Diel and seasonal patterns in activity and home range size of green turtles on their foraging grounds revealed by extended Fastloc-GPS tracking


An animal’s home range is driven by a range of factors including top-down (predation risk) and bottom-up (habitat quality) processes, which often vary in both space and time. We assessed the role of these processes in driving spatiotemporal patterns in the home range of the green turtle (Chelonia mydas), an important marine megaherbivore. We satellite tracked adult green turtles using Fastloc-GPS telemetry in the Chagos Archipelago and tracked their fine-scale movement in different foraging areas in the Indian Ocean. Using this extensive data set (5081 locations over 1675 tracking days for 8 individuals), we showed that green turtles exhibit both diel and seasonal patterns in activity and home range size. At night, turtles had smaller home ranges and lower activity levels, suggesting they were resting. In the daytime, home ranges were larger and activity levels higher, indicating that turtles were actively feeding. The transit distance between diurnal and nocturnal sites varied considerably between individuals. Further, some turtles changed resting and foraging sites seasonally. These structured movements indicate that turtles had a good understanding of their foraging grounds in regard to suitable areas for foraging and sheltered areas for resting. The clear diel patterns and the restricted size of nocturnal sites could be caused by spatiotemporal variations in predation risk, although other factors (e.g. depth, tides and currents) could also be important. The diurnal and seasonal pattern in home range sizes could similarly be driven by spatiotemporal variations in habitat (e.g. seagrass or algae) quality, although this could not be confirmed.

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  1. Aragones L, Marsh H (2000) Impact of dugong grazing and turtle cropping on tropical seagrass communities. Pac Conserv Biol 5:277–288

  2. Aragones LV, Lawler IR, Foley WJ, Marsh H (2006) Dugong grazing and turtle cropping: grazing optimization in tropical seagrass systems? Oecologia 149:635–647

  3. Atwood TB, Connolly RM, Ritchie EG et al (2015) Predators help protect carbon stocks in blue carbon ecosystems. Nat Clim Change 5:1038–1045

  4. Bailey D, Gross J, Laca E et al (1996) Mechanisms that result in large herbivore grazing distribution patterns. J Range Manage 49:386–400

  5. Ballorain K, Ciccione S, Bourjea J et al (2010) Habitat use of a multispecific seagrass meadow by green turtles Chelonia mydas at Mayotte Island. Mar Biol 157:2581–2590

  6. Barry D, Hartigan JA (1993) A Bayesian analysis for change point problems. J Am Stat Assoc 88:309–319

  7. Bjorndal KA (1980) Nutrition and grazing behavior of the green turtle Chelonia mydas. Mar Biol 56:147–154

  8. Börger L, Dalziel BD, Fryxell JM (2008) Are there general mechanisms of animal home range behaviour? A review and prospects for future research. Ecol Lett 11:637–650

  9. Boyce MS, McDonald LL (1999) Relating populations to habitats using resource selection functions. Trends Ecol Evol 14:268–272

  10. Brooks LB, Harvey JT, Nichols WJ (2009) Tidal movements of East Pacific green turtle Chelonia mydas at a foraging area in Baja California Sur, Mexico. Mar Ecol Prog Ser 386:263–274

  11. Brown JS (1988) Patch use as an indication of habitat preference, predation risk, and competition. Behav Ecol Sociobiol 22:37–47

  12. Brown JS (1999) Vigilance, patch use and habitat selection: foraging under predation risk. Evol Ecol Res 1:49–71

  13. Brown JS, Kotler BP (2004) Hazardous duty pay and the foraging cost of predation. Ecol Lett 7:999–1014

  14. Cederlund G, Sand H (1994) Home-range size in relation to age and sex in moose. J Mammal 75:1005–1012

  15. Charnov EL (1976) Optimal foraging, the marginal value theorem. Theor Popul Biol 9:129–136

  16. Christiansen F, Lusseau D (2015) Linking behavior to vital rates to measure the effects of non-lethal disturbance on wildlife. Conserv Lett 8:424–431

  17. Cowlishaw G (1997) Trade-offs between foraging and predation risk determine habitat use in a desert baboon population. Anim Behav 53:667–686

