Raising chickens in the tropics

I would like to start raising free-range chickens and eventually get going on permaculture and I was wondering if anyone has any advise for our environment. We are in Mountain View, Hi. We get quite a bit of rain here. I think we get around 150 in. a year. It rains mostly at night, with some during the day . The temperature here stays between 50 deg. at night (winter) and 80 deg. during the day (summer). We don't have any natural predators besides mongooses, which are diurnal, and rats, which are nocturnal, and I don't think they kill chickens, but do get eggs and chicks if they can. There are a couple of different types of native owls here, but I haven't seen any in our area and I have never heard of them killing chickens. Because we are in the Puna District of the Big Island we don't have much soil since lava flowed over this area within the last 1500 years or so. Our property ranges between bare lava rock to 6 in. of soil (if that). We have about 3.5 acres to work with. Our property is fenced into 4 sections: 3 one acre areas and 1 half acre area. One of the acres already has a small chicken coop on it and an animal pen from the previous owner. There's plenty of bugs and slugs and many different kinds of vegetation that grows well despite the shallow soil. I was wondering if anybody had any tips on raising chickens in a tropical environment. Also is it okay to have goats and chickens in the same pasture?

rikdabrick wrote:

Also is it okay to have goats and chickens in the same pasture

I have had no experience with chickens in the tropics, but as for the goat with chicken thing...
We have a goat on the farm where I work and we were keeping her with the chickens in a standard coop/run setting.  Although they got along fine, the chickens would eat the grain we fed her if she wasn't fast enough, she was getting bad diarrhea.  We moved her and it cleared up.  We never put her back in there, so I don't know if it was a coincidence.  The area was less then ideal.  While not covered in poop there was a fair amount around.  There was also plenty of grass for the goat to graze. 

misfit wrote:
I have had no experience with chickens in the tropics, but as for the goat with chicken thing...
We have a goat on the farm where I work and we were keeping her with the chickens in a standard coop/run setting.  Although they got along fine, the chickens would eat the grain we fed her if she wasn't fast enough, she was getting bad diarrhea.  We moved her and it cleared up.  We never put her back in there, so I don't know if it was a coincidence.  The area was less then ideal.  While not covered in poop there was a fair amount around.  There was also plenty of grass for the goat to graze. 

Thanks for the reply. The goats have alternate fields to free-range on and I feed them only about 1/3 cup of grain a day by hand, so the chickens stealing the grain probably won't be a problem.  Also, in my last post I worded a couple of things incorrectly. I actually want to rotate them between the fields, like the rotating paddock system that Paul Wheaton talks about on his website. And where we live is more like a rainforest climate, not so much tropical. Thanks again for the reply, I well keep an eye out for any problems like that.