bird is the macOS daemon that syncs iCloud Drive, including your Desktop and Documents folders if you turned that on; it's part of macOS and safe despite the odd name. It's busy while files upload or download, and if it keeps transferring when nothing has changed, look for files stuck uploading in iCloud Drive in the Finder.
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One Mac, macOS 26.5 (25F71) on Apple silicon, read with ps and codesign on October 29, 2026
| Path | /System/Library/PrivateFrameworks/iCloudDriveCore.framework/Versions/A/Support/bird |
|---|---|
| Runs as | your user account |
| Signed by | Apple (Software Signing), identifier com.apple.bird |
bird is the macOS daemon responsible for syncing files between your Mac and iCloud Drive. It handles the upload and download of documents, Desktop and Documents folder syncing, and manages the 'optimized storage' feature that offloads files to iCloud to free up local disk space.
High CPU and disk usage during initial iCloud Drive sync or after enabling Desktop & Documents syncing
Files stuck in an 'uploading' or 'downloading' state indefinitely
Excessive bandwidth usage when syncing large folders to iCloud Drive
Conflicts between local and cloud versions of files
Open Finder, click on iCloud Drive in the sidebar, and look for the circular progress indicator next to the iCloud Drive label. If files have a dotted cloud icon, they're waiting to sync. Give large syncs time to complete before troubleshooting.
Open Terminal and run 'killall bird' to restart the sync daemon. launchd will automatically restart it within seconds. This can resolve stuck file uploads or downloads without affecting your files.
Very large files, files with unusual characters in their names, or files locked by other applications can block bird from syncing. Check Console.app for bird-related errors that identify specific problem files.
Go to System Settings > Apple Account > iCloud > iCloud Drive and toggle it off. Wait 60 seconds, then toggle it back on. Choose to keep a local copy when disabling to avoid re-downloading everything.
bird using resources during file sync operations is normal, especially when you've recently added many files to iCloud Drive. Be concerned if bird is continuously transferring data when you haven't made any recent file changes, which could indicate a sync loop. Check Console.app for repeated error messages.
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bird is the Apple system daemon that synchronizes files between your Mac and iCloud Drive; its man page calls it one of the daemons backing Documents in the Cloud. It handles iCloud Drive file transfers, including Desktop & Documents Folders syncing and the Optimize Mac Storage feature.
bird transfers data whenever files in iCloud Drive change. High data usage occurs during initial sync, after enabling Desktop & Documents syncing, or when many files change at once. If you have a metered connection, consider pausing large syncs by temporarily disabling iCloud Drive until you're on an unmetered network.
No. bird is a legitimate Apple system process for iCloud Drive file synchronization. Despite its unusual name, it is code-signed by Apple and ships with every macOS installation. On macOS 26.5 it runs for your user account from /System/Library/PrivateFrameworks/iCloudDriveCore.framework/Versions/A/Support/bird, in a folder System Integrity Protection guards.
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