Who Got to Mastodon First? Ice Age Wolves, Bears, or Man?

The Morrow County, Ohio, Cedar Creek Mastodon, might have met this fate, its dead carcass scavenged by dire wolves and other predators such as bears and saber-toothed "tigers", not to mention vultures.  This 1911 illustration  of dire wolves fighting with the tiger in the  LaBrea Tar Pits of California is in the public domain..

Life wasn’t easy in the Ice Age, so it shouldn’t be surprising that it’s beginning to look like Ohio’s Morrow County Mastodon might have been torn apart by a pack of Ice Age wolves.

We know that there was at least one wolf that bit into the mastodon’s bones because the excavation uncovered forensic evidence left behind by the guilty party—a canine tooth embedded in the bone.

There were several species of Ice Age wolves, but the “Dire” wolf  is the likeliest suspect because it depended on scavenging dead bodies more than killing, especially in the case of big game.   Although it weighed about 25 percent more than modern wolves, it was slower than other Ice Age wolf species, so it resorted to hunting in packs and killing slower moving animals like the mastodon or scavenging any corpse it stumbled into.

In the most complete report to date, to the volunteers participating in the dig, excavation leader Nigel Brush said he and his colleagues are beginning to wonder if the mastodon might have died of old age and then been eaten by the Dire wolf and other scavengers.

But they have not discarded the original hypothesis—that the mastodon was killed by Paleo-Indians   and butchered.  In that case, the scavenging was done after the men were through with the carcass.

Brush is an associate professor of geology at Ashland University in Ohio.

Brush reported that Brian Redmond , head of archaeology at the Cleveland Museum of Natural History, will have the bone with the embedded wolf tooth X-rayed to get a better view of the tooth.  He also wrote that, “The mastodon bones contain an abundance of gnaw and puncture marks from predators such as wolves and bears.  Among the bones of the mastodon, we have found a tooth (an incisor) and several fragments of leg bone that appear to be from some other Ice Age herbivore (perhaps a musk-ox or stag-moose ?).”

It seems to me that the scavenger hypothesis arose when Brush learned, from geological studies being done at the site, that the broken bones found in the excavation site had been carried there by water flowing from upland of the site, farther from the bog that would have made a natural trap-and-kill site for Paleo-Indians.

Brush also cited the fact that only two possible man-made cut marks on the bones have been found so far, leaving open the possibility that those cuts are not the work of human tools after all.   And most of the flint flakes found were the result of natural weathering and frost or from being washed into the excavation site, rather than from man using or making flint weapons or butchering tools.

But, Metin Eren,  an expert on lithics, the study of the human use of stone for tools, came to the lab at Ashland University and found that about a  the dozen of the flint pieces were possibly worked by people, so a few of the flakes will be sent to another lab for further analysis for blood and protein residues and edge wear from butchering.

Nick Kardulias, another lithics expert, will be doing a more detailed examination of the flint pieces and soil cores recovered from the site.  Kardulias and his students from the College of Wooster  in Ohio have been helping with the excavation along with students from Ashland University and other universities.

Dueling Hypotheses:  Man or Wolf?

He said the only way to decide between the two competing hypotheses is through the lab analyses that will continue through the winter at Ashland University.  He said that one of the critical pieces of evidence to support the Paleo-Indian kill hypothesis would be if the mastodon bones are found-- through carbon-14 testing--to be between 16,000 and 10,000 years old, when Paleo-Indians and mastodons co-existed.

Brush’ report included a Florida lab’s carbon-14 test results on samples taken from the bottom and top of the bog near the excavation site:  Plant material taken from the top of the bog dated to about 11,200 years ago,  while a wood sample from the bottom of the bog was about 12,500 years old.
Another critical piece of evidence to support the kill/butchery site hypothesis, he wrote, would be if they found mastodon blood and protein residues on some of the flint pieces they found that appeared to be used to butcher.   A fourth piece of critical evidence would be confirmation that the possible cut marks on two mastodon bones “are indeed cut marks.”

