Next, Jeremy shared his really exciting news. In mid-February 2008, he was on Nonsuch carrying out some repairs to the solar-powered sound system that has been installed at the new nest site. It plays back courtship calls to encourage any cahow within hearing distance to investigate. Jeremy decided to stay overnight on the island to see how it was working.
“About forty-five minutes after nightfall,” Jeremy told me, “the first cahow swept in from the open ocean and started circling above the translocation site; more came in and began to carry out acrobatic high-speed courtship flights until within another hour I could see a maximum of six to eight birds at once. Sometimes they circled high above; sometimes [they] made low, acrobatic high-speed courtship flights just above the artificial nest burrows, often making their eerie moaning calls.”
Eventually, some of the birds began to land among the burrows, “culminating with one bird landing right beside me! I was able to just reach right over and gently pick it up without any fuss.” Jeremy confirmed from its band number that it was indeed a bird that had been moved to Nonsuch as a chick in 2005. “My heart just leaped when I realized that this bird had not just survived the last three years at sea after being partly raised by us, but had in fact returned to its point of departure as hoped!”
More cahows were recaptured at the site over the next month or so, and all were the birds that had been translocated. In mid-March, one of them was found for the first time staying for a whole day in one of the Nonsuch burrows, excavating a large pile of soil outside the nest entrance, digging a nest scrape in the nest chamber, and pulling in nest material. “A sure sign that this bird has now ‘claimed’ this burrow,” said Jeremy. I could hear his excitement as he told me that he had checked its band and found that this was the exact same burrow to which it had been moved in 2005! “And,” he said, “I had watched it fledge to sea during a night watch in June 2005. How amazing to think it has carried out a perfect ‘return to the point of departure’ after living God knows where out on the ocean!”
In all, four cahows translocated to Nonsuch in 2005 were captured near the nest burrows. Between six and eight were observed some nights flying over the site; at least six nest burrows received prospecting visits, some more than half a dozen times. And cahows have stayed over for the day in three of these burrows on several occasions. Jeremy thinks those birds were probably males, which seem to return a year or two earlier than the females, and he hopes that next season they will return and start attracting females to their burrows. “And by then, the first of the 2006 translocated cohort should also be joining them. I can hardly wait!”
When the cahow that fledged on Nonsuch return to breed there themselves, it will be a major milestone in the restoration of this resilient seafaring bird and a tribute to the determination of Jeremy Madeiros, Nicholas Carlile, and, above all, David Wingate, who fell in love with the cahow as a schoolboy fifty-nine years ago.
NONSUCH ISLAND
Situated off the coast of Bermuda, Nonsuch Island has a strange and altogether fascinating history. In 1860, the British colonial government wanted to establish a yellow fever quarantine station. So it bought the tiny Nonsuch Island (less than fifteen acres and sixty feet at its highest) from a private owner who had been using it for grazing cattle.
The quarantine station and hospital that were built served their purpose for fifty years before it was decided, for logistical reasons, to move the operation to Coney Island. Soon after this, in 1928, the island was loaned to the New York Zoological Society for use as a marine research station. Then, in 1934, Nonsuch became, of all things, the site of a training school for delinquent boys. But in 1948, because the island was so very isolated, and because of its rocky shoreline that made access really difficult, the school was moved elsewhere.
For the next three years, the little island was left to itself. By this time it had become a rather sad and barren place, for an epidemic of a juniper scale insect had destroyed almost 95 percent of the forest that previously covered the Bermuda islands—and Nonsuch was virtually denuded. Then, in 1951, something happened that would utterly change the future of Nonsuch. A small colony of cahow was rediscovered breeding on a couple of offshore rocky islets. And it became apparent that the birds would soon be truly extinct if they did not have a more appropriate habitat for breeding. Nonsuch Island was, it was thought, ideal—for cahow had bred there before. But first its damaged environment would have to be restored
In 1962 David Wingate, who years before as a sixteen-year-old schoolboy had been with the group that made the cahow discovery, moved onto Nonsuch Island as a warden. This was the start of the extraordinary restoration project, which was the focus of David’s career for the next forty years.
More than eight thousand seedlings of native tree species, some of them endemic to Bermuda, were planted, along with two fast growing non-native species—the Australian casuarina and European tamarisk. These were used as a stopgap measure to replace the windbreak lost after the endemic cedars had been killed during the juniper scale insect epidemic. Over the next twenty years, the upland forest became well established, and when Hurricane Emily hit the island in 1987 it caused little damage to the endemic and native trees. As the forest thrived, the non-native trees were gradually ring-barked—a thin strip of bark was removed around the base of each tree so that it died slowly, causing minimal disruption.
Meanwhile another major project began in the mid-1970s, when two small artificial ponds were constructed to re-create saltwater and freshwater marsh habitats. Nicholas Carlile, who has several times visited Nonsuch, told me that it was truly amazing—on one tiny island of just fifteen acres “they have re-created several complete ecosystems,” including the rocky coast, coastal hillside, marshes, upland forest, and beach dunes.
