If you‘ve ever opened Activity Monitor on your Mac to check on CPU and memory usage, you may have noticed an unfamiliar process called "bird" running in the background. Don‘t let the quirky name fool you – the bird process (also known as bird daemon or birdd) is a crucial part of macOS that helps maintain the integrity and security of the Apple File System (APFS).
In this comprehensive guide, we‘ll dive deep into what exactly the bird process is, how it works, and what to do if you encounter issues with it consuming too many system resources. Whether you‘re a Mac pro or just curious about what‘s going on under the hood, read on to learn everything you need to know about the bird daemon.
What is the bird process?
The bird process is a core system daemon that was introduced in macOS High Sierra (10.13) when Apple replaced the old HFS+ file system with the new APFS format. Its technical name is "apfs_ftm_bird_daemon" which stands for "APFS File Timestamp Maintenance Bird Daemon".
As the name suggests, the main purpose of the bird process is to continuously scan and validate the file system metadata on APFS volumes to ensure permissions and timestamps are correct and up-to-date. It acts as a watchdog process to monitor for any unauthorized changes or corruption in the APFS structure.
How does the bird process work?
To understand how bird works, it helps to know a bit about how the APFS file system stores and manages metadata. Unlike older formats like HFS+ that used simple file allocation tables, APFS utilizes a more complex B-tree structure to track file and directory attributes, extent mappings, and snapshot data.
The bird daemon operates by periodically traversing this B-tree hierarchy to check that all file and directory permissions, access control lists, and timestamps are valid and have not been tampered with. It does this by comparing the live metadata against the cryptographically signed "seal" records that are generated when changes are made.
If bird detects any discrepancies or unauthorized modifications, it will automatically attempt to repair the file system to maintain security and integrity. This could involve updating access control lists, rebuilding extent records, or reverting changes from a previous snapshot.
According to Apple‘s official documentation, the bird process runs automatically every 24 hours or after 10,000 file system modifications, whichever comes first. It coordinates with other related daemons like fseventsd (File System Events Daemon) and mds (Metadata Server) to keep APFS healthy.
Is the bird process safe?
Yes, bird is a legitimate, Apple-signed process that is an essential part of the macOS operating system. It should not be interfered with or disabled as that could compromise the security and stability of APFS.
While the bird daemon does consume some CPU cycles and memory while it is actively scanning and repairing, it is designed to run efficiently in the background without impacting system performance. Apple has stated that users do not need to worry about or micromanage the bird process under normal conditions.
Common issues and fixes for the bird process
That said, in rare cases, some users have reported the bird daemon exhibiting unusual behavior like:
- Consistently consuming very high CPU usage (80-100%)
- Using excessive amounts of memory (several GBs)
- Repeatedly crashing and restarting with errors
- Slowing down overall system responsiveness
If you notice any of these symptoms, don‘t panic. There are several troubleshooting steps you can take to resolve issues with the bird process.
1. Restart your Mac
The first and simplest thing to try is rebooting your Mac normally. This will terminate and restart the bird daemon process, which can resolve transient issues caused by bugs or resource leaks.
2. Check for macOS updates
If restarting doesn‘t help, check to see if there are any pending macOS software updates that could include bug fixes or reliability improvements for the APFS file system and bird process.
Go to Apple menu > System Preferences > Software Update and install any available updates. For example, the macOS Monterey 12.3 update included a fix for an issue that could cause bird to consume excessive CPU for long periods.
3. Run First Aid in Disk Utility
APFS file system corruption or inconsistencies could cause bird to work harder to scan and repair issues. Running Disk Utility‘s built-in First Aid tool can check the integrity of APFS metadata and file system structure.
Open Disk Utility, select your boot volume, and click "First Aid". This will scan for and attempt to repair any errors with the file system or volume structures. If it finds issues, repeat the First Aid process until it reports no more problems.
4. Disable third-party software
Incompatible third-party system extensions, drivers, or security software could interfere with core macOS system processes like bird. If you suspect an app or extension could be the culprit, try booting in Safe Mode to see if the issue persists.
