The Asphalt Abyass: Why Predators outnumber Prey

A Predatory Paradox: The Trap of the Pits

Visitors to the La Brea Tar Pits are often shocked to learn that the fossils recovered are overwhelmingly carnivorous. In a typical ecosystem, herbivores far outnumber predators, but at La Brea, the ratio is roughly nine to one in favor of carnivores like the dire wolf and saber-toothed cat. This "predator trap" occurred because a single herbivore—such as a mammoth or bison—would become ensnared in the sticky asphalt. Its distressed cries and the scent of its struggle acted as "bait," drawing in multiple opportunistic predators who then became trapped themselves, creating a concentrated graveyard of Ice Age hunters.

The Scavenger’s Spiral: A Chain Reaction

The high concentration of predators wasn't just a fluke of the first animal getting stuck; it was a self-perpetuating chain reaction. Once a large herbivore was immobilized, it became a "calling card" for local scavengers. A single mired horse could attract a pack of dire wolves, who would then get stuck while fighting over the carcass. Their presence, in turn, would lure in soaring teratorns (giant vultures) or saber-toothed cats looking for an easy meal. This cycle turned a single patch of asphalt into a multi-layered tomb, stacking generation after generation of hunters on top of their intended dinner.

The Kern County Connection: The Maricopa Tar Seeps

While La Brea is world-famous, it isn't the only asphalt trap in California; located just a few hours north is the Maricopa Tar Seeps in Kern County. Historically, these seeps provided a similar service to paleontology, though on a smaller and more rugged scale. Much like La Brea, Maricopa trapped a variety of Pleistocene megafauna, including camels and horses, offering a crucial comparative look at the region's prehistoric biodiversity. Interestingly, while La Brea was famously excavated by early 20th-century scientists in a race for museum specimens, the Maricopa seeps remain a quieter, less-disturbed relative that helps tell the broader story of how California’s geology shaped its fossil record.

Photo taken at La Brea Tar Pits and Museum