Glass is a favored building material for modern architecture, yet it is also very dangerous for wild birds. Because they often cannot distinguish between glass and open air, millions of birds are harmed every year when they try to fly through glass windows. There are, however, several solutions that responsible businesses can use to prevent injuries to birds.
One solution is to replace the regular, clear glass with one-way glass that is transparent in only one direction. The occupants of the building can see out, but birds and others cannot see in. If birds cannot see through a window, they will understand that the glass forms a solid barrier and will not try to fly through it.
A second solution is to paint colorful lines or other designs on regular window glass. For example, a window could have a design of thin stripes painted over the glass. People would still be able to see through the openings in the design where there is no paint, while birds would see the stripes and thus avoid trying to fly through the glass. Architects can be encouraged to include colorful painted patterns on glass as part of the general design of buildings.
The third solution is to create an artificial magnetic field to guide birds away from buildings. Humans use an instrument called a magnetic compass to determine directions—either north, south, east, or west. Bird research has shown that birds have a natural ability to sense Earth's magnetic fields; this ability works just like a compass, and it helps birds navigate in the right direction when they fly. A building in a bird flight path can be equipped with powerful electromagnets that emit magnetic signals that steer birds in a direction away from the building.
Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific solutions proposed in the reading passage.