This IBA encompasses two islands, Cat Island and Lone Tree Island, located in southernmost Green Bay, and the adjacent Bay Beach Wildlife Sanctuary (BBWS) on the mainland. The two islands are small, mostly barren islands located 2.4 km north of the mouth of the Fox River. Cat Island was dominated by eastern cottonwoods in the 1960?s, and Lone Tree Island was formerly a manned Coast Guard Station of mostly gravel and stone, with vegetation limited to a few cottonwoods, red osier dogwood, elderberry, burdock, wild cucumber, jewelweed, nightshade, and raspberry. The BBWS is an urban wildlife refuge that is open to the public year-round, and offers hiking trails, wildlife viewing opportunities, interpretive exhibits and materials, and nature education programs. Facilities include three main buildings containing exhibits, dioramas, wildlife feeding stations, outdoor and indoor wildlife viewing areas, and a library. Habitats include diverse forest, field, and wetland habitat types. Most of the forest is lowland hardwood forest. Fields are reclaimed areas with prairie restoration efforts underway. Wetlands are cattail pockets, flooded forest, 55 acres of lagoons/ponds, and the adjacent open waters of Green Bay.
The islands provide habitat for breeding colonial waterbirds, including large numbers of American White Pelican and Double-crested Cormorant; Cat Island is the only Green Bay location for nesting Great Egret, a threatened species in Wisconsin. In the past, the state endangered Common Tern and Snowy Egret (as recently as 1998) also nested here. BBWS is well known as a significant concentration area for migrating landbirds in both fall and spring. Green Bay acts as a funnel, directing birds through the property in large numbers. Over 200 species have been recorded at BBWS, and the site is especially known for diversity and abundance of warblers. BBWS is periodically visited by Forster?s Terns feeding on fathead minnows. Snowy Egrets, Great Egrets and three species of heron all forage here. Osprey perch and fish in the lagoons and Bald Eagles use the area for roosting in winter. This site also is important for research, monitoring, and education. The islands? colonial waterbirds have been studied for over 30 years by Thomas Erdman of UW-Green Bay?s Richter Museum of Natural History. BBWS is a valuable nature-based recreational and educational resource for the City of Green Bay. A wide variety of live bird and animal programs are presented to the public and school groups in BBWS?s outdoor Raptor Theater, larger amphitheater, and at the Nature Center?s Whistling Wings gallery. Large numbers of taxidermy specimens, study skins, and parts (nests, eggs, talons, beaks, skulls, skeletons, feathers) are utilized in hands-on education programs. Over 3,000 sick, injured, and orphaned animals are brought into BBWS?s wildlife rehabilitation program each year. These include many bird species, some of which are endangered and threatened. BBWS also offers guided tours, weekly bird walks, crane count coordination, wildlife rehabilitation training, Eagle Scout bird related projects, birdseed sales (through the Friends of the Sanctuary), and a meeting place for the Bay Area Bird Club. The site is extremely popular with birders and receives many visits each year; these visits, along with survey efforts by BBWS staff during both migration and the breeding season, have contributed to decades of bird monitoring data at this site.
The islands are affected by water levels, storm activity, and presence of large numbers of breeding colonial waterbirds, but are not subject to many of the threats affecting mainland sites. Colonial waterbirds and other bird species (e.g., fish-eating raptors) have been affected by industrial contaminants in Green Bay waters. BBWS is a protected area, owned and managed by the City of Green Bay?s Parks Department. In accordance with the site?s Master Plan, 25% of the acreage is open to the public and 75% is set aside for wildlife with minimal human activity. As such, it is free of direct threats from development, agricultural conversion, motorized vehicles, etc. However, the site is affected by exotic species, overabundant wildlife, and water quality problems. Conservation and management actions are guided by the Master Plan, 5-Year Plan, and Annual Action Plan. Goose/waterfowl hazing is conducted in autumn to discourage large migratory flocks from staging and to curtail lagoon degradation, overgrazing, and erosion. White-tailed deer are harvested to reduce overgrazing and to keep numbers within carrying capacity. Introduced animals such as feral cats and dogs and domestic waterfowl are actively removed to humane shelters. A natural balance of predators has been encouraged for the most part, with some live trapping and removal/release required for certain species (e.g., raccoons). Pesticides are used sparingly for controlling invasive plants (garlic mustard, burdock, etc.), and only under proper weather conditions; alternatives are used as a first choice when practical (e.g. beetles, hand-pulling of purple loosestrife). A lagoon restoration project carried out in 2006 removed thousands of cubic yards of sediment from the BBWS lagoons, improving water clarity and quality.