A new scientific paper published by an Idaho team suggests that illegal shooting is a leading cause of bird deaths along power lines in the West, but media reports generally got the story wrong, while some of the most revealing information about the study wasn’t disclosed in the published paper at all.
A Science Daily article last week was headlined “Illegal shooting kills most birds found dead near power lines” – even though that’s not what researchers found. Numerous other news sites ran similar headlines.
The New York Times reported, “A survey of power lines in four Western states found bullet fragments and shotgun pellets in most of the dead birds that were collected” (not true) and “In a survey of five sites in the western United States, two-thirds of birds found dead beneath power lines had been shot” (also not true).
In fact, 28% of the dead birds recovered during the study could be attributed to gunshot deaths – a far cry from the “two-thirds” reported by the Times or the “most birds found dead” reported in Science Daily.
The research making the news comes from a new paper detailing surveys of all bird deaths documented along designated power line surveys in locations in four states (Jordan Valley, Oregon; two locations to the east of the Jordan Valley in Idaho; a location near Vernal, Utah; and southwestern Wyoming near Seedskadee National Wildlife Refuge).
Of the 410 dead birds recovered during the study, the cause of death could not be determined in more than half the birds (235). What the news media probably meant to report was that of the 175 carcasses where the cause of death could be determined, 66% of the bird deaths were attributed to gunshots.
Most of the media reports on the new paper included images of eagles or hawks (because we’ve heard for years about the dangers power lines pose to raptors), but the researchers collected carcasses of all birds found dead near power lines, not just raptors. About 45% of the dead birds collected were raptors, 32% were ravens, and the remainder included numerous other species, including sage grouse, sage thrashers, pigeons, ducks, and sparrows. Many of these other species likely represented prey remains left by predatory birds feeding while perched on nearby power poles, and some of these species are legally hunted.
The large number of gunshot deaths of protected species is an alarming finding without the need to embellish, as the research paper itself headlined, “Illegal shooting along power lines a leading cause of death for bald eagles, protected birds in the West.” While the paper appears to upend the long-held assumption that birds found dead near power lines were probably electrocuted, I find new assumptions to be somewhat questionable as well.
Perhaps the most revealing information from the paper is in what it did not disclose. What the paper did not share is that 80% of the gunshot deaths (93 of 116) occurred within just one of the five survey locations – all within the Morley Nelson Snake River Birds of Prey National Conservation Area (NCA) of Idaho. This information is only found in the supplemental information available on the publisher’s website, not within the published paper itself, and the raw data from the study is not publicly available.
Unlike some of the other survey locations, the NCA is subject to a high level of recreational shooting, although that wasn’t mentioned in the new paper either. The NCA is home to the what is believed to be the world’s densest population of nesting birds of prey and is located just 15 miles outside of Boise (an area of high human population density). Other researchers were shocked by the amount of illegal poaching of birds that occurs in the area, as reported back in 2018.
I found a paper published in 2020 by the same Idaho researchers as the new paper that noted the high density of ground squirrels, the proximity to urban areas, and the open-access management of the NCA attracts large numbers of legal recreational shooters. They wrote: “On weekends from February to July, many hundreds of shooters are distributed along only a few kilometers of roadway in the NCA.” Most of the gunshot birds were found in areas of this area of “high intensity of recreational shooting” and “The locations of the 28 birds that died of unknown causes also were strongly associated with recreational shooting.”
In the new paper, the authors reference their other work: “In parallel work focused on illegal shooting at the National Conservation Area (NCA), we documented spatial and temporal patterns in the rates at which we found shot birds and we established networks by which this information was channeled to law enforcement agencies. This information flow was critical to a subsequent successful law enforcement action addressing some of this illegal shooting.”
The problem with illegal shooting of birds in the NCA was already well known, but the new paper also keyed on two other study sites nearby with the same poaching problem. The other Idaho survey location is located just west of the NCA and had six gunshot birds and no electrocutions. Oregon’s Jordan Valley, just across the state border from the two Idaho study sites, had 8 gunshot birds and 7 electrocutions, and was selected because it was already known to have a large amount of illegal bird killing (as mentioned in the 2020 paper by the same authors).
What about the other survey sites? In the Wyoming portion of the study (near Seedskadee), 7 birds were gunshot, while 8 were electrocuted. Vernal had 2 gunshot birds and no electrocutions. Thus, the Idaho/Oregon bird deaths to gunshots accounted for 92% of all known gunshot deaths.
While any shooting of federally protected birds is unacceptable, it appears that the high level of bird poaching from Jordan Valley eastward through the NCA is an important regional issue.
Readers of some of the media reports on this study could logically walk away with the assumption that illegal shooting of birds has overtaken electrocutions as the top killer of birds throughout the West, but that would be a shaky foundation on which to stand.
What we do know is that power companies have made substantial invests to retrofit power lines to reduce the risk of bird mortalities from collisions and electrocutions. Existing estimates of bird collusion and electrocution at power lines are speculative or based on extrapolation of results from one study to other U.S. power lines.
Similarly, it would be erroneous to assume that the Idaho study on bird gunshots deaths along power lines is representative of the situation throughout the western states.
Cat Urbigkit is an author and rancher who lives on the range in Sublette County, Wyoming. Her column, Range Writing, appears weekly in Cowboy State Daily.