Droll Yankees Warning Web - Bird Collision Decals
The Warning Web
How does it work? The Warning Web by Droll Yankees is a patented method of preventing birds from colliding with windows by displaying a printed pattern of the center of a spider web that includes a prominent stabilimentum. The static cling decal can be placed on the inside or outside of the window. Birds will avoid the window thinking that the window is a spider web.
What is a stabilimentum? The stabilimentum is the prominent white zigzag in the center of an orbital web. The original theory proposed that the purpose of the stabilimentum was to stabilize the web - thus the name. Scientists have since determined that spiders place the stabilimentum on the web to make the web visible to birds and large flying insects. The spicer does not want its web to be destroyed. Birds in flight will swerve to avoid the sticky web. This interaction has served the mutual benefit of both spiders and birds that have evolved together for hundreds of millions of years.
What is an orbital Web? Spiders construct webs by running radial threads from the center and attaching them to a frame. Then a sticky thread is placed over this frame spiraling inwards toward the center. The orbital web is designed to catch flying insects. Many orbital webs are put up in the evening and taken down at dawn, but the ones left up during the day are likely to have a stabilimentum.
Which spider makes the stabilimentum on the decal? The Golden Garden Spider, also called the Black and Yellow Spider (Argiope Aurantia) was chosen as the model for the decal. It ranges over the continental United States and sourthern Canada but is not common in the Rockies. Stabilimenta are produced by spiders of the two major families of orb weavers, Araneidae and Uloboridae. Some stabilmenta are a linear pattern (the Golden Garden Spider), some are an X pattern and some cover a disc.
What if there are no spiders like that in my area? Chances are good that there are orb weaving spiders in your area which display a stabilimentum but you will see them only at certain times of the year. The Golden Garden Spider, for example, is seen only in late summer and fall. Migratory birds traveling through different areas are affected by the spiders they encounter along the way.
How many decals should I put on a window? On an average size window, one decal should be enough. A sliding door or a large window may need two or more decals. The number needed will be determined by the placement of your bird feeders, the location of trees and shrubs, the way the light hits your windows and various other factors.
Will the decal stop all bird collisions? It has been estimated that as many as one billion birds die annually from hitting windows. Many of those are killed by colliding with lighted buildings while migrating at night. In the case of birds around our houses, we cannot expect any method to be perfect, as nothing can prevent the panic flights caused by hawks or other predators. If you work in or near buildings that are left lighted at night, please help educate those who influence that decision.