Health of bald eagles: by the numbers

We published a quantitative tool to aid resource managers in assessing the population scale impact of lead in bald eagles over a 17-year time period. 

Access RaptorHealthV4

Bald eagles in New York State

We also published the population-scale impact of lead (Pb) in New York State eagles from 1990 to 2018 using methods adapted from Hanley et al. (2019) and Hanley et al. (2022). The bald eagle population grew in New York State over the past three decades (1990-2018) while incurring mortalities from ingested Pb. However, partial remediation of Pb (i.e., removal of mortalities that arise as a direct result of Pb) would increase survival for non-breeding eagles of both sexes, increase survival of female breeding eagles, and increase the long-term growth rate for both sexes. Removal of all Pb (i.e., removal of a mix of mortalities that arise in association with and as a direct result of Pb) would increase survival of male non-breeders, increase survival of breeders of both sexes, and increase the long-term growth rate for both sexes.

Management implications

Our New York State-specific analysis can be used by wildlife managers, educators, and policymakers to be better informed about the role Pb plays in eagle population dynamics, to create hunter education materials to inform hunter choices, and to potentially regulate Pb ammunitions in areas frequented by eagles.

Using cutting edge computational techniques, we assessed the population-scale impacts of Pb on bald eagles in New York State.

Bald eagle in a nest

Impact of lead (Pb) on eagles

View the published dynamics of Pb, Pb-reduced, and Pb-free eagles in New York State:

Female dynamics      Male dynamics

Explore the hypothetical dynamics of Pb, Pb-reduced, and Pb-free eagles when immigration and emigration are closed in New York State:

Female closed dynamics      Male closed dynamics

Explore the preliminary dynamics of Pb, Pb-reduced, and Pb-free eagles separated into the first and second parts of the timeline (Early: 1990 – 2006, Late: 2002 – 2018) in New York State:

Female early dynamics      Male early dynamics

Female late dynamics      Male late dynamics

Explore the hypothetical preliminary dynamics of Pb, Pb-reduced, and Pb-free eagles when immigration and emigration are closed, separated into the first and second parts of the timeline (Early: 1990 – 2006, Late: 2002 – 2018) in New York State:

Female closed early dynamics      Male closed early dynamics

Female closed late dynamics      Male closed late dynamics

Explore the life history plasticity of Pb, Pb-reduced, and Pb-free eagles in New York State:

Female plasticity      Male plasticity

Further details

Questions can be directed to K. Schuler.

Financial support was provided in part by the New York State Department of Environmental Conservation and the Morris Animal Foundation under grant # D18ZO-103. The contents of this web site, the links, the interactive apps, cited literature, and the narratives have not been reviewed nor endorsed by the Department nor the Foundation, and the views expressed in this content do not necessarily reflect the views of the Department nor Foundation, its officers, directors, affiliates, or agents. 

Citations

Publications

Hanley BJ, Dhondt AA, Forzan M, Bunting EM, Pokras MA, Hynes KP, Domínguez-Villegas E. & Schuler KL. Raptor Health V4: Software to assess the long-term population-scale impacts of mortality in raptors. In peer revision.

Hanley, BJ, Them, CE, Hynes, KP, Connelly, PJ, Bunting, EM, & Schuler, KL. Population impact to bald eagles of ingested lead (Pb) in New York State, 1990-2018. Wildlife Society Bulletin. DOI: https://doi.org/10.1002/wsb.1444.

Hanley, BJ, Dhondt, AA, Forzán, MJ, Bunting, EM, Pokras, M, Hynes, KP, Dominguez-Villegas, E. & Schuler, KL. 2022. The population scale impacts of lead toxicosis on Bald Eagles (Haliaeetus leucocephalus) in the Northeast United States. Journal of Wildlife Management. DOI: https://doi.org/10.1002/jwmg.22177.

Hanley, BJ, Dhondt, AA, Dennis, B, & Schuler, KL. 2019. Using time series data to assess recent population dynamics of Bald Eagles in the northeast United States. Ecosphere. DOI: https://doi.org/10.1002/ecs2.2963.

Software

Hanley, BJ, Dhondt, AA, Forzan MJ, Pokras, MA, Hynes, KP, Dominquez-Villegas, E, & Schuler, KL. 2023. Raptor Health V4: Software to assess the population-scale impact of mortality in raptors [Software]. Cornell University Library eCommons Repository. DOI: https://doi.org/10.7298/0dm3-tf51.4.

Hanley, BJ, Them, CE, Connelly, PJ, Hynes, KP, Bunting, EM, & Schuler, KL. 2022. NYCounterPOPd Version 2 [Software]. Cornell University Library eCommons Repository. DOI: https://doi.org/10.7298/rsse-e634.2.​​

Them CE, Hanley BJ, Connelly PJ, Hynes KP, Bunting EM, & Schuler, KL. 2023. NYClosedCounterPOPd Version 2 [Software]. Cornell University Library eCommons Repository. DOI: https://doi.org/10.7298/ewr7-xj09.2.

Them CE, Hanley BJ, Connelly PJ, Hynes KP, Bunting EM, & Schuler, KL. 2023. NYClosedDensiPOPd Version 2 [Software]. Cornell University Library eCommons Repository. DOI: https://doi.org/10.7298/dm2c-kb03  

Them CE, Hanley BJ, Connelly PJ, Hynes KP, Bunting EM, & Schuler, KL. 2023. NYDensiPOPd Version 2 [Software]. Cornell University Library eCommons Repository. DOI: https://doi.org/10.7298/z3ym-1357