SPECIES UP­DATE

Bird Watching (UK) - - Contents -

THETFORD FOR­EST OC­CU­PIES much of the land­scape near my home in Nor­folk. It is a patch­work of habi­tats, with the dark quiet stands of dense com­mer­cial conifers in­ter­spersed with open ar­eas, colonised with grasses, heather and bracken. In early spring, these clear­ings ring with the songs of Wood Larks, and, in April, their smaller coun­ter­parts, Tree Pip­its, ar­rive from their win­ter­ing grounds in Africa. A Tree Pipit de­liv­er­ing a parachut­ing song flight to a still clear­ing, un­der a hot June sky is, for me, one of the sounds of the for­est. Thetford For­est pro­vides per­fect habi­tat for breed­ing Tree Pip­its, which need open ar­eas dot­ted with tall perches, such as heath­land with trees, or young plan­ta­tions. How­ever, the dis­tri­bu­tion maps in the 2007-11 Bird At­las, show that while there are good num­bers of Tree Pip­its in Thetford For­est, this Nor­folk pop­u­la­tion is be­com­ing in­creas­ingly iso­lated. Most Tree Pip­its are found in wood­lands in Scot­land, Wales and north­ern England, with other pop­u­la­tions in scrubby down­land in south­ern England. How­ever, they are now ab­sent from much of east­ern and cen­tral England. BTO mon­i­tor­ing data show that Tree Pip­its de­clined dra­mat­i­cally be­tween the late 80s and the mid-90s, co­in­cid­ing with their loss from cen­tral and south east­ern England, par­tic­u­larly wood­land and com­mon land. The Breed­ing Bird Sur­vey mon­i­tor­ing scheme started in 1994, and these an­nual counts by vol­un­teer bird­watch­ers show that Tree Pip­its have con­tin­ued to de­cline, mov­ing from the green list to the am­ber list in 2002, and then to the red list in 2009, in­di­cat­ing the great­est con­ser­va­tion con­cern. How­ever, the re­sults from these sur­vey sites vary markedly across the coun­try, and the na­tional de­cline is driven by the ex­treme losses in England, while Tree Pipit num­bers in Scot­land have ac­tu­ally more than dou­bled over the past 20 years. There is plenty of ev­i­dence avail­able link­ing this de­cline of Tree Pip­its in England with the chang­ing struc­ture of our forests. His­tor­i­cally, wood was reg­u­larly har­vested from many of our low­land wood­lands through cop­pic­ing, and this man­age­ment kept the struc­ture open, per­fect for Tree Pip­its. How­ever, by the mid­dle of the 20th RISE AND FALL The song of the Tree Pipit is heard less of­ten in England in re­cent years, but more of­ten in Scot­land The BTO runs vol­un­teer sur­veys to mon­i­tor and ex­plain changes in bird pop­u­la­tions. To find out more about the Water­ways Breed­ing Bird Sur­vey visit Cen­tury cop­pic­ing was in rapid de­cline, for­est canopies closed over, and our wood­lands be­came un­suit­able. In Scot­land, the in­crease of com­mer­cial conifer forestry may have ben­e­fited this species, though only where the forests are reg­u­larly har­vested to pro­duce the clear­fell ar­eas and young plan­ta­tions that they pre­fer. Re­search on tar­geted man­age­ment has shown that pro­vid­ing large blocks of their favoured habi­tats, and re­tain­ing some ma­ture trees as song posts, can suc­cess­fully in­crease Tree Pipit num­bers in com­mer­cial forests. While Tree Pip­its can be found in our wood­lands dur­ing the spring and sum­mer, by Septem­ber they are on the move, on their way to the hu­mid forests south of the Sa­hara. There are clearly sig­nif­i­cant is­sues with the habi­tat in, or on the way to, these ar­eas, since all of our hu­mid-zone mi­grants are show­ing sim­i­lar de­clines. We don’t know ex­actly where British Tree Pip­its win­ter. How­ever, if we want to know the full story about what is caus­ing our bird pop­u­la­tions to de­cline, it’s clear that the ques­tions about what is hap­pen­ing be­yond our shores are the next big ones to an­swer.

Kate Risely is the British Trust for Or­nithol­ogy’s Gar­den Birdwatch Or­gan­iser

Most Tree Pip­its are found in wood­lands in Scot­land, Wales and north­ern England, with other pop­u­la­tions in scrubby down­land in south­ern England

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