Posts Tagged ‘cougars’

Errors in Georgia Before People: Land of the saber-tooths, mastodons, vampire bats, and other strange creatures

January 14, 2011

“To error is human; to forgive divine.”

I tried very hard to write a perfect book with no factual mistakes, typos, or bad grammar.  I’m not a scientist nor a well known writer.  Moreover, my book is self-published.  So I was doubly motivated to produce a flawless product.  I could’ve paid a professional editor to go over my book, but they cost at least $500–more money than I actually expect to make from publishing this book.  And even after paying such a fee, the book could still have mistakes because editors are not Gods.  (As a self-published author, it always delights me to find typos and misspellings in books produced by big book publishers.  I know that’s a shameful attitude.)  Anyway, I didn’t write the book, and I don’t write this blog for money–I write about this subject matter because I love it.  The link below is for my book on amazon.

http://www.amazon.com/Georgia-Before-People-Saber-Tooths-Mastodons/dp/0557330157/ref=sr_1_1?ie=UTF8&s=books&qid=1295010612&sr=8-1#reader_0557330157

I was hoping a photo of my book would appear when I cut and pasted the link.  Most of my book sales have been from amazon.com.  I only make $1.31 when my book sells on amazon.  Amazon and Lulu publishers get the rest.  I make a very small piece of the pie.  Incidentally, you can get the book cheaper directly from me.  I charge $24 which includes shipping for a signed copy.  You can get an electronic copy of the book from lulu.com for just $3.

Since I published my book, I’ve become aware of 3 errors in it.  I’m sure there are more.  Readers, please let me know of any.  Just write a response to this blog entry, and I’ll note it.

The first error is my portrayal of Panthera atrox, formerly Panthera leo atrox, as an animal behaving exactly like an African lion in my chapter recounting an imaginary journey through what’s now Augusta, Georgia 20,000 BP.   Approximately the same time I wrote my book, a scientist was thoroughly studying the anatomy of this species, and he determined it was not a lion, but rather an extinct distinct species within the Panthera genus.  It was a kind of giant panther with a skull like a lion but with a jaw like a jaguar.  I discuss this paper in a July blog entry entitled “Panthera atrox.  What kind of cat was it?”   I was unaware of this study at the time I wrote my book.  Given this new information, I believe it unlikely this giant extinct panther was a social cat, though I’m certain it did battle packs of dire wolves over prey.  I imagine it was less successful in conflicts with dire wolves than a pride of lions would’ve been.

The second error I blame on my carelessness.  I wrote, rewrote, and edited the entire book countless times, yet I goofed in one instance and garbled a whole sentence.  (How this happened, I’ll never know.)  In my chapter recounting an imaginary journey through what’s now Georgia 13,000 BP, I describe a group of paleo-Indian boys practicing their skills with primitive weapons.  On page 181 the first sentence should read “the oldest boy takes his turn” rather than “the oldest boy makes him sturn.”

The third error is the only one that embarrasses me.  In my section on cougars (Puma concolor) I mistakenly wrote that Charlie Killmaster is the hunter who killed a cougar in Georgia in 2008.  Actually, the name of the hunter from my source is never given.  Charlie Killmaster was the Department of Natural Resources employee who documented the event.  The reason this mistake embarrasses me is because I sent a free copy of my book to Rob Pavey, the outdoor editor of the Augusta Chronicle.  He wrote the article I used as my source.  Oh well, I flubbed that one.

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I have one more comment.  I posted a few excerpts from my book on one of my favorite websites–the Fossil Forum.  An unfavorable critic there suggested that I shouldn’t give up my day job.  This reveals a misleading belief some people have of the writing profession.  For every John Grisham or Stephen King, there are hundreds, if not thousands of published writers, who can’t afford to give up their day jobs.  Most published writers are English professors or journalists who must continue to work their day jobs, even after they publish their book in order to put food on the table.  ($1.31 doesn’t go far these days, even if multiplied by a 100.)  We don’t write for money; we write because we love the subject we’re writing about.

