Saving the Cape Sable Seaside Sparrow

Endemic to marl prairie habitats in the southern Everglades, the Cape Sable Seaside Sparrow is sensitive to subtle shifts in water levels: Nesting success demands dry enough ground during the February–August breeding window. Over time, altered water flow from water control infrastructure and high water levels have placed severe stress on its habitat, especially in subpopulation A, which continues a downward trend even as other sparrow subpopulations (B through F) have shown relative stability or modest improvement (see map).

According to recent projections, the sparrow’s total population stands at just 2,176 individuals, with only 136 adult males identified. Such low figures underscore the fragility of this already small population and the narrow margin for error in habitat management. The strongest of these populations are sadly the most vulnerable to sea level rise in the near-term, and the bird’s long-term survival will depend upon relocation to suitable marl prairie elsewhere in the Everglades. This will require breeding in captivity to produce the individuals for relocation, a process akin to the recent successful releases of Florida Grasshopper Sparrows in the Northern Everglades. With a population this small however, there is no time to waste.

In a decisive move toward greater protection in late 2024, the South Florida Water Management District approved a five-year pilot conservation breeding program for the sparrow, backed by an initial funding commitment of $584,322. The idea is to remove a small number of birds into managed conditions to serve as an “assurance” population. This would allow for translocation to an identified suitable marl prairie habitat. In addition, Audubon worked together with the Miccosukee Tribe of Indians of Florida to acquire additional federal funding for this program via Senator Moody’s office in the Interior Report. Earlier this summer, Zoo Miami announced that it would be the lead for the program and serve as the breeding location.

That said, conservation breeding is viewed by Audubon not as a solution, itself, but as a bridge while habitat, water flow, and ecosystem restoration continue. Relocating will also reduce tension between restoring natural water flows and protecting sparrow nesting habitat. Audubon will continue to work with the Zoo and other partners as this moves forward, applying lessons learned from the successful Florida Grasshopper Sparrow Conservation Breeding program.

This article original appeared in the Fall 2025 State of the Everglades report. Read the full report here.