Dietary niche relationships of white ibis, tricolored heron and snowy egret nestlings in the northern Everglades

Food availability is the primary factor affecting the reproductive success in many species of birds. Diet composition can indicate diet quality, habitat use and niche requirements for breeding birds and may be variable across short and long-term time scales. Identifying primary prey types of nesting wading birds is important for the hydrologic restoration of wetlands. I collected nestling boluses during the 2008 and 2009 nesting seasons from three species of wading birds that nest in the northern Everglades: White Ibis, Tricolored Herons and Snowy Egrets. White Ibis bolus composition was dominated by crayfish in both years, but exhibited some variation with landscape water depth in 2009; fish use was greatest when the wetland landscape was relatively dry. In contrast, the prey of Tricolored Herons and Snowy Egrets were primarily fish and their respective diets did not differ from one another in either fish species composition or size structure.