Monday, April 11: Factors Affecting Foraging Microhabitat Selection by Wading Birds at an Artificial Weir

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Topic: Factors Affecting Foraging Microhabitat Selection by Wading Birds at an Artificial Weir

Speaker: Rachel C. Renken

Date/Time: Monday, April 11; 7:30 pm

Location: The Donut Whole 1720 E Douglas

 

Factors Affecting Foraging Microhabitat Selection by Wading Birds at an Artificial Weir

Rachel C. Renken, Jeane A. Thompson, and Alan D. Maccarone

Biology Department, Friends University, 2100 University, Wichita, Kansas, 67213, USA

Abstract.—-To better understand how different species of long-legged wading birds select among foraging microhabitats that show spatial and temporal heterogeneity, a 100-m-long concrete weir located at the terminus of the Little Arkansas River in Wichita, Kansas, was divided into patches based on water depth. Black-crowned Night-Herons, Great Egrets, Snowy Egrets, and Great Blue Herons were observed feeding during 60 1-h periods from 12 June-29 July 2015. The independent variables collected before each session included date, time of day, water level, water clarity, and flow velocity. We recorded weir attendance, species-specific patch use, behavioral interactions, and feeding activity. Only time of day and water level predicted of the number of birds at the weir. A total of 348 fish were captured, of which 108 were large (> 3/4 bill length). Wading bird species differed in capture efficiency, lengths of captured fish, and patch use. Great Blue Herons and Black-crowned Night-Herons captured large fish toward the center of the weir. Great Egrets captured both large and small fish, and Snowy Egrets captured small fish (minnows) at the ends of the weir. Total aggression correlated with the number of large fish caught but not with total fish. Per capita aggression correlated with the number of birds at the weir.

Rachel, originally from Downs in North Central Kansas, has lived in Wichita for 5 years. She attended Friends University where she graduated with a degree in Field Biology in 2014. She has been doing bird behavioral research with Dr. Alan Maccarone for the past two summers and has plans to travel to Maine with a group to carry out a study on great blue herons in June.

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