>> More than 100 million birds fly through Chicago during migration season.

But thousands of them are killed or injured every year after colliding with the city's buildings.

Wildlife advocates say the city can and should do more to protect birds.

This week the City Council committee heard testimony on what can be done to provide birds with safe passage and what some of the obstacles might be when it comes to passing Bird friendly building ordinance.

Patty Wet Lee joins us now.

Walk through some of these issues Patty.

So what makes Chicago so dangerous for birds?

And what is the current status of Bird friendly building guidelines rate?

So Chicago is the biggest city on a major migratory flyway.

The Mississippi flyway, you know, birds have been using this route for hundreds thousands of years.

And we put buildings in their way.

>> And we like them up and we attract them into our buildings and they wind up colliding with them.

And at the moment, there aren't really a whole lot of protections for birds.

There is under the Department of Planning and development their sustainable development policy which offers developers points for including Bird friendly design in their projects.

But that's voluntary.

And only about 50 to 75 projects in the city every year.

Even need to meet those sustainable guidelines, which is not sufficient.

According to Bird advocates.

>> What would wildlife advocate?

What would they like to see in terms of protection?

They want to see ordinance something like what New York in Toronto and San Francisco have that would make it the law and mandate.

>> Bird friendly designs for both new construction and possibly retrofits for existing buildings.

And those are techniques like putting pattern on glass that birds can actually see.

And they point to a building like McCormick Place Lakeside, which is many of us know 1000 birds were killed in one day.

There.

They put some film on their acres of windows and bird strikes are down about 95% in just one year.

So people say there's the technology.

Let's use it.

>> Yeah, that's impressive.

So what are some of the stumbling blocks to getting legislation passed?

Well, some officials from the Department of Planning and development say they've heard from developers and designers that using some of that bird friendly glass can double the cost of glass.

>> And they also heard from building owners, the trade association that represents a lot of buildings in Chicago.

You know, we've got 29 30% vacancy rate now is not the time to add millions of dollars to building owners budgets to spend on Bird advocates say, wait a minute, the glass only costs, you know, less than a percent of a building's entire cost.

Not as expensive as people say that it is.

And also, if you want to talk economics, the birding burger economy is huge.

A lot of people come to Chicago.

We've got one of the top destinations in the country for burgers.

Those people come here and they spend money to do so.

There's a lot of pros and cons, OK?

So there's that hearing this week.

What's next?

What now?

What now?

I Alderman Maria had the committee, you know, needs to maybe go back to her colleagues and see how much political will is there to actually get something like this done.

But I think that Chicago's birding wildlife advocates have shown that they're not going away and they're not really going to accept anything less than ordinance and burn safe mandates for building design.

So they're going to keep coming We'll be hearing more from when that time comes.