2025/09/30 by J. Matthew Carroll, Garret Gallion, Rachel Carroll +3 · 2 voices
Environmental Science · #Avian ecology and behavior #Fire effects on ecosystems #Species Distribution and Climate Change
paper · doi:10.1080/15594491.2025.2556507
openalex publication_date 2025/09/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/18
While often overlooked, permanent wetlands (e.g., lakes, rivers) can provide consistent stopover habitat for interior migrating shorebirds. We studied shorebird use and forage abundance during autumn migration on mudflats associated with Kentucky Lake (Kentucky, USA), a major reservoir situated in a mid-continental agroecosystem landscape. We focused our work on seasonally exposed Kentucky Lake mudflats, which are the result of lake drawdowns (i.e. incremental reduction of water levels from July to November) conducted by the Tennessee Valley Authority for power production and water level control. Our objectives were to: (1) assess shorebird abundance and migration phenology via census counts, (2) estimate the effects of shorebird foraging activity on benthic macroinvertebrate (hereafter, invertebrate) resources using exclosures, and (3) determine factors influencing variation in invertebrate abundance along transects perpendicular to the waterline. We found that shorebirds routinely used mudflats (n = 2,121 detections) and individuals were observed within as little as 1 day after initial mudflat exposure in late summer, suggesting that earlier lake drawdown would provide additional foraging habitat, especially for early long-distance migrants. Foraging was the most commonly observed shorebird behavior ( >73% in both years), yet we found no difference in invertebrate abundance or size class inside versus outside of foraging exclosures (n = 343 core samples; P > 0.05), suggesting that shorebirds did not deplete prey resources. Invertebrate abundance declined from 342 ± 47 individuals per m2 in the first half of the season to 150 ± 7 individuals per m2 in the second half, and also declined with increasing vegetation cover upslope of the waterline (n = 249 core samples; P < 0.05). Future research should examine whether shorebirds deplete prey during periods of extreme drought when shorebirds may concentrate on mudflats due to reduced availability of other wetland habitats.