{"id":191,"date":"2015-01-27T18:46:00","date_gmt":"2015-01-27T18:46:00","guid":{"rendered":"https:\/\/esconeighbors.wpenginepowered.com\/?p=191"},"modified":"2015-01-27T18:46:00","modified_gmt":"2015-01-27T18:46:00","slug":"why-we-oppose-the-glass-walls-next-to-habitat-information-on-bird-mortality-and-glass-surfaces","status":"publish","type":"post","link":"https:\/\/escondidoneighbors.org\/?p=191","title":{"rendered":"Why we oppose the glass walls next to habitat. Information on Bird Mortality and glass surfaces."},"content":{"rendered":"
\n
\n<\/o:p><\/div>\n
\nWindows: The Bane of Birds (or ‘What a Pane!’)<\/span><\/b><\/o:p><\/span><\/b><\/div>\n

FULL ARTICLE HERE<\/a><\/p>\n

\nBy John Martin, Wildlife Biologist, U.S. Fish
\nand Wildlife Service, San Diego National Wildlife Refuge <\/span><\/b>
\n
<\/b>
\nOn a Saturday morning, as I walk into the kitchen to top off my coffee, an
\nunmistakable thud takes precedence over all the other little sounds in the
\nhouse. I move into the living room, quickly running through and instantly
\ndismissing a series of alternatives: a log settling in the stove, something on
\nthe radio, a distant car door\u2026. No, that thud was a bird hitting the window,
\nand I can see the ghostly splayed imprint of feather dust on the glass as I
\napproach. I look over the sill, and on the ground beneath the window, on its
\nback, wings quivering, is a splendid splash of black, white and red: a
\nred-breasted sapsucker. I rush out the door, to either help the bird or recover
\nthe specimen, but in the seconds it takes for me to get there, the bird had
\nregained its equilibrium enough to see a big, rapidly-approaching person, and
\nfly across the road to disappear into the oaks and chaparral.
\nA happy ending? Probably not. How can a body as complex and delicate as a
\nbird\u2019s hit a solid object hard enough to make that sound, and fly away
\nunscathed? If the woodpecker sustained any injury, he\u2019d now be in the
\nunforgiving woods, with his ability to keep warm, find food, and avoid
\npredators compromised. It\u2019s a grim outlook for this woodpecker, a continued
\nrisk for the rest of the birds in my yard, and a risk around the world wherever
\nbirds and glass share the airspace.
\nIn 2014, scientists from U.S. Fish and Wildlife Service and the Smithsonian
\nInstitution analyzed 23 recent studies of bird\/window collisions, to better
\nestimate the magnitude of the problem. They estimated that window collisions
\nkill 365-988 million birds annually in the United States. Of these, 44 percent
\noccurred at residences, presumably because windows of homes are within the
\nrange of heights of vegetation that essentially defines habitat for most
\nsongbirds in North America. Only 44 percent? That\u2019s still hundreds of millions
\nof repetitions of the sapsucker collision at my house, every year, across the
\nnation.
\nA depressing statistic, especially when I think of the enjoyment I get out of
\nbirds. When I\u2019m out in the yard, or the oaks and chaparral in the neighborhood,
\nit\u2019s the birds that are the most conspicuous sparks of life, another song or
\nflash of motion every few seconds, livening up the landscape.
\nIs anyone studying the mechanics of bird\/window collisions, to better
\nunderstand not only the size of the problem, but how windows kill birds, and
\nwhat we can do to reduce the problem? Surprisingly few biologists have made
\nbird\/window collisions a focus of their research. But Dr. Daniel Klem Jr.,
\nProfessor of Biology at Muhlenberg College, has built his professional career
\non this issue, publishing over a dozen papers elucidating the mechanisms of
\ninjury, the factors that affect the likelihood of collision, and what we can do
\nto reduce collisions and injuries.
\nDr. Klem has taken a closer look at exactly what happens to birds that strike windows,
\nand found a surprising result. Though it\u2019s commonly assumed that birds that die
\nstriking windows die from a broken neck, this isn\u2019t the case. It makes sense:
\nbreaking a bird\u2019s neck is like trying to break a rope by pushing it into a
\nsolid object. Birds have 13-27 neck vertebrae (compared to 7 in mammals such as
\nourselves), and the articulations between them are especially flexible.
\nDissection of hundreds of birds killed by window strikes reveals that none of
\nthem had broken necks. But essentially all of them suffered ruptured blood
\nvessels in the cranium, and died of intracranial bleeding and\/or associated
\ndamage to the brain. Most birds that have apparently \u201crecovered\u201d after striking
\nwindows also suffered intracranial bleeding. A bird that regains consciousness
\nand flies off after hitting a window isn\u2019t necessarily in the clear: it may
\nhave recovered enough to seek shelter, and die later of its injuries.
\n\"https:\/\/gallery.mailchimp.com\/cc4045d6e594ee9d4aeb9f70a\/images\/e9575baf-5ecd-4470-baa2-fae453cbcd0a.bmp\"
\nWhat can we do to reduce bird mortality at our own windows? One approach is to
\nreduce the likelihood that birds will fly into the window. Birds presumably
\nstrike windows either because the transparent glass creates the illusion that
\nthey can fly straight to the habitat that they see beyond the invisible
\nbarrier, or because they see habitat reflected in the smooth surface of the
