Editing Painted turtle (section)

==Life cycle==

===Mating===

[[File:Chrysemys picta dorsalis (aka).jpg|thumb|right|Male southern painted turtle shows his long front claws.]]
[[File:Painted turtle.jpg|thumb|Female painted turtle]]
The painted turtles mate in spring and fall in waters of {{convert|10|-|25|C|F|abbr=on|0}}.{{sfn|Ernst|Barbour|1989|p=202}} Males start [[Spermatogenesis|producing sperm]] in early spring, when they can bask to an internal temperature of {{convert|17|C|F|abbr=on|0}}.{{sfn|Ernst|Barbour|Lovich|1994|p=289}}{{sfn|Ernst|Barbour|Lovich|1994|p=287}} Females begin their reproductive cycles <!-- Please do not wikilink to menstrual cycle as that is a mammalian process. Most of the sex articles in wiki are human or perhaps mammal descriptive. As of DEC2010, there was no suitable wikilink, so the simple term reproductive cycle was used. A red link is probably not a good idea either as people keep wanting to link to the inappropriate mammalian sex articles. Probably better to leave as is, is understandable, or just write an article on the sexual cycles of reptiles if you so choose. -->in mid-summer, and [[Ovulation#Ovulation|ovulate]] the following spring.<ref name="wcsu.edu-Reproduction" />

[[Courtship display|Courtship]] begins when a male follows a female until he meets her face-to-face.<ref name="sbaa.ca">{{cite web | url = http://www.sbaa.ca/projects.asp?cn=316 | title = Painted turtle research in Algonquin provincial park | access-date = 2010-09-17 | date = 2005 | publisher = The Friends of Algonquin Park| archive-url = https://web.archive.org/web/20071011165743/http://sbaa.ca/projects.asp?cn=316 | archive-date = 2007-10-11 }}</ref> He then strokes her face and neck with his elongated front claws, a gesture returned by a receptive female. The pair repeat the process several times, with the male retreating from and then returning to the female until she swims to the bottom, where they [[copulation (zoology)|copulate]].<ref name="wcsu.edu-Reproduction" /><ref name="sbaa.ca" /> As the male is smaller than the female, he is not dominant.<ref name="sbaa.ca" /> Although not directly observed, evidence indicates that the male will inflict injury on the female in attempts of coercion.<ref>{{cite journal |last1=Moldowan |first1=P.D. |last2=Brooks |first2=R.J. |last3=Litzgus |first3=J.D. |date=2020 |title=Demographics of injuries indicate sexual coercion in a population of Painted Turtles (''Chrysemys picta'') |journal=Canadian Journal of Zoology |volume=98 |issue=4 |pages=269–278 |doi=10.1139/cjz-2019-0238 |s2cid=214093193 }}</ref> Males will use their tooth-like cusps on their beaks and their foreclaws during this act of coercion with the female.<ref>{{cite journal |last1=Moldowan |first1=Patrick D. |last2=Brooks |first2=Ronald J. |last3=Litzgus |first3=Jacqueline D. |title=Sex, shells, and weaponry: coercive reproductive tactics in the painted turtle, Chrysemys picta |journal=Behavioral Ecology and Sociobiology |date=10 November 2020 |volume=74 |issue=12 |pages=142 |id={{ProQuest|2471612605}} |doi=10.1007/s00265-020-02926-w |doi-access=free }}</ref> The female stores [[sperm]], to be used for up to three [[clutch (eggs)|clutches]], in her [[Oviduct#Amniotes|oviducts]]; the sperm may remain viable for up to three&nbsp;years.{{sfn|Ernst|Lovich|2009|p=200}} A single clutch [[Superfecundation#Heteropaternal superfecundation|may have multiple fathers]].{{sfn|Ernst|Lovich|2009|p=200}}

===Egg-laying===

[[Nesting instinct|Nesting]] is done, by the females only, between late May and mid-July.<ref name="wcsu.edu-Reproduction" /> The nests are vase-shaped and are usually dug in sandy soil, often at sites with southern exposures.{{sfn|Ernst|Lovich|2009|p=201}} Nests are often within {{convert|200|m|yd|abbr=on|-1}} of water, but may be as far away as {{convert|600|m|yd|abbr=on|-1}}, with older females tending to nest further inland. Nest sizes vary depending on female sizes and locations but are about {{convert|5|-|11|cm|in|abbr=on|0}} deep.{{sfn|Ernst|Lovich|2009|p=201}} Females may return to the same sites several consecutive years, but if several females make their nests close together, the eggs become more vulnerable to predators.{{sfn|Ernst|Lovich|2009|p=201}} Female eastern painted turtles have been shown to nest together, possibly even participating in communal nesting.<ref name=Kell/>

[[File:Eastern Painted Turtle laying eggs 01.jpg|thumb|upright|alt=A female with four eggs in a nest|Eastern female laying eggs in a nest]]

