BBC Wildlife - UK (2019-12)

December 2019 BBC Wildlife 25

WILDNEWS

Clifdennonpareil

CONSERVATIONREPORT

Thismonth,MarkTunmoreshinesthespotlight

on the ‘Holy Grail’ of British moth species.

Whyarenaturalistsexcited about

thismigrantmoth?

It is a spectacularspecieswithquitea

mythicalstatusamongstentomologists

intheUK.Comparedtoothermoth

specieshere,it is huge,witha

wingspanthatcanreach11cmand

blueunderwings– a colourthat is

quiteraretoseeona moth.

Whyisitdiculttoseeone?

Theblueunderwing,asit alsoknown,

becameextinctasa breedingspecies

intheUKthe1960s.Onefamous

site,OrlestoneForestinKent,lostthe

speciesduetothepost-warchanges

inforestryandtheclearingofaspen

andpoplar(thecaterpillar’smain

foodplants)andothertrees.Fordecades

afterwards,it wasonlyrecordedasa

scarceimmigrantmothfromEurope,

withlessthanonesighting a year.

Whathaschanged?

Someoftheseimmigrantmothshave

re-establishedbreedingcoloniesin

southernEnglandinthelastdecade

orso,andrecordsfrom 2018 suggest

thatit is spreadingintoWalesand

theMidlands.Thereis somevery

interestingdatafromWarwickshire

thisyearthatdemonstratesthe

species’ increased range.

Howdoyouknowthemothis

breedingintheUKagain?

CaterpillarshavebeenfoundinSussex,

partofthespecies’formerUKrange,

butonlya fewsofar,becausethey

areverydifficulttofind– theyfeed

nocturnallyandinthetreecanopy.One

thingthattellsusit is residentagainis

repeatedoccurenceoverseveralseasons

atrecolonisedsites,anditsappearance

inmultiplenumbersat someofthose

samesites,manyinland.Thisis not the

patternofa migrantspecies.

Cananythingbedonetoimprove

itsbreedingsuccess?

I suspectfromthetrendweareseeing

thatit doesn’tactuallyneedmuch

helpfromus.However,plantingtheir

caterpillarfoodplantsmayhelp,as

wouldretainingwoodlandandlooking

aftertrees,whichweshouldbedoing

anyway.Withsomanywidespread

mothspeciesindeclineit is niceto

havea goodnewsstoryforonceabout

anenigmaticmoththat is doing well.

Megan Shersby

Crypticcoloration

reduces visibility

PLANTS

M

anyplantsclosetheirflowers

atnightinSouthAfrica’s

Namaqualandsemi-desertregion.This

behaviouris especiallycommonin

vibrant,ephemeralspeciesthatbriefly

carpetthelandscapefollowingspring

rains.Butthenightis alsoabuzzwith

pollinatinginsects,sowhydothe

flowersclose-downandmissout?

StudiesbyJureneKempandAllanEllis

ofStellenboschUniversity,revealthatit’s

gotnothingtodowiththenightitself:by

closingat night,flowersarealsoclosed

intheearlymorningandlateafternoon.

“Thistimingis keybecausethesearethe

peakactivityperiodsforflower-eating

animalssuchasantelopeandtortoises,”

explainsEllis.

Oddly,petalundersidesareoftengreen.

But,whenKempandElliscomparedthe

lightspectrareflectedbypetal-undersides

withwavelengthsto whichpotential

herbivoresaremostandleastsensitive,

theyfoundtheycouldnotseethegreen.

Consequently,byclosing,flowers

effectivelybecomeinvisibleto flower-

eaters.So,byopeninglater,inthefew

hoursbeforeandaftermidday,theplants

avoidpredationfromhungryherbivores

thatseekshadebutareavailableto insects

thatdon’tseemto mindtheheat.

“Arctothecacalendulaand

Dimorphothecapluvialishighlightthe

diverseevolutionaryforcesshaping

angiospermflower form,” says Ellis.

AdrianBarnett

FINDOUTMORE

Functional Ecologybit.ly/2IGZ690

MARKTUNMOREiseditorofAtropos and

founderofMothNight.

Moth: F. Hecker/blickwinkel/Alamy; flower: saulgranda/Getty

REDLIST

STATUS:

NOT LISTED

FINDOUTMORE

Moth Night:mothnight.info

Capedandelions

candeter

herbivores.

ThenameClifden

nonpareilmeans

‘beyond compare’.