JP and I were able to get out on the Cahow breeding grounds on the Castle Harbour Islands yesterday, (31st January 2024), as conditions were perfect with easterly winds at just 6 to 9 knots, with the forecast for the next few days being strong winds gusting to gale-force. What a difference a day makes, as 24 hours later we have recorded winds at 51 to 64 knots (49 to 75 mph) at the west end of Bermuda, and I just lost my power about 30 minutes ago!
During yesterday's check, the calm conditions finally enabled us to land on Green Island, which has been imposible to land on for the whole month due to strong winds, rough seas and adverse tides. Expecting the worse, I was happily surprised by a high percentage of nests with Cahows incubating fertile eggs. Although I only had time to check about half the nests on the island, out of 12 nests checked, 8 of them contained fertile eggs that were being incubated by adult birds. This is the highest breeding success rates confirmed on this island at this stage in 16 years.
Over on Nonsuch, we had a real surprise with the CahowCam 2 (R832) nest. The longtime male Cahow claiming this nest recently lost his partner and mate of 14 years, who did not return for the courtship stage of the current nesting season in October & November 2023. However, in late November, a new young female Cahow started entering the nest, and the male, after initial hostility eventually accepted her, with the pair observed mating and resting together, before separately heading back out to sea for the month of December as is the norm for all Cahows.
As a result, we were waiting to see her back to lay her 1st egg in early January (eggs are usually laid between the 1st and 15th of January, (with the latest date recorded around the 22nd Jan). As of my last check on the 24th she still had not returned and as a result, we had given up hope of seeing the female lay her first egg this season. Imagine our surprise when i checked the CahowCam 2 nest on the 31st of January and found the male bird incubating a recently laid egg! When JP checked the camera logs (the CahowCam live-streaming network is still facing challenges, however, the system JP developed is still archiving recordings on Nonsuch), we were able to determine that the female had returned on the night of the 26th/27th of January to lay her first egg (see replay video), the latest egg-laying date that I have ever recorded. This was probably due to the pair not getting together until the latter half of November.
As we are grounded for the next few days as this strong storm system moves through the Bermuda area, I am left once again with a deep respect for the natural toughness of the Cahow and it's ability to survive the most adverse weather conditions. And while I have been writing this update, my power has come back on, although the gale continúes to rage outside. I also checked my rain gauge and found that we have recorded 3.92 inches of rainfall in a 14-hour period between 1.00am this morning and 3.00pm this afternoon. I am very glad that I am not out at sea or on those tiny nesting islands in these conditions!
Jeremy Madeiros Senior Terrestrial Conservation Officer