In Islam's belief, which bird accompanied pilgrims on their hajj to Mecca in autumn, and it is said to have shown Noah the way from Mount Ararat to the fertile valley of the Euphrates after the flood?

The Northern bald ibis (Geronticus eremita). The species was once widespread throughout the Middle East and North Africa, but has become critically endangered in modern times.

Religious traditions helped this species to survive in one Turkish colony long after the species had disappeared from Europe, since it was believed that the ibis migrated each year to guide Hajj pilgrims to Mecca. The ibis was protected by its religious significance, and a festival was held annually to celebrate its return north.

https://en.wikipedia.org/wiki/Northern_bald_ibis#Habitat_and_range

The Northern bald ibis is also associated with the story of Noah, who is said to have been guided by the bird from Mount Ararat to the fertile valley of the Euphrates after the Flood.
https://en.wikipedia.org/wiki/Northern_bald_ibis#In_culture