Editing Sea turtle (section)

==Life cycle==
[[File:Life Cycle of a Sea Turtle.svg|thumb|300px|1) Male and female sea turtles age in the ocean and migrate to shallow coastal water. 2) Sea turtles mate in the water near offshore nesting sites. 3) The adult male sea turtles return to the feeding sites in the water. 4) Female sea turtles cycle between mating and nesting. 5) Female sea turtles lay their eggs. 6) When the season is over, female sea turtles return to feeding sites. 7) Baby sea turtles incubate for 60–80 days and hatch. 8) Newly hatched baby sea turtles emerge from nests and travel from the shore to the water. 9) Baby sea turtles mature in the ocean until they are ready to begin the cycle again.]]
Sea turtles are thought to reach sexual maturity from about 10−20 years old depending on species and methodology. However, reliable estimates are difficult to ascertain.<ref>{{cite journal |last1=Bedolla-Ochoa |first1=C. |last2=Reyes-López |first2=M. A. |last3=Rodríguez-González |first3=H. |last4=Delgado-Trejo |first4=C. |title=Black Sea Turtle (Chelonia mydas agassizii) Life History in the Sanctuary of Colola Beach, Michoacan, Mexico |journal=Animals |date=2023 |volume=13 |issue=3 |page=406 |doi=10.3390/ani13030406|pmid=36766296 |pmc=9913439 |doi-access=free }}</ref><ref>{{cite journal |last1=Caillouet |first1=C. W. |last2=Shaver |first2=D. J. |last3=Landry |first3=A. M. |last4=Owens |first4=D. W. |last5=Pritchard |first5=P. C. H. |title=Kemp's Ridley Sea Turtle (Lepidochelys kempii) Age at First Nesting |journal=Chelonian Conservation and Biology |date=2011 |volume=10 |issue=2 |pages=288–293 |doi=10.2744/CCB-0836.1|s2cid=86092201 }}</ref><ref>{{cite journal |last1=Levasseur |first1=K. E. |last2=Stapleton |first2=S. P. |last3=Quattro |first3=J. M. |title=Precise natal homing and an estimate of age at sexual maturity in hawksbill turtles |journal=Animal Conservation |date=2021 |volume=24 |issue=3 |pages=523–535 |doi=10.1111/acv.12657|bibcode=2021AnCon..24..523L |s2cid=228861161 }}</ref><ref>{{cite journal |last1=Jones |first1=T. T. |last2=Hastings |first2=M. D. |last3=Bostrom |first3=B. L. |last4=Pauly |first4=D. |last5=Jones |first5=D. R. |title=Growth of captive leatherback turtles, Dermochelys coriacea, with inferences on growth in the wild: Implications for population decline and recovery |journal=Journal of Experimental Marine Biology and Ecology |date=2011 |volume=399 |issue=1 |pages=84–92 |doi=10.1016/j.jembe.2011.01.007|bibcode=2011JEMBE.399...84J }}</ref> Mature sea turtles may migrate thousands of miles to reach breeding sites. After mating at sea, adult female sea turtles return to land to lay their eggs. Different species of sea turtles exhibit various levels of [[philopatry]]. In the extreme case, females return to the same beach where they hatched. This can take place every two to four years in maturity.

[[File:Turtle golfina escobilla Oaxaca Mexico Claudio Giovenzana 2010.jpg|thumbnail|left|An olive ridley sea turtle nesting on Escobilla Beach, [[Oaxaca]], [[Mexico]]]]The mature nesting female hauls herself onto the beach, nearly always at night, and finds suitable sand in which to create a nest. Using her hind flippers, she digs a circular hole {{convert|40|to|50|cm|in}} deep. After the hole is dug, the female then starts filling the nest with her clutch of soft-shelled eggs. Depending on the species, a typical clutch may contain 50–350 eggs. After laying, she re-fills the nest with sand, re-sculpting and smoothing the surface, and then camouflaging the nest with vegetation until it is relatively undetectable visually.<ref name="PelagicDev" /> She may also dig decoy nests.<ref>{{cite news |last1=Waldstein |first1=David |title=Mother Sea Turtles Might Be Sneakier Than They Look |url=https://www.nytimes.com/2020/05/19/science/sea-turtles-decoy-nests.html |access-date=19 May 2020 |work=[[The New York Times]] |date=19 May 2020}}</ref>  The whole process takes 30 to 60 minutes. She then returns to the ocean, leaving the eggs untended.<ref name="Audubon1897">{{cite book | last =Audubon | first =Maria R. | author-link =Maria Audubon | title =Audubon and His Journals: Dover Publications Reprint | publisher =Scribner's Sons | orig-year=First published 1897 |year=1986 | location =New York | pages = 373–375| isbn = 978-0-486-25144-8}}</ref>

Females may lay 1–8 clutches in a single season. Female sea turtles alternate between mating in the water and laying their eggs on land. Most sea turtle species nest individually. But ridley sea turtles come ashore en masse, known as an ''arribada'' (arrival). With the Kemp's ridley sea turtle this occurs during the day.

