Kelly, J. P., N. Nur
As top wetland predators that operate over large areas of the San Francisco Estuary, herons and egrets depend on extensive tidal marshes, seasonal wetlands, and associated freshwater systems. The State of the Estuary Report uses prefledging brood size among successful heron and egret nests to assess ecological conditions across broad wetland landscapes. The section on “Feeding Chicks,” in the “Processes” chapter of the 2015 State of the Estuary Report, summarizes the Heron and Egret Broodsize Indicator, described more fully here. This indicator uses the number of young produced in successful nests to index conditions that affect the availability of food, the productivity of estuarine food webs, and the quality of wetland feeding areas.
Kelly, J. P., and N. Nur. 2015. Processes–heron and egret brood size indicator. Technical summary and appendix, in State of the San Francisco Estuary 2015: Status and Trends Update on 33 Indicators of Ecosystem Health, San Francisco Estuary Partnership. [www.sfestuary.org/about-the-estuary/soter/]