Update:

- All my code for this little project is now at This GitHub Page, including full documentation.

- Code-wise, it's working really well, thanks to the help from everyone on this BBS.

- I am still in the process of trying to solve the physical problem of the seagulls eating the food before the crows get to it. I have modified a "squirrel proof" bird feeder so that it will accept the weight of crows and squirrels, but a seagull is too heavy. It works perfectly, but the crows are skittish about the feeder and are not yet using it regularly. My hope is that, long-term, the crows will get used to the feeder and be able to use it unhindered all day long, allowing for more crow activity on the camera during the day.

Examples of the feeder at work:
Seagull thwarted by feeder: https://youtu.be/3M-P3IpzxM8?t=8791
Crows tentatively using the feeder: https://youtu.be/EFMM2s0IonI?t=10355

In those examples, we've put some additional food out on the platform to attract the crows, but long-term, we expect to put the food only in the hopper, once the crows learn to use the feeder.

Thanks again for all your help!