Spatial and temporal dynamics of foraging habitat availability for reddish egrets in the Laguna Madre, Texas

The reddish egret (Egretta rufescens) is the rarest heron in North America and much remains to be learned about in the ecology of the species. The reddish egret is a foraging habitat specialist and relies on shallow coastal ecosystems. There is a paucity of information on foraging habitat requirements and the availability of foraging habitat throughout the annual cycle. Characteristics of foraging habitat at locations within the Laguna Madre, Texas where reddish egrets were observed foraging were measured. These characteristics were used to conduct a geospatial analysis that estimated the spatial and temporal distributions of foraging habitat in the Laguna Madre across 120 weeks from 2012 to 2014. Reddish egrets (n = 372) foraged in an average water depth of 10.1 ± 0.68 cm and in areas with average seagrass cover of 12.3 ± 2.74%. Approximately, 75 000 ha of foraging habitat were delineated to be available in the Laguna Madre across the study period; of this, 4 003 ha were available ≥ 50% of the time. The amount of available foraging habitat was relatively high during the spring and summer, and decreased by ~50% during winter. This model-based approach can be used throughout the species’ range to examine foraging habitat availability which is a current conservation need according to the Reddish Egret Conservation Action Plan. Key words: Egretta rufescens, foraging habitat, Laguna Madre, reddish egret, Texas.