How numbers of nesting sea turtles can be over-estimated by nearly a factor of two

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1 How numbers of nesting sea turtles can be over-estimated by nearly a factor of two Nicole Esteban 1, Jeanne A. Mortimer 2,3, Graeme C. Hays 4, 1 Swansea University, Department of Biosciences, Swansea, SA2 8PP, Wales, United Kingdom 2 Turtle Action Group of Seychelles, P.O. Box 1443, Victoria, Mahé, Seychelles, and 3 University of Florida, Department of Biology, Gainesville, FL 32611, United States of America 4 Deakin University, School of Life and Environmental Sciences, Centre for Integrative Ecology, Warrnambool, VIC 3280, Australia Author for correspondence: Graeme Hays, g.hays@deakin.edu.au Electronic supplementary material: Supplementary Table S1 Evidence of 50 subsequent clutch depositions by 10 green turtles using Fastloc-GPS transmitter locations. Supplementary Table S2 Estimates of the mean clutch frequency grouped by region for green turtles and loggerhead turtles measured around the World by beach patrols. Supplementary Figure S1 Timing of nesting activities during estimated clutch frequency intervals Supplementary Figure S2 The 221 Fastloc-GPS locations of Turtle around Diego Garcia from 11 July until 14 October Supplementary Figure S3 The 7 Fastloc-GPS locations of Turtle around Diego Garcia from 11 July until 29 September Supplementary Figure S4 The 73 Fastloc-GPS locations of Turtle around Diego Garcia from 8 July until 31 August Supplementary Figure S5 The 181 Fastloc-GPS locations of Turtle around Diego Garcia from 14 July until 30 September Supplementary Figure S6 The 586 Fastloc-GPS locations of Turtle around Diego Garcia from 9 July until 21 October Supplementary Figure S7 The 395 Fastloc-GPS locations of Turtle around Diego Garcia from 13 July until 28 September Supplementary Figure S8 The 80 Fastloc-GPS locations of Turtle around Diego Garcia from 6 July until 10 August Supplementary Figure S9 The 203 Fastloc-GPS locations of Turtle around Diego Garcia from 4 July until 14 August Supplementary Figure S10 The 246 Fastloc-GPS locations of Turtle around Diego Garcia from 5 July until 31 August Supplementary Figure S11 The 33 Fastloc-GPS locations of Turtle around Diego Garcia from 6 July until 19 July

2 Supplementary Table S1 Evidence of 50 subsequent clutch depositions by 10 green turtles using Fastloc-GPS transmitter locations. Nests 1 preceded transmitter attachment on the index beach in Diego Garcia, British Indian Ocean Territory (BIOT) in July Successive nests (2-9) were determined using multiple lines of evidence: filtered Fastloc-GPS (F), Haulout of >20 min (H) or Interpolation based on modal inter-nesting interval (I). Local times are used (GMT +6 h). Fastloc-GPS stopped working on between nests 1 and 2 so subsequent Argos data were used. Turtle ID Size CCL (cm) Nest 1 Tagged Date/hr Nest 2 Evidence Date/hr Nest 3 Evidence Date/hr Nest 4 Evidence Date/hr Nest 5 Evidence Date/hr Nest 6 Evidence Date/hr Nest 7 Evidence Date/hr Nest 8 Evidence Date/hr Nest 9 Evidence Date/hr H H F F H H F H F H 10 Jul 22:20 24 Jul 22:05 8 Aug 00:03 20 Aug 19:50 4 Sep 01:23 16 Sep 23:32 30 Sep 23:10 13 Oct 23:01 - H H H H H H H 7 Jul 20 Jul 31 Jul 11 Aug 23 Aug 4 Sep 16 Sep 29 Sep 22:30 05:26 06:00 22:37 06:00 22:43 06:00 08:41 - H H F F H 8 Jul 20 Jul 3 Aug 13 Aug 30 Aug 22:00 21:49 00:06 20:05 01:37 - F H F F I F F 14 Jul 27 Jul 8 Aug 20 Aug 2 Sep 15 Sep 28 Sep 22:30 22:03 21:32 21:41 06:00 05:53 04:50 - F H F H F H F H F H F H F H F H 9 Jul 23 Jul 3 Aug 15 Aug 29 Aug 10 Sep 24 Sep 6 Oct 20 Oct 21:45 05:29 00:07 23:56 03:07 23:08 22:49 20:21 23:15 - F H F F F H F H F H 13 Jul 26 Jul 7 Aug 19 Aug 1 Sep 14 Sep 27 Sep 23:30 20:17 04:55 21:18 23:45 23:42 00:30 - F H F F H 6 Jul 17 Jul 28 Jul 6 Aug 00:30 02:08 22:44 00:26 - F H F H F 4 Jul 17 Jul 29 Jul 13 Aug 05:20 03:14 21:14 04:03 - F H F F F H F H 6 Jul 16 Jul 26 Jul 5 Aug 20 Aug 31 Aug 00:30 20:52 20:37 20:33 06:06 04:28 - F H 6 July 18 Jul 22:10 02:45 2

