Prospecting adult documented threatening CahowCam chick.
The Cahow chick that hatched on March 2nd in the CahowCam nest on Nonsuch Island has already had an eventful life.
* See update at end of article.
After hatching, the adult male stayed with the chick for two days, feeding it at least three times before flying back out to sea on Saturday evening. Both parents are now into the cycle of lengthy feeding trips to gather squid, shrimp-like organisms and small fish from cooler water hundreds of miles from the nesting islands, and will only be feeding the chick every 3 to 5 days at night for an hour or two before heading back out to look for more food. The chicks are well equipped with their thick coats of warm down to wait for up to a week or more on their own for these brief feeding visits.
On Sunday night/early Monday morning when a adult Cahow appeared in the nest at 1.40am my first thought was that the adult female had returned to feed the chick. It was soon evident, however that something was wrong, as the adult was nervous and edgy and was very aggressive towards the chick; rather than gentle preening the adult was biting the chick quite hard in what could only be described as an attack. Luckily, the chick basically played dead and after 18 minutes the adult left the nest. However, it looked back in at least 3 times over the next few hours, but turned and went back out as soon as the chick began cheeping.
It is now evident that the mystery intruder was in fact a young prospecting Cahow that was looking for an empty nest burrow, which they can be quite aggressive about as it is one of the more important decisions in their lives. This incident however, as revealed by the CahowCam, finally confirms a suspicion about a rather alarming threat to the newly hatched chicks. Every year, I have noted that one or two chicks that appear to be healthy and growing normally during one check are found dead during the next check without any of the marks generally associated with, for example a rat attack. It now appears likely that aggressive young prospecting adults may sometimes get rid of the chick in order to try and take over the burrow.
This chick was lucky to have survived the attack, and indicates that despite all of the management that we carry out to help the Cahow a better chance to survive and recover, that life is still precarious for one of the world's rarest seabirds. Let's hope that the next visitor is in fact one of the legitimate parents coming to feed the chick!
UPDATE March 7th 00:05 am | Fortunately one of the parents seems to have returned the following night for a traditional feeding session.
UPDATE March 8th 01:40 am | For the second night in a row a parent has returned, this time more than likely the male. It should be noted that though the above event was distressing to watch that the Conservation Services Team have mitigated 99% of similar threats to the Cahows through the ongoing suppression of rat infestations on the islands and through the installation of baffles to stop the prospecting Tropic Birds from taking over the nests.
Jeremy Madeiros, Senior Conservation Officer (Terrestrial), Dept. of Environment and Natural Resources, BERMUDA