From Audubon’s Florida Coastal Islands Sanctuaries to Bermuda: A Yellow-crowned Night Heron Success Story

Bermuda, a British Overseas Territory located in the Atlantic Ocean about 1,000 miles northeast of Florida, is well known for its clear blue waters and pink sandy beaches. At least 25 bird species breed across the beautiful landscapes of Bermuda, including one that has a special story and connection to Audubon’s Florida Coastal Islands Sanctuaries (FCIS): the Yellow-crowned Night Heron (Nyctanassa violacea).

David B. Wingate, PhD, born in Bermuda in 1935, was Bermuda’s first-ever conservation officer, a position he held from 1966 until his retirement in 2000. He is well known, in Bermuda and around the globe, for his extensive work and unwavering dedication to the natural world. Among many other accomplishments, Dr. Wingate rediscovered the Bermuda Petrel (Pterodroma cahow), locally known as the Cahow, at just 15 years old, and dedicated his entire career to restoring this species that was believed to be extinct for 300 years. Another of his lifelong projects is the Nonsuch Island Living Museum, an effort to restore Nonsuch Island—one of the islands that make up Bermuda—to its pre-colonial state with native flora and fauna. FCIS played a crucial role in Dr. Wingate's reintroduction of the Yellow-crowned Night Heron to Bermuda in the 1970s through a collaborative project at Nonsuch Island.

Throughout the mid-20th century, the native land crab (Gecarcinus lateralis) was considered a pest in Bermuda, causing erosion and severe damage to lawns, crop lands, and golf courses; they were so abundant that they would crawl up the walls of people’s homes! Their populations exploded due to English settlers who likely caused the extinction of their natural predator, a bird similar to the Yellow-crowned Night Heron but with a “stockier build, shorter tarsus, and broader, heavier bill.” That bird was later described by Dr. Wingate and Storrs L. Olson, PhD, in 2006 as the extinct Bermuda Night Heron.

Until the 1970s, the Bermudan government used poison baits to cull the nuisance crab populations. Dr. Wingate saw an opportunity to reestablish a native nesting species, reduce the use of poison, and provide biological control of the crabs, aiding both the environment and the people who call Bermuda home.

The following info is based on physical typewritten documents sent between Dr. Wingate, Frank Dustan, Sanctuary Manager in 1976 for Tampa Bay Wildlife Sanctuaries (now FCIS), and James “Jim” Rogers, Sanctuary Manager in 1977 and 1978, as well as Dr. Wingate’s 1982 publication “Successful Reintroduction of the Yellow-crowned Night Heron as a Nesting Resident on Bermuda.”

In late 1975, now 50 years ago, with support from the U.S. Fish and Wildlife Service, Audubon and Dr. Wingate began planning the collection of 10 Yellow-crowned Night Heron chicks from the Alafia Banks Sanctuary in Tampa Bay. Co-managed by Audubon, Port Tampa Bay, and The Mosaic Company, the Alafia Banks Critical Wildlife Area is home to thousands of nesting birds across 18 species, including the Brown Pelican, Roseate Spoonbill, and Yellow-crowned Night Heron.

The FCIS herons traveled by airplane to Bermuda in a specially made wooden crate intended for their safe travel.

Upon arrival at Bermuda L.F. Wade International Airport, Dr. Wingate went to collect his luggage. But, where were the herons? He frantically searched for answers, only to eventually discover the issue:  10 minutes prior to the plane departing again, “in getting from aircraft to terminal, the crate was delayed by so many curious onlookers among the staff that time was completely forgotten.” Following the debacle at baggage claim, Dr. Wingate retrieved his wayward crate and immediately made his way to Nonsuch Island to band and release the young birds into the remnants of an old building with a large central tree. Dr. Wingate acted as a foster parent to the young herons, with great success.

By the end of the first year of the project, Dr. Wingate reported that nearly the entire diet of the herons was land crab, exactly what he hoped for. He also reported that four birds had presumably left for mainland Bermuda, a promising sign. Only a couple of hurdles were remaining in the project to call it a full-fledged success: winter survival of the transplants without leaving Bermuda with migratory Yellow-crowned Night Herons, and eventually establishing a breeding colony on Nonsuch or in other large mangrove swamps nearby. With the early success of the project, Dr. Wingate was already confident that these hurdles would be cleared in the future.

In 1977 and 1978,  Jim Rogers took over for Frank Dustan as sanctuary manager, and Audubon continued working with Dr. Wingate on this project, collecting and sending over 17 Yellow-crowned Night Herons in 1977 and 19 in 1978. All of the herons from 1977 fledged successfully, and some of the herons from 1976 had molted into adult plumage. In 1978, the impact of herons on land crab populations became clear. In order to collect enough crabs to feed the young herons, Dr. Wingate and his late wife Helge would sometimes have to hunt crabs from 10 p.m. to midnight, and again from 4 a.m. to dawn!

In July of 1978, reported in Dr. Wingate’s 1982 publication in Colonial Waterbirds, two birds from the 1976 shipment in adult breeding plumage were observed making flights between Nonsuch Island and Walsingham Bay, an area of Bermuda with no land crabs. Dr. Wingate suspected nesting may be underway already, but he refrained from searching for nests to avoid disturbance during the crucial final stage of the reintroduction project. In 1979, he observed a heron from the 1977 group flying out of Nonsuch with a stick in its beak and another adult heron alongside it. It wasn’t until 1980 that Dr. Wingate officially confirmed nesting in Walsingham, following a thorough nest-searching effort. By the summer of 1982, 14 active nests were found, all in Walsingham. At least seven of the adults associated with these nests were from the batches of the Alafia Banks transplants. With successful nesting and an already significant impact on the land crab population, Dr. Wingate dubbed the project a resounding success, and to this day, thanks to the collaboration and creativity of bold and dedicated conservationists one thousand miles apart, Yellow-crowned Night Herons continue to thrive in Bermuda.

Sources and additional information:

• https://audubon.bm/birding/bermudas-birds/
• https://www.jstor.org/stable/1521041
• https://www.thebermudian.com/home-a-garden/nature/the-crab-concern/
• https://repository.si.edu/server/api/core/bitstreams/25abf585-0da4-43e6-b308-77f8ddba6772/content
• Physical documents of correspondence between Audubon and Dr. Wingate