Landscape, Legal, and Biodiversity Threats that Windows Pose to Birds: A Review of an Important Conservation Issue
Windows in human residential and commercial structures in urban, suburban, and rural landscapes contribute to the deaths of billions of birds worldwide. International treaties, federal, provincial, state, and municipal laws exist to reduce human-associated avian mortality, but are most often not enforced for bird kills resulting from window strikes. As an additive, compared to a compensatory mortality factor, window collisions pose threats to the sustainability and overall population health of common as well as species of special concern. Several solutions to address the window hazard for birds exist, but the most innovative and promising need encouragement and support to market, manufacture, and implement.
Comparison of fatal bird injuries from collisions with towers and windows
Abstract Birds killed by colliding with towers and windows were studied to describe the type and extent of injuries and, more precisely, to suggest the actual cause of death. A total of 502 specimens (247 tower kills, 255 window kills) were dissected, radiographed, and examined. Tower and window collision categories were further subdivided to consider age (subadult versus adult) and weight (<39 g, sparrow-size or smaller, versus > 39 g, cardinal size or larger) differences in injury and differential vulnerability. Injuries were classified as superficial, subdermal, or skeletal fractures. Comparisons of injuries between tower- and window-killed specimens indicate that the consequences of these two types of collisions are similar. Subdermal injuries were more severe in tower kills than in window kills. Subadults experienced more severe subdermal injuries than adult tower and window casualties. Among window kills, larger birds had more severe subdermal injuries than smaller birds. Collision victims may show blood or fluid in the mouth or nose cavities (30–60%), almost all have subdermal intracranial hemorrhaging (98–99%), and most lack any evidence of skeletal fractures (82–91%). Histological examination of the brain of two specimens revealed blood pools in the cerebrum and cerebellum. The extravascular bleeding in and around the brain is probably the actual cause of death in collision fatalities. Treatment to reduce brain edema if administered within 6–8 h shortly after impact can save some strike casualties.
UNIVERSAL LOCALLY COMPACT SCATTERED SPACES
If δ is an ordinal, we denote by C(δ) the class of all cardinal sequences of length δ of locally compact scattered (in short: LCS) spaces. If λ is an infinite cardinal, we write Cλ(δ) = {s ∈ C(δ) : s(0) = λ = min[s(ζ) : ζ < δ]}. An LCS space X is called Cλ(δ)-universal if SEQ(X) ∈ Cλ(δ), and for each sequence s ∈ Cλ(δ) there is an open subspace Y of X with SEQ(Y ) = s. We show that • there is a Cω(ω1)-universal LCS space, • under CH there is a Cω(δ)-universal LCS space for every ordinal δ < ω2, • under GCH for every infinite cardinal λ and every ordinal δ < ω2, there is a Cλ(δ)-universal LCS space, • there may exist a Cω(ω2)-universal LCS space. As a consequence, we obtain that it is consistent that 2 = ω2 and Cω(ω2) is large as possible, i.e. Cω(ω2) = {s ∈ 2{ω, ω1, ω2} : s(0) = ω}. 2000 Mathematics Subject Classification. 54A25, 06E05, 54G12, 03E35.