Many of the plants now flourishing on Nonsuch are endangered on Bermuda’s main islands, where approximately 95 percent of the total biomass is exotic. The Nonsuch project was one of the very first to involve restoration of an island on which virtually all of the flora and fauna had been totally eliminated by human degradation or invasive pests. The extraordinary success resulted from taking a holistic approach: eliminating the pests and restoring the entire terrestrial ecosystem as close as possible to its original state. It was the success on Nonsuch Island that led to other restoration projects on other islands as far away as New Zealand.
Once the habitat had been restored, it was possible to use Nonsuch as a reintroduction point for a variety of species including a night-heron, the West Indian top shell, and green turtles, all of which have been locally extinct in Bermuda for a hundred or more years. Out of one man’s dreams and determination sprang the “living museum” concept that has inspired the transformation of Nonsuch Island. It now presents an almost true replica of the prehistoric native environment of Bermuda and its islands before humans destroyed so much. From the outset, it was David’s ultimate goal “to create on Nonsuch an optimal habitat for Bermuda’s banner species and national bird—the burrow-nesting cahow.” As we have seen, that ultimate goal was reached.
The name of Carl Jones is synonymous with restoration of endangered species on Mauritius. Shown here with the dazzling, emerald-green echo parakeet, the last of perhaps as many as seven parakeet species once found on the islands of the western Indian Ocean. (Gregory Guida)
The Birds of Mauritius
Mauritius Kestrel (Falco punctatus)
Pink Pigeon (Columba
[formerly Nesoenas] mayeri)
Echo Parakeet (Psittacula eques echo)
When I think of these birds, I think of Carl Jones. If he had not gone to Mauritius (an island nation off the coast of Africa), it is more than possible that all three species would be extinct, for he has led the fight to save them—even when, at times, it must have seemed a daunting, if not impossible, task.
It took me some time to track Carl down at his home in Wales, where he spends time when he is neither in the field nor at the offices of the Durrell Wildlife
Conservation Trust in Jersey. We had a long conversation by telephone, and although I would have preferred to meet him in person, Carl’s warmth and his love for his work are so genuine, his enthusiasm so infectious, that I feel I have known him for a long time. I learned that he is very interested in bird psychology and that he lives on a small holding with his family that includes some parrots, an eagle—and a tame condor that is imprinted on humans and treats Carl as his partner! Carl told me that he shares my belief that not only is it okay for a scientist to feel empathy with the animals he studies, it’s in fact necessary for real understanding.
The three stories I want to share together represent a heroic struggle, ultimately successful, to save three very different species from extinction—a falcon, a pigeon, and a parakeet. By the late 1970s when Carl stepped in, all three of these species had been critically endangered for many years and were on the very brink of extinction: There were only four Mauritius falcons in the world, only ten or eleven pink pigeons, and around twelve echo parakeets.
The Mauritius Kestrel (Falco punctatus)
Carl’s fondest memories are of the many seasons that he worked with Mauritius kestrels in their last home, the Black River Gorges. At that time, he told me, much of his life revolved around this small, charismatic falcon. It is just under a foot in length, with the male weighing only about 4.7 ounces—smaller than the 6.3-ounce female. They have pure white underparts with round or heart-shaped spots. “For me,” Carl said, “they were the most beautiful of birds, and I used to get very excited when I just got a glimpse of one. They have distinctive rounded wings and are very maneuverable. They weave in and out of the forest canopy chasing and feeding on the bright red and green day geckos that are their main prey.
“They used to ride the updrafts from the sides of the cliffs, rising hundreds of feet, and then just close their wings to plummet earthward, hurtling vertically downward at great speed,” he continued. “Sometimes they would pull out of their stoop and just land gently on a tree or on the cliff; more usually they used the momentum to shoot upward again.”
As the breeding season approached, they became more and more aerial, Carl told me. “They would chase each other around and fly in the most beautiful ‘sky dances,’ rising and falling in gentle undulations or in jagged zigzags. Often they would just rise in the sky on a thermal, flying around together and calling until sometimes this courtship display culminated in mating in their nest cavity.” Although Carl was talking of his experiences of some thirty years ago, he told me, “I cannot think about these early observations of the kestrels without a flush of excitement and a quickening of the pulse.”
Teetering on the Brink
The Mauritius kestrel had been pushed to the verge of extinction as a result of severe deforestation during the eighteenth century—accelerated by the devastating effects of cyclones, predation from invasive species (especially crab-eating macaques, mongooses, cats, and rats), and the 1950s and 1960s use of pesticides, especially DDT, for malaria control and food crop protection.
In 1973, the Mauritius government had agreed to the capture of one of the last pairs of these falcons for an attempt at captive breeding—which failed. One chick was born but it died when the incubator broke down, and subsequently the female died as well. By the following year, there were only four Mauritius kestrels remaining in the wild, and it was considered the rarest bird in the world.
It was in 1979 that Carl started his work on Mauritius, under the auspices of the Durrell Wildlife Conservation Trust. He became the sixth biologist in as many years to work with the kestrels. Although he was only twenty-four years old, he had spent many years keeping and rehabilitating injured birds. Fresh from college with a degree in biology and knowledge of recent advances in breeding falcons in captivity, he had, he told me, “the enthusiasm and arrogance of youth.” He had seen breeding success with injured common kestrels in his parents’ garden and was sure that he could save this the rarest of all birds where others had failed.
