After fighting for several months, the pigs haven’t given up even though the birds have wipe out several pigs (and so are the birds that were killed during the fights). When the birds see that the pigs are still pretty much alive, they build a car that would eliminate all the pigs that are out on the road. The birds have selected their best driver to drive the car.
Help the birds seek out and run over the pigs that are on the road. Be careful when driving though as there are cliffs in the area. Another obstacle that you might want to watch out for is that mountains since they are too high and might cause your truck to crash.