I have always been fascinated by the variety and beauty of birds. While preparing for a visit to Bermuda, I came across a reference to a rare bird called a cahow. "The small surviving population of this species," said a bird guide, "is confined to the group of islands of Castle Harbor, the most remote part of Bermuda. Here they are under the watchful eye and protection of a guardian.
My interest was piqued! Determined to see this exotic bird for myself, I went to the former Bermuda Conservation Director(retired) but was also a director of Castle Harbor Island Group at the time.He kindly allowed me to accompany him on a visit to the protected nesting area of the cahow.
A "living museum"
The Castle Harbor Nature Reserve is located near the main Bermuda Islands, which are located in the Atlantic Ocean, approximately 900 km east of North Carolina, United States. Nonsuch Island is the largest of the nine small islands that make up the reserve. Nonsuch covers approximately 15 acres and is located at the eastern tip of Bermuda.The island has been transformed into a 'living museum' for the eventual restoration of Bermuda's remaining native plant and animal species.
The day is clear and beautiful as we continue aboard on small motorboat from Nonsuch to a nearby islet. An osprey glides over the calm sea, the white feathers on its bottom reflecting the vibrant turquoise water. Beautiful tropical birds, called Long-tailed Bermuda, fly enthusiastically in a procession, with huge tail feathers swaying up and down. Although this show was generally very moving for me, today I can only think of cahow.
The "off" Cahow reappears
It is reported that the first seabird settlers only come ashore at night and only during nesting, which is characteristic of the cahow. Back then, the numbers were in the tens of thousands, but things have changed. Around 1560, the Spaniards introduced pigs to Bermuda. This was disastrous for the cahow population as the pigs ate cahow eggs and possibly young and even adult cahows. Cahows were also an important part of the settlers' diet. When the mice were accidentally introduced to Bermuda in 1614, many more died. The rats swam to the small islands where the cahows nestled and ate their eggs and chicks. As a result, by 1630 the cahow had grown from a population of several thousand to being considered completely extinct.
How were cahows rediscovered?
In 1906, Louis Mowbray, a naturalist, found a living but strange seabird on an island in Castle Harbor. Eventually he was identified as a cahow. Later, in 1935, a young cahow was found who collided with a lighthouse and was dead. And in 1945, an adult cahow ended up on the beach at Cooper Island, Bermuda. This was sufficient evidence to justify an expedition in search of other specimens of this "extinct" species. The expedition was led by Dr. Robert Cushman Murphy of the American Museum of Natural History and Louis S. Mowbray, Curator of the Bermuda Government Aquarium, son of Louis Mowbray who founded the cahow in 1906
Cahows make nests in burrows 2 to 12 m long, with one elbow so light does not reach the nest.To provide more nesting sites,more of artificial burrows are built. These were made by digging trenches and covering them with concrete. The nesting chamber at the end of the nest has a removable cover. This allows to check the nests to see if an egg has been laid or hatched or its lost.When a rotten egg is thrown away,it’s taken out and examined to try to determine what went wrong.
We finally reached the small island. In the midst of the waves of the sea, we left the boat carefully on the uneven rocks. To get to the nests we have to climb steep and pointed rock formations. A nest is only accessible by stairs. It may be a routine workers here,but for me its was unique and inspiring!
The Bermuda Conservation Director reviewed each position, reading the evidence. Do couples always visit their nests? Are there footprints inside and outside the burrows? Is there a missing egg? We found a broken egg, but since the parents have not yet given up,the egg got left right there.Cahows often continue to incubate a spoiled egg, refusing to give up.The Bermuda Conservation Director(our guide)also made an unexpected discovery: a chick that hasn't even realized that he has laid an egg! This discovery overcomes the disappointment of the unhatched egg.
That all the effort is worth it is evident when He removed a cap from a burrow and looks at a small ball of gray fluff: a cahow cub. From time to time, it moves slightly, annoyed by the light. In other burrows, I looked down and see an adult hatching an egg.
So far, efforts to fully restore cahow are slowly paying off. In fact, the cahow was considered a symbol of hope for environmentalists around the world.