As answered in the Quizzes and Puzzle section.
There are only two current racecourses, other than any point-to-point courses, in West Sussex. They are Fontwell Park and Goodwood. The first is a small course in an area of parkland and has large trees alongside the track, and the other is in the extensively wooded estate of Goodwood House. Can't see why either would be free of birdsong. It's possible that, poetically, Goodwood has been described as having no birds sing when, for example, one of the family of the Dukes of Richmond and Gordon , its owners, was killed in some war.
http://www.theanswerbank.co.uk/History/Questio n790130.html