Does an empty baseball field really need outdoor lighting all night?

Countless ball fields, tennis courts and other athletic facilities are regularly bathed in artificial light after dark — sometimes from dusk until dawn, even if no one is using them. There can be good reasons to leave on outdoor lights at night, like deterring crime or improving safety in public places. There are also good reasons to turn them off, however, especially if they're powerful floodlights illuminating an empty baseball field at 2 a.m. It would save energy, of course, but it could also save a variety of wild animals from the growing scourge of light pollution.