We analyzed counts from the annual Midwinter Bald Eagle Survey to examine state, regional, and national trends in counts of wintering Bald Eagles (Haliaeetus leucocephalus) within the conterminous 48 United States from 1986 to 2010. Using hierarchical mixed model methods, we report trends in counts from 11 729 surveys along 844 routes in 44 states. Nationwide Bald Eagle counts increased 0.6% per yr over the 25-yr period, compared to an estimate of 1.9% per yr from 1986 to 2000. Trend estimates for Bald Eagles were significant (P ≤ 0.05) and positive in the northeastern and northwestern U.S. (3.9% and 1.1%, respectively), while trend estimates for Bald Eagles were negative (P ≤ 0.05) in the southwestern U.S. (−2.2%). After accounting for potential biases resulting from temporal and regional differences in surveys, we believe trends reflect post-DDT recovery and subsequent early effects of density-dependent population regulation.
Wintering Bald Eagle count trends in the conterminous United States, 1986–2010
Journal of Raptor Research
By: Wade Eakle, Laura S. Bond, Mark R. Fuller, Richard A Fischer, and Karen Steenhof
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: Publisher Index Page
- Download citation as: RIS | Dublin Core
Abstract
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Wintering Bald Eagle count trends in the conterminous United States, 1986–2010 |
| Series title | Journal of Raptor Research |
| DOI | 10.3356/JRR-14-86.1 |
| Volume | 49 |
| Issue | 3 |
| Year Published | 2015 |
| Language | English |
| Publisher | BioOne |
| Contributing office(s) | Forest and Rangeland Ecosystem Science Center |
| Description | 10 p. |
| First page | 259 |
| Last page | 268 |
| Country | United States |
| Google Analytic Metrics | Metrics page |