Posts Tagged ‘canis familiaris’

The American Dingo

February 11, 2013

The famous dingo of Australia is an ancient breed of dog that has gone feral.  Aborigines colonized Australia ~40,000 years ago–probably before man domesticated dogs–and there is no evidence they brought dogs with them.  Instead, some humans from the subcontinent of India apparently brought dogs with them to Australia about 5,000 years ago.  The Indians assimilated with the aborigines, and many of the dogs they brought reverted to a wild state and became a top predator on the island continent.  Asians also brought this ancient breed of dog with them when they colonized America.  Scientists don’t know exactly when the ancestors of modern dogs were first domesticated, but it was probably about 12,000 years ago.  (Some genetic studies suggest dogs began to evolve from wolves as long as 100,000 years ago, but many of those early lineages died out.)   In America, just as in Australia, this ancient breed of dog goes feral.  The circumstances likely varied.  If a tribe died out naturally or was destroyed by another tribe, dingos were capable of reverting to a wild state and surviving without their human masters.  On occasion some may even have purposefully escaped captivity.  In any case American dingos weren’t recognized as a distinct wild canid until the 1970’s.  Dr. Lehr Brisbin jr., a research ecologist for the University of Georgia at the Savannah River Ecology Lab, first noticed them running wild at the Savannah River Site in South Carolina.  This area itself  reverted to wilderness when the federal government purchased the land surrounding a nuclear reactor.  Dingos have since been discovered on the Fort Gordon army base in Georgia and other lightly populated areas across the south.  Dr. Brisbin has given tame American dingos the common name of Carolina dog.

An American dingo.  Adults weigh between 40-60 pounds.  They’re an ancient breed of dog capable of surviving without humans.  Tame dingos are known as Carolina dogs.  A Korean dog, the chindo-ka, is probably the same ancient breed.

I’m not sure what scientific name to give the American dingo.  When adopted, wild puppies make good pets, though they require 24 hour companionship and attention.  And they breed with other dogs.  In human households and backyards, they can be given the scientific name Canis familiaris–the domestic dog.  Australian dingos are given the scientific name Canis lupus dingo–and are considered a subspecies of wolf.  Wolves and dogs can interbeed and produce fertile offspring as well, and some scientist give dogs a wolf subspecies status with the name Canis lupus familiaris.  But others consider dogs a separate species based on differences in behavior patterns and some slight physical differences.  The classification of species is an invention of man and in this case murky.

Wild dingos reproduce faster than domesticated dogs.  It’s thought that they breed rapidly to overcome natural mortality from parasites, such as heartworm.  They are much better hunters than domesticated dogs.  They instinctively know how to pounce on mice and shrews with their forepaws.  They are snake-killing specialists.  Dingos bite the snake and whip their neck around, cracking the snake’s vertebrae.  Domesticated dogs don’t know how to do this.  Dingos form packs and also hunt raccoon, rabbit, and probably deer.   Nursing dingos bury their feces and dig numerous small pits around their dens. The dens are burrows they dig themselves or take from other animals.  These behaviors also differentiate them from domesticated dogs.

Young pups from a wild dingo are easily domesticated and reportedly make good pets, but they require constant care.  Dingos follow their human masters everywhere and, if escape from an enclosure is possible, they will figure out how immediately.  They are an intelligent breed.

Dingos are probably the oldest breed of domesticated dog still extant and are more closely related to wolves than other breeds.  This would explain their ability to survive in the wild without people.  When native Americans were forced to leave southeastern North America, they must have left many of their dogs behind.  An increased wild dingo population must have already been established by the 1830s because Indian tribes had been decimated by European diseases.  In the mid-19th century there were still hundreds of square miles of wilderness in the south where humans and domesticated dogs were scarce, and dingos could thrive.  Then, following the Civil War, vast acreages of agricultural land were abandoned.  American dingos served as top predators in these “waste” places after cougars and wolves were exterminated by settlers.  Many settlers adopted dingos, and this is the breed of dog celebrated in the famous children’s novel, Old Yeller, by Fred Gipson.  It’s kind of surprising they weren’t recognized as a wild canid until recently, but most people that saw them probably thought they were just somebody’s dogs that got loose.