\nglass. In either case, they don\u2019t perceive the glass as a barrier. To allow
\nbirds to recognize the glass as a barrier, people have tried applying opaque
\nobjects or patterns to windows. Isolated objects or patterns (such as falcon or
\nowl silhouettes) don\u2019t work: the bird sees the object, but not the window. The
\nbirds attempt to fly around the falcon graphic, and in avoiding the object they
\nsmack into the adjacent glass. Experiments by Dr. Klem and other researchers
\nindicate that to deter birds in an aviary from flying through an empty window
\nframe, the critical dimension for visual obstructions (objects or patterns on
\nthe glass) is about 2 inches apart horizontally, and 4 inches apart vertically.
\nWindows marked with patterns of dots, stripes, or other shapes (at least \u00bc inch
\nwide) effectively show birds that the window is a barrier, and greatly reduce
\nor eliminate window collisions. There are several brands of commercially
\navailable window films that apply a pattern sufficient to deter birds, or you
\ncan design your own with opaque tape (such as American Bird Conservancy\u2019s
\nBirdTape). It\u2019s important to apply the pattern to the outside of the glass,
\nrather than the inside, to allow the pattern to disrupt the reflected image of
\nan unobstructed flight path, as well as the transparent window.
\nUnfortunately, obscuring the window sufficiently to eliminate bird strikes
\ncontradicts the whole point of having glass windows: we want to see through
\nthem. Yet it may be possible to make a pattern on the window that birds can see
\nand we can\u2019t! Generally, birds can see a wider spectrum of light than humans,
\nincluding ultravio-let wavelengths. Experiments have been conducted to
\ndetermine if glass marked with a pattern of materials that absorb or reflect
\nultraviolet light (invisible to us) dissuades birds from flying into the glass.
\nResults of laboratory experiments are promising, but investigators note that
\nunder natural, outdoor light, the ultraviolet-marked glass may not function as
\nit does in the laboratory. Until bird mortality at glass windows is more
\nwidely-recognized as a problem, glass manufacturers are unlikely to invest in
\nthe research, development, and marketing of bird-friendly glass. But
\nornithologists continue to research this potential solution.
\nA different approach to reducing bird mortality due to window strikes is to
\nreduce the force with which birds hit windows. Kinetic energy (say, of a flying
\nbird) = \u00bd (mass)(velocity)2. Can\u2019t do much about the mass, but we can help
\nreduce the velocity at which birds are moving when they hit the window,
\nreducing their kinetic energy and thus the damage that occurs inside their
\nskull when it abruptly stops at the glass. If you have a bird feeder, place it
\nwithin 3 feet of a window. Birds leaving the feeder will not have built up
\nsufficient speed to hit the glass hard, so are less likely to get hurt striking
\nthe window. Researchers have also investigated reducing bird mortality by
\ninstalling windows at an angle (20-40\u02da from vertical), such that birds are
\ndeflected when they hit the window. Under laboratory conditions, birds are
\nindeed less likely to die when flying into an angled window, but in nature,
\nwhere birds can approach the glass from a variety of angles, it\u2019s clear that
\nfatal collisions still result from birds striking angled windows. Installation of
\nbird netting (such as that used to protect fruit trees from birds) over the
\nentire window several inches out from the surface, has the potential to reduce
\nthe force of impact of a bird striking the window. Netting may also reduce the
\nlikelihood of a bird striking the window in the first place, because the birds
\nmay see it.
\nIf you\u2019re looking for more detailed information on reducing bird mortality on
\nglass in your home, a good place to start is the American Bird Conservancy\u2019s
\nweb page devoted to the issue:www.abcbirds.org\/abcprograms\/policy\/collisions\/glass.html<\/span><\/a>.
\nAt my house, I believe a pattern of tape on my living room window is in order.
\nSapsuckers are back for the winter, and I don\u2019t want to hear that unmistakable
\nthump again.<\/span><\/o:p><\/div>\n","protected":false},"excerpt":{"rendered":"

Windows: The Bane of Birds (or ‘What a Pane!’) FULL ARTICLE HERE By John Martin, Wildlife Biologist, U.S. Fish and Wildlife Service, San Diego National Wildlife Refuge  On a Saturday morning, as I walk into the kitchen to top off … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-191","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"featured_image_src":null,"featured_image_src_square":null,"author_info":{"display_name":"Escondido Neighbors United","author_link":"https:\/\/escondidoneighbors.org\/?author=1"},"_links":{"self":[{"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=\/wp\/v2\/posts\/191","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=191"}],"version-history":[{"count":0,"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=\/wp\/v2\/posts\/191\/revisions"}],"wp:attachment":[{"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=191"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/escondidoneighbors.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}