Brush discounted speculation that some of the rounded stones found near the bones were used to hammer bones to crush them, saying that the stones could just be one of the many cobble stones found  in the natural stone-and-gravel deposits below the excavation site.   He reported that, “We have washed dozens of these cobbles in the lab and have yet to find any fresh surface alteration that we could unequivocally equate with human tool use.”

Occam’s Razor

At that point in his report, Brush wrote that “Occam’s Razor is often quite useful in science:  The simplest explanation is usually the best explanation.  Given the highly battered condition of the cobbles thus far recovered from the site, natural weathering appears to be a much more likely explanation than human utilization.”  He showed a number of the possible hammerstones and other possible stone tools to several other professional archaeologists and all agreed  with Brush.

Brush also cites another axiom from his scientific experience:  “Extraordinary claims require extraordinary evidence.”

As part of this search for strong evidence, Greg Wiles, professor of geology at the College of Wooster, will submit two charcoal samples for carbon-14 dating to the same Florida lab that dated the bog samples, to see if the soil layer where the mastodon bones were found are in the same age range as the bog.  And, Redmond will submit a collagen sample, from one of the four mastodon teeth found, to the Florida lab for carbon dating--hoping there is enough collagen present to do the test.   Earlier this fall, Redmond had submitted a thoracic vertebrae from the Morrow County mastodon, but heavy weathering had removed too much collagen for carbon dating to succeed.

Brush’ report also said that Gregory McDonald, a bone specialist and senior curator of natural history at the National Park Service in Fort Collins, Colorado, might have time to visit the Ashland lab to identify some of the mastodon bones, when he speaks on December 12 at the Cleveland Museum, on "The Snowmastodon Project" .

Note:  What I call the Morrow County mastodon is officially called the Cedar Creek Mastodon, for the creek that runs near the excavation site.  Also, I have a website where I post information and photos on archaeology finds as well as all other aspects of Nature and natural history.  I began this blog and website to catch the spillover from the monthly stories I write for the Apple Valley Cider Press, mainly a regular "Nature Article" feature.  All of my writing is done on a volunteer basis.

Fragments of a  leg bone found at the Cedar Creek Mastodon Site could be that of the stag-moose, possibly another victim of the bone-crushing teeth of the Ice Age dire wolf.  (1912 illustration in public domain.) 

Leave the Predictions to Weatherbug, Not Woolly Bears!

The wide reddish-brown band on this woolly bear caterpillar could raise false hopes of a mild winter.  All the wide brown band tells you is that this caterpillar is mature and well fed.  That's good preparation for this creature as it crosses a bike path to seek shelter for the winter.  The caterpillar can survive even frozen solid.  (Photo by Don Comis)

On my annual walk from Kenyon College to my home in Apple Valley, using the Koksosing Gap Trail for 4.5 miles of the approximately 8-mile walk, I saw my first all-black caterpillar—well, actually I saw two of them, along with a few woolly bear caterpillars.

I probably had seen black caterpillars before but thought they were woolly bear caterpillars predicting a totally bad winter.   But I've learned that the width of the middle reddish-brown band on the brown and black woolly bears being a predictor of the severity of the upcoming winter is a myth.  Ironically it was started by a scientist, but later disproved.  Now scientists know that the only thing more brown on a woolly bear means is that the woolly bear is older, or  better fed, or both.

 The caterpillars are born mostly black and the brown band grows wider as the caterpillar gets bigger, with age and diet.

Since I saw two of these all-black caterpillars on Nov. 10, I believe they  are the caterpillars of the giant leopard tiger moth,not woolly bears--which become Isabella moths next year.   (Photo by Don Comis)

I also learned that woolly bears become Isabella tiger moths in the spring.   I found that out when I sent a photo of a woolly bear to the “Butterflies and Moths of North America” website and added that moth to my list of 111 moth species in Knox County, mostly found in Apple Valley.

But, fortuitously, the day before my big walk on Monday, Nov.10, I read a column in the Sunday Columbus Dispatch by John Switzer, one of my two favorite Nature columnists in the Sunday paper. Switzer was describing his daily walks in the country in November and mentions not only the woolly bear-Isabella connection, but also the fact that the all-black caterpillars become giant leopard tiger moths.  He quotes my other favorite Columbus Dispatch columnist, Jim McCormac, as saying that this moth is quite attractive.  McCormac, whose blog convinced me to use “blogspot.com” for my blog, also told Switzer that almost all the furry caterpillars we see in the fall turn into one of the many species of tiger moths.

