Hen standing off alone.

[Rigdawg]

Yesterday I let the girls free range for the first time since I got them last December. They have been in a large coop with a 10x20 foot run. I also added a 150 ft. chicken tunnel for them. When I went out to check on how things were going, they were all in the coop and not out roaming my 5 acres. Now, one of the 9 hens is hiding under the egg box area or under the hanging water bucket and is keeping to herself all the sudden. I don't see any kind or injuries and she is not standing in a way that might suggest being egg bound. None of the others are like this. I don't know if she found something bad to eat or an animal may have attacked her or what. I is about 100* today but we have had a lot of hotter weather here this summer. What should I be on the lookout for? She is the only one like this but I do find it odd that all of the chickens are back in the coop instead of out eating some of the thousands of crickets and grasshoppers here. I dunno

 

[aart]

I also added a 150 ft. chicken tunnel for them.

I would love to see pics of this!
Have they been using that for a good long time or is it new for them to exit the run and free range?

 

[The Chickens' Maid]

It sounds like something might have happened to scare them, maybe they saw a predator or something came close and tried to attack. I could have even been a hawk that swooped too close. Sometimes a hen will isolate herself after a scare like that, same way people do if they can't process something traumatizing. The heat could also have a lot to do with it, they might be trying to find the coolest area to hang out in. Ice is a great thing to provide continuously in a pan to give them something cool to congregate around.
So, it could be a combination of both things. Might not hurt to set up a security or game camera to take a look at what is roaming your backyard. For the hiding hen, you could try taking her inside and letting her sit in a box for a few hours with some water and treats. The new environment and the feeling of safety might calm her enough so she can rejoin the flock.

 

[Perris]

Yesterday I let the girls free range for the first time since I got them last December.

So for 9 months they have been confined. It will take them time to gain the confidence needed to venture beyond the only space they have known.

a 10x20 foot run

that's a lot smaller than 5 acres. They need time to adjust.

I also added a 150 ft. chicken tunnel for them

If you are expecting them to walk from a 20' run into a 150' tunnel (chicken sized, presumably) you'll be waiting forever. Think of it from their perspective: it is a death trap.

When I went out to check on how things were going, they were all in the coop and not out roaming my 5 acres.

I'm not at all surprised in the circumstances as I understand them from what you have written about them.

Now, one of the 9 hens is hiding under the egg box area or under the hanging water bucket and is keeping to herself all the sudden.

Perhaps she has started moulting and her skin is very sensitive. Do not touch her if so.

She is the only one like this but I do find it odd that all of the chickens are back in the coop instead of out eating some of the thousands of crickets and grasshoppers here.

Please post some photos so we can get a clear idea of the set up and advise better. Whatever on that, it will take your birds some time to venture forth. They will explore out from their comfort zone gradually.

 

[Ridgerunner]

I agree. I'd like to see photos of this set-up to better be able to talk about it.

Yesterday I let the girls free range for the first time since I got them last December....... I do find it odd that all of the chickens are back in the coop instead of out eating some of the thousands of crickets and grasshoppers here.

My brooder is in the coop. I usually have brooder of around 20 chicks. Sometimes when I open the brooder door (usually around 5 weeks) every chick is on the coop floor within 15 minutes. The other extreme is that it once took into the 2nd day before every chick came out. Typically it is a few hours. Each brood is different. Each flock is different. Sometimes when you first open the run gate every chicken is out in a pretty short time. Sometimes it can take days. Usually when they go out they hang really close to the run but the longer they are out the bolder they become. Some people have more patience than others but I'm quite happy to let them go at their own pace.

I also added a 150 ft. chicken tunnel for them.

This is the photo I'm really interested in. I've never used a tunnel longer than 18", which was not a problem. It's been a few years but I remember some threads on here about people building some fairly long tunnels and getting their chickens to use them. I don't remember how they trained them, probably with food.

one of the 9 hens is hiding under the egg box area or under the hanging water bucket and is keeping to herself all the sudden.

I don't know what is going on here. The change may have something to do with it. Or it might be a change in the flock pecking order. That can happen as they mature. As long as there are no injuries I'd let them work it out. Byut do keep an eye on her in case there are injuries.

 

[tlcmurphy]

Our Chunnel goes from our coop to the extended run on the other side of our living room, so maybe 15-20 feet (under the window sill for our entertainment). I put treats on the other end of that sucker and they learned to use it in about 30 seconds flat.
We did not free range until they were almost a year old, they calmly walked out the door and stood about 2-3 feet away until dusk when they marched back in. They did that for several weeks before they started expanding their horizons