Posts Tagged ‘Snowshoe hare’

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

 

What was the Pleistocene Range of the Canadian Lynx (Lynx canadensis)?

July 15, 2013

William Brewster was an ornithologist who went on an expedition to the North Carolina mountains in 1885 before much of it was logged.  He was interested in finding boreal species of birds in the higher elevations where spruce forests replaced deciduous forests.  On Whiteside Mountain he found a remarkable forest of 70 foot tall hemlock trees with a thick understory of 25 foot tall rhododendrons.  The highlight of his expedition though was his journey to the summit of Black Mountain.  Below 4050 feet, a forest of oak, hickory, chestnut, tulip, beech, and sugar maple covered the mountain.  Brewster declared it the finest forest he had ever seen–many of the trees were 6-7 feet in diameter, 125 feet tall, and neatly spaced 100 feet apart.  At 4050 feet, Brewster encountered the first red spruce tree.  A mixed forest of red spruce and deciduous trees stood between 4050 and 5050 feet.  At this elevation he encountered red squirrels–an animal that prefers boreal forests, but he had begun seeing boreal species of birds at 3600 feet..  Above 5050 feet, the forest consisted of red spruce, balsam fir, and a few yellow birches.  Stunted black spruce trees grew at the summit.  Brewster camped near the summit and heard a wolf howl and saw sign of bear and deer.  Evidentally, large mammals hadn’t been extirpated from this region yet.  He also mentioned in his journal that locals believed Canadian lynx lived at higher elevations, replacing bobcats which roamed the lower elevations.  Other than this passage, I can find no evidence in the scientific literature of Canadian lynx in North Carolina.

Historical range map of the Canadian lynx.  There’s no concrete evidence they lived farther south than this within historical times. However, 90% of their historical range was under glacial ice during the height of the last Ice Age.  They must have occurred farther south then.

Canadian lynx.  Note the big paws and long legs that help them run through snow.  This gives them a competitive advantage over their close relative–the bobcat–in regions with heavy snowfall.  Bobcats outcompete lynx everywhere else.

The Canadian lynx is well adapted to living in deep snow.  They have wider paws and longer legs than those of bobcats, and this gives them an advantage over their close relatives when running through soft snow.  Historical records show Canadian lynx were plentiful in mountainous regions of New York and Pennsylvania, and a few even lived in West Virginia.    There are no records of Canadian lynx in Virginia, North Carolina, or Tennessee where potential habitat at higher elevations existed.  It’s likely deep snows didn’t occur often enough to give Canadian lynx a competitive advantage over bobcats here.  Overall, bobcats (Lynx rufus) are a more adaptable cat species.  I believe the locals Brewster mentioned were mistaken.  However, it is probable that Canadian lynx ranged farther south during the height of the Ice Age when over 90% of their current range was covered by glacial ice, making all of Canada unsuitable for most organisms.

Canadian lynx prefer habitat favorable to the main item in their diet–snowshoe hares (Lepus americanus).  Snowshoe hares make up 75% of the Canadian lynx’s diet.  Snowshoe hares are most abundant in disturbed spruce/fir or spruce/northern hardwood forests.  They thrive in the brushy second growth that covers clear cut tracts in the decade following logging.  This kind of habitat also occurs naturally when blizzards blow down large stretches of spruce/fir forests.  Like Canadian lynx, snowshoe hares are well adapted to living in regions with deep snow, but lose their competitive edge to similar species in areas with a more moderate climate.  Cottontails breed faster and are more adaptable than snowshoe hares.  Historically, snowshoe hares did live farther south than Canadian lynx, occupying the higher elevations in the mountains of Virginia, North Carolina, and Tennessee.  They still live in West Virginia.  But I think bobcats, not Canadian lynx, were their main feline enemies in the more southerly parts of their range.

The snowshoe hare turns brown during summer to blend in with the forest floor and white during winter to blend in with the snow.  They are part brown and part white in fall and spring.  They are also known as varying hares because their coat color varies with the seasons.

Historical range map of the snowshoe hare.  I believe it has been extirpated from North Carolina, Tennessee, and Virginia.

