By Travis Longcore

The migration each year of nearly 5 billion birds from breeding grounds in North America to wintering grounds in Central and South America and the Caribbean (the “Neotropics”) is both one of the wonders of nature and what marks the season for birders. Some of those birds even stay and overwinter here in Los Angeles and other southern reaches of North America. A Western Tanager stopped under our oak tree as this column was going to press but it will be another month before the Yellow-rumped Warblers arrive for the winter.

Protecting birds through all the phases of the year from breeding, migrating, to wintering, is known as full life-cycle conservation (1). During the migratory period, birds are particularly vulnerable to the impacts of artificial light at night, because most diurnal species, including Neotropical migrants, move at night when it is cooler. Migrating birds are attracted to light, and the lights of cities draw them off course and dramatically influence their migratory pathways, which is not to their benefit. Birds attracted to lights of cities then must face the perils of the daytime, including walls of glass that pose a collision hazard during the day.

Glass is a problem because birds literally do not see it as a barrier and either try to fly through it to something on the other side, or perceive the sky or vegetation reflected in it and attempt to fly to it. Birds can see the magnetic polarity of the Earth and use it to orient, which humans cannot. We humans can see glass and understand it is a barrier, while birds cannot. An estimated 600 million birds per year die at windows in the United States each year (2). Spring and fall migrations are peaks of these deaths and the attraction of birds to lights puts them in places where this occurs.

Two pieces of legislation are in the works to help save birds from lights and glass. In California, a bill (Assembly Bill 2382) has been introduced by Assemblymember Alex Lee (Milpitas) that would reduce light pollution from State of California-owned and operated buildings. This is an Audubon-supported effort: Santa Clara Valley Audubon Society worked to get the bill introduced and Audubon California has taken it up as one of their legislative priorities. Los Angeles Audubon Society members joined SCVAS and Audubon California representatives to meet with State Senator Ben Allen (Santa Monica) and encourage that he support the bill and other statewide legislative priorities for birds. Senator Allen has now signed on as a coauthor of AB 2382, which we greatly appreciate.

AB 2382 has passed the Assembly and the Senate and is now awaiting the Governor’s signature. You can help by calling the Governor’s office at (916) 445-2841and encouraging that he sign AB 2382. Written comments can be submitted at https://govapps.gov.ca.gov/gov40mail/. Please also thank Assemblymember Alex Lee (https://a25.asmdc.org/contact) and Senator Ben Allen (https://sd26.senate.ca.gov/contact/message) for their leadership on this issue.

At the federal level, Congressman Mike Quigley (Illinois) and Senator Cory Booker (New Jersey) have introduced the Federal Bird Safe Buildings Act. This bill would require that federal buildings be designed and managed with bird-safe features and that the federal government create and disseminate a design guide for bird safe buildings. Bird safe or bird friendly building involves breaking up expanses of glass with architectural detail, using screens or grills to both avoid collisions and manage heat and light, and control of light at night to reduce bird attraction. This legislation has passed the House before, but still needs to make it through the Senate. You can call your Senators and let them know that you support the Federal Bird Safe Buildings Act and that they should too. A tool from National Audubon will send messages to all your members of Congress, https://act.audubon.org/a/bird-safe-buildings-act.

The effects on birds from light pollution and window collisions can be reduced. These two pieces of legislations are important steps to show state and federal leadership so that the private sector can follow suit. Other cities and states have already acted on bird-friendly building and light pollution controls, so we hope you will encourage the same here in California and at the federal level.

References

1. P. P. Marra, E. B. Cohen, S. R. Loss, J. E. Rutter, C. M. Tonra, A call for full annual cycle research in animal ecology. Biology Letters 11, 20150552 (2015).

2. S. R. Loss, T. Will, S. S. Loss, P. P. Marra, Bird–building collisions in the United States: estimates of annual mortality and species vulnerability. Condor 116, 8–23 (2014).