I thought the carrion crow was finding insects to eat in the soil, and occasionally going down to the water for a drink.
When I looked closer, I could see that every time it went down to the water it was bringing back a piece of sodden bread. There was a cache floating from when someone had been feeding the ducks, and leaving more than the ducks actually wanted to eat.
As I finished taking these pictures, the crow went back down to the water again. This time it came back with a complete slice of bread, which it look set to demolish as I left.