Editing Painted turtle (section)

===Seasonal routine and hibernation===
<!-- [[File:Muskrat lodge.jpg|thumb|right|alt=mound of sticks in the water about 10 feet from shore|Muskrat burrow—possible painted turtle hibernation spot]] not enough room-->

In the spring, when the water reaches {{convert|15|-|18|C|F|abbr=on|0}}, the turtle begins actively foraging. However, if the water temperature exceeds {{nowrap|{{convert|30|C|F|abbr=on|0}}}}, the turtle will not feed. In fall, the turtle stops foraging when temperatures drop below the spring set-point.{{sfn|Ernst|Lovich|2009|p=293}}

During the winter, the turtle hibernates. In the north, the inactive season may be as long as from October to March, while the southernmost populations may not hibernate at all.{{sfn|Carr|1952|p=217}} While hibernating, the body temperature of the painted turtle averages {{nowrap|{{convert|6|C|F|abbr=on|0}}}}.{{sfn|Ernst|Barbour|Lovich|1994|p=284}} Periods of warm weather bring the turtle out of hibernation, and even in the north, individuals have been seen basking in February.{{sfn|Ernst|Barbour|Lovich|1994|p=281}}

The painted turtle hibernates by burying itself, either on the bottom of a body of water, near water in the shore-bank or the burrow of a [[muskrat]], or in woods or pastures. When hibernating underwater, the turtle prefers shallow depths, no more than {{nowrap|{{convert|2|m|ft|abbr=on|0}}}}. Within the mud, it may dig down an additional {{nowrap|{{convert|1|m|ft|abbr=on|0}}}}.{{sfn|Ernst|Barbour|Lovich|1994|p=284}} In this state, the turtle does not breathe, although if surroundings allow, it may get some oxygen through its skin.<ref name="Jackson">{{cite journal |last=Jackson |first=D. C. |author2=Rauer, E. M. |author3=Feldman, R. A. |author4= Reese, S. A.  |title=Avenues of extrapulmonary oxygen uptake in western painted turtles (''Chrysemys picta belli'') at 10 °C |journal=Comparative Biochemistry and Physiology A |date=August 2004 |volume=139 |issue=2 |pages=221–227 |pmid=15528171 |doi=10.1016/j.cbpb.2004.09.005 }}</ref> The species is one of the best-studied [[vertebrate]]s able to survive long periods [[Hypoxia (medical)|without oxygen]]. Adaptations of its blood chemistry, brain, heart, and particularly its shell allow the turtle to survive extreme [[lactic acid]] buildup while oxygen-deprived.<ref name="Jackson 2002">{{cite journal|last=Jackson|first=Donald C.|date=2002|title=Hibernating without oxygen: physiological adaptations of the painted turtle|journal=The Journal of Physiology|volume=543|issue=3|pages=731–737|doi=10.1113/jphysiol.2002.024729|pmc=2290531|pmid=12231634}}<!--|access-date=2010-12-13 --></ref>

The painted turtle, like many other turtles, has the ability to breathe through its anus, or cloaca. This unusual adaptation, known as cloacal respiration, allows turtles to hibernate overwinter in colder climates where water surfaces may freeze over. Painted turtles also have specialized skin cells that absorb oxygen from the water. This process is known as cutaneous respiration. These two respiratory strategies, along with their other resilient traits, are vital to this reptile's success in colder climates.