Do towers kill birds? That sticky question has long gummed up the broadcast industry, environmental advocates and regulators.
New interim regulatory procedures will take effect soon for certain new towers to address bird kills, as RW has reported; yet the issue remains a sensitive one for many people in broadcasting.
This graphic from the report summarizes estimated avian mortality by source, based on studies. The report said towers “contribute a very small percentage (0.3 percent) of annual avian mortality, especially when compared to other anthropogenic sources and predation by cats.” It then explored the likely impact of various possible regulatory changes to ASR rules.
A new report from the FCC is likely to be scrutinized by anyone involved in the debate. Among its assertions: Communications towers in the United States — tower steel, lights and guy wires — do kill 6.6 million birds a year by the best available estimate; yet while proposed regulatory changes may affect the total somewhat, bird deaths from towers are, and will remain, only a tiny fraction of bird deaths from all causes.
These findings are part of a Federal Communications Commission report assessing the environmental impacts of its Antenna Structure Registration System. The report was prepared by the URS Group Inc., a Maryland firm, for the FCC Wireless Telecommunications Bureau.
Some background: The Antenna Structure Registration system generally applies to structures over 200 feet and those near an airport runway. The program does not routinely require a tower owner to prepare an environmental assessment about the potential impacts to migratory birds. But in 2008, a federal court said the FCC had not adequately evaluated effects of the program on endangered species and migratory birds. This report is one result. The FCC also recently adopted those new interim procedures, as RW has reported; they will take effect once approved by the government’s Office of Management and Budget. (Applicants for new tower registration will have to provide 30 days for public comment; and towers above 450 feet will require an environmental assessment regarding migratory birds.)
The report this week determines that the impact of the ASR program at the national level “on all resources, including migratory birds” is not significant. But depending on how it is implemented, situations could arise where “potentially significant” impact — on migratory birds, bald eagles or golden eagles — aren’t addressed. The report then delves into the effects of several regulatory options in considerable detail; those options include continuing the current ASR program; using the newly adopted interim program; changing FAA rules to rely only on steady (not flashing) lights for new towers; and various combinations of such steps.
The biggest aid in reducing impacts to birds, it found, would be changes to FAA rules to cut down on the use of red steady-burning lights. Voluntary changes to lights on existing towers would help too.
But while estimated bird mortality as a result of collisions with towers under the ASR program is a large number, the report concludes, “the anticipated annual bird mortality from existing and future communications towers under any alternative is not significant at the national level.”
A notable paragraph: “While communications towers contribute to the overall adverse impacts of all human activities on bird populations, communications tower collisions are only responsible for approximately 0.3 percent of the more than 2 billion annual bird deaths that currently occur due to cat predation and anthropogenic sources. In addition, these deaths occur against a backdrop of high natural mortality to migrating birds due to a number of factors. Indeed, communications tower collisions annually kill approximately 0.07 percent ofthe total migratory bird population (6.6 million out of 10 billion). Although the absolute number of birds killed at communications towers is large, towers are a relatively minor contributor to total human-caused avian mortality, and the impact of these deaths is likely even smaller when considered in the context of high natural mortality.”
The report is likely to continue the ongoing debate over what the permanent tower registration rules and procedures should be. You can read the details here.
The authors also summarize plenty of interesting data (estimated population of land birds by state, for instance, and migratory flight altitudes for various bird groups). It also attempts to summarize various reports and findings on the causes and extent of avian mortality (how many millions of birds die each year from hitting windows? from being attacked by cats?).