Today, the American dingo is in danger of becoming extinct in the wild.  Increasing conversion of abandoned farmland to suburbs is bringing them into contact with domesticated dogs, causing them to become genetically swamped when they interbreed.  And coyotes may be outcompeting them.  Both coyotes and dingos occupy the same niche–marginal wilderness habitats where larger predators are rare or have been eliminated by man.

The University of Florida Museum of Natural History database lists 9 specimens of Canis familiaris from the late Pleistocene fossil record found in Florida.  This is evidence the Paleo-indians brought dogs with them somewhat earlier than scientists think dogs were domesticated.  The breed they brought with them was most likely the dingo.  For a few millennia wild dingos likely shared the landscape with Pleistocene megafauna.

References:

Brisbin jr., I.L.; and T.S. Risch

“Primitive Dogs, their Ecology and Behavior: Unique Opportunities to study the Early Development of the Human-Canine Bond”

Journal of American Veterinary Medical Association 210 April 1997

Pigoch, Iris; et. al.

“Genome-wide Dates Substantiate Holocene Gene Flow from India to Australia”

PNAS 110 (5) Jan 2013

Pleistocene Fossil Canid Ratios Recorded in the University of Florida Database

January 11, 2012

The abundance of Pleistocene fossil sites in Florida has allowed the university in Gainesville to become a center of information for other scientists.  Scientists excavating new fossil sites use existing fossils at the University of Florida Museum of Natural History to help identify the new specimens they pull from the earth.  It’s not always easy to differentiate closely related species–the subject of this blog entry, the canids, are notoriously difficult to distinguish.  Vertebrate zoologists and paleontologists measure and describe every part of every bone and tooth when examining new specimens.  They publish this information in scientific journals and accumulate knowledge of the size limits and shape variations of a particular species’ anatomy.  If a newly discovered fossil tooth for example doesn’t fit any known pattern of shape or size, than scientists suspect they may have discovered a new species.  The more data scientists have, the better able they are to identify new species and spot evolutionary trends over time within a species.

Fossil collecting is popular in Florida, thanks to all the sinkhole lakes and caves with basal chemistry in the soil that preserves bones.  Amateur fossil collectors have many more fossils in their collections than the University of Florida’s Natural History Museum..  Many are for sale as well.  It would be a great benefit to science, if collectors made arrangements to donate their collections to the museum upon their deaths.  Many valuable specimens have been lost when their owners die and family members, not interested in the subject, lose track of where they put the old bones.

My little study is limited to canid fossils listed on the University of Florida database and leaves out the great many more in the hands of amateur fossil collectors.  I also limited this survey to the Rancholabrean Land Mammal Age (300,000 BP-11,000 BP), leaving out Armbruster’s wolf which dominated the middle Pleistocene before being replaced by dire wolves.  Nevertheless, I think there’s enough information to suggest relative canid species abundance during the late Pleistocene.  Keep in mind, I was counting on a computer screen while scrolling down, so my numbers may be off slightly.

Listed on the Florida Museum of Natural History’s database, I counted 64 dire wolf (Canis dirus) specimens, 34 coyote (Canis latrans) specimens, 1 red wolf (Canis niger) specimen, 9 domestic dog (Canis familiaris) specimens, 0 dhole (Cuon alpinus) specimens, and 55 gray fox (Urocyon cineorgenteus) specimens.

The fossil record strongly suggests that from 300,000 BP to about 11,000 BP dire wolves were by far the most common large canid being about twice as abundant as coyotes.  Red wolves were rare but present.  Gray foxes were just as common during the Pleistocene as they are today.  These neat little foxes have the ability to climb trees, a skill that saves them from their larger relatives.  There is no evidence of dholes but as I wrote in a previous blog entry http://markgelbart.wordpress.com/2011/06/01/did-the-dhole-cuon-alpinus-range-into-southeastern-north-america-during-the-pleistocene/ , I suspect they may have periodically colonized parts of the southeast but in numbers too low to leave fossil evidence.