3 Supplementary Table S2 Estimates of the mean clutch frequency (CF) grouped by region for green turtles and loggerhead turtles measured around the World by beach patrols. In some cases observed clutch frequency (OCF) and estimated clutch frequency (ECF) are also indicated. Where there were multiple estimates for the same location the most recent value was used. The midpoint of a range was taken. Note that the composition of the various tag types and the methodologies employed have evolved over the decades. Tag retention is lower for Monel tags than for non-corroding Inconel and Titanium tags; and double tagging is more effective than applying only a single tag to each female. Bracketed citations refer to the following review papers: Dodd CK Synopsis of the biological data on the Loggerhead sea turtle Caretta caretta (Linnaeus 1758). US Fish. Wildl. Serv. Biol. Rep. 88(14). 110 pp. Hirth HF Some aspects of the nesting behavior and reproductive biology of sea turtles. Amer. Zool., 20, Hirth HF Synopsis of the biological data on the green turtle, Chelonia mydas (Linnaeus 1758). Biological Report 97(1), US Department of Interior. Schroeder BA, Foley AM, Bagley DA Nesting patterns, reproductive migrations, andadult foraging areas of loggerhead turtles. In: Bolten AB, Witherington BE. (Eds.), Loggerhead sea turtles, Smithsonian Books Washington, DC. Species Location Clutch Frequency Methods Citation Reference Green turtle, Chelonia mydas Mediterranean C. mydas Mediterranean Cypress (N) later pooled to C. mydas Mediterranean (Same as above) Paper discusses energetic & size issues (Plastic Jumbotags Dalton); Plastic Supertags (Dalton); Titanium tags; since 1997 PIT tags. OCF & ECF calculated. Broderick et al Broderick et al Broderick AC, Glen F, Godley BJ, Hays GC Estimating the number of green and loggerhead turtles nesting annually in the Mediterranean. Oryx 36(3), Broderick AC, Glen F, Godley BJ, Hays GC Variation in reproductive output of marine turtles. J. Exp. Mar. Biol. Ecol. 288,