  18. Creel S, Winnie J, Maxwell B et al (2005) Elk alter habitat selection as an antipredator response to wolves. Ecology 86:3387–3397

  19. Dujon AM, Lindstrom RT, Hays GC (2014) The accuracy of Fastloc-GPS locations and implications for animal tracking. Methods Ecol Evol 5:1162–1169

  20. Erdman C, Emerson JW (2007) bcp: an R package for performing a Bayesian analysis of change point problems. J Stat Softw 23:1–13

  21. Festa-Bianchet M (1988) Seasonal range selection in bighorn sheep: conflicts between forage quality, forage quantity, and predator avoidance. Oecologia 75:580–586

  22. Forester JD, Ives AR, Turner MG et al (2007) State-space models link elk movement patterns to landscape characteristics in Yellowstone National Park. Ecol Monogr 77:285–299

  23. Fretwell SD, Lucas HL (1970) On territorial behaviour and other factors influencing habitat distribution in birds. I. Theoretical development. Acta Biol 19:16–36

  24. Fryxell JM (1991) Forage quality and aggregation by large herbivores. Am Nat 138:478–498

  25. Fryxell JM, Wilmshurst JF, Sinclair ARE (2004) Predictive models of movement by serengeti grazers. Ecology 85:2429–2435

  26. Fryxell JM, Hazell M, Börger L et al (2008) Multiple movement modes by large herbivores at multiple spatiotemporal scales. PNAS 105:19114–19119

  27. Godley BJ, Richardson S, Broderick AC et al (2002) Long-term satellite telemetry of the movements and habitat utilisation by green turtles in the Mediterranean. Ecography 25:352–362

  28. Gredzens C, Marsh H, Fuentes MMPB et al (2014) Satellite tracking of sympatric marine megafauna can inform the biological basis for species co-management. PLoS ONE 9:e98944

  29. Hays GC, Luschi P, Papi F et al (1999) Changes in behaviour during the internesting period and postnesting migration for Ascension Island green turtles. Mar Ecol Prog Ser 189:263–273

  30. Hays GC, Adams CR, Broderick AC et al (2000) The diving behaviour of green turtles at Ascension Island. Anim Behav 59:577–586

  31. Hays GC, Mortimer JA, Ierodiaconou D, Esteban N (2014) Use of long-distance migration patterns of an endangered species to inform conservation planning for the world’s largest marine protected area. Conserv Biol 28:1636–1644

  32. Hays GC, Ferreira LC, Sequeira AMM et al (2016) Key questions in marine megafauna movement ecology. Trends Ecol Evol 31:463–475

  33. Hazel J (2009) Evaluation of fast-acquisition GPS in stationary tests and fine-scale tracking of green turtles. J Exp Mar Bio Ecol 374:58–68

  34. Hazel J, Lawler IR, Hamann M (2009) Diving at the shallow end: green turtle behaviour in near-shore foraging habitat. J Exp Mar Bio Ecol 371:84–92

  35. Heithaus MR, Dill LM (2002) Food availability and tiger shark predation risk influence bottlenose dolphin habitat use. Ecology 83:480–491

  36. Heithaus MR, Dill LM (2006) Does tiger shark predation risk influence foraging habitat use by bottlenose dolphins at multiple spatial scales? Oikos 114:257–264

  37. Heithaus MR, Frid A, Dill LM (2002) Shark-inflicted injury frequencies, escape ability, and habitat use of green and loggerhead turtles. Mar Biol 140:229–236

  38. Heithaus MR, Frid A, Wirsing AJ et al (2007) State-dependent risk-taking by green sea turtles mediates top-down effects of tiger shark intimidation in a marine ecosystem. J Anim Ecol 76:837–844

  39. Hobbs NT (1996) Modification of ecosystems by ungulates. J Wildl Manage 60:695–713

  40. Hopcraft JGC, Morales JM, Beyer HL et al (2014) Competition, predation, and migration: individual choice patterns of Serengeti migrants captured by hierarchical models. Ecol Monogr 84:355–372

  41. Houston AI, McNamara JM, Hutchinson JMC (1993) General results concerning the trade-off between gaining energy and avoiding predation. Philos Trans R Soc B 341:375–397

