How to stop my cats from killing birds?

I know it might sound silly because cats are natural hunters. Before, my cats would just hunt and play with mice. I would find the bodies on our doorstep or somewhere else. *shivers*

However, lately, my dad told me that my cat Pochi has been killing birds. This week alone, she has killed three. What's worse is that the birds she killed are very rare in our area. They are not just sparrow. They are blue with grey and very beautiful.

I don't know how to stop my cat from killing the birds. When I try to stop her, she just runs away with her kill.