Thirty Years of Bald Eagle Population Recovery and Nesting Ecology in Kansas, 1989–2018

Abstract

Bald Eagle (Haliaeetus leucocephalus) populations have been recovering throughout North America for the past several decades, and long-term monitoring efforts have been useful for understanding the ecological and anthropogenic drivers that influence population trajectories. We analyzed data on Bald Eagles in Kansas over 30 breeding seasons (1989–2018) to describe population growth, habitat selection, temporal trends in productivity, and predictors of nesting attempts. The breeding Bald Eagle population in Kansas recovered from a single documented nesting pair in 1989 to 137 documented nesting pairs in 2018. Habitat in and around large artificial reservoirs was important for early colonizing nesting pairs. However, as the population grew, nesting territories along river shorelines made up a majority of the total. Birds nesting in territories near rivers and large artificial reservoirs, newer territories, and territories closer to electrical lines were significantly more likely to have a nesting attempt compared to those in other territories. Capture-mark-resighting efforts allowed us to track productivity, recruitment, and site fidelity for a portion of the breeding population in Kansas (272 banded individuals). Growth of the breeding Bald Eagle population in Kansas has shown little sign of slowing in the first three decades following recolonization. Continued annual increases in the number of new nesting territories indicate that the availability of suitable habitat does not appear to be limiting population growth.