Window strikes kill an estimated one billion birds annually in North America alone, representing a massive and largely preventable source of bird suffering and mortality.
A bird that survives a window strike may appear stunned and recover, but internal injuries including hemorrhage and brain injury may cause delayed death. The bird that flies away after a few minutes may still die hours later from internal bleeding. Those who do not recover immediately may be taken by predators while disoriented. At the population level, one billion deaths annually represents a staggering welfare and conservation impact from a completely preventable source. The ease and low cost of prevention makes this one of the most cost-effective wildlife welfare interventions available to individuals.