com.apple.bird
That file is a cache file produced by the bird process.
Bird (and cloudd) and the major processes that are used with the iCloud service.
I think your bird file is likely supposed to reset to defaults from time to time, and for some reason is not doing that.
You could turn your iCloud OFF.
Check in your Activity Monitor, and force quit both cloudd and bird processes.
That may automatically remove that big file that you found. 23 GB might possibly take several minutes to be removed. Or, you can delete it manually at that point.
You can turn iCloud back on, after removing that big file. That might be a good fix, and the enormous file might not return, although that file will come back, it may be working properly from now on - maybe.
My suggestion - something may not be quite right with your system. A good step would be to boot to Yosemite Recovery system (restart holding Command-R), and run Reinstall OS X. You won't lose your own apps, docs, or settings, but OS X will do a full reinstall, and will likely clean up your system settings that you don't really have direct control over (like how often the iCloud cache files are reset.)
I have downloaded the Yosemite installer, and made a bootable flash drive with only the Yosemite installler. It's easy to do with an app called DiskmakerX, or there's easy instructions that you can find to help with that. When you have that USB installer, it's a much quicker reinstall - you don't have to wait for the installer files to download.
