Given the choice between eating a worm and eating a juicy, sweet, sun-ripened plum, I will almost always choose the plum. I suspect many of you feel the same.
Birds, as it happens, agree with us.
I wouldn't mind birds eating the plums if they were content to eat a certain portion of individual fruits, even a large portion. Birds, however, take more of what I think of as a hard-to-please Goldilocks approach, sampling a little bit of every single fruit they can reach and never finding one that's just right.
If you grow plums in your slice of the Desert Garden, or any other soft fruit, you'll want to protect them from bird damage. Birds have an uncanny ability to know exactly when the fruit is almost ripe, and will start pecking it to pieces. While some gardening books suggest you should harvest the fruit early to avoid bird damage, and then allow it to ripen off the tree, that's not a satisfactory approach; unripe plums you can buy at the grocery.
Your best option is to net the tree. Bird netting is readily available at any hardware store, and not that difficult to put over a tree, especially with a helper.
If the netting snags too much on the leaves and branches, and you're feeling ambitious, buy some very long pieces of PVC pipe and some fittings, and fashion them into a frame over your tree. You can then easily slide the netting up over the frame, minimizing the snagging.
When you net your fruit tree, be certain that there are no gaps in the netting, and that the netting goes all the way to the ground; weight the ends of the netting with stones or bricks. If there are any gaps, the birds will find them, get in, and peck the fruit (Exhibit A, above). Perhaps more importantly, any birds that get in will find themselves tangled and trapped in the netting, and you will be obligated to cut your netting to set them free or they will die. And yes, you must cut them free.
I had a visiting Chihuahua get caught in bird netting once, and had to think long and hard about it, but that's a whole 'nother story.