Bird charities are ecstatic after identifying the winter home of the northern bald ibis, a critically endangered species.
Three birds have now been followed by satellite tags from their summer grounds in Syria to Ethiopia.
Britain's Royal Society for the Protection of Birds (RSPB) describes the find as a "major breakthrough".
It says the ibis is the rarest bird in the Middle East; exact numbers are unknown but could be under 1,000.
The internationally-recognised Red List of Threatened Species categorises the northern bald ibis (Geronticus eremita) as critically endangered because of habitat loss, farming, human encroachment and pollution.
There are thought to be only two surviving summer populations, one in Syria and one in Morocco. Its range used to extend into Europe.
"Knowing where these birds go and how they get there is a major breakthrough," said Chris Bowden, a bald ibis specialist with RSPB.
"This has answered a big question mark that remained for this species, and one that we feared we might never resolve."
Deity in danger
Scientists followed the birds by tagging them with satellite transmitters.
Three tagged ibis, nicknamed Sultan, Salam and Zenobia, turned up in Ethiopia, as did one untagged member of the same group.
Images of Thoth, the "ibis god", are found on tombs of some Pharaohs
Getting there entailed a journey of 3,100km (1,900 miles).
The location surprised researchers who had been looking for them further north.
"As we searched, we were not getting any signals from the transmitters, so finding the birds in such a remote area was a wonderful surprise," said Mengistu Wondafrash from the Ethiopian Wildlife and Natural History Society.
"We will be doing all we can to implement conservation measures to help increase the numbers of this rare but special bird."
The ibis is familiar to Egyptologists from images of Thoth, the "ibis god", found on tombs of some Pharaohs.