  42. Humphries NE, Queiroz N, Dyer JR et al (2010) Environmental context explains Lévy and Brownian movement patterns of marine predators. Nature 465:1066–1069

  43. Illius AW, Fitzgibbon C (1994) Costs of vigilance in foraging ungulates. Anim Behav 47:481–484

  44. Kittle AM, Fryxell JM, Desy GE, Hamr J (2008) The scale-dependent impact of wolf predation risk on resource selection by three sympatric ungulates. Oecologia 157:163–175

  45. Langvatn R, Hanley TA (1993) Feeding-patch choice by red deer in relation to foraging efficiency. Oecologia 95:164–170

  46. Laundré JW, Hernandez L, Altendorf KB (2001) Wolves, elk, and bison: reestablishing the “landscape of fear” in Yellowstone National Park, USA. Can J Zool 79:1401–1409

  47. Lima SL (2002) Putting predators back into predator-prey behavioral interactions. Trends Ecol Evol 17:70–75

  48. Lima SL, Dill LM (1990) Behavioral decisions made under the risk of predation: a review and prospectus. Can J Zool 68:619–640

  49. Limpus CJ, Limpus DJ (2000) Mangroves in the diet of Chelonia mydas in Queensland, Australia. Mar Turt Newsl 89:13–15

  50. MacDonald BD, Madrak SV, Lewison RL et al (2013) Fine scale diel movement of the east Pacific green turtle, Chelonia mydas, in a highly urbanized foraging environment. J Exp Mar Bio Ecol 443:56–64

  51. Makowski C, Seminoff JA, Salmon M (2006) Home range and habitat use of juvenile Atlantic green turtles (Chelonia mydas L.) on shallow reef habitats in Palm Beach, Florida, USA. Mar Biol 148:1167–1179

  52. McLoughlin PD, Ferguson SH (2000) A hierarchical pattern of limiting factors helps explain variation in home range size. Écoscience 7:123–130

  53. McNaughton SJ, Banyikwa FF, McNaughton MM (1997) Promotion of the cycling of diet-enhancing nutrients by African grazers. Science 278:1798–1800

  54. Mech LD (1977) Productivity, mortality, and population trends of wolves in northeastern Minnesota. J Mammal 58:559–574

  55. Minamikawa S, Naito Y, Sato K et al (2000) Maintenance of neutral buoyancy by depth selection in the loggerhead turtle Caretta caretta. J Exp Biol 203:2967–2975

  56. New LF, Clark JS, Costa DP et al (2014) Using short-term measures of behaviour to estimate long-term fitness of southern elephant seals. Mar Ecol Prog Ser 496:99–108

  57. R Core Team (2014) R: a language and environment for statistical computing.

  58. Rasheed MA (1999) Recovery of experimentally created gaps within a tropical Zostera capricorni (Aschers.) seagrass meadow, Queensland Australia. J Exp Mar Bio Ecol 235:183–200

  59. Rasheed MA, McKenna SA, Carter AB, Coles RG (2014) Contrasting recovery of shallow and deep water seagrass communities following climate associated losses in tropical north Queensland, Australia. Mar Pollut Bull 83:491–499

  60. Riginos C, Grace JB (2008) Savanna tree density, herbivores, and the herbaceous community: bottom-up vs. top-down effects. Ecology 89:2228–2238

  61. Ritchie ME, Tilman D, Knops JMH (1998) Herbivore effects on plant and nitrogen dynamics in Oak savanna. Ecology 79:165–177

  62. Robbins BD, Bell SS (2000) Dynamics of a subtidal seagrass landscape: seasonal and annual change in relation to water depth. Ecology 81:1193–1205

  63. Seminoff JA, Jones TT (2006) Diel movements and activity ranges of Green turtle (Chelonia mydas) at a temperate foraging area in the Gulf of California, Mexico. Herpetol Conserv Biol 1:81–86

  64. Seminoff JA, Resendiz A, Nichols WJ (2002) Home range of green turtles Chelonia mydas at a coastal foraging area in the Gulf of California, Mexico. Mar Ecol Prog Ser 242:253–265

