The Migratory Bird Treaty Act (MBTA) has a famously broad scope, outlawing the taking of over 1000 species of birds, ranging from hummingbirds to robins and crows. It is also a criminal statute, although most violations are treated as misdemeanors subject to (not-insubstantial) fines. Enforcement of the statute has been criticized as uneven, and critics have noted that bird deaths associated with mining, oil and gas operations have often been treated as serious offenses subject to substantial penalties, while thousands of birds, many of them hawks and eagles, have been chopped up by wind farms with no enforcement response. Apparently stung by the criticism, agencies are now taking a serious look at the bird mortality issues associated with another source of renewable energy, solar.

Although the Wildlife Society published a report in March estimating that wind farms kill over a half-million birds annually, it is two bird deaths at large solar projects under construction in southern California this spring and summer that have led to a spate of agency activity involving the Fish and Wildlife Service, the Bureau of Land Management and the California Energy Commission. Each of the two California incidents involved a single bird – an endangered Yuma clapper rail and a peregrine falcon – with no formal determination yet on the cause of death in either instance. After the second dead bird was reported, the Bureau of Land Management announced it was forming a panel of regulators and energy developers to examine whether the large solar plants being built in the area are a threat to birds, including bald eagles. The California Energy Commission also released a report this month on a proposed 500 megawatt facility, raising questions about whether the proposed Palen project in Riverside County, California can be operated without a significant impact on avian species, including bald and golden eagles. Concerns have been focused on the potential for birds to crash into power towers, and on the potential for burning or blinding from “solar flux” between mirrors and the towers. For farms using photovoltaic solar panels, another concern is that the array of panels may appear to be water to passing birds.

If the pattern of enforcement at wind facilities continues, the potential prosecution for bird mortalities at solar facilities is unlikely to do much to slow the drive to build large solar facilities throughout the western U.S. desert lands. However, the increased scrutiny by federal and state agencies may force the industry to do much more to examine the impact of their operations on birds, in particular highly valued hunting species such as hawks, falcons and eagles. The potential may also give an additional weapon to environmental groups concerned about the unprecedented rush to build large facilities in the fragile habitat of the California desert. One benefit to the industry, however, may be that a single suite of bird safety requirements is developed, giving certainty to plant developers now operating without consistent guidance from the agencies.