When Canada was underneath the Laurentide Glacier some 20,000 years ago, the Canadian lynx must have ranged farther south than it does today.  Paleobotanical evidence does show that boreal forests, their required habitat, predominated as far south as the north Georgia mountains when cooler climates and lower atmospheric CO2 levels allowed spruce trees to grow at lower elevations.  Deeper snows likely occurred more often in these southerly latitudes then.  Unfortunately, Pleistocene-aged fossils of Canadian lynx are scarce throughout the whole continent and completely absent in the south, unlike bobcat fossils which are among the most common mammals found in fossil sites all over North America.  Some of the fossils of Canadian lynx that have been found date to the Sangamonian Interglacial over 118,000 years ago, indicating it is not a recently evolved species, so it must have been present somewhere south of the ice sheet.  It may be possible to predict the Ice Age distribution of Canadian lynx by using snowshoe hare fossils as a proxy.  Snowshoe hare fossils have been found in Arkansas and Missouri–well south of their present day range.  The presence of snowshoe hares makes it likely Canadian lynx were in the environment preying upon them this far south as well. Fossils of carnivores are usually less common than fossils of herbivores because they are less abundant than their food source.  This explains the absence of Canadian lynx fossils  in areas where they may have lived in the past.  Although fossil evidence in Georgia is lacking, Arkansas is close in latitude to north Georgia.  I assume Canadian lynx and snowshoe hares occupied the higher elevations of north Georgia during snowy climate phases of the Last Glacial Maximum.

On the fringes of their ranges, Canadian lynx and bobcats occasionally interbreed.  In all recorded cases of interbreeding, it was a male bobcat that mated with a female Canadian lynx.  Bobcats are much fiercer than their northern cousins, and a male tom bobcat will always drive off male lynx.  From what I’ve read, it’s not clear whether bobcat/Canadian lynx offspring are fertile.  Attempts by fur farmers to backcross bobcat/lynx hybrids have failed.

Rabbits will Inherit the Earth

February 16, 2011

Matthew 5:5 (“Blessed are the meek for they shall inherit the earth”) always reminds me of rabbits for these meek creatures surely could outlast man.  Imagine if humans destroyed each other with nuclear, chemical, or biological weapons.  With a penchant for rapid breeding, rabbits could rapidly recolonize the world after the warlike species, Homo sapiens, annihilated itself.

Georgia is home to 4 species of rabbits, and during the Pleistocene the southeast also harbored at least 2 kinds of hares.  At various times the lagomorphs (hares and rabbits) may have been more abundant (as a biological mass) than any single species of megafauna.  Scientists interpeted a fossil site near Gainesville, Florida to have been a dire wolf den because they found a skull belonging to Canis dirus in association with hundreds of rabbit bones.  Rabbits must have been an easy and abundant food source, more reliable than any single species of megafauna.  Rabbits easily survived the Pleistocene extinction event that wiped out many of the larger, fiercer animals.  The meek really did inherit the earth.

Here’s a review of rabbit and hare species found or formerly found in Georgia.

Rabbits

Eastern Cottontail–Sylvilagus floridanus

Photo of an eastern cottontail from google images.

While this species is by no means endangered, there are likely far fewer than there were as recently as 50 years ago.  Suburbs and shopping centers are replacing the early successional forests they prefer.  And the natural areas we let remain are maturing into older stands of timberland which is not as favorable a habitat for rabbits.  Rabbits like young forests with saplings, shrubs, and grassy open areas.  This type of habitat was abundant during the Pleistocene, thanks to rapid climate fluctuations, unchecked fires, and megafauna foraging.

New England Cottontail–Sylvilagus transitionalis

In a blog entry from a few weeks ago I listed the species found at the Ladds fossil site and mistakenly noted, about the New England cottontail, that I thought it was doubtful a subspecies could be determined based on a bone.  I didn’t realize the New England cottontail was a distinct species, not just a subspecies.  Today, the New England cottontail is being considered a candidate for the endangered species list.  Hunters introduced the eastern cottontail to New England, and it is doing well, but the New England cottontail is not adapting to suburbanization and is restricted to a small number of locations.  It looks much like an eastern cottontail.  They can hybridize with eastern cottontails in captivity but won’t do so in the wild.  Before advances in DNA research, scientists had to compare skulls to determine whether a cottontail was an eastern or a New England.  But now scientists can analyze the DNA of rabbit scat to identify species.  However, the fossil specimen from Ladds that Clayton Ray identified as a New England cottontail was probably an Appalachian cottontail.

Appalachian cottontail–Sylvilagus obscura

Photo of an Appalachian cottontail.  They look exactly like New England cottontails.  Only DNA analysis can determine the difference.  For that matter, visual inspection can’t differentiate between this and the eastern cottontail.  A skull comparison or a DNA anlysis is necessary for species determination between those species as well.

