BOSTON (AP) — Along with all the usual declarations and deductions, Massachusetts residents have been asked to keep something else in mind this tax season: pigeon droppings.

MassWildlife is urging taxpayers to check a box on their tax forms to donate money to the state’s endangered species program. One beneficiary of the program is the peregrine falcon, which preys on pigeons.

In a recent posting on the state agency’s website, officials noted that pigeon droppings are extremely corrosive. The sticky messes can damage a car’s paint job and cause bridges to deteriorate faster

A program to reintroduce the peregrine falcon to Massachusetts after the raptor disappeared from the state in the 1950s has met with success.

As the peregrine population increases, the pigeon one is retreating.