Spin-off of Project Mountain range

You've seen that Perlin noise is sometimes better at simulating natural patterns than randomness, like how the program below makes a mountain range with just a few lines of noise-controlled code. Keep using noise and randomness to paint a landscape below:
1. Make several mountain ranges, seemingly receding farther into the background, with different colours.
2. Use randomness to draw birds in the sky.
3. Use noise to create a white cloud against a blue sky.
4. Use randomness to dot the mountain ranges with little trees.
What else can you do? Go wild!