Sea turtles have [[temperature-dependent sex determination]].<ref name=":3">{{cite journal|last=Mrosovsky|first=N.|title=Sex ratio bias in hatchling sea turtles from artificially incubated eggs|journal=Biological Conservation|date=August 1982|volume=23|issue=4|pages=309–314|doi=10.1016/0006-3207(82)90087-8|bibcode=1982BCons..23..309M }}</ref><ref name=":4">{{cite journal|last=Morreale|first=S.|author2=Ruiz, G. |author3=Spotila, J. |author4= Standora, E. |title=Temperature-dependent sex determination: current practices threaten conservation of sea turtles|journal=Science|date=11 June 1982|volume=216|issue=4551|pages=1245–1247|doi=10.1126/science.7079758 |pmid=7079758|bibcode=1982Sci...216.1245M}}</ref><ref name=":5">{{cite journal|last=Mrosovsky|first=N.|author2=Hopkins-Murphy, S. R. |author3=Richardson, J. I. |title=Sex Ratio of Sea Turtles: Seasonal Changes|journal=Science|date=17 August 1984|volume=225|issue=4663|pages=739–741|doi=10.1126/science.225.4663.739|pmid=17810293|bibcode=1984Sci...225..739M|s2cid=43726465}}</ref><ref name=":6">{{cite journal|last=Godfrey|first=Matthew H.|author2=Barreto, R. |author3=Mrosovsky, N. |title=Metabolically-Generated Heat of Developing Eggs and Its Potential Effect on Sex Ratio of Sea Turtle Hatchlings|journal=Journal of Herpetology|date=December 1997|volume=31|issue=4|pages=616–619|doi=10.2307/1565626|jstor=1565626}}</ref><ref name=":7">{{cite journal|last=Ewert|first=Michael A.|author2=Jackson, Dale R. |author3=Nelson, Craig E. |title=Patterns of temperature-dependent sex determination in turtles|journal=Journal of Experimental Zoology|date=15 September 1994|volume=270|issue=1|pages=3–15|doi=10.1002/jez.1402700103|bibcode=1994JEZ...270....3E }}</ref> Warmer temperatures produce female hatchlings, while cooler temperatures produce male hatchlings.<ref name=":3" /><ref name=":4" /><ref name=":5" /><ref name=":6" /><ref name=":7" /><ref>{{Cite journal|title = Temperature dependent sex determination in sea turtles|last1 = Standora |first1=Edward |last2=Spotila |first2=James|date = Aug 5, 1985|journal = Copeia|doi = 10.2307/1444765|jstor=1444765|volume=1985|issue = 3 |pages=711–722}}</ref> The eggs will incubate for 50–60 days. The eggs in one nest hatch together over a short period of time. The baby sea turtles break free of the egg shell, dig through the sand, and crawl into the sea. Most species of sea turtles hatch at night. However, the Kemp's ridley sea turtle commonly hatches during the day. Sea turtle nests that hatch during the day are more vulnerable to predators, and may encounter more human activity on the beach.

[[Image:YosriTelurPenyu6.jpg|thumb|Sea turtle sex depends on sand temperature while the egg is incubating.]]
Larger hatchlings have a higher probability of survival than smaller individuals, which can be explained by the fact that larger offspring are faster and thus less exposed to predation. Predators can only functionally intake so much; larger individuals are not targeted as often. A study conducted on this topic shows that body size is positively correlated with speed, so larger baby sea turtles are exposed to predators for a shorter amount of time.<ref>{{cite journal|last1=Janzen|first1=Fredric J.|last2=Tucker|first2=John K.|last3=Paukstis|first3=Gary L. |year=2007 |title=Experimental analysis of an early life-history stage: direct or indirect selection on body size of hatchling turtles? |journal=Functional Ecology |volume=21 |issue=1 |pages=162–170 |doi=10.1111/j.1365-2435.2006.01220.x |bibcode=2007FuEco..21..162J |url=http://www.public.iastate.edu/~fjanzen/pdf/00Ecology.pdf}}</ref> The fact that there is size dependent predation on [[Chelonia (order)|chelonians]] has led to the evolutionary development of large body sizes.

In 1987, Carr discovered that the young of green and loggerhead sea turtles spent a great deal of their [[pelagic]] lives in floating [[sargassum]] mats. Within these mats, they found ample shelter and food. In the absence of sargassum, young sea turtles feed in the vicinity of [[upwelling]] "fronts".<ref name="PelagicDev">{{cite journal | last =Carr | first =Archie | author-link =Archie Carr | title =New Perspectives on the Pelagic Stage of Sea Turtle Development | journal =Conservation Biology | volume =1 | issue =2 | pages =103–121 | doi = 10.1111/j.1523-1739.1987.tb00020.x|date=August 1987 | jstor=2385827| bibcode =1987ConBi...1..103C | hdl =2027/uc1.31822031475700 | url =https://babel.hathitrust.org/cgi/imgsrv/download/pdf?id=uc1.31822031475700;orient=0;size=100;seq=1;attachment=0 | hdl-access =free }}</ref> In 2007, Reich determined that green sea turtle hatchlings spend the first three to five years of their lives in [[pelagic]] waters. In the open ocean, pre-juveniles of this particular species were found to feed on [[zooplankton]] and smaller [[nekton]] before they are recruited into inshore [[seagrass meadow]]s as obligate herbivores.<ref name="LS20070918">{{cite news | last =Brynner | first =Jeanna | title =Sea Turtles' Mystery Hideout Revealed | work =LiveScience | publisher =Imaginova Corp. | date =19 September 2007 | url =http://www.livescience.com/animals/070919_sea_turtle.html | access-date =20 September 2007}}</ref><ref name="Reich2007">{{cite journal | last =Reich | first =Kimberly J. | author-link =Kimberly Reich |author2=Karen A. Bjorndal |author3= Alan B. Bolten | title =The 'lost years' of green turtles: using stable isotopes to study cryptic lifestages | journal =Biology Letters |volume= 3|issue=6 |pages=712–714 | date =18 September 2007 | doi =10.1098/rsbl.2007.0394 | pmid =17878144 | pmc =2391226}}</ref>