nithol­ogy’s Gar­den Bird­watch Or­gan­iser

The Bearded Tit will con­tinue to do well in the UK given the right con­di­tions

BEARDED TITS ARE not mem­bers of the tit fam­ily, and the males’ eye-catch­ing fa­cial mark­ings look more like or­nate mous­taches than a beard, so per­haps they would be bet­ter named ‘Mous­ta­chioed Par­rot­bills’. While this is un­likely to catch on, their other names ‘Bearded Reedlings’ or just ‘Reedlings’ also fit the bill pretty well, since these are spe­cial­ist birds of reedbeds. Fam­ily groups can be de­tected by their ‘ping­ing’ calls, but they can of­ten go un­seen, un­less they de­cide to feed on seed heads or fly above the reeds. Their global dis­tri­bu­tion stretches from Europe across cen­tral Asia and Kaza­khstan to Mon­go­lia and China, and it is in eastern ar­eas where other species of par­rot­bill are found. Their Euro­pean pop­u­la­tions are ex­tremely patchy and frag­mented, as they only oc­cur in large reedbeds, and they don’t oc­cupy all ar­eas of suit­able habi­tat. It may be that they are also sparsely dis­trib­uted through­out eastern ar­eas of their range, but these pop­u­la­tions are not as well studied. They are not mi­grants in the tra­di­tional sense of the word, but they will dis­perse to dif­fer­ent sites in the au­tumn and win­ter, par­tic­u­larly if they have had a good breed­ing sea­son and pro­duced large num­bers of young. Some birds will make a re­turn mi­gra­tion in spring, but oth­ers will stay to breed at dif­fer­ent sites, so they are of­ten quick to colonise new ar­eas. This pi­o­neer­ing spirit is helped by very strong pair bonds, pos­si­bly even forged when birds are still ju­ve­niles just a few months old, and pairs are known to stay to­gether even when trav­el­ling be­tween sites for win­ter. At all times of year they live in reedbeds, and de­pend on the re­sources they find there. They feed ex­clu­sively on in­sects dur­ing the breed­ing sea­son, but in the win­ter they switch to feed­ing on reed seeds. This switch is ac­com­pa­nied by a re­mark­able change in their bod­ies, as their gut en­larges and hard­ens to cope with the change in diet. They in­gest grit, up to 600 tiny frag­ments, which are held in their stom­achs to help break down seeds. In spring, they ex­crete the grit and their di­ges­tive sys­tems re­turn to nor­mal. This re­liance on seeds means they suf­fer in hard win­ters, when snow­fall smoth­ers the reeds, but they are pro­lific breed­ers, pro­duc­ing up to three broods of young in a sea­son, and can quickly BEARDED TITS Warmer win­ters and the cor­rect habi­tat will help this bird thrive bounce back given favourable con­di­tions. Around the early 19th Cen­tury, Bearded Tits were found in suit­able habi­tats across much of south-eastern Eng­land, but fol­low­ing drainage and agri­cul­tural in­ten­si­fi­ca­tion their num­bers dropped. They were nearly wiped out by the hard win­ter of 1946–47. It has been sug­gested that the to­tal Euro­pean pop­u­la­tion may have fallen to just a few hun­dred pairs at this time. Re­cov­ery, how­ever, was rapid, and was boosted by the mas­sive reedbeds cre­ated as part of land recla­ma­tion in the Nether­lands in the 1950s. These cre­ated per­fect con­di­tions for thou­sands of Bearded Tits, and im­mi­gra­tion from this pop­u­la­tion is thought to have driven the sub­se­quent Bri­tish in­crease. Dur­ing the 1968–72 breed­ing bird at­las they were recorded in coastal ar­eas in East Anglia and a few sites along the south coast and in­land. By the time of the Bird At­las 2007–11 these eastern ar­eas had been con­sol­i­dated, and breed­ing birds had spread to the Tay reedbeds in Scot­land as well as sites in north-west and south-west Eng­land, and North Wales. The to­tal pop­u­la­tion of Bearded Tits was es­ti­mated at 718 pairs in 2010, but this is thought to be an un­der-es­ti­mate, and, bar­ring habi­tat loss or ex­treme snow­fall, their num­bers are ex­pected to con­tinue to in­crease.

Pairs are known to stay to­gether even when trav­el­ling be­tween sites for win­ter

The BTO runs vol­un­teer sur­veys to mon­i­tor and ex­plain changes in bird pop­u­la­tions, in­clud­ing the Bird­track. To find out more visit bto.org/ vol­un­teer-sur­veys or email info@bto.org

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