Varia%on(in(Breeding(Success(of(Red3billed(Tropicbirds((Phaethon(aethereus)(on(St.(Eusta%us(
SCSCB(Regional(Mee%ng,(27(–(31(July(2013(Hannah(Madden(
St.(Eusta%us(Na%onal(Parks((STENAPA)!
St.(Eusta%us((Sta%a)(
Sta%a:!' 11!sq!miles!' !Es%mate!+/'!300'500!pairs!of!RBTR!' !Together!with!Saba,!33'40%!of!global!RBTR!popula%on!
Saba!
Primary(Nes%ng(and(Study(Sites(
Zeelandia!
Pilot!Hill!
Pilot!Ridge!
Signal!Hill!
Crooks!Castle!
Ra%onale(
A(similar(study(conducted(on(Saba((2011)(resulted(in(the(discovery(of(high(levels((100%)(of(preda%on(at(one(nes%ng(site(
Status( TENT(Colony(
Eggs(laid( 39(
Eggs((probably)(hatched( 34(
Chicks(fledged( 0(
%(Breeding(Success( 0.00%(
Methods(
Record!%ming!of!egg!laying! !!Individually!marked!nests!and!adult!birds! !!Status!of!nests!regularly!followed! !!Chick!growth!and!development!recorded! !!Fieldwork!supported!by!24'hour!infra'red!
cameras! !Preliminary!predator!control!(rat!traps)!
Results(
Eggs(laid:!99!Eggs(hatched:!59!Not(yet(hatched:!4!Eggs(lost:!36!
0.0%!
10.0%!
20.0%!
30.0%!
40.0%!
50.0%!
60.0%!
70.0%!
80.0%!
90.0%!
100.0%!
Signal!Hill! Crooks!Castle! Zeelandia! Pilot!Hill! Pilot!Ridge! Total!
Hatching(Success(
Birds(banded:!146!Primary(and(secondary(nests:!197!Primary(nests:!85!
n=11! n=4! n=14! n=45! n=25! n=99!
Percen
t!Hatching!Success!
RBTR!Colonies!
(percentage!of!hatched!eggs!per!number!of!eggs)!!
Results(Chicks(apparently(fledged:!46!Dead(chicks:!2!(not!preda%on)!Fate(unknown:!11!
0.0%!
10.0%!
20.0%!
30.0%!
40.0%!
50.0%!
60.0%!
70.0%!
80.0%!
90.0%!
100.0%!
Signal!Hill! Crooks!Castle! Zeelandia! Pilot!Hill! Pilot!Ridge! Total!
Apparent(Fledging(Success(
n=11! n=4! n=14! n=45! n=25! n=99!
Percen
t!Fledging!Success!
RBTR!Colonies!
(%!fledged!chicks!per!number!of!hatched!eggs)!
Results(
0.0%!
10.0%!
20.0%!
30.0%!
40.0%!
50.0%!
60.0%!
70.0%!
80.0%!
90.0%!
100.0%!
Signal!Hill! Crooks!Castle! Zeelandia! Pilot!Hill! Pilot!Ridge! Total!
Apparent(Breeding(Success((
n=11! n=4! n=14! n=45! n=25! n=99!
Percen
t!Breed
ing!Success!
RBTR!Colonies!
(%!fledged!chicks!per!number!of!laid!eggs)!
0.0%!
10.0%!
20.0%!
30.0%!
40.0%!
50.0%!
60.0%!
70.0%!
80.0%!
90.0%!
100.0%!
%!Hatching!Success!! %!Fledging!Success!! %!Breeding!Success!
Apparent(Nes%ng(Success(
Signal!Hill!
Crooks!
Zeelandia!
Pilot!Hill!
Pilot!Ridge!
TOTAL!
Results(Percen
t!success!
Biological!Measure!
Saba,(2011(Percen
t!success!
Biological!Measure!!
0.0%!
10.0%!
20.0%!
30.0%!
40.0%!
50.0%!
60.0%!
70.0%!
80.0%!
90.0%!
100.0%!
%!Hatching!Success!! %!Fledging!Success!! %!Breeding!Success!
TENT!
OBH!
Overall/Total!
Egg(Loss/Chick(Mortality(
Evidence(of(Predators(
Future(Plans(
!Inves%gate!egg!loss!at!one!site!(Pilot!Hill)!in!2014!!
!Possible!diet!study!in!collabora%on!with!IMARES!(NL)!and!Science!Centre!(Sta%a)!
!Long'term!monitoring!of!nest!fidelity!/!inter'island!movements!(Saba/Sta%a)!
!RBTR!movements!'!geolocators!(Dr.!Pat!Jodice,!Clemson!University)!
Con%nued!popula%on!and!produc%vity!monitoring!
Acknowledgements(
'!NFWF/SCSCB!!'!Intern!Andrew!Ellis!'!NuStar!'!Dutch!Caribbean!Nature!Alliance!(DCNA)!'!Dr.!Adrian!Delnevo,!Dr.!Pat!Jodice!&!Dr.!Will!Mackin!'!Jose'Luis!Garcia!and!Giovanni!Balensuela!
Ques%ons(