4 Species Location Clutch Frequency Methods Citation Reference Atlantic Ocean C. mydas Florida Atlantic coast, Brevard County (Melbourne Beach) USA OCF = 2.4 ECF = 3.0 (n=145).no correlations with size Monel tags double tagging Based on two seasons: km long study beach Johnson, Ehrhart 1996 Johnson SA, Ehrhart LM Reproductive ecology of the Florida green turtle: clutch frequency. J. Herpetology 30(3), C. mydas Tortuguero, Costa Rica 2.8 (Range 1-8).Remigrants had higher CFs than previously untagged Monel tagging, single tag per female Carr & Hirth 1962; Carr et al [Hirth 1980] [Hirth 1997] Carr A, Hirth H The ecology and migrations of sea turtles, 5. Comparative features of isolated green turtle colonies. Amer. Mus. Novitates 2091, Carr A, Carr MH, Meylan AB The ecology and migrations of sea turtles, 7. The west Caribbean green turtle colony. Bull. Amer. Mus. Nat. Hist. 162,1-46. C. mydas Surinam 2.9 (Range 1-9) N=602 Remigrants had higher CFs than previously untagged. C. mydas Ascension Island 3.0 (SD=1.65) N=78; Remigrants had higher CFs than previously untagged. Monel tagging Schulz 1975 [Hirth 1980] Monel tagging, single tag per female Mortimer & Carr 1987 Schulz JP Sea turtles nesting in Surinam. Neder. Comm. Int. Natuur. Med. 23, Stichting Natuur. Suriname (Stinasu), Verhandeling No. 3. Mortimer JA, Carr A Reproduction and migrations of the Ascension Island green turtle (Chelonia mydas). Copeia 1987(1), C. mydas Ascension Island Pacific Ocean 6.3 (n=40) Combination of VHF radiotelemetry and Argos-linked Fastloc GPS devices (in Dec 2011-Jan 2012) Weber et al Weber N, Weber SB, Godley BJ, Ellick J, Witt M, Broderick AC Telemetry as a tool for improving estimates of marine turtle abundance. Biol. Conserv. 167, C. mydas Colola Beach, Michoacán, Mexico Mean OCF= 2.5; Mean ECF = 3.1 Double tagging: one monel and one plastic rototag on each turtle. Clutch frequency calculated for each of a random sample of 50 turtles per year (from an average annual population of ~394 females assuming 3.1 clutches per female). Alvarado- Díaz et al Alvarado-Díaz J, Arias-Coyotl E, Delgado-Trejo C Clutch frequency of the Michoacán Green Sea turtle. J. Herpetology 37(1),

5 Species Location Clutch Frequency Methods Citation Reference C. mydas Playa Cabuyal, Costa Rica (Pacific coast) C. mydas Nombre de Jesús, Costa Rica (Pacific coast) ECF=4.3 (SD=2.3) ECF= 3.67 (SD=1.79); Ultrasound= 5.13 (SD=1.32). Double tagged: 1 Inconel; 1 PIT Surveyed 1.4 km long beach intensely Patrol from July to Nov PIT tags & Ultrasound scanner Tomillo et al Blanco et al Tomillo PS, Roberts SA, Hernández R, Spotila JR, Paladino FV Nesting Ecology of East Pacific Green Turtles at Playa Cabuyal, Gulf of Papagayo, Costa Rica. Marine Ecology 36(3), Blanco GS, Morreale SJ, Vélez E, Piedra R, Montes WM, Paladino FV, Spotila JR Reproductive output and ultrasonography of an endangered population of East Pacific green turtles. J Wildlife Management 76(4), C. mydas Playa Naranjo, Costa Rica (Pacific coast) C. mydas Galapagos Islands, Ecuador ca 2 (Range 2-4) Probably single monel tagging Cornelius 1976 [Hirth 1997] Cornelius SE Marine turtle nesting activity at Playa Naranjo, Costa Rica. Brenesia 8, ca 3 (Range 1-7) Double tagging: one monel and one plastic rototag on each turtle. Green 1994 Green 1979 [Hirth 1997] Green D Galapagos sea turtles: an overview. Pages in B. A. Schroeder BA, Witherington BE (compilers) Proceedings of the thirteenth annual symposium on sea turtle biology and conservation. NOAA Tech. Memo. NMFS-SEFSC-341,281 pp. Green D Double tagging of green turtles in the Galapagos Islands: Marine Turtle Newsletter 13, 4-9. C. mydas French Frigate Shoals, Hawaii C. mydas French Frigate Shoals, Hawaii 1.8 (Range 1-6) N=208 females, at East Island 4 (Range: 1-9) at East Island; Monel tags from Inconel from 1976 onward 2 to 3 tags per female. Based on saturation surveys using Inconel tags, during (G. Balazs unpubl. data) Balazs 1980; Pilcher et al [Hirth 1980] [Hirth 1997] Tiwari et al Balazs GH Synopsis of biological data on the green turtle in the Hawaiian Islands. NOAA-TM-NMFS-SWFC-7. October pp. Pilcher NJ, Chaloupka MY, Woods E Chelonia mydas (Hawaiian subpopulation). The IUCN Red List of Threatened Species 2012, e.t a Tiwari M, Balazs GH, Hargrove S Estimating carrying capacity at the green turtle nesting beach of East Island, French Frigate Shoals. Mar. Ecol. Prog. Ser. 419, C. mydas French Frigate Shoals, Hawaii C. mydas Ogasawara Islands, Japan Study sites: 1.8 (Balazs 1980) 4 (Range: 1-9) at East Island (Tiwari et al. 2010); 2.8 (Range: 1-6) at Tern Island (Pepi 2002, MSc study, cited in Tiwari et al. 2010). Cites previous studies 3.9 Females captured early in season, confined in breeding pool prior to slaughter. Balazs et al Balazs GH, Van Houtan KS, Hargrove SA, Brunson SM, Murakawa SKK A review of the demographic features of Hawaiian green turtles (Chelonia mydas). Chel. Conserv. Biol. 14(2), Kazuo Horikoshi, pers comm. in Mortimer & Carr

