"Occassional weekends away" - do you mean one night, two nights, three nights?
Who will let them in/out daily and refill waterers?
Are you urban, suburban or rural?
What size chicken (small breed vs. large breed)?
These are all things to think of....
My large breed heritage Black Java chickens (6 chickens, cockeral is a bit over 8#'s, pullets are anywhere from 6#'s to 7#'s), eat about 5#'s of feed per week - but that's not including treats, scraps, foraging and whatever my sons sneak out to them too. In other words, these chickens are well fed!
I use a 3 gallon plastic hanging waterer, that I refill daily - I'd say they drink about a gallon a day total. However, it's been raining here some every day, so they might be drinking less from the waterer and more from God's sources! A pullet or hen without access to water will NOT lay.
When we have trips and events we need to go to out of town (we're heavily active outdoorsmen, and often find ourselves going in different directions) - I hire a local pet sitter. For a small nominal charge she'll come to our property, let the chickens in/out, change waterers, give treats I leave for her to feed them (oatmeal, grapes, watermelon, strawberries, etc.) and in general check their physical condition. In our suburban area, chickens are becoming quite common and she actually has about 7-10 customers now with chickens (along with the more traditional cat/dog/parrot/hamster/fish). I taught her how to bribe chickens to come into their pen when she needs to shut them in (she spent over an hour chasing chickens around someone's yard because they wouldn't go into their pen!) - they'll readily come for food treats! Because she's a professional service, she has insurance that covers her business; she has vet contacts in the odd case of need; she knows what she's doing around animals in general. I feel very confident about leaving all our critters in her care.
In the past we have been 'duck sitters' for friends. In exchange for our help, we kept the eggs! Great deal! At the time, we had a huge variety of pets, but knew very little about birds....it all worked out fine. And the experience helped me 'jump' into chickens. Who knows what you'll start by spreading the love!
Hope this information helps you!