This species wasn’t identified or recognized until 1992.  Before then, it was considered the same species as the New England cottontail.  Scientists noted enough genetic differences to mark it as a distinct species, though there is academic debate about this.  Again, visual determination of live speciments can’t distinguish the difference between this and the eastern cottontail.  Instead, DNA tests or skull measurements are necessary.  The Appalachian cottontail inhabits heath balds in the north Georgia mountains.

Swamp rabbit–Sylvilagus aquatica

As this photo from google images shows, swamp rabbits readily take to water.  This is the rabbit that attacked President Carter.

Many readers of this blog may be too young to know about an event that occurred involving this species during the presidency of Jimmy Carter.  On vacation from the presidency Jimmy Carter sat in a canoe and fished a  Georgia swamp.  A swamp rabbit attacked his boat–probably the only instance when a sitting president was attacked by an animal.  I guess the rabbit was swimming in the swamp and felt threatened by the canoe.

Swamp rabbits occur alongside rivers and streams in the Georgia piedmont.  They’re known as canecutters because they eat bamboo cane which used to grow in thick stands many miles long in low areas of central Georgia.  Though canebrakes are rare today, swamp rabbits still can reside near the existing and numerous beaver ponds, another favored habitat.

Marsh rabbit–Sylvilagus palustris

Photo of a marsh rabbit from google images.

The range of this species takes up where the swamp rabbit’s leaves.  Whereas swamp rabbits occur in low areas of the piedmont, marsh rabbits inhabit coastal plain wetlands.

Hares

Antelope Jackrabbit–Lepus alleni

 

 

Photo of an antelope jackrabbit from google images.

Fossil hunters occasionally find jackrabbit bones in florida.  Antelope jackrabbits inhabited the southeast until, at least, the middle Pleistocene (~300,000 BP).  Dry climate phases created large scale grassland and even desert-like chapparel habitats where antelope jackrabbits shared the range with pronghorns, cheetahs, and camels.  As I speculated in my blog entry “The disjunct range of the burrowing owl,” a corridor between western grasslands and eastern grasslands must have existed until the Stagell Interglacial.  Forested habitats increased during this lengthy interglacial, and this probably ended the occurrence of many western species (though not all) in the east.  The skeleton of a large unnamed extinct species of jackrabbit, estimated to be about 2 million years old, has also been discovered in Florda.  Both species undoubtedly occurred in what’s now Georgia.  Today, antelope jackrabbits must be considered a relic species, restricted to southwestern deserts.

Snowshoe hare–Lepus americanus

 

 

Lynx attacking a snowshoe hare.  Photo from google images.

Fossil evidence proves Arkansas was home to snowshoe hares during the last Ice Age.  It’s quite possible snowshoe hares occured in north Georgia during the Pleistocene, and they probably lived in what’s now Tennessee.  Arkansas is well south of the present day range of this species.

Red Stewed Rabbit

In my irregular series on this blog, “If I could live in the Pleistocene,” I imagine living 41,000 years ago in what’s now east central Georgia but with modern conveniences such as a nice adobe brick home with solar-powered electricity, woodstoves,  running water from a well, and fresh produce grown in a well protected garden. (See my September and December archives) Though I raise poultry and milk cows in this imaginary utopia, I try to utilize as much game and fish as I can.  Rabbit would likely have to be an item in my diet, though I’m not too keen on killing them–their alarm call sounds like a human baby crying.  In real life I’ve experimented with rabbit and have learned that it is a good stewing meat.  Rabbit is all white meat with a flavor slightly superior to chicken.  If you’ve never had it, and someone served it to you, and you didn’t notice the different bone structure, you would think you were eating chicken. There’s not much fat on a rabbit but that’s the only part that might taste a little unusual in my opinion.

Many people fry rabbit like chicken.  It’s ok this way but I think a little dry.  Other cooking methods are apt to make the rabbit have a rubbery texture.  That’s why I recommend stewing rabbit in a crockpot.  Here’s the best recipe for rabbit I know.

Marinate a disjointed rabbit in 1 cup of soy sauce, 2 tbls of vegetable oil, 2 tbls of honey, 1 bunch of chopped green onions, and 5 spice powder and ginger powder to taste.  Place the rabbit pieces and the marinade in the crockpot and cook for 6 hours.  The meat falls of the bone.  A little bit of the sauce goes a long way–it’s a marinade, not a gravy, but a couple of sp0onfuls will season a side of egg noodles well.

Rabbit meat stewed in a crockpot with just onions, water, and salt also makes a good base for a Brunswick stew.  Just shred the meat, remove the bones, and add crushed tomatoes, cooked potatoes, canned limas, canned corn, and red and black pepper.