San Francisco officials have launched a program to document the number of birds that die by crashing into windows in an effort to reduce such collisions.

The San Francisco Chronicle reports that the city's planning department is seeking volunteers to count the number of dead birds around their homes each week during peak migration periods. The participants would then log that information on a city website.

City officials say the goal is to raise awareness about the dangers windows pose to birds and get better numbers about how many birds are dying that way.

The American Bird Conservancy says at least 100 million birds die each year in North America by striking windows. A San Francisco ordinance passed three years ago requires some new development projects to treat certain windows to reduce the potential threat to birds.