macOS processes

What is bird on Mac?

bird is one of the macOS daemons behind iCloud Drive. Its traffic is your iCloud Drive files going up and down.

Process: birdApplies to: macOS 15 Sequoia and later for the Saved to iCloud path. Seen on macOS 27.2.Checked: 29 October 2026

Where you see it

  • bird is in the list in Activity Monitor › Network, in nettop or in Kilobat.
  • A firewall or network monitor asks if bird can connect.
  • The Mac uploads for a long time after you copy files into iCloud Drive.

What it is

The man page calls bird one of the daemons “backing the Documents in the Cloud feature”. That feature is iCloud Drive.

The program is in the iCloudDriveCore framework of macOS. The man page points to brctl, which manages the CloudDocs daemon and shows sync status.

Why it uses the network

  • Uploads. Files that you add or change in iCloud Drive go to iCloud.
  • Downloads. Files that change on other devices come to this Mac.
  • Desktop and Documents. With Desktop & Documents Folders on, those folders sync too.

Is it normal?

Yes. Traffic after you add or change files is usual. Large folders take a long time.

Look closer if a sync never ends. A file that cannot sync can stay in the queue.

See how much it uses

  1. Open Activity Monitor from Applications > Utilities. Click Network.

  2. Type bird in the search field. The Sent Bytes and Rcvd Bytes columns show what it moved.

  3. In Terminal, watch only this process. Press d to show the change per second, and q to quit.

    nettop -p bird -P

  4. Show the iCloud Drive status in Terminal.

    brctl status

Reduce or pause it safely

  1. Do large copies into iCloud Drive on your usual network, not on a hotspot.

  2. Choose Apple menu > System Settings. Click your name, then click iCloud. Click Drive.

  3. To stop the sync of the Desktop and Documents folders, turn off Desktop & Documents Folders. Apple's article explains what stays where.

  4. To stop iCloud Drive on this Mac, turn off “Sync this Mac”. Read Apple's article first.

  5. On a hotspot or a capped network, turn on Low Data Mode. Choose Apple menu > System Settings > Wi-Fi. Click Details next to the network, then turn on Low data mode.

  6. Do not quit bird in Activity Monitor. It is part of macOS, and other features depend on it.

With Kilobat

  1. Open the Kilobat app list and search for bird. Its row shows the live rate and the bytes it moved.

  2. Kilobat puts this service in the System downloads group, with one line about what it does. Expand the group to see each service.

  3. With the network filter on, click the service. The panel names the apps that the downloads were for, for example “For Music”.

  4. Without the filter, macOS shows only the service. Then Kilobat cannot say which app a download was for.

  5. In Terminal, see the same live list. Press / and type the name to search.

    kilobat status --watch

  6. Show its traffic over one day. Names match kilobat report --summary.

    kilobat bandwidth bird day

  7. Through MCP, an AI agent gets the same history with get_app_bandwidth and the name bird.

  8. The live view is free. History in the app needs Pro. Kilobat records history only while the app runs.

Questions

Is bird a virus?

No. It is part of macOS, in the iCloudDriveCore framework, and it has a man page.

How do I see what iCloud Drive syncs?

Run brctl status in Terminal. It lists the iCloud containers and their sync state.

Sources

Sources checked on 29 October 2026. Man pages are the ones installed with macOS; open one with man <name> in Terminal.