Tag Archives: Window strikes

Help Us Learn About Bird-Window Strikes Downtown

Calling all citizen scientists near Boston!

Mass Audubon needs your help monitoring an underappreciated threat to migratory birds: window collisions. We’re looking for volunteers to collect data on bird-building collisions and rescue birds that survive a strike.

A Black-throated Green Warbler that died on migration from a window collision.

The Problem

Window collisions are a surprisingly significant source of bird mortality in the US, causing several hundred million casualties annually.

Birds struggle to distinguish reflections from reality, and often strike glass windows that reflect the sky or nearby greenery. City lights also confuse night-migrating birds, which use the stars to navigate, and which often land near sources of light pollution. Many window strikes occur as birds try to re-orient in the morning, after being drawn in to an unfamiliar concrete jungle.

How to Help

The Avian Collision Team (ACT) is a new volunteer initiative to get as much data as we can about building strikes in Boston. We want to understand the scale of the problem in Boston, where the trouble spots are, and which species are most affected.

The program runs from April 13–June 4. Volunteers need to sign up for 1-4 weekly shifts, Saturday–Tuesday, from 8 am to around 9 am.

We are looking for two kinds of volunteers:

1. Monitoring volunteers who will walk predetermined routes to collect deceased specimens, fill out data sheets, and occasionally rescue live birds.

2. Transport volunteers who can pick up specimens from monitors and bring them to a collection site at Harvard. Drivers will also bring occasional injured, live birds to Tufts Wildlife Clinic in Westborough as needed.

Similar programs have shown that in parts of some cities, there are practically no casualties. In others, certain buildings can kill a dozen birds a day during peak migration. Scientists have developed guidelines for what makes buildings especially dangerous to migrating birds, but they’re still pretty rough. The best way to know where and to what extent there’s a problem in Boston… is to check! 

If this sounds interesting, sign up here!

Cities Need Bird-Friendly Buildings

Between 100 million and 1 billion birds die annually from collisions with windows. Glass windowpanes can reflect nearby trees, shrubs, and sky. Birds’ eyes aren’t able to distinguish clear reflections from the real thing, so they sometimes aim for a reflection and fly smack into a pane of glass.

Earlier this year, Mass Audubon’s advocacy team expressed concern about a plan to install an all-glass façade on a building facing Post Office Square in Boston. An island of green in downtown’s sea of concrete, Post Office Square is a locally important stopover site for migratory birds. A few plantings in the middle of a nearly treeless part of the city attracts a surprising diversity of species, and adding a wall of glass panels across from one side of the park increases the risk of collisions . The well-meaning developer wanted to add a perimeter garden and a green roof to the site, which ironically would increase window strikes by attracting birds to reflections of the greenery.

Luckily, when told about the risk the project posed for birds, this developer was willing to make the site safer. They are in the process of installing glass with non-reflective stripes, which will break up reflections of what’s outside and steer birds away from the windows. Many similar technologies exist to make windows visible obstacles to birds without interfering with peoples’ view—from glass incorporating ultraviolet patterns that only birds can see, to entire panes made of non-reflective material.

Post Office Square, an urban stopover site for migrating birds (Photo by Will Freedberg)

You Can Help!

Skyscrapers account for disproportionate numbers of bird deaths, but the number of single-story buildings in the US make them an equally important front for reducing window strikes. Every homeowner interested in conservation can take steps to make their homes safer for birds:

  1. Keeping window screens on year-round. This is a great option because it provides a visual barrier as well as soft, springy physical barrier to incoming birds.
  2. Purchase and apply a one-way, see-through film to your windows, which both cuts reflections for birds and blocks the view into your home from outside.
  3. Finally, any birdfeeders close to your house (within 15 feet) should be even closer to windows (less than 1.5 feet away). While this sounds weird, birds do slow down before perching, so any window collisions as a bird comes in to land at your feeder is unlikely to injure the bird.

 

 

 

 

 

 

 

References: Daniel Klem, 1990: Collisions Between Birds And Windows: Mortality And Prevention