Over 1,500 years ago, parts of the Negev were being farmed, to an extent that astounded latter-day archaeologists. The miracle of lushness in the desert turns out to have relied not only on perseverance and water management, but on pigeons relieving themselves.
Archaeologists had already deduced that the Negev Byzantines' building their giant dovecotes splat in the middle of fields meant that farmers were using the birds' by-product as fertilizer. But they wondered at the primary impetus behind flock management, i.e., whether these fairly early Christians were breeding doves (a.k.a. pigeons) to eat.
Clearly the ancients of Shivta and Saadon also ate of the dove, as did everybody else in the Middle East. Indeed, in contrast to urban westerners and their distaste for the "flying rats," this entire region has appreciated the pigeon going back millennia. But the study has now proven that the pigeons living in the Negev farming settlements were wild-type (Columba livia palaestinae), small, and muscular ("athletic").
If the Byzantine farmers had been breeding them mainly for meat, they would have selected for large size, Dr. Nimrod Marom of the University of Haifa and Tel Hai College, with Prof. Bar-Oz and Dr. Yotam Tepper of the Institute of Archaeology at the University of Haifa and Dr. Baruch Rosen of the Volcani Center, write in PLOS One.
Skull and skeleton measurements of the pigeons at Shivta and Saadon were compared with measurements made by none other than Charles Darwin, among many other things. (Darwin's pigeon specimens are at the British Museum.)
Breeding for size as a flock management strategy would have involved protecting the birds from the desert conditions, which all other things being equal, keeps creatures small. The pigeon bones found at Shivta and Saadon were much smaller than those of pigeons bred for the meat industry, they write. Ergo, the birds were not buffered from natural selection pressures.
Pigeons bred for meat in ancient Rome, for instance, were larger. So if the scrawny pigeons of the Negev were kept, and the huge pigeon towers up to 9 meters tall in the middle of the fields shows they were, that argues for that the Byzantines' main goal was the "secondary product."
"Bird guano is the best natural fertilizer, better than horse, camel or cow manure," Tepper says.
Your average dove outputs about 10 liters of guano goodness a year. Each Shivta dovecote had compartments for 1,200 to 1,600 birds (under optimal conditions), Tepper tells Haaretz – which translates into as much as 12 to 15 tons of lovely guano for olives and grapevines.
Furthermore, the Shivta cotes were as much as 800 meters from the homes, not conveniently near the hearth. Others in the Middle East kept their doves in proximity to the home. That in and of itself indicates that the primary goal of pigeon husbandry in the Negev farms was for fertilizer, Tepper says.
Also, the Christians of Shivta didn't need to breed birds for sacrifice, which had been very much the norm among Jews in ancient Israel.
"During the Second Temple period, when the Temple stood in Jerusalem at the height of its glory, the most common sacrifice among the Jewish pilgrims was a pair of doves," Tepper told Haaretz, adding: "Legend has it that King Herod loved pigeons and raised them: his palaces in Jericho, Masada and elsewhere had cotes."
Jird in the hand
The sheer extent of farming discovered in the Byzantine-era Negev, sustained for hundreds of years, was a surprise. A hospitable environment, it is not, with rainfall ranging from almost none to anywhere from 50 to 100 millimeters a year. Shivta and Saadon average less than 100mm a year.
Given the vicissitudes of the weather on top of the poor loess soil, the nutrients in pigeon poo were vital to sustaining long-term agriculture (on top of together remarkable water harvesting and management and terracing). "This risk-abating product meant long-term settlement viability," the team writes.
Pigeon droppings are rich in phosphorus, potassium, and nitrogen, Tepper says.
In Shivta, the team excavated four cotes, the earliest dating to the 2nd century C.E. Roman period, Tepper says. They were only abandoned when Byzantine society collapsed in the late 6th century or early 7th (based on pottery, coins and carbon dating).
Poignantly, one of the four cotes featured a thick, 40-centimeter layer of pigeon dirt on the bottom of the triangular dove-compartments, with bird bones, eggshell fragments, plant material and more – a sort of archaeological time-capsule of living conditions at the time. But mainly it seems the birds continued to live there for a while after the community collapsed in the late Byzantine, and stopped harvesting the crucial droppings.
On top of sustenance crops, the people of Shivta needed the manure for their grapes. No less than three big Byzantine-era winepresses were found in the settlement, Tepper tells Haaretz. The archaeologists think the Shivtans exported their wine, perhaps to Egypt (by camel train) and probably around the whole Mediterranean basin (by ship from the coast), in so-called "Gaza jars". These pottery jars themselves were apparently imported from the southern coastal area (not abroad): they were made there, and no big kilns were found at Shivta.
While historians of eld extolled the virtues of Gaza and Ashkelon wine, Shivta's vintage seems to have gone without comment. Even so: "Viticulture provided the storable and redistributable commodity that could be traded for staples during bad years in a marginal zone," the team writes.
In short, wild-type pigeons found it convenient to nest in dove towers amid rolling fields where they could forage for grain, and played a key role in sustaining the Byzantine Negev and its wine industry, olives, pomegranates and grains going back over 1,500 years. That continued a tradition in the inhospitable ranges of the Middle East going back millennia.
The extent to which these early Christians transformed the local ecology was recently demonstrated by the revelation that during their time, a relatively delicate rodent called Tristram’s jird that cannot tolerate desert conditions was thriving at Shivta. After the village's collapse, its jirds disappeared.
Why Shivta, Saadon and the other Christian settlements in the Negev suddenly collapsed is not known, at least yet. Perhaps the immediate cause was earthquake, given the proximity to the Great Rift Valley; or other natural disaster.
Finally, the archaeologists speculate on the process of pigeon domestication, for which there is precious little bio-archaeological data. Did caveman and pigeon begin it all in the Pleistocene, as commensal relations (between a big host that typically remains unchanged, and a small animal that moves in and changes over time)?
The little remains found show the cave inhabitants did not cavil at eating muscular pigeons but sustainable co-habitation can't be proven. It's when people began to farm that grains would have attracted birds, write the archaeologists, noting the Neolithic site of Qumran near Jericho. "From that time, when constant motivation to live and nest by humans was created, a Rubicon was crossed," they write. "Pigeons were bound to human environments, drawn to it by foraging opportunities, and could be exploited with varying degrees of intensity."