Birds that eat insects, this is because their is more of their primary food source for them. If they're constantly there from the locust they wont have to look for food and will be able to reproduce and populate their territory. An example would be how when the Euorpean rabbit came to Australia, it took out the native competiton and was able to eat the vast amount of plants that was perfect for their diet back in Europe, but not so much for the other animals.
