Microtus ochrogaster Wagner, 1843

Prairie Vole

Microtus ochrogaster are known from one location in southwestern Louisiana (Iowa, Calcasieu Parish). These specimens were collected by Vernon Bailey in 1899 with vouchers deposited in NMNH and LSUMZ. Bailey originally assigned the specimens as M. ludovicianus primarily due to their isolation (> 800 km) from other populations of M. ochrogaster . However, Lowery (1974) decided to treat those specimens as a subspecies, M. o. ludovicianus, because up to that point no one had examined morphological differences between the populations and thus saw no justification for providing them species rank. Since the 1930’s Lowery and many others (including some of the current authors) have set traps in the general vicinity of Bailey’s original field site and have yielded no captures of M. ochrogaster . Recent phylogenetic work suggested a high amount of taxonomic uncertainly surrounding the specimens from Louisiana in so much as they may represent a separate species (Robinson 2020).

Microtus pinetorum Le Conte, 1830

Woodland Vole

Microtus pinetorum are found in the northern parishes and parishes directly west of the Mississippi River in eastern Louisiana. Since Lowery (1974), new specimen records were reported from Jackson, Livingston, and Morehouse parishes. Additionally, one nonvouchered record was reported from La Salle Parish.

Specimen records (6).— Jackson Parish (4): 1/ 2 mi S Clay, 32.404N, - 92.677W, 1 (FHSM 15539) ; Ansley, 32.396N, - 92.693W, 2 (FHSM 15540, 15541); 2 mi SW Ansley, 32.375N, - 92.717W, 1 (FHSM 15542) . Livingston Parish (1): 3.3 mi NNE Denham Springs, 30.526N, - 90.928W, 1 (LSUMZ 20058) . Morehouse Parish (1): Prairie Mer Rouge, 1 (AMNH M-16011) .

Nonvouchered records (1).— La Salle Parish (1): Jena, LA, USA, private property, 31.698N, - 92.122W, 1 (iNaturalist 125567843) .