There are many types of birds that can be welcome in farm settings. Birds in nests can eat insects and bugs that are harmful to plant and vegetation.
There are, however, nuisance and pest birds that can be a large problem for farmers and animals. Starlings especially can be a huge problem in farms.
Starlings are fiercely protective of their homes and are known to attack and frighten away farming animals from their feed and eat the grain. When birds become a problem to the farmers and the animals, they have to go!