AUTHORS: Presenter: Ryan McGinty (SUNY Brockport, Brockport, NY)
Co-Authors: Kristen Malone (SUNY Brockport, Brockport, NY), Lisa Webb (USGS, Columbia, MO), Arianne Messerman (Missouri Department of Conservation, Columbia, MO), Janet Haslerig (Missouri Department of Conservation, Jefferson City, MO), and Doreen Mengel (University of Missouri, Columbia, MO)
ABSTRACT: Several species of secretive Marsh are facing population declines in the U.S., including the King Rail which is listed as endangered in several U.S. states. Wetland management practices commonly used on public properties in Missouri and elsewhere have been developed to produce vegetation and water conditions that benefit waterfowl. However, the effects of waterfowl-focused wetland management on secretive marsh birds are not well known. The purpose of this project is to determine the current distribution of King Rail in Missouri and to evaluate the effects of habitat characteristics and wetland management practices on breeding secretive marsh birds. In 2023, we conducted call-playback surveys at 84 survey points across 14 publicly managed properties in Missouri. We detected King Rail at 4 survey points across 3 wetland pools. Two of these wetland pools were permanently inundated with water and the other as drawn down in the month of May. Due to few detections of King Rail, we used Least Bittern as a surrogate in occupancy analyses. We detected Least Bittern at 18 survey points. Their site occupancy was positively associated with percent cover of both tall emergent vegetation (β = 4.616, 85% CI = 1.901 – 7.931), percent cover of water (3.696, 1.596 – 6.496), and water depth (2.329, 0.449 – 4.720). Points with greater interspersion were more likely to be occupied by Least Bittern (4.496, 0.852 – 10.088). Wetland pools that were drawn down annually were less likely to be occupied by Least Bittern than sites that were permanently inundated with water (-7.117, -13.886 – -1.551). Least Bittern occupancy was also positively associated with a later initiation of spring drawdowns (6.555, 2.457 – 12.645). Our results represent an important first step for moving forward King Rail conservation in Missouri and for testing the assumption that waterfowl habitat management produces habitat for secretive marsh birds.
