Understanding the Functioning of Woolly Mammoths

Essential Insights

Imagine journeying 4,000 years into the past to a secluded Arctic island in Russia, where you might encounter robust, furry creatures with trunks plucking grass and feeding themselves with their tusked mouths. Though they share some traits with elephants, their unique features—like the sloping backs, specialized trunk tips, and small, cold-resistant ears and tails—set them apart unmistakably.

However, even with blurred vision, you couldn’t overlook that these creatures stand barely taller than you. You’ve stumbled upon the Wrangel Island mammoths, the dwarfed descendants of Mammuthus primigenius, the woolly mammoth. They represent the final chapter of their lineage.

Unlike their larger ancestors, which once numbered in the millions across Eurasia and North America, these smaller mammoths outlasted the wave of extinction that wiped out numerous large mammals over 6,000 years prior. They roamed Wrangel Island while humans were erecting pyramids in Egypt and assembling Stonehenge in Great Britain. Yet, eventually, they too succumbed to the same forces—likely climate change, human hunting, or a mix of both—that doomed their forebears [sources: Lister and Bahn; MGP].

Our knowledge of woolly mammoths and mammoths as a whole surpasses that of any other extinct species. Unlike the dinosaurs, which vanished 65 million years ago, mammoths disappeared relatively recently, allowing ancient humans to hunt, consume, and utilize their ivory for tools. They even immortalized them in early sculptures and cave art [sources: Conard; Lister and Bahn; MGP]. Remarkably preserved remains, sometimes entire bodies preserved in frozen soil, have revealed muscle, blood, teeth, bone, tusks, and even brain matter. Scientists have also successfully extracted and sequenced mammoth DNA [sources: Lister and Bahn; Mueller; Poinar].

Additionally, we have three living relatives to study, albeit distant ones: two Loxodonta species—the African bush and forest elephant—and one Elephas species, the Asian elephant, which is the mammoth’s closest living relative [source: Krause et al.]. By merging insights from modern elephants with evidence from mammoth fossils, preserved dung, and gut contents, we can vividly reconstruct the lives and behaviors of these ancient giants.

So, hop back into your time machine, rewind the clock by a few hundred thousand years, and let’s explore the world as it was when mammoths freely roamed the Earth.

A Day in the Life of a Woolly Mammoth

We often imagine woolly mammoths trudging through icy Arctic tundras or foraging across marshy Russian plains. In reality, these creatures inhabited environments vastly different from today’s landscapes. During much of the Pleistocene epoch—spanning 1.7 million to 11,500 years ago and concluding with the last ice age—a diverse array of grasses, herbs, and sedges stretched from Ireland to Siberia, crossing the Bering land bridge into much of present-day Canada. This mammoth steppe thrived under a unique climate. As glaciers expanded and locked away water, sea levels fell, revealing vast expanses of land characterized by dry, clear, and windy blue skies [sources: Lister and Bahn; Mueller;

Roaming these plains in a relentless 20-hour daily search for food were countless Mammuthus primigenius, creatures comparable in size to modern elephants. These woolly mammoths lived either as solitary males, standing 9-11 feet (3-4 meters) tall and weighing around 6 tons, or in matriarchal herds of 2-20 smaller females and calves. They endured the frigid northern climates thanks to adaptations like a 3-4-inch (8-10-centimeter) layer of fat, inch-thick oily skin, and a dense woolly undercoat. This undercoat was covered by coarser guard hairs, ranging from a few inches to up to 3 feet (1 meter) long, with the longest forming a musk-ox-like fringe along their sides and belly [sources: BBC; Lister and Bahn; Mueller; National Geographic]. Even their hemoglobin was adapted to retain heat, a feature shared by many cold-adapted mammals today [sources: Campbell; Rummer].

Woolly mammoths coexisted with other large mammals, including grazers like woolly rhinoceroses and long-horned bison, as well as predators such as saber-tooth cats and cave hyenas. Given their size and formidable tusks, healthy adult mammoths could defend themselves against most threats, especially when in a group. Predators likely targeted sick or injured adults or isolated calves [sources: Lister and Bahn; Mueller].

Mammoth calves were typically born in spring, a time when new plant growth provided ample nourishment for nursing mothers. With a 22-month gestation period, conception occurred in late summer. Males, detecting a female in estrus, would compete through tusk displays, ritualized sparring, or outright battles to prove their fitness. Similar to modern elephants, male woolly mammoths possessed a musth gland, which released a fluid that helped establish dominance during their aggressive and unpredictable musth phase [source: Lister and Bahn].

If, as experts believe, mammoths behaved like today's elephants, they were likely highly social creatures. They educated their young, possibly protected their dead, and may have even buried them. They might have gathered in large migratory herds periodically and were capable of swimming to nearby islands [sources: BBC; Lister and Bahn; Poinar]. In essence, they were animals perfectly adapted to their environment.

