Posts Tagged ‘Sylvilagus palustris’

The Enigmatic Dwarf Marsh Rabbit (Sylvilagus palustrellus) of the Pleistocene

December 17, 2015

The marsh rabbit (Sylvilagus palustris) ranges throughout Florida and the coastal plain of Georgia, South Carolina, and North Carolina.  Wetlands are their preferred habitat.  During the Pleistocene they co-occurred with a little known related species, the dwarf marsh rabbit (S. palustrellus).  Fossil evidence of the dwarf marsh rabbit has been found at just 3 sites-the Ichetucknee River, Melbourne, and Vero.  All of these fossil sites are located in Florida.

Distribution of Sylvilagus palustris

Range map of the marsh rabbit (Sylvilagus palustris).  A dwarf relative of this species (S. palustrellus) lived in Florida and perhaps the coastal plain as well during the Pleistocene.

Some doubt S. palustrellus is a valid species because there is so little evidence of its former existence.  However, Dennis Ruez, a scientist who teaches at the University of Southern Illinois, is convinced there was  a dwarf marsh rabbit inhabiting late Pleistocene wetlands in Florida.  Dennis Ruez is the only living scientist to really study this species.  He believes the dwarf marsh rabbit was a distinct species from any other species of rabbit because its teeth were “SO much smaller.”  The specimen he examined was an adult lower 3rd pre-molar.  He compared it with the lower 3rd pre-molar of a marsh rabbit and also noticed some distinct differences besides size.  The only illustration of this species is of this tooth in a short paper he authored.  This paper can be accessed via the following link. https://www.researchgate.net/publication/263425470_A_new_record_of_Sylvilagus_palustrellus_from_the_Rancholabrean_late_Pleistocene_of_Florida

The dwarf marsh rabbit may never have been a common species.  Fossil hunters have discovered 22 marsh rabbit teeth in the Ichetucknee River, but only 1 tooth of the dwarf marsh rabbit.  The drastic environmental changes experienced in Florida likely explain the evolutionary history of the dwarf marsh rabbit.  During interglacials sea level rise inundated most of Florida, leaving some marsh rabbits stranded on islands where some populations evolved to a larger or smaller size.  Conversely, during glacials marshes became separated by large dry prairies unsuitable for marsh rabbits and some populations evolved differing sizes following these isolating events.  The uncommon smaller species was more vulnerable to extinction through disease or predation.  It’s 1 of the few small mammal species to become extinct at the end of the Pleistocene.

There are 3 extant subspecies of marsh rabbit.  The lower keys marsh rabbit (S. palustris hefneri) lives on Key West and is in danger of extinction there because of suburban development and house cats.  This subspecies was named after Hugh Hefner, founder of the Playboy Magazine empire.

AMI's David Pecker Hosts Playboy's 50th Anniversary Celebration

Playboy bunnies.

Working to conserve endangered 'Playboy' bunnies

A real playboy bunny, the lower keys marsh rabbit (Sylvilagus palustris hefneri), a subspecies named after Hugh Hefner, founder of the Playboy magazine empire.

References:

Ruez, Dennis

“Dental Variation in Pleistocene Marsh Rabbits from the Ichetucknee River, Florida”

Current Research in the Pleistocene 2011

Ruez, Dennis

“A New Record of Sylvilagus palustrellus from the Rancholabrean (Late Pleistocene) of Florida”

Current Research in the Pleistocene 2003

 

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.