Editing Painted turtle (section)

===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}}