Unlikely bedfellows: The cahow and the skink
It's an unlikely friendship — but peer into a cahow burrow, and while Daisy — the chick who was born there — looks up at you with her big black eyes, Findlay the friendly skink slowly emerges, blinking, from his playmate's fluffy baby feathers.
It's a friendship that goes back many millennia but hasn't been seen on Nonsuch Island for 400 years — shortly after Bermuda was settled, the last cahow left the shores of that island never to return, and the species retreated to the remoter, more secure islets in the outer reaches of Castle Harbour. The skinks, however, did remain and it has become a sanctuary for the endangered reptile, along with the other islands and remote parts of the mainland where it is still found. Now, the old friends have reunited on the shores of Nonsuch Island, where today new cahow burrows lie, populated with cahows and their chicks.
Jeremy Madeiros, Government's Conservation Officer together with JP Rouja of Look Bermuda, is going to talk about the skink, as well as the longtail, the cahow and other inhabitants of Nonsuch Island during a lecture at the Bermuda Underwater Exploration Institute tomorrow evening that will bring the audience up-to-date on many aspects of the work being done on the protected island.
Mr Madeiros will describe how returning Nonsuch to its endemic roots has allowed researchers to observe how pre-discovery species interact. “We're now starting to see how the ecology actually worked,” he said. “Each species is a piece of the puzzle.”
Mr Madeiros said during his talk he will emphasise the importance of this reptile, pointing out: “It is our only endemic four-legged land animal.”
The Conservation Officer explained that little is known about skinks yet. “We do know there are these interesting symmetries between the skink and the cahow — and we see skinks in the longtail nests as well.”
He explained the skinks eat spilled food, excrement and bugs. “If an egg goes bad or a chick dies, the skink will scavenge it, so the burrow is disease-free for next season. And the birds don't mind their presence.”
An adult pair of birds may also share their nest with a skink. “I've often seen two cahows in a burrow and a skink lying off beside them.”
Mr Madeiros said this isn't a unique interspecies friendship. “In New Zealand, the Tuatara lizard, which are living fossils that have existed since the age of the dinausaurs, live in shearwater nests.” The shearwater is a petrel and is closely related to the cahow.
And other creatures also inhabit the nests of petrels. Mr Madeiros recalled working in Australia with the Gould's petrel, another relation of the cahow. “One of the things we had to look out for was the golden crowned snake. It is a highly venomous snake, and it lives in the burrows of these birds as well. But they never bother the birds at all — it's a beneficial relationship because it controls bugs, parasites et cetera.”
In Bermuda, he explained he has “real concerns” that Bermuda might lose skinks from the main islands, but said offshore, selected islands offer hope. “The real value of making offshore island reserves is that the threat of animals and predators is absent. For example, one cat can wipe out a colony of skinks. Cats, terriers, kiskadees are all predators — and Argentine ants can destroy a clutch of eggs, for example. Construction developments can destroy the dry stone walls in which they live. Their environment is under real stress.”
Efforts are being made to protect and encourage the lizardlike species. Nonsuch, for example, is a protected area and is free of the skink's predators, such as cats and terrier breeds. And now a dozen of the endemic creatures have been sent to Chester Zoo in the UK, where specialists are hoping to breed them so the population can grow. “It's a captive breeding programme for endangered lizards from around the world,” he said.
“We'd like to replicate those techniques here, and restore the skink in places where they have been threatened or wiped out.”
Nonsuch Island itself has “come full circle”, he said. “And on Thursday, we're going to be reporting on the whole Nonsuch project, including the progress made by the cahow.”
Having embarked on the cahow relocation project decades earlier than originally planned, “this bird has continued to surprise us”, said Mr Madeiros. “It's going from strength to strength.
He explained: “Since 1989, we've had 10 major hurricane impacts with huge seas. We may have light winds, but 20ft to 25ft seas. During the 30 previous years we had just one or two impacts. Bermuda is being hit every one or two years on average.”
It was this change in climatic conditions which inspired Mr Madeiros and his team to embark on moving cahow chicks to Nonsuch Island in the hope that they would make the larger, safer island its home.
Years of careful management have resulted in the birds coming back, using techniques developed in breeding areas from Maine to New Zealand, and the environmental managers are now also able to keep track of the birds' movements using new technology that improves year by year.
Having successfully translocated more than 100 chicks to Nonsuch, Mr Madeiros is translocating more chicks to a second site on the island, and at an accelerated pace. “Never put all your eggs in one basket,” he quipped. “If there was a disaster, a lightning strike or something like that, we have this second site.”
Mr Madeiros will also describe the longtail population. Remarkably, about one fifth of the North Atlantic's longtails nest in Castle Harbour. “This is a very important area for the species. And now research is being done to determine if our longtail, or tropic bird, is a unique species. Are they?” he asked. “They have been isolated genetically, and these are the most northerly breeding of the species in the world.”
He said: “The tropic bird is such an iconic bird for Bermuda, and with 3,000 pairs in total here, this is the biggest nesting population in the North Atlantic — there are only 2,000 pairs from the Bahamas to Trinidad.”
Tickets for Mr Madeiros' talk — along with Mr Rouja who will talk about the cahow cam project monitoring the bird in its burrow — are $15. Call 294-0204 or visit Oceans Gift Shop at BUEI. Doors open at 6:30pm; the lecture starts at 7pm.