“Dole” is one of the older, less common alternatives to “bale,” and its root is a bit unexpected: it’s related to an old English word for sorrow or grief, the same root behind terms like “a dole of doves” in historic collective-noun lists. Applied to turtles, the connection seems to be more about their slow, solemn movements than any actual sadness, more mood than meaning.
The behavior behind it is the same basking and shelter-sharing seen across freshwater turtle species. Ponds, slow rivers, and marshes with limited log or rock basking spots naturally concentrate turtles into the same small areas, where they’ll tolerate close company for the sake of a good sunny perch. Freshwater turtles also often overwinter by burying themselves in mud at the bottom of a pond, another context where several individuals end up sharing the same patch of habitat without much active interaction.
“Dole” has largely faded from everyday use, kept alive mostly by lists like this one rather than common speech.
Example: “Old field guides still list ‘a dole of turtles’ alongside the more familiar ‘bale.'”
Related: Collective Nouns for Reptiles · What Is a Group of Turtles Called?