Dire wolves were the dominant large canid in the southeast (and all across North America south of the Ice Sheets) during the late Pleistocene.

Coyotes probably occupied a niche similar to African jackals.

Gray foxes thrived in areas where they had access to trees and could escape larger predators.

The presence of domesticated dogs in the Pleistocene fossil record puzzled and surprised me.  I almost didn’t even do a database search for Canis familiaris and only did so as an afterthought.  Most anthropologists don’t think humans domesticated dogs until after the Pleistocene about 10,000 years ago, but the fossil evidence contradicts this.  In fact scientists recently discovered the skull of a domesticated dog in a Siberian cave that dates to 33,000 BP.  They determined  this particular domesticated dog was not the ancestor of the lineage that led to today’s dogs but instead its descendents died out.  It’s probable that there were many early lineages of domesticated dogs that ceased to exist for various reasons.  Perhaps that group of people died out or stopped keeping dogs.  The popular idea that people domesticated dogs by kidnapping and raising wolf pups is a misconception.  Scientists think it’s the other way around–dogs adopted us.  Dogs are descended from the wolves which had the least flight response.  Wolves that hung closely around human campsites for access to leftovers gave birth to pups with floppy ears, multi-colored coats, and other dog traits that differentiate them from other wolves.  The gene for tameness shares a pathway with the gene for these physical characteristics.  So it’s likely that dogs adopted people in many different geographic locations wherever wolves (Canis lupus) began occupying areas adjacent to human campsites.  Obviously, dogs either followed or were brought to Florida by the Paleo-Indians.

The authors of a chapter in the book The First Floridians and the Last Mastodons suggest that all the coyote fossils found in Florida are actually domesticated dog fossils, but they only knew of a handful of coyote fossils.  Apparently, they didn’t know 34 specimens had been found.  I doubt scientists made that many misidentifications.

Dire wolves succeeded in becoming one of the dominant predators in the environments of southeastern North America where they found a wealth of prey roaming the open woodlands and savannahs.  Everything from bison and horses to deer and rabbits sustained them, and a mammoth or mastodon that died of natural causes provided a feast.  Coyotes successfully co-existed with dire wolves by scavenging large predator kills and by hunting rodents.  Red wolves must have been restricted to islands and perhaps deeply wooded swamps where they could survive on deer and small game.  Their niche must have been areas with lower densities of prey as opposed to grasslands that hosted large herds of ungulates.  Following the extinction of the megafauna and dire wolves, forests replaced grasslands and red wolves increased in number and drove coyotes completely out of the south.  But after European settlers wiped out the red wolves, coyotes returned.

References:

Ovodov, Nikolai, et. al.

“A 33,000 Year Old Incipient Dog from the Altai Mountains of Siberia: Evidence of the Earliest Domestication Disrupted by the Last Glacial Maximum”

Plos One 6 (7) 2011

http://www.flmnh.ufl.edu/databases/vp/intro.htm

The Dunwoody Nature Center

I attended my nephew’s bar mitzvah in Dunwoody, Georgia last weekend.  Dunwoody consists of dozens of subdivisions and plenty of shopping centers and absolutely no rural farmland.  I didn’t hold out much hope for a nice nature walk here–the traffic is terrible.  But at least the developers left a lot of trees standing.  I decided to walk from my sister’s house to a little park known as the Dunwoody Nature Center and I discovered a surprising gem.

This white oak was about 4 feet in diameter.  White oak is a common tree in Dunwoody.

From the composition of the trees left standing most of Dunwoody must have once hosted a pretty nice dry upland forest.  Too bad developers converted it into a crowded suburb.  Today, white oaks, black oaks, southern red oaks, shortleaf pines, and loblolly pines are the dominant trees.  The Dunwoody Nature Center slopes sharply down toward Wildcat Creek, the name of which is a relic to its former status as a wilderness.  The woods here are dominated by beech, white oak, sweetgum, river birch, and loblolly pine.  I was stunned to see a woodlot of mostly beech trees in central Georgia.

