title: An estimate of avian mortality at communication towers in the United States and Canada.
abstract: Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action.
authors.affiliation: The Urban Wildlands Group, Los Angeles, California, United States of America. longcore@urbanwildlands.org
authors.forename: Travis
authors.initials: T
authors.lastname: Longcore
authors.forename: Catherine
authors.initials: C
authors.lastname: Rich
authors.forename: Pierre
authors.initials: P
authors.lastname: Mineau
authors.forename: Beau
authors.initials: B
authors.lastname: MacDonald
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Bert
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Sullivan
authors.forename: Erin
authors.initials: E
authors.lastname: Mutrie
authors.forename: Sidney A
authors.initials: SA
authors.lastname: Gauthreaux
authors.forename: Michael L
authors.initials: ML
authors.lastname: Avery
authors.forename: Robert L
authors.initials: RL
authors.lastname: Crawford
authors.forename: Albert M
authors.initials: AM
authors.lastname: Manville
authors.forename: Emilie R
authors.initials: ER
authors.lastname: Travis
authors.forename: David
authors.initials: D
authors.lastname: Drake
mesh_terms: D000059:Accidents / Q000706:statistics & numerical data*; D000531:Altitude; D000818:Animals; D001717:Birds / Q000293:injuries*; D002170:Canada; D003195:Computer Communication Networks / Q000295:instrumentation*; D003247:Conservation of Natural Resources / Q000706:statistics & numerical data*; D005426:Flight, Animal; D009026:Mortality; D012044:Regression Analysis; D014481:United States