6 Species Location Clutch Frequency Methods Citation Reference C. mydas Sarawak Islands ca 6-7 (Range 1-11) Monel metal tags (saturation tagging) Hendrickson 1958 Hendrickson JR The green sea turtle, Chelonian mydas (Linn.) in Malaya and Sarawak. Proc Zool Soc Lond 130, C. mydas Heron Island (Southern Great Barrier Reef) Australia 4.5 (Range 3-6) Monel tags; One per female Bustard 1972 [Hirth 1980] Bustard R Sea turtles: Their natural history and conservation. Taplinger Publ. Co., New York. C. mydas Heron Island (Southern Great Barrier Reef) 5.06 (SD=1.99) Range=1-9 N=878 Titanium tags, double tagging. Saturation tagging attempted. Limpus 2008 Limpus C A biological review of Australian marine turtle species. 2. Green turtle, Chelonia mydas (Linnaeus). Queensland Government, Environmental Protection Agency. 96 pp. C. mydas Bramble Cay (Northern Great Barrier Reef) 6.2 (SD=2.1) Range=1-10 N=684 Monel tags, double tagging. Saturation tagging achieved ( , ). Limpus et al Limpus CJ, Carter D, Hamann M The green turtle, Chelonia mydas, in Queensland: the Bramble Cay rookery in the breeding season. Chel. Conserv. Biol. 4(1), C. mydas Xisha Island, China ca 3 No methodology described. Note: This CF figure may be based on literature search. Huang Chu- Chien 1982 [Hirth 1997] Huang Chu-Chien Distribution of sea turtles in China seas. Pages in K. A. Bjomdal (ed.), Biology and conservation of sea turtles. Smithsonian Institution Press, Washington D. C., 583 pp. Indian Ocean C. mydas Huyong Island, Thailand (Andaman sea) 3.7 ± 2.3 (n = 9) for turtles began nesting October; 7.0 ± 2.9 (n = 5) for turtles began nesting in November. (Varied by month over 12 yr period). Combination PIT and Inconel tagging yearround. Looks like near saturation tagging of a small population. Yasuda et al Yasuda T, Kittiwattanawong K, Klom-in W, Arai N Seasonal changes in reproductive output of a year-round nesting population of the green turtle Chelonia mydas at Huyong Island, Thailand. Amphibia-Reptilia 29, C. mydas Huyong Island, Thailand (Andaman sea) (n=11); (n=9) (Depended on time of year turtle first encountered) Combination PIT and Inconel tagging yearround. Looks like near saturation tagging of a small population. Yasuda et al Yasuda T, Tanaka H, Kittiwattanawong K, Mitamura H, Klom-in W, Arai N Do female green turtles exhibit reproductive seasonality in a year-round nesting rookery? J. Zool. (Lond.) 269, C. mydas Aldabra atoll 3-5 (unpublished data; prelim estimate) Titanium tags: both single and double tagged Mortimer et al Mortimer JA, von Brandis RG, Liljevik A, Chapman R, Collie J Fall and Rise of the Nesting Green Turtles (Chelonia mydas) at Aldabra Atoll, Seychelles: Positive Response to Four Decades of Projection ( ). Chel. Conserv. Biol. 10(2),