A mature beech tree growing on the edge of a rocky creek.  It’s surrounded by many immature beech saplings.

Fossil pollen studies show beech was a common tree in the south during the end of the Ice Age when the Laurentide glacier began melting and releasing more moisture in the atmosphere creating a climate that was still cool but more rainy than it was during the height of the Ice Age.  The presence of abundant beech in the fossil record is indirect evidence of massive flocks of passenger pigeons.  Passenger pigeons fed on acorns–in some places completely eliminating the oak seed crop…and the beech’s competition.  Although beech trees produce an edible nut, they can also spread from roots and could survive their seed being consumed by passenger pigeon flocks.  Since the passenger pigeon’s demise, oak forests have been replacing beech forests in many areas.  So I was delighted to see this remnant beech forest in central Georgia.

Wildcat Creek flows through a granite outcropping.  Here is a miniature waterfall.

Two little league baseball fields take up about half the space of the park.  The park is heavily used by dog and toddler walkers.  It’s popularity shows that the planning commission in charge of developing Dunwoody should have arranged for the purchase of more land for more parks.

Irrational Anti-Wolf Hysteria in the Rocky Mountains

July 21, 2011

Photo of Yellowstone gray wolves from google images.  Note the color variations within the same pack.

The timber wolf (Canis lupus) is a beautiful animal well adapted to hunting big game.  It’s an ancient species having first evolved in Eurasia about 1 million years ago.  They crossed the Bering Landbridge and became widespread in western North America at least 300,000 years ago.  Based on the number and distribution of fossil specimens, dire wolves (Canis dirus) outnumbered timber wolves during most of the Pleistocene in the southern regions and lowlands, and apparently, timber wolves never penetrated the southeast, perhaps because red wolves (Canis rufus) were already present and occupying a niche not directly in competition with dire wolves.

The extermination of wolves from Yellowstone National Park and many sparsely populated regions of the west was an ecological disaster.  Elk and deer overpopulated the range, forcing National Park officials into the awkward position of having to shoot elk inside National Parks.  Canadian wolf populations rebounded, and they began recolonizing Montana and Idaho naturally in the early 1990’s.  Scientists reintroduced wolves back into Yellowstone National Park in 1995, improving the quality of the ecosystem.  Wolves now number between 1300-1600 in the northern Rocky Mountains.  Idaho held a spring hunting season on wolves in 2010 that led to the deaths of 188, not counting the puppies that starved to death following the deaths of their parents. 

The furious anger of irrational wolf haters pressured the Idaho Fish and Game Department into planning annual hunting seasons on wolves that will begin this upcoming fall, unless a lawsuit stops it.  The Idaho Fish and Game Department itself showed a bias in favor of killing wolves with the leading questions they asked on a pre-hunt survey such as “”Should wolves be managed to protect public safety?” instead of questions I would ask such as “Should wolves be slaughtered so their puppies will starve?”

The hatred of wolves is not based on reality or facts and seems most vocal among hunters who believe humans are the only animals on earth with the God-given right to kill other animals.  Although the Idaho Fish and Game Department only wants a sustainable “harvest” of wolves, many militant anti-wolf fanatics insist that wolves should be completely exterminated.  According to them, wolves “destroy all wildlife” and are causing big game populations to collapse.  It doesn’t occur to them that wolves are wildlife.  Hunter “harvest” statistics don’t support their erroneous beliefs.  I researched this and discovered how wrong they are.

Hunter “Harvest” Record from Wyoming Fish and Game Department for Selected Years

…………………………………..Elk …………………………..Deer

1994…………………………….24,534…………………………………….44,488

1996……………………………..20,612…………………………………….NA

2001…………………………….22,772…………………………………….47,943

2009……………………………22,971……………………………………..53,267

Note the elk “harvest” has remained steady in Wyoming, despite the reintroduction of wolves.  Deer “harvests” show a noticeable rise.  People spent an estimated $35 million in Wyoming just to see wolves, so their reintroduction has been beneficial economically as well as ecologically.

