as far as i know, there is no wr or route. only some maps with marks for all rats.
tip: dont do it. you need heli, sniper and rocketlauncher/grenades. you could do romans sorrow first to open all islands.
have fun :)
Kill as many as you can in Broker, Dukes and Bohan, then head over to the third island, grab the heli near the water, get a weapon, get to a vantage point to kill enough cops, pick SWAT rifle ammo off the ground, gain enough ammo, head out to kill all the birds. Most of the pigeons can probably be shot from a rooftop. Use the heli wisely. A SWAT van will protect you pretty well, you could drive around in one as well and probably get most of the birds at street level on the 2nd and 3rd island.
annihilator would be a big help because you can shoot with it. problem is you have to do some missions. and if you lose it, the F U N begins.
Our understanding of the game has evolved over the years and, with that, we've been slowly moving toward redefining the ruleset for the modern era of GTA IV speedrunning. All of these rules MUST be followed by those submitting top 10 runs, not just for world record runs, in all categories. I want to