Switzer says that in addition to black and brown, the furry fall caterpillars also come in blond and reddish-blonde.   At Apple Valley, I've seen two different species that are white—the banded tussock or pale tiger moth and the hickory tussock or hickory tiger moth.  I managed to photograph both the caterpillar and moth stages of the hickory tiger moth.

Certainly if Switzer, a former weather columnist, had any hopes left of a mild winter after seeing a woolly bear with a wide brown band, it's gone as the second snow of the season is falling tonight, one that could bring 2 to 3 inches--and be followed by below zero nights!  The snow came earlier than usual this year, with Cleveland getting 8 to 10 inches recently.

But then what does a woolly bear care about weather when it can survive the winter frozen solid?

The funny thing is that the very first blog I wrote, on Nov. 6, 2013, was on the woolly bear’s inability to predict weather.  Up to recently it had remained in the top five most popular of my postings, until the weekly mastodon reports wiped it and all other topics out of the top five.

White is one of the many colors the furry tiger moth caterpillars come in, depending on the species.  This is the hickory tiger moth caterpillar.  (Photo by Don Comis)

Note:  I also have a website where I post information and photos on archaeology finds as well as all other aspects of natural history.  This blog and website began to catch the spillover from the monthly stories I write for the Apple Valley Cider Press, mainly a regular "Nature Article" feature.

Mastodon Dig Turns to Lab for Answers

A look at the Nov. 9, 2014 mastodon dig.  It's likely that some or all of the mastodon bones were washed into the excavation site from upland drainage thousands of years ago.  (Photo by Don Comis)

You can see how cold it was on Nov. 9 by the winter clothing worn by volunteers.  (Photo by Don Comis)

As the search for mastodon bones on a soybean farm in Morrow County, Ohio, winds down before winter, the work shifts to a lab at Ashland University where the excavated materials will be analyzed to decide if it’s worth continuing the excavation in the spring.

Excavation leader, Dr. Nigel Brush-- Ashland University associate professor of geology--wrote in an e-mail answer to my questions, that the lab tests “will provide the final answer” as to whether the mastodon was killed and butchered by Paleo-Indians, as it appears.

Right Site?

Even if the answer is “yes”, the next question is whether the excavation site is the butchery site.  Brush wrote that, “Based on the geological work that is being done at the site, it is appearing more and more likely that the bones were brought to their present location by a debris flow from a site at a higher elevation. “  He added that an upland kill and butchery site doesn’t make as much sense as the current excavation site, which is right near the remnants of an ancient bog where the animal could have been trapped in the soft sediment by its weight.

The bog traces back to the Pleistocene era when it was a muddy glacial lake.

Students from Ohio’s Wooster College’s Climate Change class sank a probe more than 20 feet into the mud, gaining a record of environmental change over about the past 15,000 years.   Brush said, “They also found possible evidence for an old preglacial stream channel running through the bog."

Discovering the Ice Age

Students from Brush’  'Discovering the Ice Age” class are also among the volunteers on the dig.  

Since the skeleton parts found so far are very crushed and shattered, the focus of the excavation shifted after the first month, from recovering a complete skeleton for exhibit, to finding evidence of Paleo-Indians killing and butchering a mastodon.

Brush’s e-mail to me continued, “We have ample evidence from Ohio and surrounding states that Paleoindians were present during this time period.  Butchery sites are not as common, although their number is steadily growing (due to the work of Dan Fisher at the University of Michigan, and other archaeologists).

Paleo-Indian (also written as "Paleoindian") is the term for the first people to arrive in North America, about 16,000 years ago, near the end of the Ice Age.  The website www.Indians.org says that, “Their name, Paleo, actually comes from the Greek word “palaios,” meaning ancient.”

Tools, such as flint scrapers, used to possibly butcher the mastodon are being sent to another lab for DNA analysis to test for mastodon blood.  At the Ashland lab, bones and other materials are being power washed with water and examined for cut marks made by butchering tools.

