BBC Wildlife - UK (2020-09)

Te r n : M i k e P o t t s /n a t u r e p l. c o m ; a e r i a l : P e t e r L a n e /A l a m y

TheUK’slargestbreedingcolony

ofArcticternshascollapsed,and

lockdown may be to blame.

BIRDS

Social distancing

Scientistsneedthe

public’shelptofind

outwhyArcticterns

haveabandonedtheir

breedingcolonyonthe

Skerries, Wales(below).

F

ewaspectsofliferemainunaffected

bycoronavirus.InNorthWales,

thestrangeeventsof 2020 arebelieved

to haveledto theabandonmentofthe

UK’slargestArcticternbreedingcolony.

Andscientistswantthepublic’shelpin

workingoutwherethebirdshavegone.

TheSkerries– a groupofisletslying

offAnglesey– arehosteveryyearto

thousandsofArcticterns.Normally,RSPB

wardenswouldbeonsiteto monitor

thepopulationandprotectit from

disturbance.Butnotthisyear.

InlateMay,RachelTaylor,a senior

ecologistwiththeBTO,receivedanemail

fromanRSPBcolleaguewhohadgone

to checkonthecolonyandfoundjusta

handfulofbirds.

“Healsosawa maleperegrinesittingon

thelighthouseashearrived,”saysTaylor.

“Theyhaven’thada peregrineroosting

onthelighthousewhenit’shadwardens

livinginit. Myguessis that,hadthe

wardensbeenthere,theternswouldn’t

have abandoned the island this year.”

Butwhateverthetriggerfortheexodus,

it wasa momentthatTaylorwasprepared

for.Since2012,sheandhercolleagues

havebeenringing 500 chicksa yearon

theislands.“Weknewtherewasalways

a chancethatthecolonywouldcollapse

• it’swhatseabirdcoloniesdo,”she
  says. “Every colony north of the Skerries

hascollapsedat somepointandthen

subsequentlyrecovered.”

Theringedbirdswouldallowtheteam

to establishwherethebirdsgowhen

disasterstrikes.OneSkerriesbirdhas

alreadybeenspottedwitha largechickin

DublinBay.Manyothersseemto have

joineda colonyat Cemlyn,aroundthe

coastfromAnglesey.

About 80 percentofthebirds,though,

arestillunaccountedfor.“There’splenty

wecanlearnfromanyonewho’swilling

to lookthatlittlebitharderat terns’legs,”

saysTaylor.

Thereis alsothequestionofwhether

theywillreturn.“Whena colony

recovers,is it becausethesamebirds

havecomeback?Oris it mostlyyoung

birdsthatdidn’tgothroughthecollapse

event– effectivelya newcolony?The

nextfewyearsaregoingto beabsolutely

fascinating.”StuartBlackman

D I D Y O U

KNOW?

Arcticterns’famous

annualmigration

betweentheArctic

andAntarcticcircles

meanstheyprobably

experiencemore

daylightthananyother

species on the planet.

FINDOUTMORE

BTO Ringing blog:bit.ly/2BLEeNw

24 BBC Wildlife September 2020

WILDNEWS