With a small amount of energy, you can give birds shelter.
You only need a few products and a few minutes of work to make a feeder. Check out how to make one.
Even though hydraulic oils are made to withstand significant heat, and can even be heated up to their boiling point and still maintain their consistency and handling characteristics, they should not be allowed to get too hot they will break down, and the viscosity will increase dramatically, and they will lose the ability to lubricate moving parts, either of which can lead to an expensive repair or a mechanical failure.