Get this...

I heard this weekend of something that goes on at Spillway Park to exterminate pigeons.  It seems that on a regular basis, someone comes out in a van that has a sign something like "Pigeons and Possums."  They get out a 4 x 6 wooden frame, about a foot or so high that has a screen on one side of it.  They spread feed on the ground, place the frame over the feed and prop it up with a stick.  They wait as the pigeons flock to get to the feed and then they kick the stick out from under the frame.  This catches the pigeons.  Somehow they bag the birds.  A friend of mine asked what they do with them and he said that they kill them with chloroform. He didn't say exactly who he worked for, but it seemed to be done to prevent corrosion on the flood control structure there caused by pigeon guano. 

Has anyone seen this or heard about this technique?  The guy doing it thought the whole thing was dubious as there seemed to be a never ending supply of pigeons.