Scavengers

Brush wrote, “There are a lot of gnaw and bite marks on the bone”, suggesting the possibility that the mastodon merely died of old age, its corpse eaten by scavenging animals.  But, it’s also possible that the scavengers were just mopping up what was left after the Paleo-Indians butchered it.

On Nov. 9, volunteers found another possible hammerstone, a large round stone used to as a hammer or maul to crush things.  Amateur “surface hunters” identify hammerstones by the pecks or pockmarks caused as the stones are pounded on things.   The latest hammerstone was found in the same plot where at least one other hammerstone was found.  Volunteers also found possible vertebrae on Nov. 9.

We also found more pieces of flint and fragments of bones, including small pieces of tusk.

Other items found since the dig began include possible leg bones, ankle bones, rib bones, jaw bones, wrist bones, and all four lower teeth of the mastodon.   And we found pieces of flint brought to the area by man from other parts of Ohio as well as pieces of charcoal that could have come from fires used to cook parts of the mastodon.  A possible fire pit was also found.

As far as I know, the only proven weapon found was a tiny projectile point (a “Merom Expanding Stemmed point “)—a Stone Age spear or arrow head—that belonged to Native Americans who arrived long after the mastodon was extinct.  While the mastodon dates back to beyond 8,000 B.C., the projectile “only” dates to between 1,600 B.C. to 810 B.C.

Mastodon On Its Last Legs

An analysis of the mastodon’s lower four teeth by volunteer Scott Donaldson showed that the mastodon had lived to a ripe old age that likely made it more vulnerable to predation by man or beast, as explained in my previous blog.  Donaldson led the work on restoring and preserving the teeth and served as one of the crew chiefs during the excavation.

In the fall of 2013, a soybean farmer found two of the teeth, two feet apart, after they were unearthed when a ditch was dug to lay drainage pipe.  This triggered the excavation which began Aug. 23, 2014.

The Nov. 9 dig was planned as the last dig before winter, but Brush later said that, weather permitting, he would schedule one more dig, after the weekend of Nov. 15-16.

Note:  I also have a website where I post information and photos on archaeology finds as well as all other aspects of natural history.  This blog and website began to catch the spillover from the monthly stories I write for the Apple Valley Cider Press, mainly a regular "Nature Article" feature.

Teeth Show Mastodon May Have Been Easy Mark

The photo  shows the full complement of four lower teeth.  It is "looking down" on the lower jaw (jaw bone absent) and the big teeth with the rounded ends are the back teeth.  (Photo by Scott Donaldson)

More confirmation that the mastodon killed and butchered in Morrow County was old came from an analysis of all four teeth recovered from the Cedar Creek Mastodon Site in Morrow County.

Scott Donaldson, who has led the work on restoring and preserving the teeth and served as one of the crew chiefs during the excavation, wrote a summary of his analysis that was e-mailed to volunteers on Nov. 2.

In his report, Donaldson said that if a mastodon lives to “ a ripe old age”, it will go through 24 teeth, shedding badly worn teeth from the front and erupting new ones at the back of the mouth, with either two or three teeth on each side of each jaw present at a given time.

He identified this mastodon as having its last teeth (numbers 5 and 6) on each side of the lower jaw. This and the amount of wear on the teeth indicated an advanced age.

He added that “…the apparent old age suggests a degree of infirmity which possibly made the animal vulnerable to being killed by man or beast, or which might be associated with a natural death.”

In the fall of 2013, a soybean farmer found two of the teeth, two feet apart, after they were unearthed when a ditch was dug to lay drainage pipe.  This triggered the excavation which began Aug. 23, 2014, and will end with a two-day excavation the weekend of Nov. 7-9.

Donaldson says the location of one of the teeth in Unit 5, one of  several 2- by 2-meter square excavation plots, “suggests that the as yet unidentified bone material nearby is part of the lower mandible [jaw bone]” the tooth came from.   A piece of jaw bone associated with the other three teeth was also found in the excavation.

Donaldson has done graduate work in anthropology/archaeology at Kent State University.  He has also done archaeology field and lab work with Dr. David Bush of Case Western Reserve University in Cleveland and the Cleveland Museum of Natural History field school.

