Housing
Corvids should be given a large, strongly built aviary in which to live. A concrete floor is best to help avoid the problem of rats and mice getting in. These can be a problem if the floor is just earth as the rodents will dig their way in, crows do tend to bury some of their food to eat later, and these food stores can be a magnet to rodents.
The concrete can be left bare, which will keep the bird’s claws short, but it is harder to clean as the droppings will have to be scraped off, then washed with disinfectant and rinsed thoroughly with clean water. If you prefer, you can cover the concrete with sand or bark-chip. If using sand or bark-chippings for floor coverings, this will make the cleaning a lot easier as the droppings and dirty materials can just be removed and raked over and then topped up with fresh coverings, sand and bark-chippings are also better if you have a disabled bird - if it falls from its perch, the soft covering will cushion the fall.
The aviary will still need a big clean out at least once a year with all the sand and bark-chippings removed and the floor thoroughly cleaned and disinfected.
Any dirty coverings should be cleared away at least once a week in the meantime as corvids tend to spend a lot of time on the ground, and should not have to walk around in their own dirt. It is worth putting a safety porch on the aviary construction to avoid the bird(s) escaping.
The roof of the aviary should be partially covered to provide some shelter against the worst weather - but make sure to leave a section uncovered as crows do enjoy sitting in the rain. You may also put a roosting box in, although most corvids will rarely use this.
A bath should be provided in the aviary. This can be a shallow sided wash basin, a large terracotta plant pot saucer or a cat litter tray. Plastic baths should have a rough surface on the bottom so that the birds do not slip. If it does not already have a rough surface, this can be achieved by lightly sanding the bottom. Baths are an extremely important addition to any corvid aviary as most will bathe at least once a day and they need to be given this opportunity.