United States

United States

Influential bird death report badly flawed -- Inaccurate and inflated fatality rates says wind group

A highly controversial and widely circulated 2004 report on bird deaths in the Altamont Pass wind resource area in California is deeply flawed in its scientific approach and resulted in the dissemination of inaccurate and inflated avian fatality rates compared to the available data used to support it. These are the key conclusions made by the California's Wind Energy Association (CalWEA) studying the results of three independent reviews of the 2004 report. The reviews were initiated by CalWEA.

The 2004 report, "Developing Methods to Reduce Bird Mortality in the Altamont Pass Wind Resource Area" by K Shawn Smallwood and Carl G Thelander of BioResource Consultants was commissioned by the California Energy Commission (CEC). It suggested that 4000 of the turbines at the sprawling wind resource area are obsolete and kill an estimated 880 to 1300 eagles, hawks and falcons each year. The widely publicised report whipped up anti wind energy feeling around the globe and became a genuine black eye for the industry. It was also prominently cited by the Center for Biological Diversity, an environmental organisation, which filed a lawsuit in 2004 against the wind turbine operators at Altamont Pass. Last month that lawsuit was dismissed on technicalities.

CalWEA and the wider wind community were highly suspect of the 2004 report from the beginning because it described fatality levels significantly higher than those found in previous studies. The association has never argued there were no avian collisions, nor suggested it was not an important concern specific to Altamont Pass, but it had never seen data quite like that presented by BioResource Consultants.

Unavailable data

Seeking answers, CalWEA commissioned three separate independent reviews of the 2004 report. They were conducted by William Warren-Hicks, an environmental statistician at EcoStat, a consulting firm specialising in quantitative environmental sciences, Eric Smith, an environmental statistician and interim chair of the statistics department at Virginia Tech, and LPL Quality Services, an independent quality assurance firm whose clients include federal government agencies. The reviews were based on the portion of data that has been made publicly available by the CEC. The balance of that data is still not available, despite a Public Records Act request by one of CalWEA's members, Pilz & Co.

CalWEA says the report authors found numerous data quality issues -- any of which could have a substantial impact on the findings of the report. In 72% of field data sheets (81 of 113) where the field biologist indicated complete uncertainty as to the cause of death, the database attributes the cause of death to "turbine collision" with no explanation given.

CalWEA says this is pertinent because the area, which covers some 79 square miles in Alameda and Contra Costa counties, has a large bird population and will have natural bird mortality as well as mortality from other causes, commonly referred to as "background" mortality. More specifically, no control study was conducted to determine the natural background mortality.

Eagle death discrepancy

Most troubling, says CalWEA, is a data discrepancy in the reported figure for the species of greatest concern, the Golden Eagle, where the mortality rate in the 2004 report is 2.6 times higher than what is supported by the released portion of the data. Again, CalWEA says it is greatly unfortunate the CEC did not make the entire data set available, which prevents full independent verifications of the results to be made.

"In criticising this report, we wish to make it very clear that the industry does not deny the relatively high level of avian fatalities that occur at Altamont as compared to wind resource areas across the state and country," states CalWEA in a letter to the CEC. "Rather, we are extremely troubled by the quality of CEC PIER-sponsored science and the absence of quality assurance procedures that enabled such a flawed report to be published and then promoted by CEC staff as a proper basis for the expenditure of millions of dollars despite the raising of many red flags. No one is served -- least of all California's wildlife -- by inaccurate research that could result in the ineffective expenditure of the limited resources that are available to address avian issues while preserving the viability of clean energy production."

CalWEA makes three requests: that the CEC ensure the report, and others based on it, will not be used in future government decision making, that the CEC undertake an internal investigation into how its internal procedures "failed to ensure quality work," that quality control procedures be implemented, and that all data supporting CEC research is made fully available, beginning with an immediate release of the unreleased portions of the 2004 report in question.

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