Note:  I also have a website where I post information and photos on archaeology finds as well as all other aspects of natural history.  This blog and website began to catch the spillover from the monthly stories I write for the Apple Valley Cider Press, mainly a regular "Nature Article" feature.

From Christmas Bird Count to Road-Kill Bugs

An interesting set of articles in the current issue of Audubon Magazine.

The November/December 2014 issue of Audubon Magazine has an interesting set of articles on “three innovators who have led the charge in studying birds”—Chan Robbins (“The Pioneer”); Sam Droege (“The Incubator”); and, Jessica Zelt (“The Futurist”).

The articles, under the umbrella of “Citizen Science: Passing the Torch”, show how the torch was passed from 96-year-old Robbins to 56-year-old Droege to 31-year-old Zelt.

At least as far as birds go, the Audubon Christmas Bird Count —which both Robbins and Droege have participated in—at 115 years old, is the oldest citizen science project.  Robbins in fact, through his father who participated in the very first of these counts, has a lineage back to the entire 115 years of bird citizen science.

The Audubon bird count is the oldest citizen science project period, at least since the end of the era in which all science was done by citizen scientists rather than professionals.  It is definitely, as the magazine states, “the world’s oldest continuous wildlife census”.

I am fortunate enough to be preparing for about my 12th consecutive Christmas bird count.  From 2003 through 2011, I participated in the counts on the U.S. Department of Agriculture’s Beltsville Agricultural Research Center in Maryland.   Droege also participated in those counts, since his office is on the grounds of the Center, from which I retired after the 2011 Christmas bird count.  Droege is a biologist at the U.S. Geological Survey’s Patuxent Wildlife Research Center, which is headquartered on 12,840 acres adjacent to the Agricultural Center’s 7,000 acres.   Robbins has studied these grounds for more than 70 years.

Robbins created the 50-year-old annual Breeding Bird Survey, a citizen science project that Droege was hired to take over in 1985.  I had the honor of interviewing Robbins twice about his life’s work.

The Johnny Appleseed of Citizen Science

Droege has formed local teams to participate in many citizen science projects, including Bioblitz , Frogwatch USA, and Cricket Crawl .  His professional research activities include work on developing native bee survey techniques and monitoring programs, surveys of saltmarsh birds and surveys of Rusty Blackbirds.  The bee survey work could spawn a national citizen science project.

Droege hired Zelt in 2008 to digitize about six million records of bird arrivals and departures, dating back to 1880.  Over the next six years, she managed to turn the task into a citizen science empire .

I've blogged about both Robbins (9/19/14 , 8/24/14, and 7/17/14)  and Droege (9-16-14, 6/29/14, 6/22/14, and 11/19/13) before.

Bug Road-Kill?

The magazine’s cover has the intriguing title of “115 Years of Citizen Science:  From the Christmas Bird Count to…Road-Killed Bugs?”

Although I knew of a regional U.S. project in which volunteers count road-kill as a measure of animal populations, this was the first I had heard of a road-killed bugs project.  In this project 250 volunteers drove around with adhesive on their front bumpers and license plates to capture bugs that splatter against cars.  Scientists analyzed the results and determined that each car kills two bugs for every 6.2 miles traveled.   The project is limited to the Netherlands currently, but with one in the United Kingdom, the U.S. can’t be far behind.  The magazine says that in the U.S., more than 300 million cars each travel 13,500 miles a year, on average, “so bug mortalities add up”.

Science Wants You!

In addition to the bug road-kill project, the magazine lists six other citizen science projects at the bottom of four of the pages of the three articles, under the title of “Scientists Want You”:

• Frogwatch USA 
• Kestrel nest watch 
• Project Budburst watch  
• Celebrate Urban Birds
• Yard Map  
• Christmas Bird Count    (The Christmas Bird Count occurs each year between  December 14 to January 5, with the one day count date varying by location.  For example,  now that I am in Howard, Ohio, I will participate in the Dec. 21 count sponsored by the Brown Family Environmental Center at Kenyon College in Gambier.  To register for this event, e-mail  dohertyh@kenyon.edu or call 740-427-5052.)