‘Cahow-Cam’ puts national bird in the infrared spotlight
Bird enthusiasts are now able to study the nocturnal cahow from the comfort of their own computer screens thanks to a new website.
Nonsuch Island Nature Reserve has set up its own web portal — www.nonsuchisland.com — which features a video feed from a cahow burrow.
The infrared cameras are powered by solar panels on the island, providing live action of a chick, named Lightning, 24 hours a day.
The underground burrow is kept in complete darkness. The infrared lighting is completely invisible to the birds.
Footage is already providing naturalists with fresh insights into the habits of Bermuda’s national bird.
Senior Terrestrial Conservation Officer Jeremy Madeiros, who has managed the Cahow Recovery Project and the Nonsuch Island Restoration for the last 14 years, said: “The infrared CahowCam has enabled both the researchers managing the recovery of the cahow and the general public to look into the private life of one of the rarest seabirds on Earth for the first time, and follow the development of a chick in its deep, pitch-dark nest burrow.
“This has given us a fresh understanding of various aspects of behaviour by the chick as it develops, as well as allowing us to watch the interaction between the chick and adult cahows during the brief feeding visits by adults after long, multi-thousand mile foraging trips to gather squid, small fish and shrimp-like organisms for the hungry, growing chick.
“The infrared burrow-cam has already proved its worth, both in revealing previously unknown behaviour and in allowing the public to follow the development of the chick at the same time it is seen by the researchers.
“It has revealed the private life of Bermuda’s critically endangered national bird to anyone, anywhere over the internet.
“We are looking forward already to the final stage of development of this current cahow chick and its departure out to sea, and are especially looking forward to November when the adult cahows return to the burrow to start their courtship, mating and nest-building period at the start of another nesting season.
“We are sure that we will see many more previously unknown aspects of behaviour at that time.”
Bermuda Audubon Society president Andrew Dobson added: “The nonsuchisland.com website is going to provide a great opportunity for interested persons around the world to follow the success of the cahow recovery programme. They will also learn about the extraordinary restoration project of Nonsuch Island itself.”
Yesterday the feed showed Lightning asleep in his burrow.
An explanatory note below the screen reads: “If the nest appears empty the chick is most likely exploring the tunnel to its burrow or if it is night time, it may be outside exercising/imprinting on its surroundings, so please check back in a little while.
“You may also view some amazing archived footage from earlier today in the blog. We expect Lightning to fledge/depart at some point in the upcoming few nights.”
Once the cahows have fledged for the season, the cameras will be moved to the Nonsuch Longtail burrows to give a view into their nesting habits.
The following are a few of the things that the CahowCam has revealed:
(1) Cahow chicks from a young age seem to spend much of their time building up and rearranging the nest material under themselves, showing that nest-building is an innate or instinctual behaviour.
(2) When not sleeping, cahow chicks spend much of their time preening their down and feathers, especially around the growing wings. They also frequently spread, stretch and briefly exercise their wings in the nest chamber, especially as they get older.
It was previously thought that their wingspan was too long for them to open their wings fully in the nest chamber, but as the wings lengthen, they often spread them out one wing at a time to fit in the restricted space of the burrow.
(3) When the adult cahows carry out a feeding visit to the chick, it usually lasts only an hour or two before the adult flies back out to sea.
The chick is often so frantic and hungry when the adult first arrives that it swarms over and pecks at the adult bird.
The adult has to preen the chick around its face and head for about ten minutes, which seems to calm down the chick enough so that successful feeding can take place.
(4) The chick inserts its bill crosswise into the bill of the parent bird, which regurgitates the food in a series of 16 to 25 very brief feeding periods, each lasting only three to five seconds, over a ten-minute period.
Once the feeding is completed, the adult will then intensively preen the head and body of the chick, followed by a rest period where the adult sleeps next to the chick for up to an hour or more.
The chick is often restless during this period, and the adult will often preen the chick for a brief period to calm it down before returning to sleep.
(5) The adult after an hour or two will wake up and sometimes completely pull apart the nest, throwing grass and leaves over the chick (which does not appear to be alarmed by this strange behaviour).
The adult may then feed the chick one or two more times before leaving the nest and flying back out to sea to begin another foraging trip.
The chick then spends a couple of hours pulling the scattered nest material back together and rebuilding the nest.
This behaviour may represent “turning over the bedsheets”, aerating the nest material and preventing it from decomposing or building up insect or parasite loads.
