Two distinctly different populations have come to depend on the unique characteristics of a small strip of land located on the Westside of Kaua‘i. Both the wedge-tailed shearwater (Puffinus pacificus), a migratory seabird, and the men and women who work
Two distinctly different populations have come to depend on the unique characteristics of a small strip of land located on the Westside of Kaua‘i.
Both the wedge-tailed shearwater (Puffinus pacificus), a migratory seabird, and the men and women who work at the U.S. Navy’s Pacific Missile Range Facility call the area home.
PMRF, a small but highly important U.S. Navy test and training range, is situated on a half-mile wide, seven-mile long parcel of land located on the western side of what is called the Mana plain.
Mana was once a wetland area that in the early twentieth century had been drained in order to grow sugar. The arid plain is bordered by the Pacific on its western front, the majestic cliffs of Na Pali on its northern and eastern sides and the rural town of Kekaha constitutes its southern flank.
Development at Mana has been restricted to agriculture only. As a result, instead of condos, stripmalls and fast food restaurants, the seven mile-long and half-mile wide PMRF is bordered by thousands of acres of farmland.
This lack of urban development equates to less of the radio frequency, noise, light and air traffic that can impair or interfere with data captured by the myriad radar and telemetry instruments on the range.
For the “wedgies,” as the wedge-tailed shearwaters are known, PMRF’s relative isolation represents an ideal nesting area.
Although not listed as a threatened or endangered species, wedgies are protected by the Migratory Bird Treaty Act. Their population is monitored, and the ground-dwelling wedge-tailed shearwater has not dealt well with the twin dangers of human encroachment and predation from both wild and domestic animals.
The largest of the tropical shearwaters, wedgies exhibit an average length of 17 inches and a wingspan of around 38 inches. Their bodies tend to be long and slender, featuring their namesake wedge-shaped tail and a dark gray, hooked bill. These stunning birds are polymorphic, meaning their coloration can vary from a light gray to soot brown form.
The Navy, recognizing an opportunity to foster a small wedgies population that had sprung up near the middle of the base, built a fenced-in compound to facilitate nesting there.
This one-acre site grants obstacle-free access to the birds’ prime hunting ground, the Pacific itself. A six-foot wooden fence guards the compound, meant not only to keep unwanted guests out, but also to discourage the birds from creating burrows outside of the relative safety of the protected perimeter.
While the fence does keep people out and provides some measure of protection against potential predators like feral cats and wandering dogs, PMRF also pursued an inter-service contract with the Animal and Plant Health Inspection Service of the U.S. Department of Agriculture to establish predation control for the area.
According to PMRF Environmental Coordinator John Burger, the base’s approach to the wedge-tailed shearwater is somewhat unique.
“The sanctuary is protected and enhanced, while co-existing successfully on a military facility,” said Burger.
Another aspect of the colony improved upon by the Navy concerns the wedgies’ burrows, which are subject to collapse due to unfavorable soil conditions.
According to experts, these collapses are often the result of invasive plant species that have taken over a breeding area. In most cases, the invasive plants do not provide a root structure capable of supporting the walls inside the burrows. If wedgies are in the burrow when it caves in, they can become trapped and die of starvation.
Vanessa Pepi, a graduate field biologist with Pearl Harbor’s Naval Facilities Engineering Command Pacific, and PMRF Environmental Coordinator John Burger initiated a project to install PVC pipe segments into the wedgies’ compound in order to provide some artificial burrows that would not suffer from collapse and to encourage the expanding colony population to remain within the fenced colony rather than spill outside the protected boundary.
The underlying problem of invasive plants is also being addressed. PMRF, with the support of the Kauai Invasive Species Committee and base contractor ITT, recently executed the removal of invasive wooded species that had grown thick inside the compound. Pepi has also begun the process to eventually sow native species such as beach naupaka back into the soil throughout the colony.
Burger attributes much of the success the colony has enjoyed to the efforts of Pepi and NAVFACPAC.
“I’ve got an awesome support system,” Burger explained.
Apart from establishing burrows in a safe location, another serious threat wedgies face is light pollution.
The problem of light pollution becomes especially acute during the month of November for these birds, when fledgling wedgies must fly for the first time or risk starvation. During their first few flights they are easily confused by artificial lights, which they can mistake for the moon, and as a result they are prone to colliding with utility lines or circling a light source until exhausted.
The lack of a significant human population on Mana translates to less light overall than other parts of the island. However, the base still needs various lights to function. Recognizing the hazard these might represent to the wedgies specifically and shearwaters in general, PMRF took action to ensure their light sources posed the least danger to the birds possible.
The most obvious example of the base’s efforts to avoid light pollution is found at its recreation complex, which features a softball field, two basketball courts, a tennis court and a multi-purpose recreation field. Stadium lighting illuminates the area for night-time recreation, but was identified as a possible danger and was retrofitted to include focused hoods which ensured that only the areas which needed the light received it.
“I believe our lighting system is unique, as compared to other recreational field lighting on Kauai,” said Burger.
Decades ago this issue was brought to the fore on Kaua‘i by the high fallout numbers of a close relative of the wedgies, the Newell’s shearwater. The Newell’s tend to nest deep in the interior of the island and thus have a longer distance to travel to reach their hunting grounds. During their long flight they have a greater chance of flying over heavily lighted areas and falling victim to a hazard.
In the late 1970s, the Newell’s fallout rate was so high that the State Division of Forestry and Wildlife initiated the Save Our Shearwaters program. Since 1979 the state, other biologists and a dedicated corps of volunteers helped rescue more than 31,000 grounded seabirds, including wedgies.
Recently, Kauai Island Utility Cooperative hired full-time staff, including Sharon Reilly, to work alongside the state biologists to implement an expanded version of the SOS program which now includes rehabilitation of birds that cannot be released immediately.
Reilly commits her time as the coordinator for SOS to educate island residents to the plight of the wedgies and other seabirds. During the main fallout period of mid-September through mid-December, SOS sets up aid stations around the island where people can bring in fallen birds. SOS personnel tend to these birds, providing the care they need before releasing them back into the wild.
According to Burger, the assistance of Reilly and the SOS has given PMRF an additional advantage in being better able to serve the interests of the wedgies.
The overall success of the PMRF wedgies project was recently acknowledged with the posting of a large, full-color sign which provides details of the Wedgies, complete with high-resolution photos, to visitors. The sign is another example of the collaboration between PMRF and NAVFACPAC, with Pepi and Burger working together in the design and ITT furnishing the materials.
“Thanks to people like Sharon, our friends at NAVFACPAC and the extremely capable PMRF environmental team, the Navy is able to prove that we can be the world’s best military and still be good stewards of the environment,” said PMRF Commanding Officer, Capt. Mark Darrah.
Reilly points to the colony as a project which demonstrates that responsible planning and development can prove fruitful for all involved.
“This is a great example of how birds and people can coexist.”
