Heather Feather...After raising chickens for 6 decades and on this ranch for 15 years, I pretty well know what works and what does not. What works for you in your part of the world , just doen't here on  my 20 acres. You have bears, while I have never seen or even heard of one around here. Cougar... YES, killed one of my yearling fillies 4 years ago. There are NO rattlesnakes here while just 10 miles to the East of our place in the foothills there are quite a few.  We only get about 6.5" of rain a year. Here in the high desert climate and soils... IF one is able to get irrigation water one can grow just about anything year round and lots of it. I am not so lucky. I breed/ raise horses, (currently 33 horses+ outside mares/ foals for breeding)  which means I have lots of foals.  Colts are very curious and have hooves.  Therefore a chicken and a chciken tractor are a toy and won't last a week as they paw at it untill it is destroyed.  There are way too many coyotes, fox and redtailed hawks etc. around here to make free ranging an option. Noone keeps any chickens within 10 miles radious of my place.  Only several long ago abandoned chicken coops/ pens.  We have NO rain from late April/ first week of May to late Nov. /early Dec. .  Temps go from average of 95* to 105*during the  day and drops down to the low 80's at night, last year 's summer the temps were 115*-117* for 2+ weeks and droped down to 99* at night then 102*-105* and down to 90* at night for the next 6 weeks straight so the ground is like asphalt.  Chickens just don't scratch anything up to any significance.  Trefoil does not grow here ( not enough moisture and too hot)  burr clover does grow here, but the horses won't eat it.  I disc the pastures every fall after first rain and plant endophite free fescue or I would be beseaged with my mares aborting their foals.  I have also planted oats, wheat and barley and most years there is just not enough rain for them to survive. After the first rain, they sprout, then if it dosn't rain again within the week , they grow only about 2" tall then die  out. Same goes for timothy, too dry and too hot .  Orchard grass will grow here but it grows in clumps and it is very hard to walk on ( like walking on a newly plowed field with large clods).  So my pastures are fescue, fox tail, native grasses, burmuda, fillaree and burr clover. They grow ankle to mid calf high before they all die and turn brown by mid May. Since I don't have any irrigation water available at all, I have to rely on the big sprinkler in the sky.   Dry land forage for everyone it is. So, I buy over 100 tons of alfalfa hay and 40 tons of grain to feed the horses year round. I have much better harvest of chicken meat and much more of it,  when I raise them inside the barn.  I also get much better chicken manure fertilizer + horse manure fertilizer from my barn when I spread it out on the pastures  with my wheelbarrow.  So, to  obey the laws of Mother Nature...  adapt and evolve , move on, or die... I adapt !