7 Species Location Clutch Frequency C. mydas Mayotte Island (max=10 in a female) Methods Citation Reference Monel tags, single tag per turtle. Yearround monitoring from 1 Jan 1998 to Dec Bourjea et al Bourjea J, Frappier J, Quillard M, Ciccione S, Roos D, Hughes G, Grizel H Mayotte Island: another important green turtle nesting site in the southwest Indian Ocean. Endangered Species Res. 2007(3), C. mydas Tromelin Island Monel tags, single tag per turtle. 3-mo-long period during 2009/10 nesting peak (8 Dec-8 Mar). Derville et al Derville S, Jean C, Dalleau M, Le Gall J- Y, Ciccione S, Bourjea J Longterm monitoring of green turtle nesting on Tromelin Island demonstrates stable reproduction and population parameters. Chel. Conserv. Biol. 14(1), C. mydas Tromelin Island 3.5 Monel tags, single tag per turtle. Entire island surveyed over 3 mos period. Le Gall 1988; LeGall et al Le Gall JY Biologie et évaluation des populations de tortues vertes Chelonia mydas des atolls Tromelin et Europa (Océan Indien S.O.). Mésogée 48, Le Gall J-Y, Bosc P, Chateau D, Taquet M Estimation due nombre de tortues verte femelles adultes Chelonia mydas par saison de ponte à Tromelin et Europa (Océan Indien) ( ). Oceanogr. trop. 21(1), C. mydas Europa Island 2.8 Monel tags, single tag per turtle. Surveys focused on the Plage de la Station (Station Beach) < 2 km in length, over 3 mos period Le Gall 1988; LeGall et al C. mydas Querimbas archipelago, Mozambique Titanium tagging; ~ 29% of nests tagged Garnier et al Garnier J, Hill N, Guissamulo A, Silva I, Witt M, Godley B Status and community-based conservation of marine turtles in northern Querimbas Islands (Mozambique). Oryx 46(3), C. mydas Karan Island, Saudi Arabia 4 Titanium tags: double tagged. Karan Island surveyed 3 months 1986; 1 month 1987 Miller 1989 [Hirth 1997] Miller JD Marine turtles: Vol. 1: an assessment of the conservation status of marine turtles in the Kingdom of Saudi Arabia. MEPA Coastal and Marine Management Series, Report No. 9, pp Ministry of Defense and Aviation, Kingdom of Saudi Arabia. Loggerhead turtle, Caretta caretta Global C. caretta Global CF= 1-6 (maximum 7) 7

