North-west Cays

Year of compilation: 2007

Site description
Cockroach and Sula are located approximately 5 miles off the northwest coast of St.Thomas. Dutchcap Cay is closer to the main island, about 2 miles off Botany Point, the westernmost end of St. Thomas. The total area is approximately 21.3 hectares. There are steep cliffs on all sides of the islands except the northeast corner of Cockroach where a flat shield slopes into the sea. On the east end of Cockroach, the tip of the island tilts into the sea leaving smaller Sula Cay separated by a large crevice. Dutchcap is dome-shaped with steep cliffs on the north and east faces. There are no sandy beaches or coastal plain on any of the cays. No stream or permanent water is found on the islands, nevertheless, water collects in small rock crevices on Dutchcap where doves and goats (recently eradicated) come to drink. Offshore of the cays are modest sized coral reefs.

Key biodiversity
Audubon’s Shearwater, Red-billed Tropicbird, Masked Booby, Brown Booby, Red-footed Booby, Brown Pelican, Bridled Tern, Brown Noddy, Zenaida Dove. Cockroach and Sula Cays are the only breeding colony for Masked Boobies in the VI. Cockroach harbors the largest Red-billed Tropicbird nesting colony in the Virgin Islands. Dutchcap Cay is the only nesting site for Red-footed Boobies in the USVI. The endangered Brown Pelican nests at Dutchcap.

Non-bird biodiversity: The Puerto Rican Racer snake, crested anole, Slipperyback skink, dwarf gecko, and land crabs are also present. Green and Hawksbill Sea Turtles are common in the surrounding waters. There are small coral reef areas in adjacent waters that warrant protection from boat anchoring and terrestrial runoff.

Pressure/threats to key biodiversity
The DFW has maintained sanctuary signs on the important seabird cays to limit foot traffic into the seabird colonies and to inform the public of the conservation restrictions, but their effectiveness is questionable. Enforcement of environmental laws has been lax and remains a major impediment to effective management and conservation of wildlife resources. Routine patrols at the important breeding sites when colonies are most vulnerable are needed. The effect of predation by other birds such as the Laughing Gull and Peregrine Falcon may pose a serious threat to reproductive success and should be evaluated. Fire ants are found on all of the offshore cays and can enter pipped eggs or kill newly hatched chicks. The threat of introduced plants and animals to the cays is ever present. The entanglement of seabirds in fishing line, especially on the breeding grounds, is another threat that often goes undetected because the breeding areas are not visited on a regular basis. Periodic hurricanes and tropical storms pose a threat to the cays by damaging or destroy trees, including nest sites for seabirds, and by increasing erosion. Catastrophic storms alter nesting habitat in the colonies by uprooting trees and ground cover, destroying nests, and killing adult and immature birds.

Conservation responses/actions for key biodiversity
Monitoring of the nesting seabirds has been conducted by the Fish and Wildlife Division of the V.I. Dept. of Planning and Natural Resources for many years. Vegetation encroachment into Masked and Brown Booby nesting habitat still occurs on Cockroach Cay. Hand-clearing of sedge has taken place periodically but is labor intensive. Predator control of island rats has taken place on Dutchcap and post-control monitoring occurs annually. Goats were eradicated on Dutchcap Cay in 2003.

Protected areas
The site is publicly owned by the Territorial government and subject to management and protection by the USVI Dept. of Planning and Natural Resources (DPNR) Division of Fish and Wildlife. Current use is very limited to diving/snorkeling the coral areas. Fishermen put goats on Dutchcap where they are periodically harvested. Access to the islands is difficult and there are no protected anchorages.

Habitat and land use
Cockroach and Sula are dominated by sedges (Cyperus) and shrubs (Clerodendron aculeatum). Some seagrapes and ficus occur along the cliffs. Dutchcap Cay contains dry evergreen woodland, a remnant of the original deciduous woodland, and many native and pantropical weed species. Goats on the cay have produced a selective pressure on plant species survival since most of the vegetation is weedy, spiny shrubs, and cacti.

Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: North-west Cays. Downloaded from on 11/08/2022.