Pleistocene Ravens (Corvus corvax)

Halloween is my favorite holiday, but this year I’m not in the mood.  My father slipped into a coma and died last week.  That real horror far overshadows the artificial scares of Halloween and makes them even seem kind of silly.  It had been shocking to observe the steady decline of a man who went from being able to play 2 hour tennis matches in 100 degreee F heat to someone barely able to make it from the living room to the bathroom.  The aging process is a real monster that can not be stopped.  We were able to give my dad a proper burial, but that is a luxury ancient humans didn’t always have.  Humans are part of the natural world, and for many other organisms our bodies are just a source of protein.  Pleistocene humans no doubt often died from accidents while hunting.  If fellow tribesmen failed to find the body, it became food for the wildlife.  In Eurasia and North America ravens probably consumed more human flesh than any other animal.  Ancient battlefields strewn with corpses attracted great flocks of ravens, and this species was unfairly considered an harbinger of death.  The true harbingers of death were the humans who killed each other, but superstitious people blamed the birds.

Before the Age of Reason people thought ravens were a harbinger of doom because they saw them scavenging dead corpses on battlefields.  Of course, it was the humans who were the harbingers of doom.  People instigated the killing, then blamed the birds. This illogical thought process is typical of our species.

The raven is a bird of deep wilderness, and its range has contracted with the advance of human “civilization.”  In contrast to the raven, the crow (Corvus brachyrinchus) thrives in the vicinity of man and has increased in numbers.  Crows are more social and tolerate each other’s company, while nesting raven pairs defend their territories from other ravens.  This behavioral difference explains why nesting communal crows are better able to take advantage of concentrated anthropogenic resources such as agricultural fields and garbage dumps.  The nesting strategy of the raven makes more sense when food consists mostly of more irregularly available animal carcasses. 

Ravens are known as “wolf-birds” because they are often seen in the company of wolves, scavenging their kills.  Wolves can lose up to 45 lbs of meat per day to ravens, and some think they evolved pack behavior to help defend their kills from scavenging ravens rather than from other predators.

Ravens were more widespread in southeastern North America during the Pleistocene than they are today, though evidentally they were absent from Florida.  The only known raven nest site in present day Georgia is a cliff on Brasstown Bald Mountain, but raven fossils of Pleistocene-age have been excavated from Kingston Saltpeter Cave in Bartow County, Georgia, and Bell Cave in Colbert County, Alabama.  Before man altered the environment ravens may have been more common in the upper south than crows.  Ravens fed on the deceased individuals of Pleistocene megafauna herds.  Ravens disappeared from the midwest following the extirpation of bison in the 19th century, and likely also declined in abundance in the south following the extinction of the Pleistocene megafauna thousands of years earlier.  Ravens surely followed dire wolves around, much like they follow modern day wolf packs in the Rocky Mountains.

 

 

 

 

 

 

 

 

 

 

 

Ravens are known as wolf-birds.  They hang around wolf packs for access to the meat from kills.  Wolves may have evolved pack behavior to fend off ravens.  During the Pleistocene ravens surely accompanied dire wolves.

Ravens are larger than crows growing up to 4 lbs compared to less than 1 lb for the latter.  Ravens have a 4 foot wingspan and like to soar.  Crows rarely, if ever, soar.  A large adult crow can be larger than a small juvenile raven, but there is still a distinguishing characteristic–the raven has a more rounded tail. Both are highly intelligent species with a reasoning ability that matches or maybe even exceeds that of a monkey.  And both species are omnivorous, capable of eating everything from insects, worms, birds’s eggs, and carrion to nuts, fruit, grains, garbage, and dog shit.

Ravens soar with the wind, while crows generally do not. Note the rounded tail.  Crows have a square tail.

Genetic studies suggest there are  2 clades of ravens in North America.  The most common clade is the Holarctic found in Europe, Asia, Greenland, and North America.  The California clade is found only on the southern Pacific coast of North America, and this clade is more closely related to the Chihauhan raven (Corvus cryptoleucas) than to members of its own species in the Holarctic clade.  The California clade became isolated from the Holarctic clade some time during the Pleistocene.

 Reference:

Marzluff, John; and Tony Angell

In the Company of Crows and Ravens

Yale University Press 2005

Advertisement

Tags: Pleistocene ravens, ravens a bird of deep wilderness, ravens eating human flesh, wolf-birds