8 Species Location Clutch Frequency Mediterranean C. caretta Zakynthos, Greece C. caretta Mediterranean Cyprus (N) CF = usually 1-3 clutches / season later pooled to C. caretta Mediterranean No change, but paper discusses energetic & size issues Methods Citation Reference Flipper tagging (Plastic Jumbotags Dalton); Plastic Supertags (Dalton); Titanium tags; since 1997 PIT tags. OCF & ECF calculated Margaritoulis 1983 Broderick et al Broderick et al Margaritoulis D The inter-nesting interval of Zakynthos loggerheads. Pages in N.S. Margaris. M. Arianoutsou-Faraggitaki. and R.J. Reiter (eds.). Adaptations to terrestrial environments. Plenum Press. New York. Broderick AC, Glen F, Godley BJ, Hays GC Variation in reproductive output of marine turtles. J. Exp. Mar. Biol. Ecol. 288, Atlantic Ocean C. caretta South Carolina, USA CF = mean 2-3 (range=1-6) Flipper tagging Talbert et al Talbert OR, Stancyk SE, Dean JM, Will JM Nesting activity of the loggerhead turtle (Caretta caretta) in South Carolina. I: a rookery in transition. Copeia 1980, C. caretta Little Cumberland Island, Georgia, USA CF average = 2.5 Flipper tagging Richardson & Richardson 1982 Richardson JI, Richardson TH An experimental population model for the loggerhead sea turtle (Caretta caretta). Pages in K. Bjorndal (ed.), Biology and conservation of sea turtles. Smithsonian Institution Press, Washington, DC. C. caretta Little Cumberland Island, Georgia, USA CF = Flipper tagging Stoneburner 1981 Stoneburner DL Summary of the loggerhead sea turtle research project conducted at Canaveral National Seashore, Cumberland Island National Seashore, Cape Lookout National Seashore: A final report NPS Res./Resour. Manage. Rep. No. 39. C. caretta Little Cumberland Island, Georgia, USA During , annual variation in CF: from CF=2.8 in 1982; to CF=4.2 in 1979 Flipper tagging Frazer & Richardson 1985 Frazer NB, Richardson JI Annual variation in clutch size and frequency for loggerhead turtles, Caretta caretta, nesting at Little Cumberland Island, Georgia, USA. Herpetologica 41, C. caretta Georgia, USA CF max = 7 clutches Flipper tagging Lenarz et al Lenarz MS, Frazer NB, Ralston MS, Mast RB Seven nests recorded for loggerhead turtle (Caretta caretta) in one season. Herpetol. Rev. 12,9. C. caretta S. Brevard County, Florida CF=3.4 Flipper tagging [Schroeder et al. 2003] 8

9 Species Location Clutch Frequency C. caretta Keewaydin Island, Florida Methods Citation Reference CF= Flipper tagging Addison 1996 [Shroeder et al., 2003] Addison DS Caretta caretta (loggerhead sea turtle). Nesting frequency. Herpetol. Rev. 27, 76. C. caretta Jupiter Island, Florida, USA C. caretta Casey Key, Southwest Florida, USA CF range =1-6 Experienced females (remigrants) laid more clutches than neophytes (1.61 v 1.37) Flipper tagging CF: 2.2 Argos CF: 5.4. Mode=5 Flipper tagging Lund 1986 Comparison of: Flipper tags & PIT tags on 6 km of beaches; and ARGOS transmitters. Tucker 2010 Lund F Nest production and nesting-site tenacity of the loggerhead turtle, Caretta caretta, on Jupiter Island, Florida. Unpubl. M.S. Thesis. University of Florida, Gainesville, 32 pp. Tucker AD Nesting site fidelity and clutch frequency of loggerhead turtles are better elucidated by satellite telemetry than by nocturnal tagging efforts: implications for stock estimation. J. Exp. Mar. Biol. Ecol., Pacific Ocean C. caretta Columbia, South America CF could lay at least 4 times/season & possibly more Kaufman 1975 C. caretta Japan CF = 2 Iwamoto et al Kaufmann R Studies on the loggerhead sea turtle, Caretta caretta (Linne) in Colombia, South America. Herpetologica 31, Iwamoto T, Ishii M, Nakashima Y, Takeshita H, Itoh A Nesting cycles and migrations of the loggerhead sea turtle in Miyazaki, Japan. Jpn. J. Ecol. 35, C. caretta Eastern Australia CFrange = 1-6 Limpus 1985 Limpus CJ A study of the loggerhead sea turtle, Caretta caretta, in eastern Australia. Unpubl. Ph.D. Dissertation. University of Queensland, St. Lucia, Australia. C. caretta Mon Repos, Eastern Australia CF mean = 3.41 SD=1.2 Range =1-6 n=1207 Indian Ocean C. caretta Oman CF = 4.4 Satellite telemetry C. caretta Tongaland CF typical = [Hirth] 4 to 5 [Dodd] Limpus 2008 (cited Limpus 1985 above) Rees et al [Schroeder et al. 2003] Hughes 1974 [Hirth 1980] Limpus C A biological review of Australian marine turtle species. 1. Loggerhead turtle, Caretta caretta (Linnaeus). Queensland Government, Environmental Protection Agency. 67 pp. Rees AF, Saadi SA, Coyne MS, Godley BJ Internesting habitat and nest frequency at a globally significant loggerhead nesting population described using Argos tracking. NOAA Tech. Mem. NMFS-SEFSC-569, p. 55. Hughes GR The sea turtles of south-east Africa. I. Status, morphology and distributions. II. The biology of the Tongaland loggerhead turtle Caretta caretta L. with comments on the leatherback turtle Dermochelys coriacea L. and the green turtle Chelonia mydas L. in the study region. Invest. Rep. Nos. 35, 36. South African Assoc. Mar. Biol. Res. Oceanographic Res. Institute, Durban, South Africa. 9

