“With the recent confirmation that there is a chick being fed in the first known natural Cahow burrow (dug out completely by the birds themselves) on Nonsuch Island in over 300 years, the two Nonsuch colonies now host a record number of 19 chicks! While this is proof that the nearly 20-year Cahow Translocation Projects (Two separate projects to establish the two different nesting colonies) have been successful, recent visits to the four smaller original nesting islets indicate that hatch rates on three are significantly lower than last year.
3 week old CahowCam 2 chick
This is partly due to erosion and flooding of these lower-lying islets during hurricanes "Earl" and "Fiona" in September 2022, which submerged many of the nest burrows under salt water from huge waves, more than 25' high. A number of nest burrows were damaged or their heavy concrete nest lids washed away, making extensive repairs necessary, especially on the worst affected islets of Green Island and Long Rock.
When nest burrows are submerged, this often reduces the following season's hatch rates, due to the rocks making up the burrows being saturated with salt. The salt is hygroscopic, absorbing moisture from the humid air and making the burrows permanently wet. It can take a couple of years for all the salt to seep out of the rocks so the burrows can dry out, improving hatch rates again.
On Nonsuch, there are now a total of 37 active breeding pairs (29 pairs at the "A" colony and 8 pairs at the "B" colony), of which 19 have been successful and produced chicks this season. In addition, there were 4 completely new prospecting pairs of young Cahows taking possession of empty artificial nest burrows, 2 each at both nesting colonies. Preparation has already begun for the construction/installation of additional artificial nest burrows to accommodate the growing Cahow population on Nonsuch Island.
Following recent surveys of all of the nesting islands, there appear to be 71-72 chicks in total for this nesting season. This is down from 2022s record number of 78 successfully fledged Cahow chicks, due largely to the after-effects of last year's two hurricane impacts.
Although this number is a bit disappointing, overall the total number of confirmed active breeding pairs of Cahows has risen to a record number of 164, indicating that overall, the Cahow breeding population continues its slow recovery from the edge of extinction."
Jeremy Madeiros | Chief Terrestrial Conservation Officer.