The Larsen trap is mainly a trap for magpies, although it also has been known to catch crows, jays and other corvids.
It is one of the few traps where it is legal to use a live bird to catch others - not as 'bait' in the usual sense but by using the natural instinct of these birds to guard their territory. Dominant birds, or new birds entering an area, will approach the call bird and in the course of the encounter will be caught.
The trap itself is divided into two halves; one forming the permanent cage for the 'call bird' and the other half divided into two catch chambers. Each ca