We have 5 skunks breeding under our chicken barn. They come up on our porch and block us from getting in and out. Is there a humane / preferred / tricky way to get rid of them? Pest control companies have quoted $600 - $1,000.
This is a good time to be working on this project, because pregnant female skunks will be delivering young May through June -- at which point a denning skunk problem becomes much more complex! You need to identify where the skunk(s) is/are getting under the chicken house. There's a good tip in the "Skunk Removal" section of this publication http://icwdm.org/handbook/carnivor/Skunks.asp, in which you can use flour to identify active entrances. Skunks are strong diggers, so you'll need to use durable materials such as welded wire mesh ("hardware cloth") buried beneath the surface and extending to block any surface -level entrance you've identified. Leaving the last/most active entrance open until your final evening of work, you can assure the skunk(s) is/are out and THEN block that last entrance.
An alternative approach would be to live-trap the skunk(s) in combination with the blocking of the entrances. You might consider contracting with a licensed Wildlife Control Operator http://www.dfw.state.or.us/wildlife/license_permits_apps/wildlife_control_operator_contacts.asp who already owns livetraps built specifically for skunks (solid walls to contain the spray), but it sounds like you have already explored that option.
There are no deterrents that will make the skunks "want to go elsewhere", especially with the extremely strong attractant of chickens and eggs, so blocking entrance to the spaces they've discovered is going to be your best and most effective short- and long-term option, even if you lethally remove the current family of skunks.