(ABC 6 News) — There is a new plan in place to lower the number of crows who call downtown Med City their home.

“We’ve been doing it since about 2012, but this year we’ve included and partnered with Mayo Clinic and the USDA to help kind of do a better swipe of keeping those birds from coming into downtown,” Rochester Parks and Forestry operations manager Michael Schaber said.

The additional assistance will help the city disperse the 20,000 flock.

This only happens when the weather gets colder. The goal is to encourage the crows that downtown is not an ideal roosting location.

Non-lethal methods like lasers, distress calls, pyrotechnics, and air rifles will be used from December 1 through December 5 with additional efforts taking place through February.

“Blank pistols that sort of thing that sounds like a gunshot, we’ve even tried pots and pans, we’ve tried banging shovels on the ground, anything that’ll give a different noise that’ll deter them and kind of get them to leave the roost,” Schaber said.

Most of the work will happen from 3-11 p.m.

City officials say the birds cause excess noise, and their droppings pose a health concern.