The City Council is expected to pass legislation on Tuesday requiring new buildings to be constructed with "bird-friendly" glass as part of a growing effort to stem death and injuries to tens of thousands of migratory birds that crash into the city's towering skyline.

According to the New York City Audubon, between 90,000 and 230,000 birds die from building collisions in the city every year, amounting to what experts have called a conservation crisis.

The years-in-the-making bill, which was proposed earlier this year by Brooklyn City Council member Rafael Espinal, requires that at least 90 percent of all glass installed on newly constructed or altered buildings be treated or constructed with materials that will be visible to birds. The rule applies to the first 75 feet of.a building, which is the typical flying zone for birds.

“This bill strikes a careful balance in requiring bird-friendly glass only at heights where birds are most likely to be flying,” Espinal said Monday during a meeting of the City Council’s housing and buildings committee.

The legislation currently has 21 sponsors, including City Council Speaker Corey Johnson. A spokesperson for Mayor Bill de Blasio said he supports the bill.

Thank you for your support!



And a big thanks to my other colleagues in the Council who will be voting to pass this bill to protect the birds passing through NYC by requiring bird-friendly glass on new buildings! https://t.co/osGY7WqHq2 — Rafael L Espinal Jr. (@RLEspinal) December 10, 2019

A 2019 report by the American Bird Conservancy concluded that applying bird-safe designs in new construction is cost-neutral. Costs on retrofitting existing buildings can vary on the solutions, but among the inexpensive options that the American Bird Conservancy has recommended is a special patterned tape, which runs $135 for an 82-foot-long roll. The tape, however, must be replaced every few years. And regardless, the City Council legislation does not require retrofitting existing buildings to make them safe for birds.

After initially expressing concerns about what materials would meet the requirements of the proposed law, the Real Estate Board of New York, the lobbying arm of the city's real estate industry, on Saturday issued a statement saying it was comfortable with the latest version of the bill, the AP reports.

The vote on the City Council bill comes less than a month after Governor Andrew Cuomo vetoed state legislation that would have created a council to craft regulations for bird-friendly designs in buildings across the state, citing concerns about the costs of setting up such an appointed body.

Should the city's legislation become law, New York City would become the largest city in the country to adopt such a measure. “We think of this as the most broad-reaching bird-friendly building policy in the country,” ornithologist Susan Elbin, NYC Audubon's director of conservation, told the AP.