2017-06-08 / Nature

What Happened to Rose Island's Colonial Birds?

By Charles Avenengo

American oystercatchers are an example of colonial birds that nest and breed in close proximity as a group. (Photos by Carmen Rugel) American oystercatchers are an example of colonial birds that nest and breed in close proximity as a group. (Photos by Carmen Rugel) The great egret is the symbol of the National Audubon Society. It represents a conservation success story for the powerful environmental group, whose very existence was a result of the egret and other colonial nesting bird species. Colonial birds are a species that nests and breeds in close proximity as a group.

At the turn of the 20th century, it was fashionable to adorn ladies’ hats with bird’s feathers. During this period, it was estimated that five million birds were shot annually for the feather trade. Particularly desirable were great egret’s snowy-white breeding plumes. The persecution eventually dwindled the great egret’s population to one last stand in Florida.

Enter early activism. To protect the birds, a small cadre of socialites banded together in Boston on a campaign to stop the carnage. This movement ultimately became the Audubon Society. They began by convincing fellow socialites to abandon the practice of wearing feathered hats. As momentum grew, reserves were created and conservation laws were enacted, easing the pressure of the slaughter. Despite the success, resistance was encountered, including the murder of at least three wardens protecting birds in Florida. Nevertheless, the conservation efforts eventually prevailed. The birds rebounded and found their way back up the Eastern Seaboard.

Great egret Great egret By the early 1970s, biologists were excited to discover colonial birds nesting on Little Gould Island in the Sakonnet Passage. After a few years, however, this heronry was abandoned and nesting was relocated on Hope Island.

In 1990, I was working on Rose Island for local restoration contractor Bob Zeigler during the early phases of the island’s lighthouse restoration. Rose Island is located halfway between Newport and Jamestown, and early that spring during a lunch break I observed and reported on a small flock of glossy ibises that flew into the thick vegetation. Authorities subsequently investigated and nesting of colonial bird species was confirmed for the first time on the island.

Glossy ibis Glossy ibis This was enough for the Rhode Island Department of Environmental Management to purchase the island from private ownership, which had plans to develop a hotel and marina. Most of the island was set up as a protected area for the birds. Then and now, during breeding season between April and August, the bulk of the island is restricted to the public.

The protection worked. The number of colonial breeding birds grew rapidly. By the end of the 1990s, biologists counted nests by the hundreds. Annual surveys were conducted by DEM and, at their peak, a 1997 survey revealed nearly 120 nests of glossy ibises, over 90 nests of black-crowned night-herons, 50 nests of snowy egrets, and lesser numbers of great egrets, little blue herons, cattle egrets and American oystercatchers.

Leaving behind a thriving heronry, I moved on to other work on the Aquidneck Island “mainland.” Recently, I was shocked to learn that the colonial birds were gone. Prompted by these reports, I decided to visit Rose Island to see what was going on. An overnight stay was necessary, and permission was granted by the Rose Island Lighthouse Foundation.

When I arrived last week with my wife, I observed happily that the island was kicking on all cylinders. Well-maintained and thriving, I saw dozens of school children touring the island. The island’s greenery was lush and a number of small songbird species were busy nesting, while gulls and Canada geese were everywhere. Likewise, American oystercatchers circled the island, aggressively chasing off intruders. I observed one bold oystercatcher chasing an osprey halfway back to Jamestown.

We set up a four-hour vigil from the top of the lighthouse to observe the comings and goings of the birds. By sunset, our watch yielded a tally of only 15 individual colonial birds of four species. Specifically, we sighted eight great egrets, one snowy egret, five glossy ibis and two black-crowned night herons.

I lamented as I remembered from years earlier when I frequently counted over 500 colonial birds and another 500 gulls on the island.

The following day, while being launched back to Newport, I revealed my observations to Chris Papp, Rose Island’s property manager. He was surprised that I saw any colonial birds at all. Likewise, Dr. Gerald Krausse, professor emeritus from the University of Rhode Island, who has been keeping tabs on the birds on the island for decades, was surprised to hear my findings.

Despite my observations, Krausse wasn’t convinced that these colonial birds were nesters. He indicated that what I observed may simply be birds resting after feeding on Aquidneck and Conanicut islands.

He cited possible reasons for the disappearance of the heronry from Rose Island. This included the growing vegetation that limits potential nesting habitat. Additionally, he said predators like raptors, great black-backed gulls and even coyotes that swim to the island, along with human disturbance, all might play into the disappearance.

However, there are clearly more colonial birds present locally than the 15 I observed last week. Therefore, the question is: Where are they? As recent history shows, they move around, so for now, we have to wait for the results of this year’s DEM survey to know the answer.

Naturalist Charles Avenengo has been chasing Aquidneck Island wildlife for more than 40 years.

Colonial Birds of Rose Island
American oystercatchers
Black-crowned night herons
Blue herons
Cattle egrets
Glossy ibis
Great egret
Snowy egret

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