The female's optimal body temperature while digging her nest is {{convert|29|-|30|C|F|abbr=on|0}}.{{sfn|Ernst|Lovich|2009|p=201}} If the weather is unsuitable, for instance a too hot night in the Southeast, she delays the process until later at night.{{sfn|Ernst|Lovich|2009|p=201}} Painted turtles in Virginia have been observed waiting three weeks to nest because of a hot drought.{{sfn|Ernst|Barbour|Lovich|1994|p=290}}

While preparing to dig her nest, the female sometimes exhibits a mysterious preliminary behavior. She presses her throat against the ground of different potential sites, perhaps sensing moisture, warmth, texture, or smell, although her exact motivation is unknown. She may further temporize by excavating several false nests{{sfn|Ernst|Lovich|2009|p=201}} as the [[wood turtle]]s also do.{{sfn|Ernst|Lovich|2009|p=259}}

The female relies on her hind feet for digging. She may accumulate so much sand and mud on her feet that her mobility is reduced, making her vulnerable to predators. To lighten her labors, she lubricates the area with her bladder water.{{sfn|Ernst|Lovich|2009|p=201}} Once the nest is complete, the female deposits into the hole. The freshly laid eggs are white, elliptical, porous, and flexible.{{sfn|Ernst|Lovich|2009|p=203}} From start to finish, the female's work may take four&nbsp;hours. Sometimes she remains on land overnight afterwards, before returning to her home water.{{sfn|Ernst|Lovich|2009|p=201}}

Females can lay five clutches per year, but two is a normal average after including the 30–50% of a population's females that do not produce any clutches in a given year.{{sfn|Ernst|Lovich|2009|p=201}} In some northern populations, no females lay more than one clutch per year.{{sfn|Ernst|Lovich|2009|p=201}} Bigger females tend to lay bigger eggs and more eggs per clutch.{{sfn|Ernst|Lovich|2009|p=202}} Clutch sizes of the subspecies vary, although the differences may reflect different environments, rather than different genetics. The two more northerly subspecies, western and midland, are larger and have more eggs per clutch—11.9 and 7.6, respectively—than the eastern (4.9). Within subspecies, also, the more northerly females lay larger clutches.{{sfn|Ernst|Lovich|2009|p=201}}

===Growth===
[[File:Flickr - Oregon Department of Fish & Wildlife - western painted turtle hatchlings vandebergh odfw.jpg|thumb|alt=Several baby painted turtles on moss on a light table.|Hatchlings]]
[[File:Painted turtle hatchling with egg tooth.jpg|thumb|A painted turtle hatching with an egg tooth]]
Incubation lasts 72–80&nbsp;days in the wild<ref name="wcsu.edu-Reproduction" /> and for a similar period in artificial conditions.{{sfn|Ernst|Barbour|Lovich|1994|p=290}} In August and September, the young turtle breaks out from its egg, using a special projection of its jaw called the [[egg tooth]].<ref name="BC" /> Not all offspring leave the nest immediately, though.<ref name="wcsu.edu-Reproduction" /> Hatchlings north of a line from Nebraska to northern Illinois to New Jersey{{sfn|Packard et al.|2002|p=300}} typically arrange themselves symmetrically{{sfn|Ernst|Lovich|2009|p=206}} in the nest and overwinter to emerge the following spring.<ref name="wcsu.edu-Reproduction" />

The hatchling's ability to survive winter in the nest has allowed the painted turtle to extend its range farther north than any other American turtle. The painted turtle is genetically adapted to survive extended periods of subfreezing temperatures with blood that can remain [[supercooling|supercooled]] and skin that resists penetration from ice crystals in the surrounding ground.{{sfn|Packard et al.|2002|p=300}} The hardest freezes nevertheless kill many hatchlings.<ref name="wcsu.edu-Reproduction" />

Immediately after hatching, turtles are dependent on egg yolk material for sustenance.{{sfn|Ernst|Lovich|2009|p=206}} About a week to a week and a half after emerging from their eggs (or the following spring if emergence is delayed), hatchlings begin feeding to support growth. The young turtles grow rapidly at first, sometimes doubling their size in the first year. Growth slows sharply at [[sexual maturity]] and may stop completely.{{sfn|Ernst|Barbour|Lovich|1994|p=292}} Likely owing to differences of habitat and food by water body, growth rates often differ from population to population in the same area. Among the subspecies, the western painted turtles are the quickest growers.{{sfn|Ernst|Lovich|2009|p=207}}

Females grow faster than males overall, and must be larger to mature sexually.{{sfn|Ernst|Barbour|Lovich|1994|p=292}} In most populations males reach sexual maturity at 2–4&nbsp;years old, and females at 6–10.{{sfn|Ernst|Barbour|Lovich|1994|p=287}} Size and age at maturity increase with latitude;{{sfn|Ernst|Lovich|2009|p=197}} at the northern edge of their range, males reach sexual maturity at 7–9&nbsp;years of age and females at 11–16.<ref name="sbaa.ca" />
{{Clear}}