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For next week’s blog entry I hope to write about the extinct giant chipmunk–Tamias aristus.  And I’ll have a complete list of species discovered from the Ladds fossil site and Arredondo IIA.

Cougars vs. Jaguars

July 8, 2010

Cougars and jaguars co-existed for at least 500,000 years throughout North America, and today still co-exist in many areas of South America and Mexico.  Both species are adaptable enough to occupy a wide variety of environments, including deserts, lightly wooded savannah, flooded swamps, and tropical rain forests.  They also feed upon many of the same prey species.  This spawns two questions: what ecological differentiation allows two big cat species to co-occur on the same range, and what factors allowed cougars to remain in much of North America where jaguars were extirpated?  A number of scientific studies help solve these ecological mysteries.

Comparison of cougar and jaguar diets

Studies of jaguar and cougar diets consistently show significant differentiation.  Although cougars and jaguars tackle many of the same species, the latter selects for larger sized individuals.  One study of co-occurring jaguar and cougar populations in Venezuala–a region consisting of woodland, savannah, and swamp–found the following differences in prey size selection between the two species.

…………………………………….Cougars……………………………Jaguars………………

Small size prey…………………17%……………………………………1%……………….

Medium size prey……………..31%……………………………………14%……………..

Large prey……………………….52%……………………………………85%…………….

For example in this region collared peccaries are an important diet item for both species, but cougars exclusively take small juveniles, while jaguars take mostly adults and sub-adults.  Both big cats took a wide range of prey species with cougars taking 12 different kinds of animals and jaguars taking 10.  Jaguars preyed more heavily upon capybaras here than cougars did.  Jaguars also preyed upon white-lipped peccaries–an aggressive species that cougars completely avoided.  White-lipped peccaries live in large groups and frequently come to the aid of their comrades and attack predators.  They’ve been known to kill jaguars and even humans.

Illustration by John James Audubon

Another study of jaguar diet, this one in southern Brazil where flooded plains are the predominant habitat, found that the jaguar diet there included 31% cattle, 24% caiman, 21% peccary, 4% feral hog, 3.0% marsh deer, 3.2% giant anteater, 2% capybara, 1.6% brocket deer, and about 10% other.  438 prey items were recorded, showing that jaguars will take what’s generally available.  Incidentally, both jaguars and cougars are capable of killing the alligator-like caiman, but take them less than would be expected based on their abundance.

Illustration by John James Audubon

A third study, this one in Mexico where both jaguars and cougars mostly prey on deer, peccary, and armadillo, also found that jaguars select for larger prey items.  This study concludes that the “cougar’s ability to exploit smaller prey gives them an advantage over jaguars when faced with human-induced habitat changes.”  This conclusion brings to obvious light one of the reasons why cougars survived throughout much of North America where jaguars didn’t.  After Indians overhunted much of North America’s megafauna, jaguars had difficulty finding the larger prey they preferred.  The extinction of two Pleistocene species of peccary in North America was probably devastating.  Indians even overhunted white tail deer into scarcity as John Lawson, an early European explorer (circa 1704) noted when he pointed out that deer were rare around large Indian settlements in South Carolina.  But cougars could survive in these areas on rabbits, possums, raccoons, and turkeys.

I agree that the preference for larger game that no longer exists is one factor that’s limited the jaguar’s range in North America, but I think there are other factors.

Evolution of size, coat color, adaptability to cold, and personality traits

The fossil record suggest jaguars, along with dire wolves, were the most common large carnivores (excluding omnivorous bears) in southeastern North America during the Pleistocene.  Yet, cougars found their niche here too.  During the Pleistocene both species were somewhat larger than the present day versions of these species.  Rancho La Brean specimens of cougars show that on average they were 5% larger than those of today, while Pleistocene jaguars approached modern day tigers in size.  I think this is due to the larger size and quality of prey available, particularly horses and the larger sized species of peccaries, and it’s clear these two big cats not only had a better diet, but further impetus to evolve to a greater size, so they could successfully exploit this larger prey.  One study reported that modern jaguars living in areas where cattle were introduced tend to approach the size of the larger Pleistocene jaguars, and it’s believed that jaguar populations increased following the introduction of European livestock to South America.

