The eastern "prairie dog", a Thirteen-lined Ground Squirrel (
Ictidomys tridecemlineatus) crouches at the entrance to one of its burrows. Like true prairie dogs, this species is a member of the squirrel family (Sciuridae) and is closely allied to the more westerly prairie dogs. Like the four species of prairie dogs, almost all of the 21 ground squirrel species (formerly in the genus
Spermophilus) are westerners. Only the Thirteen-lined Ground Squirrel and Franklin's Ground Squirrel ((
Poliocitellus franklinii) range east of the Mississippi River, and the eastern terminus of the Thirteen-lined Ground Squirrel range coincides with the former range of the great prairie ecosystem that once blanketed much of the midwestern U.S. The squirrels make it no further east than central Ohio. Franklin's Ground Squirrel barely makes it as far east as westernmost Indiana.
On August 18, Shauna and I made a run down to a relict ground squirrel population near Lancaster, Ohio. As is often the case, it took a while to let the squirrels adapt to our presence. After a bit, the chap in the previous photo popped up into its sentry posture, the better to view its surroundings. Another squirrel raced around behind it, and we observed another across the road.
This is their habitat: A closely cropped grassy field. Historically, Thirteen-lined Ground Squirrels were probably associated with the 5% or so of Ohio that was original prairie. As that habitat got pulverized with the advent of steel chisel plows - probably 99.9% or so destroyed - I suspect squirrels began to occupy artificial open habitats in those former prairie regions. Even today, the known populations are virtually all in or at least very near to ancestral prairie lands.
At the time of Jack Gottschang's book A Guide to the Mammals of Ohio in 1981, he listed records from 27 of Ohio's 88 counties, although they were likely extirpated from some of those by then, and conversely, were undoubtedly present in many other counties where they were not documented by actual specimens (Gottschang's standard for adequate documentation). Now, the squirrels are surely in far fewer places. There are many sites where there were known colonies, that no longer exist. Human persecution undoubtedly is the culprit in many cases. Ground squirrels and prairie dogs have long been treated as varmints and pests (personal observation: people who freely use the term "varmint" know very little about natural history, and less than nothing about ecology) and eradicated accordingly. Some once thriving colonies, such as the one that occupied the large field at the entrance to Green Lawn Cemetery in Columbus, were exterminated by people, in the latter case, cemetery personal.
Thirteen-lined Ground Squirrels seem to have become scarce enough that formerly listing them at some level of rarity at the level may be warranted. Collection of data on existing populations should be done, to inventory the extent of ground squirrel populations. To that end, if you know of any sites that are still extant, please let me know (locale, at least to the county level, and approximate population size). I can be reached at jimmccormac35 AT gmail.com.
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