I have few different, but potentialy interesting design concepts for you on entries #107, #108, #109, #110, #115 and #117. I've also presented my personal favorites on dark backgrounds (#120, #121 and #122), since you've stated that this design must look good at night,...just so you can have better idea, how they might look!
Hope you'll recognize branding potential behind these designs, and if you have any suggestions for improvement, feel free to let me know! Thank you!
Forgot to mention,...on designs #108/#122 and #110/#120 I've used abstract representation of actual bird (Peregrine falcon, well known for its speed and effectiveness). Thanks!