Wading birds are a key component of the Greater Everglades ecosystems. Some of the key species are Wood Stork, Great Egret, and White Ibis.
See the results for wading birds in the Greater Everglades.
How is it measured?
In the Greater Everglades, wading birds are a key indicator. There are four metrics that are combined into the wading birds score including, wood stork nesting initiation, proportion of nesting in the coastal zone, ibis supercolony, and proportion of tactile foragers.
Wood stork nesting initiation: wood stork month of initiation score. This is a score from 1 (March) to November (5) that rates how early wood storks nest in the Everglades. This is defined as the month of first egglaying in any colony within the Water Conservation Areas, Everglades National Park or Lake Okeechobee.
Proportion of nesting in the coastal zone: It is estimated that more than 90% of the nesting of the indicator species occurred in the southern ecotone region during the 1930s and early 1940s, in all likelihood because this was the most productive area. A major restoration hypothesis holds that it is the reduction of freshwater flows to this coastal region that has reduced secondary productivity and resulted in the abandonment of the area by nesting wading birds. The proportion of the entire mainland Everglades nesting population that nests in the coastal zone is one of the restoration indicators, with at least 50% of nesting as the restoration target.
Ibis supercolony: Exceptionally large breeding aggregations of ibises were characteristic of the predrainage system, and are thought to be indicators of the ability of the wetland system to produce very large pulses of prey resulting in part from typical cycles of drought and flood. Large breeding aggregations during the recent period are defined as being above 16,977 nests each year, defined as the 70th percentile of the entire period of record of annual nestings. The interval between large ibis nestings in the predrainage period was 1.6 years and this serves as the target for restoration.
Proportion of tactile foragers: This measure recognizes that the breeding wading bird community has shifted from being numerically dominated by tactile foragers (storks and ibises) during the predrainage period to one in which visual foragers such as great egrets are numerically dominant. This shift is thought to have occurred as a result of impounded, stabilized, or over drained marsh, which leads to the declining availability both of larger forage fishes (wood storks) and crayfishes (ibises). These conditions also seem to favor species like great egrets that are less reliant on the entrapment of prey and can forage both in groups and solitarily under a variety of circumstances. Restoration targets are set at 32 breeding tactile foragers to each breeding visual forager, characteristic of the 1930s breeding assemblages.