Extention tubes and Zoom lenses?

So say i have the 55-200mm nikon lens… I think its an 5.6. But anyway i would love to do wildlife photography on the cheap. So what i'm thinking is get extention tubes to help with depth of field and maybe focal length? Would this help or am i totally off on this one?

It is clear that you do not know what extension tubes do.

They basically allow the lens to shoot at near macro distances. The longer the lens, the shallower the depth of field at any given lens aperture.

The focal lengths are not affected by the extension tubes, not at all, however they will require you to increase the exposure time in order to account for what is called "bellows comp"

The 55-300 mm is just fine for shooting wildlife, no question, but you may want to do some more research when it comes to using extension tubes

They don't work as well as one might think, meaning the quality of the finished photo will be lacking and if you want a nice clean crisp photo, i suggest getting an actual zoom lens that will suffice on it's own. You can look on line for used equipment like on craigslist in your local area.don't buy anything that you can't check out personally. I have done some nice stuff with a 75 to 300 and I have a 500 MM lens but it's fixed and hard to find my subject, thats why the zoom lenses are so nice

An extension tube is not the item you are wanting. What I feel you are intending to say instead is a TELECONVERTER. These are designed to give you more effective focal length, though they also have their disadvantages, mainly with aperture reduction. Do research on teleconverters for more understanding.

Extension tubes are for macro work. What you need is a teleconverter (doubler or tripler) will do what you want. The problem is that aperture size gets smaller (doubled or tripled) pushing you to use longer shutter speeds and increase the chances of blur. They also decrease picture quality a lot. Try using camouflaged tents, clothing and scents to get nearer your subject.