Missouri’s 111 records make the state look like bog lemming country, but the map behind that number is lopsided. Eighty-four of the 111 come from St. Charles County alone, just northwest of St. Louis, while Phelps County adds 8 and the rest scatter across a dozen more counties. One well-worked site can inflate a whole state’s tally, and that appears to be the story here.
A spring trapping signature
Missouri reports crest sharply in March and April, with 34 and 38 records respectively, then nearly vanish from May onward. Southern bog lemmings stay active all year, feeding by day or night beneath thick cover, so a two-month spike like that reads as survey season, not lemming season. Where the same ground is trapped each spring, the calendar fills in whether or not the animals change anything.
The wet ground that fits
The bottomlands that match the species’ needs, Mingo National Wildlife Refuge, Big Oak Tree State Park, and Swan Lake National Wildlife Refuge, hold the soggy sedge and grass cover it favors, yet confirmed records from them are nearly absent; Mingo’s wilderness area shows a single record. That contrast, heavy records in one suburban county and almost none in the state’s best wet bottomland, is what under-sampling looks like. NatureServe ranks the species S4 in Missouri, apparently secure, and it holds no separate state listing.
Full species profile
