Sunday, July 29, 2012

RELEASE OF THE WEEK: A cormorant is released from St. Francis Wild Bird Hospital into the Connecticut River after healing from a ruptured trachea due to flying into a power line.


by Catherine Greenleaf


There's no doubt that one of the great pleasures of living in New Hampshire is enjoying the beautiful birds that grace our wooded backyards each spring and summer. Along with that comes the other enjoyable activity of setting up bird feeders and watching the birds eat. However, you want to be sure you're not creating what bird experts refer to as "The Death Triangle" when it comes to caring for your feathered backyard friends.

The Death Triangle is created when you place a birdfeeder in close proximity to the windows of your house or the sliding glass doors of your back deck. A busy birdfeeder can create chaos and commotion for the birds in the yard. Picture your average airport with several dozen planes all trying to land in the same general area. The scenario is similar for birds. Each bird is trying to land on the feeder, grab some food, and then get away safely without colliding with another bird.

The smaller the triangle, that is, the shorter the distance between your windows, the feeder, and the bird's flight pattern, the more likely you are to unwittingly create The Death Triangle. Within this hazardous triangle birds are more likely to fly straight into glass, resulting in injury and death. The Cornell Lab of Ornithology claims one billion birds die from window strikes each year.

When a bird looks at a window or sliding glass door they often see a reflection of blue sky and white clouds or the wooded landscape behind them and they treat that area as open air space to fly through.
Double-paned windows cause more bird deaths than single paned because a single pane often has enough "bounce" to partially soften the blow of a bird strike. This is particularly true with pre-1977 safety glazing. A double-paned window usually causes death due to a broken neck because the inside pane acts as a strut to support the outside pane. Sadly, a broken neck is a condition a wildlife rehabilitator like myself cannot fix. Single-paned windows often cause a concussion, which is an injury I can treat with blood-clotting medications and anti-inflammatories, provided the bird is brought to me straight away.

When it comes to bird strikes on glass, it's important to look at the bigger picture. Most species of birds, and this includes songbirds, woodpeckers, hawks and owls, require two parents to safely raise a nestful of young ones. During mating and nesting season, one bird goes off in search of food while the other sits on the newly hatched babies to keep them warm and protected. If one parent bird, while searching for food, dies flying into a window, then unfortunately, not just one bird dies but five or more birds. This is because it is a near impossible task for one parent bird to successfully feed young every 15-20 minutes from sun up until sun down, sit on them to keep them warm and dry, feed herself, and also protect the babies from predators. Often the result is the hatchlings die of starvation or hypothermia due to exposure to rain and cold. Or they are eaten by predators while the parent is flying around frantically looking for food for her hatchlings and herself.

Research shows a bird feeder should be at least 30 feet away from any windows or sliding glass doors. Forty to fifty feet would be ideal. However, this can be problematic, since many homeowners build decks onto the backs of their houses or install large picture windows with the express purpose of installing feeders so birds can be observed up close.

What's required is a compromise. If you are willing to observe the birds from a farther distance, you will be rewarded with an abundance of healthy and safe birds in your yard. No one likes to hear the awful "thwonk!" of a bird hitting glass. And no one enjoys searching the bushes or deck for unconscious Hummingbirds or dead Cedar Waxwings.

Each spring, I offer free consultations to bird-loving homeowners in Grafton and Coos counties. I come out to peoples' homes and together we brainstorm solutions for reducing the number of window strikes.

A few weeks ago, I visited a woman's home in Canaan, N.H. She asked me to come over and help her figure out a way to prevent birds from hitting her windows. She was retired and had just purchased the house the year before and was clearly distraught. When I arrived, she took me to her living room at the back of the house, and there I stood before a set of huge picture windows. These windows looked out onto a deck that was positioned directly over a dense woodland area with a stream. It was prime habitat for wildlife. And it was one of the worst Death Triangles I had ever seen. I turned my back to the windows to talk to the woman, and heard a "thwonk!"

"There's another one," she said sadly, taking a shoebox out onto the deck so she could scoop up yet another dead songbird. I followed her out and saw she was starting to cry. "This is the third one today," she said. She told me she would have never bought the house had she known the windows were such a problem. She said she had been so excited to buy the house because it had been designed by a New England architect renowned for his modern contemporaries with enormous picture windows for viewing wildlife. The situation was clearly breaking her heart. I gently touched her on the arm and said, "You know, you don't have to live with this madness."

Together we removed all the bird feeders from the deck and repositioned them on poles in her front yard next to the driveway. She said she was willing to observe the birds while sitting outdoors in her favorite lawn chair. Then we moved all the numerous potted plants and trees she had sitting against the windows inside of the livingroom. When birds can see houseplants it gives them the impression there is more outdoors beyond the glass. This is why so many birds die flying into greenhouses.

I explained her other options: she could cover the picture windows with a transparent film that would allow her to see out but appear opaque from the outside. She could tautly mount 5/8-inch mesh across the storm window frames so the birds would bounce off. She could place a large plastic bobble-headed Great Horned Owl on the railing of her back deck. She could affix extra-large decals depicting the black silhouette of a dive-bombing predator on the outside of each of the windows. (If you try this, go with at least a dozen decals. Just a few aren’t going to do the job). Songbirds are constantly checking in their peripheral vision for owls, hawks and falcons, and will gladly avoid any area with even the smallest hint of a predator. If you’re desperate and short on cash, take a bar of Ivory soap and streak the windows to break up the reflection or apply vertical tape strips.

Birds also are totally unnerved by the movement of colorful mylar spinners and sun catchers, as well as the tinkling sound of glass wind chimes or the clanking of cowbells. We also discussed other bird-safe, although more costly options, like installing an electronically operated awning over the deck to prevent reflection and block access to the "repeat offender" windows as well as outdoor shutters.

Of course, with a house plopped down in the middle of pristine wildlife habitat, it may not be possible to completely eliminate all window strikes, but the frequency can be substantially reduced with a few simple measures.

With just a slight adjustment to her property, this woman was able to recapture her love and enjoyment of birds. Sometimes when it comes to compromise, when you give just a little, you get a whole lot.

Catherine Greenleaf is a state licensed and federally permitted wildlife rehabilitator and director of St. Francis Wild Bird Hospital in Lyme, NH. The NH Fish & Game Department would like to remind readers that only a licensed and permitted wildlife rehabilitator is allowed to treat and keep wildlife.

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