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