All in the Mammoth Family

Woolly mammoths belong to a group of large herbivores, including mastodons, elephants, and other mammoth species, all descended from ancient proboscideans (from the Greek proboskis, meaning "nose"). This lineage diverged from other mammals approximately 55 million years ago [sources: BBC; Lister and Bahn; UCMP].

The earliest mammoths appeared in Africa approximately 5-6 million years ago, though they lacked the woolly coats of their later relatives [sources: Perkins; Lister and Bahn; UCMP]. By about 3 million years ago, their descendants, such as the widespread southern mammoth (Mammuthus meridionalis), had migrated across the Sinai Peninsula into southern Eurasia. Over time, they expanded westward to the British Isles and eastward to Siberia, though whether they reached the New World 1.8 million years ago is still debated. Resembling modern elephants in many ways, except for their sloping backs, spiraled tusks, and massive size—standing around 13 feet (4 meters) tall and weighing 8-10 tons—southern mammoths primarily fed on leaves, fruit, and tree bark. Their foraging habits significantly impacted forests, as they stripped bark, toppled trees, and created habitats for other grazing animals [sources: BBC; Lister and Bahn; Mueller; Poinar; UCMP].

Around 750,000 years ago, M.meridionalis was replaced by the steppe mammoth (Mammuthus trogontherii), the largest mammoth species, standing 14 feet (4.3 meters) tall and weighing at least 10 tons. Likely originating in northeastern Eurasia 2.0-1.5 million years ago, it is considered the probable ancestor of the woolly mammoth. This species featured smaller ears and tail, along with a slightly shaggy coat. While primarily a grazer, it also consumed trees and shrubs [sources: Lister and Bahn; Poinar].

The smaller woolly mammoth, which emerged around 400,000 years ago, likely evolved specialized traits to survive Siberia's harsh climate. The first woolly mammoth carcass was discovered in 1806 by botanist Mikhail Adams in this icy region [sources: Lister and Bahn; Mueller]. Over time, the species spread as far as modern Ireland and, beginning 125,000 years ago, crossed the Bering Strait into Canada, eventually reaching the eastern coast [sources: Mueller; Poinar; UCMP]. Another species, the Columbian mammoth (Mammuthus columbi), coexisted during this period, inhabiting parklands and open forests in what is now the U.S. and Mexico. It likely descended from steppe mammoths that arrived in the region 1.5 million years ago [sources: Lister and Bahn; Poinar].

Mammoths were highly adaptable to the climatic shifts of the Pleistocene. However, within a short span of 14,000-10,000 years ago, they, along with most other large mammals in the Northern Hemisphere, went extinct [source: Mueller]. The reasons for this remain a subject of investigation.

The Fate of the Mammoth

Paleontologists have proposed various theories to explain the sudden disappearance of mammoths at the end of the last ice age, including meteor impacts, diseases, climate shifts, and human hunting. Evidence supporting meteor strikes has been lacking. Regarding diseases spread by humans or dogs, experts find it unlikely that a single pathogen could target such a diverse range of large animals exclusively [sources: Lister and Bahn; UCMP]. This leaves climate change and hunting as the most plausible explanations.

Mammoths were unable to thrive in environments resembling today's steppes, deserts, savannas, or tropical forests. They were restricted to the unique plant ecosystems of the mammoth steppe and parkland biomes. The climate hypothesis suggests that this specialization may have led to their isolation and eventual starvation. As glaciers melted and sea levels rose, continents contracted, and wetter conditions emerged. Unable to adapt, mammoths faced dwindling food supplies, leading to population declines [sources: Lister and Bahn; Mueller; Saey; Willerslev et al.].

Similar to the disease theory, the overkill hypothesis highlights the correlation between the rapid decline of mammoths and the arrival of humans in North America 13,300-12,800 years ago. It posits that skilled hunters, armed with spears featuring fluted Clovis points, drove mammoths to extinction. Clovis points have been discovered alongside mammoth remains, and evidence shows humans utilized mammoth fur, meat, and ivory. Additionally, both Neanderthals and Stone Age humans are known to have constructed shelters using mammoth bones [sources: Bower; Demay, Péan and Patou-Mathis].

However, numerous questions persist. Considering that a single mammoth could sustain many humans, especially with the aid of natural refrigeration, and that early humans depicted these creatures in cave art, it's plausible they regarded mammoths with the same respect and moderation that Native Americans showed toward buffalo [source: MGP]. Additionally, hunter-gatherers likely had diverse diets, relying more on small to medium-sized game for meat, making it uncertain how frequently they actively hunted mammoths as opposed to scavenging their remains [sources: AMNH; Guthrie; Lister and Bahn].

In the end, the inherent limitations of large mammals like mammoths—such as low reproduction rates and massive food requirements—may have accelerated their extinction. These factors, combined with isolation, habitat destruction, and predation, left only their dwarf descendants, isolated on remote islands, to survive for another 6,000 years [sources: AMNH; Bower; Lister and Bahn; Nikolskiy and Pitulko].