Cola queue status message to stdout

I have noticed that when a caller drops out of a queue a message similar to:

cola(SIP/101-083fc680)(POSITION) = 1
cola(SIP/101-083fc680)(TIME) = 1186573453
cola(SIP/101-083fc680)(QUEUE) = QUEUE/16
cola(SIP/101-083fc680)(SERVER) = 0
cola(SIP/101-083fc680)(CLIDNAME) = TMQHP 7940
cola(SIP/101-083fc680)(CLID) = 101

is produced on STDOUT (or at least to the tty which started Asterisk).

I couldn’t track this down in the source (1.4.10) - any ideas?