The Earth Story

First insects then eventually vultures go after a carcass, Serengeti Plains, Africa

Dire wolves existed, and they likely duelled with sabertooth cats

Launched into popularity by George R.R. Martin’s A Game of Thrones, it may come as a surprise that dire wolves (Canis dirus) really did exist. Larger than today’s grey wolf (Canis lupus) – though not as large as their onscreen counterparts – the dire wolf was a formidable predator which roamed the plains of Pleistocene America. It had powerful bone-crushing jaws - which could deliver a bite 129% the force of the modern-day grey wolf - and a broad, muscular body to match. Despite this, it was more often a scavenger rather than an active hunter, preferring to feed on the spoils of other species. That species was often the sabertooth cat (Smilodon fatalis).

Fossil records of the dire wolf and the sabertooth cat show that they both occupied the same range, feeding on herbivorous megafauna such as Megalonyx (giant sloths) or Mastodon (an ancient relative of today’s elephants). It is likely that they would have clashed often, though the outcomes would have been variable. Like modern-day wolves, dire wolves were social pack animals - giving them an advantage in competitive confrontations. It is still uncertain whether Sabertooth cats were solitary or not, and if they hunted in packs they were likely to be smaller and less robust than those of dire wolves. Either way their notably large maxillary canines would have been daunting weaponry, even if they had a relatively weak bite.

My guess is that the dire wolves - with their tight-knit pack instinct and higher numbers – would have been more likely to come out on top if it had come to blows, though not without injury. However, it seems they should have been more worried about their faster and larger-brained cousins - the grey wolves - who outcompeted them to extinction between 4,000-16,000 years ago.

VP

References: http://bit.ly/1Qox69L, http://bit.ly/1WvF6UX Image source: Wikimedia Commons (https://en.wikipedia.org/wiki/File:Smilodon_and_Canis_dirus.jpg).

On the Vulture, Part III: The Vulture as nature’s caretaker

Check out parts I and II: http://on.fb.me/1OtuBPq http://on.fb.me/1Qq0rzb

From parts I and II, we know that vultures are conversely esteemed as divine entities and bloodthirsty scavengers. Contrary to popular belief that they only feed on dead animals, vultures are actually classified as birds of prey, but only prey on healthy, living animals when carrion are in low supply. In the Pyrenees, farmers aren’t very fond of the local population of government-protected griffon vultures, who often carry off goats and sheep due to a paucity of carcasses. Part of the problem are the farmers themselves, who burn dead livestock in an effort to drive griffon vultures away from their pastures. As a result, the griffon vultures of the Pyrenees are starving, and explains how a fresh corpse (part I has the full story: http://on.fb.me/1OtuBPq) could be reduced to bones in under an hour.

The vulture’s dietary adaptations certainly explains its niche in the environment; vultures are the only animals capable of consuming a palate of putrid flesh. But their liking for decaying meat is also crucial to a healthy ecosystem: they are nature’s caretakers, cutting off the spread of many infectious diseases by eating pathogen-laden carcasses. From an evolutionary standpoint, this makes a lot of sense — these birds evolved to fill an uncarved niche in the environment, while their dietary behavior helps prevent epidemics that could wipe out the environments they inhabit.

A “vulture” is actually an umbrella name for two different groups of scavenging birds of prey: the Old World vultures in Europe, Africa, and Asia, and the New World vultures in the Americas. Despite sharing similar physical, behavioral, and ecological traits, these two groups of vultures are not closely related and evolved independent of each other — a process called “convergent evolution” — and is a fine example of nature selecting traits that benefit a balanced ecosystem.

-Darren

Photo credit: http://bit.ly/1Pof1bi

More reading: http://ind.pn/1i0mVlG http://bit.ly/1VeDjmv http://bit.ly/1Nqn9AL

On the Vulture, Part I: The Vulture and human culture

In April 2013, while on a hike in the Pyrenees of France, a woman lost her footing on the side of a cliff and fell more than 980 feet to her death. Her friends immediately alerted park authorities, and within an hour, her mangled body was found hidden under the side of the cliff. But what they discovered shocked them — only a fleshless corpse remained, with bits of frayed clothing and shoes hanging off her bare bones. Medical examiners later determined that the griffon vultures of the Pyrenees were the reason behind her fleshless body, meaning her entire body had to have been devoured by the scavenging birds in less than an hour.

We all know the classic film trope of circling vultures in films — the valiant hero, wandering despairingly through a barren desert, looks up to an unforgiving sky and spots a wake of vultures, circling malevolently as they balefully observe their next potential meal. Modern Western cultures have framed vultures alongside their obsession with death — grimly unforgiving, ravaging, and opportunistic. But in many other cultures, vultures are considered creatures of a more benevolent nature. In ancient Egypt, the goddess of death and rebirth was Nekhbet, who was often portrayed as a vulture-headed woman. The ancient Egyptians, remarkably prescient for their time, recognized the ecological importance of vultures in the food chain and ecosystem. Native American totems often depict vultures as spirit animals that represent the acceptance of hardships and vindication of the spirit.

Today, Western cultures often associate vultures with sky burials, which are mainly practiced by Buddhist and Zoroastrian communities in Tibet and South Asia. In the remote Himalayan plateaus, Tibetan Buddhists revere the vulture as a sky spirit, whose act of feeding on corpses is regarded as an important rite for the deceased. The bodies of the departed are usually dismembered by a burial master in an elaborate ritual, who then feeds their rendered remains to a wake of vultures. Tibetan Buddhism teaches that the human body is nothing more than vessel of the soul. At the time of death, the soul dispenses of its body like a shell before it moves on to the afterlife. Sky burials illustrate the connection between the human body and the natural world — feeding a human body to a wake of vultures swiftly returns its nutrients to the environment, conferring the soul’s vessel back to the cycle of life. In the isolated Himalayan peaks, where carrion-hungry fowl are more commonplace than tractable soil or firewood, sky burials remain the most practical means of honoring the dead.

-Darren

Photo credit: http://bit.ly/1P1HmUG

More reading: http://bit.ly/1nnlotz http://huff.to/1OhkAok http://bit.ly/1N6rUiA http://bit.ly/1RkYbdu http://nyti.ms/1SNK6oj http://bit.ly/1eoER7b