Army Ornithological Society

From the website:

The Army Ornithological Society (AOS) is, first and foremost, a bird club with a difference, while providing a focal point within the Army for ornithological issues. It welcomes and values everyone with an interest in birds, whether a casual bird watcher or someone who likes to make their birding contribute to conservation in the round. And it doesn't stop there. The AOS is an active Society and we are never happier than when we are getting out and adding to an understanding of birds, both on a personal level and assisting the major conservation organisations at home in the UK and overseas.