First calculate the distance covered going down:
d_down = (16 m / s) * 8 s = 128 m
Then the distance going up is:
d_up = 71 m
So the distance from the ledge to the nest is:
d = 128 m – 71 m = 57 m
Therefore the elevation is:
elevation = 1364 m + 57 m = 1421 m