The Hazards of Egg Snatching
Carl knew that common kestrels, like so many birds, will lay again if their first clutch is removed, and he determined to try the technique on the wild Mauritius kestrels. He had to climb steep cliffs to reach the “nests”—shallow depressions, or scrapes, in the substrate—of each of the two breeding pairs to take their eggs.
“The first nest was on a relatively small cliff, and I could get to it by using an extension ladder,” he said. “I found that the kestrel had laid its eggs at the back of a small cave about two meters deep. I crawled in and took the three eggs and placed them carefully in a widemouthed insulated flask that had been preheated to the correct incubation temperature.” From there they went to an incubator at the government’s captive breeding center, about five miles away.
The second nest was on a high cliff, and Carl had to be lowered down to it on a rope. “The eggs were deep in a narrow cavity that opened up into a nest chamber about four feet into the rock, and the only way I could reach them was by attaching a spoon to a long stick. The eggs had been laid in the remains of a dead tropicbird and were in a bed of soft white feathers.” Those eggs soon joined the others in the breeding center.
Because the species was so close to extinction, this was a tense time, and Carl camped on the incubator room floor to be close by in case anything went wrong. Four of the eggs hatched, and he hand-reared the chicks “on minced mouse and minced quail.” All four fledged, and since the double-clutching technique had worked so well, it was repeated in subsequent years. Thus a captive population was built up, and these birds subsequently bred successfully. Gradually the total number increased.
In 1984, Carl took a chick from the captive breeding center and put it in the nest of one of the wild kestrels, Suzie. She reared it successfully, and it became the first captive-born individual to return to freedom. Subsequently captive-bred and raised birds were released into areas where there was suitable habitat but no kestrels.
In 1985, Carl was able to announce the fiftieth successful hatching at the breeding center from captive-laid and wild-harvested eggs. And by 1991, as a result of double-clutching in the wild and captive populations, artificial insemination, and successful raising of incubator-hatched chicks, two hundred Mauritius kestrels had been successfully bred. By the end of the 1993–1994 breeding season, 333 birds had been released to the wild.
Meanwhile Carl and the DWCT, working with the Mauritius government, were continuing their work with the wild population. Supplementary food was provided, and the birds were offered—and used—nest boxes. Strict predator control served to reduce numbers of introduced predators, and work on habitat restoration was begun. This meant that captive-bred and reared birds released into the wild had a good chance of survival. Indeed, in the early 1990s the kestrel population was judged to be self-sustaining, and, said Carl, “the captive breeding program was closed down, the job was complete, and the kestrel was saved.” Indeed, recent studies have shown that there are probably more than a hundred breeding pairs and a total of about five to six hundred birds. Kestrel lovers—raise your glasses to the success of this effort!
The Pink Pigeon (Columba [formerly Nesoenas] mayeri)
Most people think of pigeons as pests. We all know the overfed birds that strut unconcerned along the pavements of busy cities, congregate around people eating in the park, and deface the walls of buildings on which they roost. Forget all that. The pink pigeon is a beautiful, medium-size pigeon with a delicate pink breast, pale head, and foxy red tail.
“This stunning bird,” said Carl, “had been rare for probably two centuries or more and for a while was thought extinct.” Then in the 1970s, a tiny population of about twenty-five to thirty birds was found surviving in a small grove of trees high on a mountainside that had one of the highest rates of rainfall in Mauritius—about fifteen feet per year. They lived there, Carl told me, not because they liked it but because the number of predators was low in this wet and often cold habitat. But even
there their numbers were declining due to habitat destruction and degradation, and because of introduced monkeys and rats that raided the nests and ate the eggs and young. Feral cats killed adult birds as well.
By 1990, there were only ten or eleven known individual pink pigeons left in the wild, and it appeared that the tiny population was in terminal decline. Fortunately in the mid-1970s, a team from the Durrell Wildlife Conservation Trust had captured a group of pigeons for a captive breeding program run by Carl. He had studied this group for his PhD degree.
“They were a real challenge to breed,” he told me. “They were very fussy about their mates, and to find compatible pairs was a real headache.” With small populations, of course, it is important to manage the genetic diversity and to prevent the mating of closely related individuals. But, said Carl, “It was common for the birds to reject the partners that you felt were most appropriate and then try and pair up with their first cousin or even a sibling! Sometimes I felt like a pink pigeon marriage guidance counselor … a compatible breeding pair might breed and then one day there would be a huge bust-up and one would be beating up the other and they would have to be separated.”
Despite the problems, the pigeons started breeding. But then they proved to be such poor parents that the eggs and young had to be reared under domestic doves. In time, however, by allowing them to practice rearing young doves, Carl was able to improve their parental skills. And so, finally, with the pink pigeons breeding and raising their young at Black River, Carl and his team developed a program for releasing them back into their native forest.
Hope for Animals and Their World Page 27