Everyone- thanks so much for these excellent suggestions! I need it to be really simple, and I think leaving a gate open is easily understandable by any reader.....so I've narrowed it down to two options: 1) he leaves a gate open and a bunch of horses get loose....the hands waste a whole afternoon rounding them up. If that's the case, which gate SPECIFICALLY would he leave open, and how many horses could reasonably get loose?
2) He leaves the hen house open, and a few get out and are eaten by coyotes (?)......I like this option because a kid would presumably feel terrible about causing the death of animals. If I use this option, what EXACTLY would the situation/wording be: For example, "Left the (such and such) open, and the $%$#! (hens?) got out, and we lost (2? 3? 6?) of them!"
#1 Gate - That's going to depend on how the place is set up and how big it is. If it's a huge place like the 4 Sixes down in TX, it could total 1/3 of a million acres. Not that big now, but it's still around 275,000 in 2 places. If the remuda gate got left open then you could have a LOT of horses milling around in places they didn't belong. If it was a pasture gate leading to the ranch house and it was daylight hours, those horses could potentially turn down the driveway and get out on to the road. I say daylight because a lot of places close the driveway gate at night. How many is a LOT? It would depend on the day and why the horses were all gathered up, call it 100? They put at least that many in their Return to the Remuda sale every year.
#2 Chickens - As others have said, if it's night time, more likely a predator (fox, dog, coyote, raccoon, skunk, 'possum, hawk, eagle, owl) got in. Day time, it's more likely to be dogs who have been dumped in the area. How many? Can be as little as 3 or 4 up to the entire flock. Birds of prey tend to only account for 1 or 2 at a time. We have problems with both hawks and owls. The birds are protected, you can't kill them regardless of how many they take. When dogs get in, the carnage is all over the place. Last time a dog got to my chooks, when I returned home it looked like a snow storm in my barnyard. Out of a small coop of about 50, I had 7 left. Especially frustrating because those birds had JUST reached point of lay. You raise them from hatchlings to about 6 months old before they start to lay, so VERY frustrating, not to mention expensive. Dogs don't just kill to eat. Chickens screaming and running all over triggers their prey drive and they run in, grab one by the neck, kill it and on to the next, and the next. Raccoons tend to behead them, skunks disembowel and given time, the skunks and coons eat most of the bird. When it's birds, it looks like an explosion of feathers with no body. Other predators will usually leave the bones or carcass for you to find. The extent of the damage is also going to depend on whether the hens are in the coop (night) or if they are out free ranging (day and if the person free ranges their birds).