Here in Germany, nearly every big city has its animal shelter where small pet birds can be brought to while one is on holiday. The teams of the animal shelters normally also have lists of people who care for birds of other people they don't even know - call them "bird hotels" if you want. If you don't have any idea who can care for your bird while you are away from home, just contact your local animal shelter or have a look at the bulletin board of your veterinary, because there might be a note of someone who offers private holiday bird care.