One of the improvements I am working on is automatically disabling timed dispense at night. Since the birds aren't looking for food at night, continuing to dispense nuts when it's dark makes it more likely rodents will stop by.

I made a simple circuit to hold the timed dispense 555 in reset when it gets sufficiently dark. It's just a voltage divider using an LDR (GL5528) and a pot on the base of small NPN transistor (BC547B). When it gets dark, the LDR resistance goes up and so does the voltage at the NPN base. This turns on the transistor, grounds pin 4 of the 555, and turns on an indicator LED. You can adjust what is considered "dark" with the pot.

In this pic it's in day mode - the red LED blinks and shows the 555 is not in reset. At night the red LED stops blinking and the blue one comes on.

I tested/calibrated it and think I have the values dialed in to work properly. Will be including this in my next PCB version.