Wildlife and nature cameras?

So, I'm looking to get my own camera, as i have been using my dads Nikon for a year, and we're starting to have disagreements over it cause i use it a lot now.
I mainly take pictures of nature, like flowers or trees, and animals, like my dog or cat.
I want a camera that is $600 or less (preferably $500 or less, but $600 is doable).
My dads camera is a Nikon D5000. Not sure what either of the lenses are, but they both have manual and auto focus. One is a short range, the other is a long range.
I know my way around that camera, but am not an expert.
Does anyone have any cameras (and lenses) under $600 that is fit for outside wildlife photography, but isn't insanely hard to figure out how to work?

Pentax K-30, but a superzoom like a P500 series, canon sx40 series or Fuji HS10 series or Pentax X-5 would be excellent too and even cheaper still and only one lens with lots of range.

http://www.amazon.co.uk/...008384CG4/

http://amzn.to/...to/1qrY2E8

http://amzn.to/...to/1qrY7Ia

http://amzn.to/...to/1kesuxQ

http://amzn.to/...to/1y4AQ3e

I'd leverage off the knowledge you have of the Nikon D5000. I've found your a refurbished D5200 with a lens.
http://www.amazon.com/...00FDW07Q2/

Refurbished often just means the box was opened. It has been checked by a qualified technician and declared good. Make sure it has a warranty, 90 day is typical.