Not really a bird, but a bird noise when I turn off the engine. After the engine stop, about 30-50 seconds after a bird chirping noise can be heard for about 5 seconds. To me it sounds like a pulley spinning down and making the noise. I‘ve tried to physically locate it, but to no avail. It doesn’t always happen and is very short. I usually don’t have time to exit the car, raise the lid and check. It’s a 2005 with BOE TVS supercharger. No unusual noise when running. About the only thing I can think it might be is the cooling pump shutting down. Is there any thing else that might run on after the engine stops?