Two initial points come to mind in answering the question in the title. Perhaps, sometimes, can owners think that their cat is stuck up a tree because they become panicky and understandably so. But perhaps their cat is not stuck 😊. Perhaps they are just taking their time to come down. I deal with that aspect of this problem immediately below. The next point that comes to mind is that if a cat is stuck up a tree it may be because they ran up it to escape a predator such as a coyote in America or a dog in the UK.
THERE ARE SOME MORE ARICLES ON CATS STUCK IN TREES AT THE END OF THE ARTICLE. YOU MIGHT GET SOME IDEAS FROM THEM.
And because they were forced to run up a tree to escape a predator, they are not adept or used to climbing trees which makes them nervous about getting down which some domestic cats find difficult or tricky in any case. Also, the particular tree in question may be difficult to climb down because of a lack of branches.
As to the first point I mention above, Dr. Bruce Fogle DVM in his book Complete Cat Care makes a good point about tree-climbing cats.
Keep calm if you can
Although difficult, the cat’s owner should try and keep cool because most cats eventually come down of their own accord. But if the owner gets a friend to climb up the tree on a ladder their cat might go further up the tree to escape the stranger coming towards them! At the same time the kind gentleman is risking his life!
The initial solution is to give your cat time and not to rush them. When you know they are hungry ask them to come down using their favourite food treats. That might do the trick without any fuss. Incidentally, a trained cat coming to their owner on command might make this problem easier to resolve. It’s an example of the benefits you can enjoy in training your cat.
descending cats jump/run from branch to branch
A barrier to domestic cats coming down is the obvious one namely their claws face backwards and therefore they are designed to climb. When domestic cats come down trees, in my experience, they jump from branch to branch or rush down the trunk and break their downwards movement on the next branch.
Sometimes, they might shimmy down backwards using their claws to cling onto the trunk. But domestic cats don’t like going in reverse. As cats are gifted athletes they will often go forwards as described. Confidence must play a role as it takes courage to do it.
So, in answering the question in the title, often cats get stuck in trees because either they’ve been forced to climb to escape a predator and found themselves in unfamiliar territory or they are not stuck but just not ready to come down.
Years ago, I wrote a rather strange article about cats climbing trees and the fact that you never hear of people finding the skeletons of domestic cats 20 feet above ground in a tree! The point I was making is that cats don’t die in trees. This indicates that they come down voluntarily eventually.
Evolution
It should be added that domestic cats love to move vertically. They love to climb. They are great climbers and athletic. It’s in their DNA to go up a tree. My cat just looks at a tree and he wants to climb it. He makes a little squeak before he shoots up. Pure excitement. Evolution will have taught them to get down. Nature through natural selection would not have granted cats the skill to climb trees without also granting them the skills to get down.
Tree surgeon?
If none of the above applies and your cat is stuck up a tree about 40 feet up you might be lucky in hearing about a tree surgeon who rescues cats from trees! There are people around who have no fear of heights because of their tree surgeon expertise. These sorts people can retrieve cats from high places. In the UK the fire department does not always come out to assist.
I am not a great believer in cat owners trying to climb a tree with a ladder or some other means and failing (I mean falling 😉). It’s just too dangerous. You will see some interesting videos on the Internet of people retrieving cats from high places. Ingenuity, in these instances, has been tested to breaking point.