Illegal shooting is now a leading cause of death of birds along power lines in the western USA

Eve C Thomason; Natalie J S Turley; James R Belthoff; Tara J Conkling; Todd E Katzner

doi:10.1016/j.isci.2023.107274

Illegal shooting is now a leading cause of death of birds along power lines in the western USA

iScience. 2023 Aug 1;26(8):107274. doi: 10.1016/j.isci.2023.107274. eCollection 2023 Aug 18.

Authors

Eve C Thomason^{1

2}, Natalie J S Turley³, James R Belthoff^{1

2}, Tara J Conkling⁴, Todd E Katzner⁴

Affiliations

¹ Department of Biological Sciences, Boise State University, Boise, ID 83725, USA.
² Raptor Research Center, Boise State University, Boise, ID 83725, USA.
³ Idaho Power Company, Boise, ID 83702, USA.
⁴ US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, ID 83702, USA.

Abstract

Human actions, both legal and illegal, affect wildlife in many ways. Inaccurate diagnosis of cause of death undermines law enforcement, management, threat assessment, and mitigation. We found 410 dead birds collected along 196 km of power lines in four western USA states during 2019-2022. We necropsied these carcasses to test conventional wisdom suggesting that electrocution is the leading cause of death of birds at electrical infrastructure. Of 175 birds with a known cause of death, 66% died from gunshot. Both raptors and corvids were more likely to die from gunshot than from other causes, along both transmission and distribution lines. Past mitigation to reduce avian deaths along power lines has focused almost exclusively on reducing electrocutions or collisions. Our work suggests that, although electrocution and collision remain important, addressing illegal shooting now may have greater relevance for avian conservation.

Keywords: Animals; Electricity.