Read the following passage and answer the item that follows. Your answer to this item should be based on the passage only.

The dawn chorus was not composed for us. A bird sings at first light because sound carries furthest in the still, cool air, and what it is doing is announcing a boundary to rivals and advertising its condition to a mate, often in the same phrase. The complexity we admire is a measure of how much the singer can afford to spend on display. That we find it beautiful is a fact about us, arriving several million years after the fact about the bird.

Based on the above passage, the following assumptions have been made:

1. The author believes birdsong exists for the enjoyment of human listeners.

2. The author considers birdsong to serve no purpose other than attracting a mate.

Which of the assumptions given above is/are valid?