Buy yourself a tree limb saw. They cost about $12.
Trim the branches of all trees back away from the house. They can jump pretty far so you may want to start with about 10'. If they're using Power Lines to gain access, I'd talk to the Utility company(s) that laid the route. (It could be one or all of the following: Telephone, Cable, and/or Electrical.) They may have an idea or 2.
You could consider putting a plastic owl there but 1) after a while, they may 'figure you out', or 2) it may keep other 'good birds' (and such) away from your house. If they're climbing a pole to get to the wires, again, talk to the Utility company(s). If they're jumping from a neighbor's home onto yours, do the homework for them and suggest some ideas.
You didn't say much about the 'bigger picture' (like how they're gaining access) so I'm out of more specific ideas. If you want to provide more info, follow up with more info.