Posts Tagged ‘coyote’

Saber-tooth Cats (Smilodon fatalis) and Dire Wolves (Canis dirus) Did Not Compete as Much as Previously Thought

August 10, 2019

Image result for Charles Knight classic painting of La Brea tar pits dire wolf

This classic painting of dire wolves contesting a carcass with a saber-tooth may give the wrong impression.  A new study suggests their diets didn’t overlap as much as previously thought.

A new study analyzing the isotopic chemistry of tooth enamel from carnivores excavated from the La Brea Tar Pits determined there was not as much overlap in the diets of saber-toothed cats and dire wolves as previously thought.  An earlier study examined the isotopic chemistry from bone collagen of La Brea carnivores, and the results of that study suggested the big 3 carnivores (saber-tooths, dire wolves, and giant lions– Panthera atrox) competed for the same prey items.  However, bone collagen can decay and become contaminated, altering the accuracy of the results.  Tooth enamel is more durable, and scientists believe it provides more accurate results.  This new study concluded both saber-tooths and giant lions were ambush predators that lived in woodlands or forests and fed upon forest-dwelling herbivores such as deer, tapir, and woodland bison.  Dire wolves and coyotes (Canis latrans) lived in more open environments and chased down horses, camels, and plains bison.  The diet of saber-tooths, giant lions, and Pleistocene cougars (Puma concolor) resulted in mathmatical values of isotopic bone chemistry identical to those of modern cougars.  The diet of coyotes changed over time.  During the Pleistocene coyotes scavenged meat from megafauna.  Following the extinction of the Pleistocene megafauna, coyotes evolved toward a reduced size and fed more on bone, smaller animals, and even fruit.  The diets of timber wolves (Canis lupus) and cougars did not change following the extinction of Pleistocene megafauna.

The results of this study did not surprise me.  Saber-tooths and giant lions were built for ambushing prey in the cover of thick vegetative growth found more in woodlands than grasslands.  So of course it makes sense they preyed upon animals in those environments.

Reference:

Desantis, L; et al

“Causes and Consequences of Pleistocene Megafauna Extinction as Revealed from Ranch La Brea Mammals”

Current Biology 29 (15) 2019

Killing Coyotes is Futile

June 1, 2013

The title of an article published in a recent issue of Georgia Outdoor News was “Save a Fawn, Kill a Coyote.”  This is the first line of that article–“Killing coyotes is fun.”  I just have to comment on this sadistic stupidity.

Ranchers have been trying to exterminate coyotes in the western states for 150 years.  Trapping, shooting, and poisoning have all failed.  Instead, coyote populations have increased, and they’ve recolonized the eastern states where they had been absent for about 10,000 years.  Wildlife management scientists understand why hunting coyotes has little impact on their long term numbers.  F.F. Knowles studied coyotes in Texas during the early 1970’s.  He found that in south Texas, where coyotes are abundant and under little hunting pressure, female coyotes produce an average litter size of 4.3, while in north Texas, where coyotes are extensively hunted, female coyotes produce an average litter size of 6.9.

Coyotes under human hunting pressure produce larger litters.  This mother has at least 9 pups.

Coyotes that are under human hunting pressure produce larger litters.  So when these stupid hunters kill a coyote, they are helping to increase the coyote population in the long term, thereby increasing fawn mortality.  They are not saving fawns as the title to the GON article falsely claims.  Another study examined the differences between populations of hunted and not hunted coyotes in Montana.  This study also found that female coyotes of the hunted population produced larger litters.  Moreover, pups from the hunted populations had a higher survival rate than pups from non hunted populations because the number of rodents and rabbits had increased from the previous year after some coyotes had been removed from the environment.  Coyote populations did temporarily dip immediately after they were hunted but completely rebounded to their former abundance in about 9 months.  Coyotes eat an average of 5 rodents a day.  Populations of mice, rats, and rabbits naturally increased until coyote numbers bounced back.  One can obviously assume from these studies that hunting coyotes serves no practical purpose for wildlife management.  Hunters should just be honest with themselves and admit they want to shoot coyotes for the hell of it because they like to kill animals, not because they are saving the deer herd.  (Note: I do believe there’s nothing wrong with farmers killing coyotes they catch in the act of attacking their livestock.)

I think anybody who kills coyotes for fun is a sadistic sociopath.  It’s like shooting your neighbor’s dog.  I’m not against hunting for food, but many hunters don’t shoot animals for food, they kill animals because they like to hurt living things.  These guys are the same kind of people who made good concentration camp guards during the holocaust.  They’re the same kind of people who participated in the My Lai massacre during the Vietnam War.  And they live amongst us.

I used to post on the Georgia Outdoor News message board, but 1 of the moderators threatened to ban me every time I expressed my opinion.  Rednecks don’t have much tolerance for people with different opinions than their own.  Nevertheless, I couldn’t resist rubbing it in after the last election.  They all think Obama is some kind of socialist anti-christ.  I think Obama and the democrats are marginally better than the republicans, but they are both bad for the environment–the 1 issue I really care about.  I posted a topic on their political forums entitled “Hicks and Haters Lost the Election.”  The moderator banned me again (I’ve come back under different aliases).  I also got banned from SEC Rant for using the word, hick.  Hicks really don’t like to be called hicks.

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I believe the species of wolf that lived in southeastern North America until the 19th century is extinct.  Genetic studies suggest the red wolves that wildlife biologists re-introduced are coywolves–hybrid coyote (Canis latrans) and gray wolf (Canis lupus) mixes.  We will never know if there was a distinct southeastern species of wolf unless scientists examine the DNA of the fossil specimen found in Fern Cave (See https://markgelbart.wordpress.com/2012/05/09/the-truth-about-the-red-wolfs-status-as-a-species/ ).  Dire wolves were the dominant canid across the south during the Rancho La Brean land mammal age of the late Pleistocene, but coyotes did occur in the region then, occupying a scavenging, rodent-killing niche.  I hypothesize that when dire wolves became extinct, southeastern coyotes evolved into a larger canid that lived across the southeast until man wiped them out.  Whether they deserved full species status is debatable.

Coyote near Atlanta, Georgia.  Looks like a wolf to me.

Red wolf.  Looks like a coyote to me.

I see coyotes quite often in Richmond County, Georgia–both live and road-killed specimens.  Coyotes patrol state highways looking for other road-killed animal to eat and often become victims of motor vehicles as well.  I’ve seen a large reddish coyote that resembles the red wolf in the above photo.  On one occasion a coyote trotted across the vacant lot on the opposite side of the street from my house and exhibited the pouncing behavior they use to catch mice.

References:

Gese

“Demographic and Spatial Responses of Coyotes to Changes in Food and Exploitation”

Wildlife Damage Management Conference 1-1-2005

Knowlton, F.F.

“Preliminary Interpetations of Coyote Population Mechanics with some Management Implications”

Journal of Wildlife Management 36 1972