Annual cycle movement patterns of Little Blue Herons Egretta caerulea wintering on the Florida Gulf Coast

Summary Effective conservation of declining migratory species requires identifying habitats used during each stage of the annual cycle and the links between them. The Little Blue Heron Egretta caerulea , a long-legged, colonial-nesting, wading bird species that primarily forages in shallow-water wetlands, is declining throughout much of its range. A lack of understanding of its annual cycle movements prevents identifying when and where populations face limiting pressures, hindering conservation efforts. This study quantifies Little Blue Heron annual cycle movements, including space use at wintering and breeding sites, colony locations, migration distances, phenology, and site fidelity of herons from two important wintering sites on Florida’s Gulf Coast that differ in availability of fresh water. Little Blue Herons tagged with GPS transmitters ( n = 30) showed a partial migration strategy; however, the ratio of migrants to residents was substantially different between the two study sites. Additionally, these birds established breeding colonies in both inland ( n = 10) and coastal ( n = 12) wetlands throughout the south-east USA and western Cuba ( n = 2) and travelled a mean of 4.46 (SE = 0.87) km from their colony to forage. About 95% of individuals established colonies within freshwater wetland habitats, regardless of their wintering site, providing support that availability of fresh water during the breeding period is a key element of the habitat for this species. The results of this study suggest that management decisions aimed at minimising the threats to high-value wintering sites will benefit this species. The coastal systems examined supported wintering individuals for at least half of the full annual cycle. During this period, individuals maintained small home ranges (mean = 153.71, SE = 17.4 ha), did not make any significant within-season movements to other locations, and displayed strong inter-year site fidelity (0.49–0.85 BAI overlap), suggesting that these are areas that provide high quality habitats, justifying continued protection.