Hi, there's lots of room for more here, but here are a couple of older posts to get you started
How common was the use of birds to carry messages during the middle ages? - /u/Celebreth tells about the pigeon Cher Ami in WWI, and about training
Were birds of prey ever trained to intercept carrier pigeons? - /u/yosoyunpayaso mentions anti-pigeon warfare in WWII