Introducing cats

Question
We live in the country and have a primary outdoor cat (male, approx 7 yrs).  Other cats live in the adjoining properties and all have gotten along with whatever rules exist.  They frequently feed at each other's homes, etc.  

We have been asked to "adopt" a friend's cat (indoor and outdoor). We will be transitioning this cat to outdoor only.  This cat is also male approx 5 yrs and smaller than our cat.  The new cat is a hider by nature.

We kept the cat in the garage for a day or two and then started feeding it in the back yard.  The existing cat feeds in the front in the am, and rear pm.

The existing cat is being very territorial and scaring the new cat by coming into the garage.  Poised to attack or so it looks.  The new cat ends up under a car or in the rafters 10 ft up....

Any suggestions to make this process easier for all?

Answer
Brian,

This is perfectly normal.  Usually, we advise giving the new cat about a week to adjust before letting any established cats meet the newbie.  However, what is done is done.

I am also going to assume both boys are neutered, if not, that would be the first order of business.  BTW, neutered and spayed cats do better at dealing with the wild. Neuters and spays are better hunters, better fighters, and just as territorial.

Cats go through a rather complicated "getting to know you ritual" which can take a number of weeks (or even months, sometimes). So, you just have to leave them be and let the two of them sort things out on their own.  As I stated above, I am assuming they are neutered, so it is unlikely there will be any real harm done to the new kid.  Cats have very, very tough skin, so a little bit of biting or scratching is not going to cause problems. Rarely will two altered cats hurt each other. So, even if it sounds like World War III and there is loose fur all over the place, as long as no one draws blood this is all part of the ritual.

Over time, what I have found is that any human interference will be counterproductive and make the whole ritual last much longer than it should.  So you need to grit your teeth and bear the "fighting" and noise (most of which is posturing and dominance/submission behavior).

Please let me know how it goes.

BTW, 10 feet is a very manageable height for cats.

Best regards... Norm.