April 2020 BBC Wildlife 25
WILDNEWS
Guamrail
CONSERVATIONREPORT
Thismonth,biologistLauraBarnhartDuenas
shines a spotlight on a recovering rail species.
Howdidthis ightlessspecies
becomeextinctinthewild?
A lotofshipmentswerecomingto
Guam,a USislandterritoryinthe
westernPacific,inanefforttorebuild
theislandafterWorldWarII,andthe
browntreesnakewasaccidentally
introduced.Theisland’sbirdshad
neverencountereda predatorlike
thisbeforeand,consequently,both
theGuamrailandGuamkingfisher
becameextinctinthewild.
HowwastheGuamrail saved
fromextinction?
Oncethethreatofthesnakehad
beenidentified,staffattheGuam
DepartmentofAgriculture,Division
ofAquaticandWildlifeResourcestried
tocaptureasmanynativebirdson
Guam,includingtherail,aspossible.
Theybroughtinanythingtheycould
find,fromadultstochicksandeven
eggsfromthenest.Thoughtheywere
abletocatcha fewindividualsfrom
everyspecies,onlythehardierbirds
wereabletosurviveincaptivity.
Whyhastherailbeenreclassi ed
asCriticallyEndangered?
Between 2010 and2012, 26 Guamrails
werereleasedontoCocos,a tinyisland
just off the southern tip of Guam where
snakesarenotpresent.OnRota,part
oftheMarianaIslands,GuamRails
havealsobeensteadilyintroduced
sincethe1990s,involving,attimes,
asmanyas 100 birdsperyear.Though
therearen’tanyGuamrailsinthewild
onGuam,theyhavebeenbreedingon
RotaandCocos,andtheirpopulation
hasbeenstableforthepastfiveyears–
approximately 260 railsexisthere,more
thanincaptivity.It is onlythesecond
birdspeciestocomebackfrombeing
classifiedasextinctinthewild.
Whathappensnext?
Workis beingdonebyourpartners
intheUSGovernmenttoresearch
methodsofsnakecontrolandtoensure
theydon’tspreadtootherlocations.We
arelookingatusingtheirtechniquesto
helpprepareareasonGuamtobeable
toreleasetherailintothewild,using
thepopulationsonRotaandCocos
Islandassourcepopulations,in
additiontocaptive-bred birds.
Megan Shersby
Teachingnew
dogs old tricks
CANINES
T
heabilitytointerprethumansocial
communicativecuesthatenables
a domesticdogtogoaftera balland
thenbringit backalsoexistsinwolves,
accordingtoiScience.
ResearchersatStockholmUniversity
discoveredeight-week-oldgreywolf
puppiesunexpectedlyshowedan
interestina ballandreturnedit to
a completestrangeruponrequest.
Thediscoveryis a surprisebecause
it hadbeenhypothesisedthatthe
cognitiveabilitiesnecessarytoplaya
gameoffetcharoseindogsonlyafter
humansdomesticatedthematleast
15,000yearsago.
Duringa standardisedtest, 13
wolfpupswerevocallyencouraged
toretrievea ballfroma humanthey
hadnevermetbeforeandthreewere
observedretrievingtheballatleast
twotimes.
“Iliterallygotgoosebumps,”says
co-authorChristinaHansenWheat.
“Itwassounexpected– I immediately
knewthismeantthatif variation
inhuman-directedplaybehaviour
existsinwolves,thisbehaviourcould
havebeena potentialtargetforearly
selectivepressuresexertedduring
dogdomestication.”
HansenWheatsuggeststhestudy
highlightstheneedforincreased
rigorindogdomesticationstudies,
intermsofincludingenoughwolves
toadequatelydetectunderlying trait
variationinbehaviour.
KatyLayton
FINDOUTMORE
iScience:bit.ly/37Bivlb
LAURABARNHARTDUENASisa
wildlifebiologistworkingwiththe
GuamDepartmentofAgriculture.
REDLIST
STATUS:
CRITICALLY
ENDANGERED
FINDOUTMORE
HowtheGuamrailcamebackfrom
extinction:birdlife.org/guam-rail
Gonebutnot
forgotten– plans
areinplaceto
returntheGuam
rail to Guam.
Somewolfpups
arefondofa
game of fetch.