Restart your Mac and hold the Shift key until you see the login screen. Safe Mode does a file system check and disables all non-Apple kernel extensions and startup items. If bird behaves normally in Safe Mode, you‘ll need to systematically isolate and uninstall the problematic software.
5. Reset SMC and NVRAM
In very rare cases, firmware issues with the System Management Controller (SMC) or Non-Volatile Random Access Memory (NVRAM) could cause erratic behavior with macOS background processes like bird.
To rule this out, you can try resetting the SMC and NVRAM. The exact steps vary by Mac model, but on modern Macs with Apple silicon, shut down the Mac, press and hold the power button for 10 seconds, then release it and wait a few more seconds before turning on the Mac again. This will reset both the SMC and NVRAM.
6. Delete bird cache files
As a last resort, you can manually delete the bird daemon‘s cache files to force it to rebuild them from scratch. This should only be done if all other troubleshooting steps have failed and bird continues misbehaving.
Open Terminal and enter the following command:
sudo rm -rf /private/var/db/appfstmd*
Enter your admin password when prompted, then reboot your Mac. The bird daemon will regenerate the cache files upon startup. Keep in mind any pending file system repairs or updates will need to be redone.
Best practices for maintaining the bird process
While you generally shouldn‘t tinker with bird, there are some proactive steps you can take to keep it running smoothly:
- Reboot your Mac regularly to clear out file system caches and temporary data that could accumulate over time
- Keep macOS updated to ensure you have the latest stability and performance fixes for APFS and bird
- Don‘t modify file or folder permissions unless absolutely necessary, as unexpected changes can trigger extra work for bird
- Be wary of "cleaner" or "optimizer" software that claims to speed up your Mac by interfering with system processes like bird
- If you use third-party SSD utilities, make sure they are fully compatible with APFS to avoid data corruption
Some Mac experts also recommend proactively running First Aid on a monthly basis to catch and repair any file system issues before they impact performance. You can automate this using a tool like Disk Utility CLI and launchd to schedule the task.
Monitoring bird process activity
If you want to keep an eye on bird process activity without relying on third-party apps, you can use the fs_usage command-line utility to monitor file system operations in real-time.
Open Terminal and enter:
sudo fs_usage -w -f filesys
This will display a live stream of file system–related system calls, including those made by the bird daemon. Look for lines containing "bird" to see which files and directories it is scanning or updating. Press Ctrl+C to stop monitoring.
You can also use the log command to search for bird-related entries in the unified macOS system log. For example, to see bird process crashes or errors, enter:
log show --predicate ‘process == "bird"‘ --style syslog
This will display any bird-related log entries in standard syslog format. Combine this with other predicates and options to filter the results further.
The bird process in context
It‘s important to remember that the bird daemon is just one of dozens of background processes that keep macOS running smoothly under the hood. While it plays a critical role in maintaining the integrity of the modern APFS file system, it is designed to work efficiently and unobtrusively.
As Apple continues to optimize and enhance APFS with each macOS release, the bird process will likely evolve and improve as well. By staying informed about how core system services like bird work, Mac users and admins can better understand and resolve issues that may arise.
At the end of the day, the bird process is a prime example of the "it just works" philosophy that sets macOS apart from other operating systems. By quietly handling the complexities of file system management behind the scenes, bird allows Mac users to stay focused on being productive instead of worrying about the plumbing.
The key is striking the right balance between proactive maintenance and letting macOS do its job. By following the best practices outlined here and intervening only when necessary, you can keep your Mac and its system daemons running like a well-oiled machine for years to come.
Key takeaways
- The bird process is a core background daemon that scans and repairs the APFS file system in macOS
- It was introduced in macOS 10.13 High Sierra to maintain the integrity of the new Apple File System
- bird periodically validates file system metadata to detect and fix unauthorized changes or corruption
- In rare cases, bird can consume high CPU or memory due to file system errors, bugs, or conflicts with third-party software
- Rebooting, updating macOS, running Disk Utility First Aid, and isolating incompatible software can resolve most bird issues
- Users can proactively monitor bird activity using the
fs_usageandlogTerminal utilities - The bird daemon is one of many essential background processes that keep macOS stable and secure