Hunter “harvest” table from Montana Fish, Wildlife, and Parks from selected years

……………………………………….Elk………………………..Deer

2001……………………………….20,578………………….111,783

2004……………………………….23,313…………………..119,266

2005………………………………26,201…………………….115,238

2010……………………………….24,744……………………94,730

Again, elk populations show no signs of collapsing.  Deer show a slight decline in the most recent year but this may be due to a severe winter.

According to the Idaho Fish and Game Department, in 2010 the elk population there was above management goals in 10 districts, within management goals in 13, and below management goals in 6.  Since wolves recolonized the state, the elk population has declined from 125,000 to 100,000, but “deterioration of habitat” is considered a greater factor than wolves, especially in districts where wolves are getting blamed.  There has been no economic loss due to a decline in big game tags issued.

Clearly, there is no collapse in big game populations in areas wolves have recolonized.  In any case I’ve asked some of these wolf haters how wolves could be increasing in numbers, if the population of their prey was supposedly collapsing.  A dearth of game would cause wolves to starve and decrease in numbers.  I’ve yet to see an answer to this logical point  that makes any sense.  One man insisted that after wolves exterminate elk they’d gobble up everything else including people–an ecological impossibility.

Many ranchers hate wolves as well.  However, losses of livestock to wolves is minimal.  In 2007 in Idaho ranchers lost 53 cattle, 170 sheep, and 8 dogs to wolves.  This out of a population of 2.2 million cows, 235,000 sheep, and probably hundreds of thousands of dogs.  For cattle this can be calculated to a loss of something like .000002%.  Infinitesimal.

Wolf haters also have an irrational fear that wolves will attack people.  The chances of this happening are remote–in North America there have been about 25 reported attacks of wolves on humans in recorded history.  In Europe and Asia documented wolf attacks on people number in the thousands.  In the Old World only the nobility were allowed to hunt and wolves didn’t learn to fear peasants; but in America where more people have guns in an egalitarian society, intelligent wolves did learn to avoid people.  Contrast these 25 reported wolf attacks in all of American history with 34 people killed by domesticated dogs (Canis familiaris) in the U.S. in one year, and the estimated 4.7 million dog attacks annually.  Yet, no rational person is calling for the extermination of domesticated dogs.

I’m not opposed to hunting for food. In my irregular series on this blog about my imaginary life living in Georgia 36,000 years BP, I hunt deer, elk, peccary, and bison for most of my meat (see the March archives for my most recent post on this).  But I’m disgusted with the attitude of many hunters today, and this certainly includes wolf haters who are all hunters unable to stand seeing other animals kill their game.  Direct TV offers 2 hunting channels.  More often than not on the hunting shows I’ve watched, hunters giggle like demented sadists after they’ve killed an animal.  When it comes to politics, the overwhelming majority of hunters are twisted fascists.

July 26, 2011 anti-wolf rally Federal judge Donald Molloy could once again halt a much needed wolf control hunt. - Sportsmen Needed To Protest Latest Wolf Hearing In Montana!

The controversial judge ruled against wolf haters in 1 case.  Freedom of speech does not include terroristic threats.  Whoever fashioned this sign should be arrested. (Note: the link to this photograph originally featured a picture of anti-wolf nuts hoisting a sign threatening Judge Molloy who ruled that wolves should remain protected.  Instead the photo on the embedded link was replaced with this asshole carting 4 dead wolves.) 

The above sign illustrates the intolerant hostility wolf haters have for people who oppose their point of view.  This sign is all one needs to know about these people.  They’re not nice guys.

Incidentally, one of these wolf haters who runs a ridiculous anti-wolf propaganda site known as save the elk.com was arrested recently for…felony poaching of an elk.  How ironic.

Another irrational fear wolf haters share is their belief that the federal government is going to take their guns away from them.  The way they carry on, one would think they were afraid the federal government was going to take their penises away.

References:

Idaho Fish and Game News 22 (2) August  2010

Montana Fish, Wildlife, and Parks Hunters “Harvest” Tables

Wyoming Fish and Game Department Hunters “Harvest” Tables