Krementz, D. G., K. Willard, J. M. Carroll, and K. M. Dugger. 2016. King rail nesting and brood-rearing ecology in a managed wetland in Oklahoma, USA. Waterbirds 39(3):241-249.
Abstract
The King Rail (Rallus elegans) is a secretive marsh bird of conservation concern and reproductive success is thought to be a limiting factor for the inland migratory population. Reproductive effort of King Rails was studied in southeastern Oklahoma from 2010 – 2012 using surveys, radio-telemetry, nest searching and brood observations. During 2011 -2012, we documented 29 King Rail territories. Ten nests were located between the first week in April and the first week in July with a mean clutch size of 10.3 (0.80 SE). Water depth at nests was shallow (<15 cm) and nest sites were in locations with more visual obstruction, more microtopographic variation, and more woody stems while open water cover was less than at random sites. Nine broods were followed that used rearing sites with deeper water, had a greater percent of tall emergent vegetation and more woody vegetation than random sites. Brood size dropped from an average of nine to two chicks by the second week. Daily chick survival rate across the breeding season was 0.969 (SE = 0.016) which resulted in a probability of a chick fledging of 21%. Reproductive effort by King Rails at our study site was low and of concern.