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 (a) (b) Supplementary Figure S1 Timing of nesting activities during estimated clutch frequency intervals (a) The daily timing of 286 locations

10 (a) (b) Supplementary Figure S1 Timing of nesting activities during estimated clutch frequency intervals (a) The daily timing of 286 locations associated with turtles moving onto the back reef and nesting beaches, indicative of nocturnal emergences to nest (86.364% occurring between sunset and sunrise, with >99.95% occurring between sunset and sunrise ±2 h). (b) The intervals between 50 estimated successive nests for 10 individuals derived from satellite tracking data (mean = 12.42, SD = 1.401, minimum = 8, maximum = 16). 10

11 Supplementary Figure S2 The 221 Fastloc-GPS locations of Turtle around Diego Garcia from 11 July until 14 October Open red circles represent locations relating to 8 nesting events. Projection: Mercator. 11

12 Supplementary Figure S3 The 7 Fastloc-GPS locations of Turtle around Diego Garcia from 11 July until 29 September Argos and haulout locations were used to generate nesting locations after the last Fastloc-GPS location on 14 July. Open red circles represent locations relating to 5 nesting events. 1 additional nesting event was interpolated. Projection: Mercator. 12

13 Supplementary Figure S4 The 73 Fastloc-GPS locations of Turtle around Diego Garcia from 8 July until 31 August Open red circles represent locations relating to 5 nesting events. Projection: Mercator. 13

14 Supplementary Figure S5 The 181 Fastloc-GPS locations of Turtle around Diego Garcia from 14 July until 30 September Open red circles represent locations relating to 6 nesting events. One additional nesting event was interpolated. Projection: Mercator. 14

15 Supplementary Figure S6 The 586 Fastloc-GPS locations of Turtle around Diego Garcia from 9 July until 21 October Open red circles represent locations relating to 9 nesting events. Projection: Mercator. 15

16 Supplementary Figure S7 The 395 Fastloc-GPS locations of Turtle around Diego Garcia from 13 July until 28 September Open red circles represent locations relating to 7 nesting events. Projection: Mercator. 16

17 Supplementary Figure S8 The 80 Fastloc-GPS locations of Turtle around Diego Garcia from 6 July until 10 August Open red circles represent locations relating to 4 nesting events. Projection: Mercator. 17

18 Supplementary Figure S9 The 203 Fastloc-GPS locations of Turtle around Diego Garcia from 4 July until 14 August Open red circles represent locations relating to 4 nesting events. Projection: Mercator. 18

19 Supplementary Figure S10 The 246 Fastloc-GPS locations of Turtle around Diego Garcia from 5 July until 31 August Open red circles represent locations relating to 6 nesting events. Projection: Mercator. 19

20 Supplementary Figure S11 The 33 Fastloc-GPS locations of Turtle around Diego Garcia from 6 July until 19 July Open red circles represent locations relating to 2 nesting events. Projection: Mercator. 20

Green Turtle (Chelonia mydas) nesting behaviour in Kigamboni District, United Republic of Tanzania.

Green Turtle (Chelonia mydas) nesting behaviour in Kigamboni District, United Republic of Tanzania. Lindsey West Sea Sense, 32 Karume Road, Oyster Bay, Dar es Salaam, Tanzania Introduction Tanzania is