WILDLIFE SURVEYS
Drones have proved ideal for
monitoring inaccessible seabird
andsealion colonies, and for
locatingherdsofherbivoresin
remotewildernessareas(oryx
antelopesinNamibia,forexample).
Ina Welshconiferplantation,
thermal-imagingdroneswereused
todetectnestingnightjars,picking
outtheir40°Cbodiesagainstthe
colderground– thesebirdsare
nocturnal,wellcamouflagedand
easilydisturbed,sonotoriously
trickytostudybytraditional
methods.InSumatraandBorneo,
thermal-equippeddroneshave
countedorangutansandproboscis
monkeysscatteredthroughthe
forestcanopy.RESEEDING HABITATS
An Oxford start-up has used drones
to sow grasses and trees over old
Australian coal mines, and replace
mangrovesinMyanmar.Afteraerial
surveystolocatesuitablesites,
biodegradableseedbombswere
firedfrommid-air.Theoretically,a
teamoftwooperatorscancarpet-
bombthousandsofseedlingsa
day,butcriticssaytheemotional
connectioninvolvedintraditional
treeplantingislost.SCALESINTHESKY
Notonlycandronesmapandcount
treesina forest,they’realsoable
toestimatetheheightandgirthof
individualtrees,bymeansoflaser
pulses,enablingtheforest’soverall
healthtobeassessed.O
thecoastofArgentina,
marinebiologistshave
employeddronesto‘weigh’
southernrightwhales,
bytakingaerialimages
fromwhichthecetaceans’
volumeandmasswere
calculated.If thesame
whalesarerephotographed
infuture,it shouldbe
possibletotracktheir
growthovertime,and
thustheirfitnessand
energyrequirements.The drone revolution
Conservationists are deploying drones for everything from wildlife
surveys to planting forests, weighing whales and catching poachers.August 2020 BBC Wildlife 49Clockwise from bottom right: Juan Mabroata/AFP/Getty;
BBC;
Wayne
Hutch
nson/FLPA;
Martyn
Ch
ma
d/A
amy;
Mark
Carward
ne/naturep
.com
Moststudiestodatehavelookedat theimpacton
birds.Theyhavetendedtoconcludethatdronesflying
at 40–50mcauselittleornoapparentdisturbanceto
mostspecies,andsothisis theheightabovewhich
manyscientificsurveysareundertaken.Notethe
‘apparent’.Howdoweknowwhata wildanimalis
feeling?Wecanobserveitsbehaviour,butthismay
notalwaysbeenough.
Forseveralyears,zoologistsfromthe
UniversityofStAndrewsandDurham
Universityhavebeentestinghowgreyseals
breedingontheIsleofMayreacttovarious
stresses,suchasa remote-controlbuggy
beingdrivennearthecolony.Byattaching
heart-rate monitors to resting seals, the team
has monitored not just observed behaviour
but also the physiological response. The
results have been startling. Some seals that
appeared totally unfazed were in reality
anything but. If we’re unable to recognise
a stressed seal, how can we be sure what
impact a drone is having? We can’t.Left: six-month-old
puma cubs are filmed
by drone (for Seven
Worlds, One Planet)
as they follow their
mother through Torres
del Paine National
Park in Chile. Above:drones are able to
provide viewpoints
that may otherwise
be tricky or costly
to achieve, such as
this shot of mobula
rays just beneath the
surface of the ocean.Ocean Alliance
uses drones during
conservation work.