  65. Senko J, Koch V, Megill WM et al (2010) Fine scale daily movements and habitat use of East Pacific green turtles at a shallow coastal lagoon in Baja California Sur, Mexico. J Exp Mar Bio Ecol 391:92–100

  66. Sheppard JK, Jones RE, Marsh H, Lawler IR (2009) Effects of tidal and diel cycles on dugong habitat use. J Wildl Manage 73:45–59

  67. Sih A (1980) Optimal behavior: can foragers balance two conflicting demands? Science 210:1041–1043

  68. Sims DW, Southall EJ, Humphries NE et al (2008) Scaling laws of marine predator search behaviour. Nature 451:1098–1102

  69. Sprogis KR, Raudino HC, Rankin R et al (2016) Home range size of adult Indo-Pacific bottlenose dolphins (Tursiops aduncus) in a coastal and estuarine system is habitat and sex-specific. Mar Mammal Sci 32:287–308

  70. Storch I (1993) Habitat selection by capercaillie in summer and autumn: is bilberry important? Oecologia 95:257–265

  71. Taquet C, Taquet M, Dempster T et al (2006) Foraging of the green sea turtle Chelonia mydas on seagrass beds at Mayotte Island (Indian Ocean), determined by acoustic transmitters. Mar Ecol Prog Ser 306:295–302

  72. Tyne JA, Johnston DW, Rankin R et al (2015) The importance of spinner dolphin (Stenella longirostris) resting habitat: implications for management. J Appl Ecol 52:621–630

  73. Valeix M, Loveridge AJ, Chamaille-Jammes S et al (2009) Behavioral adjustments of African herbivores to predation risk by lions: spatiotemporal variations influence habitat use. Ecology 90:23–30

  74. Van Beest FM, Rivrud IM, Loe LE et al (2011) What determines variation in home range size across spatiotemporal scales in a large browsing herbivore? J Anim Ecol 80:771–785

  75. Wallis de Vries MF, Laca EA, Demment MW (1999) The importance of scale of patchiness for selectivity in grazing herbivores. Oecologia 121:355–363

  76. Wang M, Grimm V (2007) Home range dynamics and population regulation: an individual-based model of the common shrew Sorex ayaneus. Ecol Modell 205:397–409

  77. Watanabe YY, Sato K, Watanuki Y et al (2011) Scaling of swim speed in breath-hold divers. J Anim Ecol 80:57–68

  78. Wirsing AJ, Heithaus MR, Dill LM (2007) Living on the edge: dugongs prefer to forage in microhabitats that allow escape from rather than avoidance of predators. Anim Behav 74:93–101

  79. Worton BJ (2002) Kernel methods for estimating the utilization distribution in home-range studies. Ecology 83:3257–3265

  80. Zieman JC, Iverson RL, Ogden JC (1984) Herbivory effects on Thalassia testudinum leaf growth and nitrogen content. Mar Ecol Prog Ser 15:151–158

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We thank British Forces BIOT, MRAG Ltd, NAVFACFE PWD DG Environmental Department, and the many volunteers on Diego Garcia for logistical support. We thank L. Avens and two anonymous reviewers for their constructive comments which helped to improve this manuscript. FC and GCH developed the study, as part of a larger project initially conceived by GCH, NE and JAM. FC led the data processing, analyses and interpretation of the data, with contribution from GCH and AMD. FC led the writing with input from GCH. All other authors commented on the manuscript.


This project was funded by a Darwin Initiative Challenge Fund grant (EIDCF008), the Department of the Environment Food and Rural Affairs (DEFRA), the Foreign and Commonwealth Office (FCO), College of Science of Swansea University, and the BIOT Scientific Advisory Group (SAG) of the FCO.

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Correspondence to Fredrik Christiansen.

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Christiansen, F., Esteban, N., Mortimer, J.A. et al. Diel and seasonal patterns in activity and home range size of green turtles on their foraging grounds revealed by extended Fastloc-GPS tracking. Mar Biol 164, 10 (2017).

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  • Home Range
  • Predation Risk
  • Home Range Size
  • Supplementary Material Table
  • Green Turtle