In ancient Egypt, ibises were gathered from their natural habitat as a sacrifice to the god of equilibrium. 

A study published on November 13, 2019, in the open-access journal PLOS ONE by Sally Wasef and colleagues, of Griffith University, Australia, rejects the idea that the ancient Egyptians domesticated wild ibises.

Ibises have been observed to hold a great deal of significance for the Egyptians. The importance of the birds is evident by the millions of bones and skeletons found in the catacombs of Egypt. Analyses of these catacombs have revealed that these places are full of millions of mummified ibises, neatly arranged from the ground to the ceiling.

Source: Cosmos

The existence of these birds has been recorded in many Philosophical and scientific writings. Aristotle has discussed in his work that thousands of sacred Ibises were found in Egypt around 350 BC. Strabo reports a large sighting of these birds in the streets of Alexandria in 20 AD. Pierre Belon referred to these birds as an odd stock, which he found during his travels to Egypt in the 1540s. Additionally, Benoît de Maillet reported in his writings that when the caravans traveled to Mecca from Egypt in the 17th century, a large flock of these birds cast over them like clouds, and followed them to the deserts to feed on the leftover food at the encampments. However, around the 1850s, the species of these birds completely vanished from Egypt, both as a bred and wild population. 

Source: Wikipedia

This discovery then led scientists to believe that the ancient Egyptians domesticated and farmed the birds. A large number of ibises suggested that the Egyptians had easy access to the birds, which allowed them to breed the animals to further use it for worship. 

Data suggests that in the years 664 BC and 250 AD, the Egyptians sacrificed and worshiped the birds, as part of the ceremony to their deity Djehuty, who is commonly referred to as the Greek god, Thoth. Once the sacrifice was completed, the birds were mummified.  

Some background information on Thoth:

In ancient Egyptian wall art, Thoth is often showed as an Ibis-headed being, with a body of a man. He is said to be responsible for writing, mathematics, measurement, time, moon and magic. In ancient Egypt, he was one of the most important gods as he was self-made. According to one story, Thoth was born from the seed of Horus (god of the sky) and the forehead of Set (god of war). Being the offspring of these two opposing forces, Thoth maintained his place in the ancient Egypt customs as the god of equilibrium. Hence, he sustained the divine balance. 

Source: PBS learning media

The research:

Considering the large number of Ibises, the researched previously believed that the birds were bred. However, the results of the current study proved otherwise. Sally Wasef and her peers took a DNA sample of forty mummified birds from Egyptian catacombs extended over six different locations. These catacombs are believed to be created at least 2500 years ago. For comparison of the results, another DNA sample was taken from the 26 modern-day Ibis species, from all over Africa.

The results found that fourteen of the mummified birds and all of the modern-day birds had a similar mitochondrial genome sequence. This provided the researchers with an incentive to draw out a genetic comparison between the modern-day wild Ibises species and the mummified birds.

The research shows evidence that the birds were not domesticated or farmed. If that were the case, the result would have a low genetic diversity as a result of the interbreeding of a limited population.

However, the data gathered by the researchers proved that the genetic diversity of the mummified birds was extremely similar to that of the modern-day birds. These results lead to the belief that the birds were not farmed, rather they were tamed for a short time, before their sacrifice.

Wasef and her colleagues further theorize an explanation suggesting that the birds may have been farmed in their natural habitat during the sacrifice season.

So, where did the birds come from?

While research provides answers to distinct questions, it also creates more inquiries on the subject. The question that comes from these findings is a simple one. 

How did the Egyptians get access to millions of Ibises?