Motion reports errors to the console when it runs in non-daemon mode. And it outputs even more information when run in setup mode.
Error logging has been implemented so that errors during daemon (background) mode are logged in the syslog.
The syslog is in most Linux systems the file /var/log/messages (e.g. RedHat/Fedora) or /var/log/syslog and /var/log/user.log (e.g. Debian).
-- KennethLavrsen - 13 Apr 2005