Pigeon Bones Reveal The Cognitive Sophistication of Neanderthals

Around sixty-seven thousand years ago, someone ate a Rock dove. In doing so, that individual began an association between a primate and a bird that would persist up until the present.

Pigeons - the urban-adapted form of Rock doves - have lived among humans longer than chickens, longer than goats and sheep, longer even than wolves. They have become adapted to urban life on all continents except Antarctica. They're so omnipresent that, for most of us, they fade into the background. But the fate of human and pigeon was not always intertwined. It had to start somewhere.

Gibraltar is located at the southern tip of Spain, just across the water from northern Africa. There, as the waves of the Mediterranean crashed into the rocky shoreline, they created a system of caves that were used by humans (for this purpose, "humans" includes both modern humans and Neanderthals) for shelter as far back as the Paleolithic. One such cave that has attracted the attention of archaeologists and anthropologists is called Gorham's Cave.

Pigeon Bones Reveal The Cognitive Sophistication of Neanderthals

Photograph from the sea of Governor's Beach, southeast side of the Rock, Gibraltar, showing Gorham's Cave, which is the focus of this research. Photo by C. Finlayson, used with permission.

In addition to evidence of human inhabitation – first by Neanderthals, and only later by modern humans – Gorham's Cave was also home to a variety of animals. The most common large mammal bones found inside belong to Red deer and to a kind of wild goat called the Alpine ibex. Smaller mammals included rabbits, wood mice, dormice, pine voles, and other rodents. The remains of at least 24 reptile and amphibian taxa have been discovered there, including newts, toads, frogs, tortoises, turtles, lizards, geckos, and snakes. At least ninety bird species have, at one time or another, called Gorham's Cave home, including birds of prey, seabirds, ducks, crows, swifts, and more. But one of the most common birds found in the cave were Rock doves, which are visually indistinguishable from modern pigeons.

Altogether, the researchers led by Ruth Blasco from The Gibraltar Museum, analyzed 1724 Rock dove bones from the site. That the cave was a popular site for the doves was not surprising, but what was striking was the evidence of a long term, persistent relationship between Neanderthals and the doves. On 28 of the bones, Blasco found evidence of cut marks made by stone tools. That's indeed a relatively small proportion of the Rock dove bones analyzed, but that could simply be because the easiest way to eat a dove is the same way most of us each chickens today: directly from the bone. Writes Blasco:

Although the proportion of cut-marked specimens is not high, it is important to emphasize that the size of these prey makes the use of stone tools unnecessary for direct consumption. After skinning or feather removal, direct use of hands and teeth would be the best way to remove the meat and fat/cartilage from the bones. The proof of this is the human tooth-marks and associated damage observed on some dove bones.

That a significant proportion of bird bones found in the cave had burn marks on them was further evidence that Rock doves, and birds more generally, were an important source of nutrition for Neanderthals.

Pigeon Bones Reveal The Cognitive Sophistication of Neanderthals

Cut-marked bones of Rock Dove specimens from Gorham's Cave. Note especially the burning of specimen F. Photos via Ruth Blasco et al., Scientific Reports.

The finding is an important one, not only because it represents one of the longest associations between humans and non-human animals in history, but because it forces us to rethink what life was like for Neanderthals. "Until now," the researchers say, "the systematic exploitation of birds has been considered to be an exclusive and defining feature of modern human behavior." The evidence from Gorham's Cave now demonstrates ("unequivocally," they write) that Neanderthals hunted Rock doves for food, well before modern humans ever found themselves in that part of the world. That also means that they figured it out on their own, rather than learning by watching modern humans.

Since their dove consumption spanned at least 40-thousand years, it underscores the point that the hunting of Rock doves wasn't just casual or opportunistic, but intentional. Hunting birds with only the most rudimentary of tools requires skill, planning, and some measure of precision; combined with other evidence from Gorham's Cave that Neanderthals were capable of snatching harder-to-catch birds, like raptors and corvids, the evidence suggests that Neanderthals had cognitive capacities similar to modern humans.

Hunting Rock doves is also sustainable. The birds breed quickly and they breed often. Few birds anywhere are as ubiquitous or numerous. A look at modern and extinct pigeons confirms this: Passenger pigeons flocked in some of the largest aggregations ever observed for any bird species, and modern dove flocks may number in the millions, as they do in Argentina.

"Traditionally in human history, the pigeon has been considered as a symbol of peace, love, and fertility, three attributes that are deeply interwoven," write Blasco and colleagues. "Its origins may well have been with the Neanderthals who exploited this very fertility in a way that allowed them to target them for food without depleting their numbers."

Read the entire open access paper for free in Scientific Reports.

Header photo: San Francisco pigeon copyright Jason G. Goldman