I theorize the spotted coat of the jaguar is another factor in its range reduction.  Indians valued the beauty of its fur and hunted them unmercifully.  There’s a possibility that Pleistocene cougars had spotted coats.  Scientists believe that cougars evolved from a kind of spotted cheetah.  Cougar kittens retain these cheetah-like spots–evidence of this evolution.  But I think many adult cougars may have been spotted until very late in the Pleistocene when man colonized the continent and hunted the spotted cougars for their coats, leaving only the dull tawny and gray coated individuals to breed, which in turn genetically swamped the spotted ones.

It has been suggested that spotted cats are more vulnerable to cold climate–another factor which may limit the jaguar’s range, but I disagree with this hypothesis.  The snow leopard of the Himalayas is an example of a spotted cat that lives in a cold region.  Moreover, jaguar fossils have been excavated from as far north as Oregon and Pennsylvania when even during the warmest interglacials, subfreezing temperatures occurred during winter. 

Jaguar fossils in Georgia have been excavated from Ladds Quarry and Kingston Saltpeter Cave.  A nearly complete skull was recovered from the former location along with giant tortoise and armadillo bones that have jaguar gnaw marks on them.  Fossils from this period probably date to a warm climate phase, but the jaguar remains from KSC are associated with the kinds of animals that live in cold and temperate climates, indicating jaguars survived colder conditions than any endured by extant populations.  Cougar fossils also were found at Ladds and in Yarbrough Cave which dates to the last glacial maximum.

One more factor in the cougar’s survival where jaguars didn’t may be evolutionary selection towards more timid individuals.  Those members of the cougar population that learned to avoid man were more likely to survive.  Timidity possibly occurred less frequently in prehistoric jaguar populations.

Cougars vs. Jaguars, wolves, and bears

So which would win in a battle between a jaguar and a cougar?  According to scientific studies, cougar and jaguar ranges frequently overlap, but they tend to avoid each other.  Certainly, a jaguar wouldn’t think it worth the effort to battle a raging mother cougar defending her kittens.  Conversely, a cougar would be out of its mind to engage in a battle with a larger, more powerful cat that bites harder than any other kind of cat in the world.  However, in one paper, international big cat expert, Howard Quigley, did cite a case of a jaguar attacking and killing a cougar.

Packs of wolves also dominate cougars in the Rocky Mountains.  Wolves occasionally kill cougar kittens, sub-adults, and even adults.  The average biomass of wolves in packs that attack a cougar outweighs the cat by a 13:1 ratio.  Rarely, cougars have been reported to kill wolves (sub-adults and adults, but not pups), but in these cases it was one-on-one and the biomass was a 1:1 ratio.  A certain percentage of cougar kills are lost to wolves and bears in areas where their ranges overlap.

References

Carvolcanti, Sandra; and Eric Gese

“Kill rates and predation patterns of jaguars (Panthera onca) in the southern pantanal of Brazil”

Journal of Mammalogy 91 (3) 722-736 2010

Hoogesteyn, Rafael; and Edgardo Mondolfi

“Body mass and skull measurements in four jaguar populations and observations on their prey base”

Bulletin of the Florida Museum of Natural History V. 39 (6) pg. 195-219 1996

Hornocker, Maurice; Sharon Negri, and Alan Rabinowitz

Cougar: Ecology and Conservation

University of Chicago Press 2002

Nunez, Rodrigo; Brian Miller, and Fred Ludjey

“Food habits of jaguars and cougars in Jalisco, Mexico”

Journal of Zoology 252 (3) 373-379

Scognamillo, Daniel; et. al.

“Co-existence of jaguar (Panthera onca) and puma (Puma concolor) in a mosaic landscape in the Venezualan llanos”

J. Zoological Society of London 259 269-277 2003