Staff at the Loch of the Lowes wildlife reserve near Dunkeld feared the worst when satellite data from November showed the bird, Blue YZ, had slowed down and stopped in a rice field in Guinea Bissau. The transmitter from her satellite tag then stopped sending any new data.
A national park warden, an anthropology fieldworker and local children have since combed the fields and found the remains of the chick.
Known as Lady, she had been migrating from her home in West Africa to breed at Loch of the Lowes for the past 23 years.
Emma Rawling, a ranger with the Scottish Wildlife Trust, said: "We can now confirm the sad news that Blue YZ has died in Guinea Bissau as her bones and the satellite tag have now been recovered."
She added: "It looks most likely that our bird died of exhaustion, injury or starvation in this field."