The Sister Islands State Natural Area, situated off the coast of Sister Bay, Wisconsin, is an ecologically significant preserve that plays a critical role in the local avian ecosystem. Comprising two small gravel islands, this area spans approximately 6 acres and serves as a vital nesting habitat for various bird species.
Ecological Significance
Designated as a State Natural Area in 1966, the Sister Islands are renowned for their importance as a nesting site for gulls and terns. The islands host a variety of breeding birds, with herring gulls being the most common. Additionally, species such as common terns, red-winged blackbirds, pintails, and mallards have also been observed in smaller numbers. The high water levels in the early 1980s significantly reduced the islands’ size, but they remain a crucial breeding ground for these birds.
Flora and Fauna
The flora of the Sister Islands is highly variable and influenced by the nesting activities of birds and fluctuating water levels. During periods of low water, the islands are dominated by shrubs and weeds. Notable plant species include boxelder, red-osier dogwood, elderberry, bittersweet nightshade, spotted jewelweed, and stinging nettle. This diverse vegetation provides essential cover and foraging opportunities for the resident and migratory bird populations.
Accessibility and Regulations
The Sister Islands are managed by the Wisconsin Department of Natural Resources (DNR). Given their ecological sensitivity, the islands are subject to strict regulations to minimize human disturbance. Access to the islands is typically limited to observational purposes, with no amenities available for visitors. Activities such as hiking, foraging, and hunting are permitted in surrounding state natural areas, but camping is strictly prohibited to protect the habitat.
Conservation Efforts
The ongoing conservation efforts by the DNR focus on maintaining the delicate balance of the island ecosystems. These efforts include monitoring bird populations, managing invasive plant species, and ensuring that human activities do not disrupt the natural habitat. The Sister Islands stand as a testament to the importance of preserving natural areas for the benefit of wildlife and future generations.
The Sister Islands State Natural Area is a crucial ecological haven that supports a diverse range of avian species. Its preservation is essential for maintaining the biodiversity and ecological health of the region. Visitors are encouraged to appreciate the natural beauty and significance of the islands while adhering to regulations designed to protect this unique environment.
