Posts Tagged ‘black-tailed jack rabbit’

Hares (Lepus sp.) in Southeastern North America during the Late Pleistocene?

April 17, 2017

Librarians can be a pain in the ass.  On 1 occasion I attempted to check out a book from the Augusta College library.  The librarian told me I needed to purchase an alumni card for the privilege of borrowing a book from my alma mater.  I shelled out $25 for the card, and the same #!#!en librarian still wouldn’t let me take the book home.  Another time I was seeking an old Alabama Journal of Science article.  The authors of the article were dead or in a nursing home so I couldn’t get a copy from them.  The journal posts new issues online but not ones this old.  I contacted a librarian from the Alabama library system and asked her to loan the journal to my nearest library where I could pick it up or at least send me a Xeroxed copy of the article.  I offered to pay for postage and use of the copy machine.  She refused because I was not affiliated with the University of Alabama library system.  My efforts to obtain this article have been stymied for 8 years, but I recently learned a surprising tidbit of information from this article that was referenced in another paper I recently came across.  A tooth identified as comparing favorably to hare was found at Bogue Chitto Creek in Dallas County, Alabama; a site where subfossil remains of late Pleistocene species are occasionally discovered.  Bones of hares have been excavated from 7 sites in Florida that date from the Miocene to the early and mid-Pleistocene, but hares are otherwise unknown from late Pleistocene sites this far south, making this an unique find.

Scientists can’t identify this specimen to a species level based on just this single tooth. Bjorn Kurten, co-author of Pleistocene Mammals of North America, states it is difficult to distinguish between rabbit (Sylvilagus sp.) and hare (Lepus sp.)  teeth, and discerning the difference between hare species based on teeth is even harder, if not impossible.  The tooth may have been from a white-tailed (Lepus townsendii), black-tailed (L. californicus), antelope (L. alleni), or an unknown extinct species of jackrabbit that occupied a small geographic range during the late Pleistocene.  This site is probably too far south for another species of hare–the snowshoe (L. americanus).  It’s also possible the tooth is incorrectly identified and belonged to a true rabbit.  Cottontails have long been abundant all over the south, and they are well represented in the fossil record here.  When paleontologists designate a specimen as comparing favorably (cf), they are not 100% certain of the identification.

Map of Alabama highlighting Dallas County

Bogue Chitto Creek, flows through Dallas County, Alabama.  Many Pleistocene fossil specimens have been found in this creek, including the tooth discussed in this article.

Image result for range map for black-tailed jack rabbit

Present day range map of the  black-tailed jackrabbit.  Western species of hares lived in the southeast during the early to mid-Pleistocene.  Scant evidence suggests they may have occurred in the Black Prairie region of central Alabama during the late Pleistocene as well.

Image result for black-tailed jackrabbit

Black-tailed jackrabbit.  Hares differ from true rabbits.  Their young are born with their eyes open and able to hop about and flee from predators.

Bogue Chitto Creek flows through the Black Prairie region of central Alabama.  The compact clay soils here favor grass over trees, and the Black Prairie region itself extends into neighboring Mississippi and Georgia.  Western hare species prefer large treeless plains, and the predominance of this environment here may explain why a relic population of hares existed in this region during the late Pleistocene.  Other environments in the southeast often climax into forests where western hare species can’t survive.  Lagomorphs (hares, rabbits, and pikas) are susceptible to disease outbreaks, and relic populations of hares in the southeast could have easily succumbed to pestilence.  Before I learned about this tooth, I wondered why there was no evidence of hares in the southeast during the late Pleistocene when arid climates led to a greater prevalence of open environments.  This evidence suggests they may have had a local distribution in some parts of the south then.

Image result for snowshoe hares

Snowshoe hares turn white in winter and brown in summer.

Unlike their western relatives, snowshoe hares prefer forested environments.  A leg bone of a snowshoe hare was found in Cave ACb-2 in Colbert County, Alabama.  This is the southernmost known occurrence of this species, although this is not far from its present day range.  There is anecdotal evidence snowshoe hares occurred as far south as the Great Smoky Mountains National Park as recently as the early 20th century where they possibly still exist today.  Snowshoe hare remains dating to the late Pleistocene have also been found in 2 other southern states–Arkansas and Kentucky.  They require areas with snowpack on the ground for at least part of the year.

Reference:

Ebersole, Jon; and Sandy Ebersole

“Late Pleistocene Mammals of Alabama: A Comprehensive Faunal Review with 21 Previously Unreported Taxon”

Alabama Museum of Natural History Bulletin 28 December 2011

 

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