Final answer:
The calculation of the rate of change of the angle of elevation requires additional information such as the bird's altitude and the given time, which is not provided in the question.
Step-by-step explanation:
The question asked involves determining how fast the angle of elevation changes as a bird flies horizontally towards a stationary observer on the ground.
However, critical information needed to calculate the rate of change of the angle of elevation is missing, such as the elevation of the bird and the specific moments in time. We need to use trigonometry, and possibly the related rates concept in calculus, to solve this, depending on additional information about the bird's altitude and the angle at the given time.