The Bermuda Petrel or Cahow, Pterodroma cahow, helped save Bermuda’s first settlers from starvation but was almost wiped out in the process. Presumed extinct for three centuries, it was rediscovered in 1951. Intensive conservation measures by the Bermuda Government have enabled it to recover from 18 breeding pairs to a record of 156 pairs for the 2021/2022 season. (For general information about Cahows click here.)
Bermuda Audubon Society has supported the Government’s Cahow Recovery Programme in many ways over the years. The society provided artificial nest boxes, specifically designed for petrels by former Government Conservation Officer Dr. David Wingate, who worked with the cahows for over 50 years. Manufactured in kit form out of durable plastic, the nest boxes are easy to install and have a removable lid so chicks can be monitored. The nest boxes could be used by any mid-sized burrowing seabird and are available for sale to seabird recovery projects worldwide (email info@audubon.bm).
If you’d like to donate to the Cahow Recovery Programme, click here.
Video: Live stream of nesting burrows on Nonsuch Island via Nonsuch Expeditions
Video: Live stream of nesting burrows on Nonsuch Island via the Cornell Lab of Ornithology
Cahows are soil-burrowing birds and in pre-colonial times they would have dug their own burrows, but those that survived settlement were displaced by predators to just a few small, rocky, soilless islands where they had to find natural crevices to nest in. As numbers increased under the conservation programme, artificial burrows were built out of cement, which was heavy, laborious work. Dr. Wingate saw the need for a mass-produceable box which was durable, light and met all the requirements of the cahow – a long, curved tunnel and a nest chamber in total darkness. Bermuda Audubon Society funded the development of molds for the nest boxes and has supplied 50 to the Cahow Recovery Programme to date. The programme uses both these and the concrete burrows for Cahow nesting.
Cahows still have the instinct to dig their own burrows and probably will start to do that now that they are nesting on Nonsuch Island, where there are appropriate conditions. However, this could delay the start of breeding by new-formed pairs by several years. The provision of ready-made burrows not only results in much higher nesting densities within a restricted area but can also speed up population recovery in a restoration project.
