Did you find anything?
Here is an article on frostbite ~ http://www.backyardchickens.com/a/frostbite
I'm only guessing this is what she has.
Oh no :( I spoke too soon. A fox has been and killed two of the three. One's gone and one we've put in a box and put in the greenhouse to bury tomorrow. Elvis is still alive but very traumatised and possibly injured; I don't know if she's going to make it through the night.
Any advice to help Elvis overnight? She's being kept safe from the cats, in a dimly-lit room, and I've put a little food and water in her crate. By chance we're going to the vet tomorrow so I'll ask if they can help, but I don't want to take her there - she'd be terrified - and chickens will definitely not be their speciality.
If Elvis does make it through the night I'm going to have to try to get another chicken or two ASAP for her sake. I know exactly how it happened - my daughter left the nesting box latch open - and it's not going to happen again, so I'm not concerned that they'd just be more fox food.
I'm also really sorry to hear about your fox attack and would reiterate everything Kim (Yorkshire coop) has said. Urban foxes are often more persistent that rural ones because they have limited alternative sources of food and may even be feeding cubs already. My first free range flock 15 years ago, got picked off one by one, with the fox coming through the day, sometimes even when I was there and I chased after it and got the chicken back a couple of times only for it to come back half an hour later and take another one. It really is heart breaking. I also had a couple of fox attacks last year but there is a shooting syndicate near by now and I think they may have despatched it although I'm conscious that it is coming up to the risky time of year again when vixens are feeding cubs. Such a shame when your chickens had just gained the freedom to forage the orchard and you were so enjoying having chickens.
I hope you are able to save Elvis and find her a little friend or two. Keeping her warm in a warm dark quiet place is key when she is in shock and injured. Chickens can make some miraculous recoveries from injury if they can overcome the shock. Good luck with her.
Thanks for the advice all. Elvis is indoors but not in a particularly dark place - I'll shut the blinds.
She's more alert and far less terrified now. She drank water when I held a bowl to her beak, but hasn't eaten yet. When I try to stand her up she's fine with being touched but puts one leg very gingerly to the floor, so I think she must have injured it when jumping out of the hen house in a hurry. I've called the hen charity I got her from to ask for advice and their vet is going to call me back, but I'm fairly hopeful. If we have to keep her in until her leg's healed then that's what we'll do, and then hopefully get some new companions for her when she's better and can sleep in the coop.
At least it looks like the coop itself is still secure - I put extra layers of chicken wire over and under everything, cement under the coop, bricks cemented into the corners, etc. They'll just need to be shut in properly kept a close eye on, I hope.
Pleased she is perking up. If she is over the worst of the shock, darkness is less important but in those initial stages of shock it helps them to feel safe, so a cardboard box in a quiet room for 24 hours can be beneficial unless they are obviously wanting to be active and get out and about.
I have a mixed young flock, 16 birds in total, barred rocks, silkies, cream crested legbars, light sussex, sultans and one of each wheaten marans and vorwerk. I previously raised a batch of Ross 308 to see how I liked having chickens around and to put some meat in the fridge/ freezer. That went well, so I got a couple of incubators and started hatching eBay eggs. With not wonderful success, so I ended up with small number of lots of different breeds, also my legbars are very unstandard and I expect so are all or most of the others.
Our foxes are incredibly bold. A few months ago, I managed to sneak up on one in a rain storm and ended up with it hiding behind my firepit so I couldn't get at it and it was growling and baring it's teeth, I expect had I pushed it, I may have been bitten.
Sam, I'm glad to hear Elvis is doing okay. Do you know which fox got your birds?