BBC Wildlife - UK 2020-07)

Clockwise from top left: Alex Mustard/NPL; David Woodfall/NPL; Suzi Eszterhas/Minden/FLPA; Stephen Da

ton/NPL;

Je

ger

Herder/M

nden/FLPA;

Aex

Hyde/NPL;

Andrew

Newman/A

amy;

Dav

dSpears/Getty

3 questionson

1

CANYOU

TELLTHEIR

LARVAEAPART?

Theaquaticlarvae,or

nymphs,ofdragonflies

anddamselflieslook

similarat firstglance.

However,theformerare

larger.Lookcloselyat their

tail.Damselflynymphsendinthreeflat,

leaf-shapedstructures– thesearegillsthat

absorboxygendissolvedinthewaterand

releasecarbondioxide.Dragonflynymphs

endinfiveshortspines.Theirgillsare

internal– theyobtainoxygenbypumping

waterinandoutoftheirabdomen.

2

HOWLONGDO

THEYLIVE?

Bigspecies,suchasthe

emperor,golden-ringedand

hawkerdragonflies,usually

spendtwoyearsasnymphs.In

smallerdragonfliesanddamselflies,the

larvalstagenormallylastsa year.But

developmenttimevariesaccordingto

thelocalclimate,latitude,altitudeand

pondsize.Asthenymphsgrow,they

haveto moulttheirtoughskin,shedding

thetightoldcuticle(bodycovering)for

a flexiblenewone.Theydothisupto 15

times.Bycontrast,adultdragonfliesand

damselfliesliveonlya fewdaysorweeks.

3

WHATDOTHEYFEEDON?

Dragonflyanddamselnymphsare

frighteninglyeffectivepondpredators.

Theyallhavelarge,powerful,toothed

jaws,attachedto theendofa bizarre

hingedfacemask.Thisis actuallythe

lowerlip,orlabium,andit’sarticulated

likeanelbow.Wheninrange,it shoots

forwardsto snatchprey.Thoughnymphs

maycrawlthroughwaterweed,orswim

aboutinthewaterofyourpond-

dippingtray,theyaremostly

sit-and-waithunters.Large

oneswilldevourtadpoles

andsmallfish...andeach

other.RichardJones

Pondwatch:dragonsanddamsels

BEHAVIOUR

Cananimalslie?

F

akenews,alternativefacts,whitelies.

Humansareprodigiousfibbers,but

whataboutotherspecies?Manyanimals

areunconsciouslydeceitful,inthatthey

foolothersviamimicryandcamouflage.

Yetpurposefulpretenceakintohuman

lyingrequiresa ‘theoryofmind’– an

understandingthatothers’beliefsand

intentionscanbedifferenttoyourown.

Studiessuggestthiscapabilityis unique

tohumans,butthatsomeanimals

possesselementsofit.Potentialcasesof

intentionaldeceptionhavebeenseenin

primates,includingwhite-facedcapuchins

givingfalsealarmcalls(watcha clip

onStoryof Life, theBBC’sfreeappthat

explorestheworkofDavidAttenborough)

andred-cappedmangabeysmisleading

groupmatesaboutthelocationoffood.

Meanwhile,a captivechimpanzeehas

beenseenhidingstonesfromhiskeepers

tothrowat visitorslater.Aretheseanimals

employingtheoryofmind,orsimply

learningbyassociation?We’renotsure.

LeomaWilliams

White-faced

capuchinscan

havea habitof

cryingwolf.

Top: adult emperor.

Bottom: large red

damselfly nymph.

Q&A

July 2020