A few weeks ago I noticed my Mac was running a bit low on disk space. It didn’t surprise me, since I have loads of RAW photos that take up massive amounts of space, and it’s a 256GB box.

However, since it hit around 15GB I’ve been keeping an eye on it. Since then, I’ve seen how almost on a daily basis the free space drops and drops…

If this situation sounds familiar to you, maybe you can find the solution here.

When it hit 10GB I started looking for an explanation. After examining with Disk Inventory X, I noticed that ~/Library/Caches folder was really fat. Fat as in ~40GB. You can browse directly to that folder by pressing CMD+Shift+G on Finder and entering ~/Library/Caches.

After further investigation, I found that folder com.apple.bird was the culprit, weighing around ~35GB.

Apparently that folder stores iCloud related stuff and you can delete it safely. I deleted it, but in a matter of weeks it got fat again. I had eradicated the symptom, but not the problem.

After searching the web again, I found an article¹ that shared the same concern. The theory is that the root problem is Whatsapp backup to iCloud. It’s not 100% proven, but after I disabled Whatsapp backups, the folder hasn’t grown again. Alternatively, I think you can enable weekly or monthly backups in Whatsapp.

Let me know in the comments if this has helped you or you have any clues on this topic.

[1] – Large com.apple.bird directory – Apple Support Communities