Fatality Estimation

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USGS has made significant strides in addressing research needs identified by resource managers and industry to understand wildlife interactions with turbines, estimate causes and magnitude of fatalities, develop wildlife and mortality survey protocols, assess population effects, describe migrations and movement patterns, and develop potential mitigation measures. USGS also has developed tools to assist partners and industry with fatality estimation at energy facilities.

Each project below is associated with a type of energy production or transmission. Types of energy production or transmission are represented by the following icons:

Transmission lines, solar and wind energy icons

Abbreviations used in project descriptions are defined on the Energy and Wildife Abbrevations page.


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Advances in Estimating Fatalities From Collisions With Energy Infrastructure

Science Center: Forest and Rangeland Ecosystem Science Center

Accurate estimates of bird and bat fatalities from collisions with energy infrastructure can be difficult because carcasses may not be detected or may be scavenged. These estimates, however, are critical to understanding the effects of collisions with energy infrastructure on species populations and devising effective methods to mitigate or minimize fatalities. Accurate estimation is complicated because carcasses may fall outside the search area, be removed by scavengers, or be missed by searchers during surveys. USGS and USFWS are working to develop new tools and improve existing tools to estimate actual bird and bat fatalities based on carcass searches near energy infrastructure. Scientists are also investigating whether accurate and precise estimates of fatalities can be derived from carcass searches conducted at easily accessed areas, such as roads and pads beneath turbines.


Solar power icon

Developing a Model to Estimate Golden Eagle Take at Wind Energy Facilities

Science Center: Forest and Rangeland Ecosystem Science Center

Simple counts of bird carcasses found at wind energy facilities do not reflect actual fatalities because some carcasses are removed by scavengers or are overlooked by or fall within areas inaccessible to searchers. USGS researchers are using data from white-tailed eagles in Norway as surrogates for U.S. bald and golden eagles that are not found in adequate numbers at any given facility to allow for reliable estimation of eagle-carcass density. The applicability of white-tailed eagle models is being tested using observations from several sites in California. Results can be used by USFWS in determining take limits for new wind-power facilities and estimating actual eagle take post-construction.


Transmission line, wind energy, and solar energy icons

Generalized Fatality Estimator (GenEst) Software and User’s Guide

Science Center: Forest and Rangeland Ecosystem Science Center

Numerous fatality estimators have been developed to estimate the number of bird and bat fatalities at wind energy facilities, but failure to meet their inherent assumptions can lead to different estimates of fatality. Working with statisticians who developed several of the estimators presently in use, the USGS, BCI, WEST, Inc., and Oregon State University are developing software that combines multiple approaches under a single generalized estimator (GenEst). GenEst will allow the user to evaluate assumptions regarding input parameters and select the approach that best reflects the situation and data. The applicability of GenEst will not be limited to wind power facilities. The tool is being designed for use in any situation in which the objective is an estimate of a super population for which detection probability is unknown but can be estimated, such as solar facilities, oil spills, fisheries by-catch, and power-line or fence-line fatality rates.