Who said 5000ft?
Below 500ft is kinda of tricky given that if there is a man (or a woman), a cow, a cat, a wombat, a house, a garden shed, down below, you are flying
illegally. And you are not going to get a radar service at 500ft
Re birds, I would like to know how they know where the birds are. I mean, even the met office with its £1BN computer cannot forecast the weather but somebody has found a way to notam where birds are, days ahead. I think that is pretty amazing and that person would make a fortune in weather forecasting.