Mid Season Review of Bermuda petrel (Cahow) 2015 Breeding Season

"At this time, there appears to be a total of 57 or 58 chicks for 2015 from a new record number of 112 nesting pairs (compared to 108 pairs in 2014, and only 17 to 18 pairs when the recovery program began in the early 1960s). Although this sounds like a large increase, it is still a dangerously tiny number as it is the entire population of the species on Earth." 4-16-2015 | Jeremy Madeiros Senior Terrestrial Conservation Officer Department of Conservation Services

Jeremy Madeiros holds Cahow chick from the 2015 season.

Jeremy Madeiros holds Cahow chick from the 2015 season.

The 2015 Cahow Breeding Season (which actually began in late October 2014 with the return of the first adult Cahows to their nesting islands) is now in it’s final phase as the  downy chicks are reaching anywhere from one-third to one-half in their growth before they are ready to fly out to sea, between late May and late June.

This is a good time to review the breeding season to date and look at the successes and challenges of the Cahow Recovery Program to date this season, as it attempts to help our National Bird, which nests no-place else on Earth except Bermuda, recover from nearly becoming extinct.

Many people may think that the Cahow has already been rescued from extinction, and so we really don’t need to spend as much time with it anymore. Nothing could be further from the truth, the Cahow is still one of the very rarest seabirds on the planet, and still faces numerous very real threats to its survival, some of which can be managed for on its breeding sites, and some of which cannot.

One of the biggest of these threats is the impact of powerful hurricanes on the tiny nesting islands, some of which are mere rocks only a half acre in size. These islands are so small and low that the huge waves and storm surge experienced in hurricanes can completely submerge these islands, tearing off huge sections of rock, causing massive erosion and damaging or destroying even the solidly built artificial concrete nest burrows. Hurricane “Fabian” in 2003 submerged and eroded most of the islands with waves reaching over 35 feet in height, and damaged or destroyed many of the burrows, but fortunately was early enough in mid-September that none of the birds had yet returned for nesting. This enabled the Government Conservation Crew to rebuild many of the burrows before the nesting season began, but even so, the number of both nesting pairs and Cahow chicks fell steeply the following year.

Eye of Hurricane Gonzalo passes over Bermuda

Eye of Hurricane Gonzalo passes over Bermuda

Hurricanes “Fay” and “Gonzalo” made direct hits on Bermuda within 5 days of each other in mid-October, 2014, causing widespread damage as winds reached 145mph as the eye of “Gonzalo” tracked directly over Bermuda. Unfortunately, this hurricane was late enough in the year that some of the male Cahows had already returned to claim and clean out their nest burrows. Cahow pairs mate for life, returning every year to the same nest burrow, and the males consistently return 7 to 10 days before the female birds. After checking and repairing all active nest burrows after the hurricane, I was able to confirm that at least four to five males had disappeared during the hurricane, and had evidently been drowned and washed out of their burrows as huge waves submerged two of the nesting islands. The female Cahows, returning and finding no males at the nests, then abandoned the sites, causing a net loss of at least four to five nesting pairs,

Despite this, at least eight new nesting pairs of Cahows colonized burrows and laid their single eggs for the first time this season, bringing the total nesting population up to a new record number of 112 nesting pairs (compared to 108 pairs in 2014, and only 17 to 18 pairs when the recovery program began in the early 1960s). Although this sounds like a large increase, it is still a dangerously tiny number as it is the entire population of the species on Earth. The Cahow is still listed as Critically Endangered, and it is a sobering fact to realize that a species is not considered to be out of the immediate risk of extinction until it reaches over a thousand breeding pairs in number, when it can be down-listed from “Critically Endangered” to “Threatened”.

Wooden "Baffle" used to keep Longtails out of Cahow nests.

Wooden "Baffle" used to keep Longtails out of Cahow nests.

Other critical threats to the Cahow include rats occasionally swimming out to the nesting islands and killing and eating the Cahow chicks or eggs, and nest competition with the numerous Longtail (White-tailed Tropicbird), which can enter Cahow burrows, kill the chicks, and take over the nests. The Cahow chicks are defenseless against the more aggressive Longtails as their parents are usually out to sea during the day to gather food to feed their chicks. This problem has been largely managed for many years by fitting the entrances of nest burrows with wood “baffles” with a precisely shaped entrance hole, which allow the Cahows to enter and leave, but normally prevent the Longtails from doing so because they have a different shape and slightly larger body. However, in early April, I unfortunately recorded the first death of a Cahow chick by a Longtail in many years as an evidently smaller than normal Tropicbird managed to squeeze through a baffle and kill the chick. I immediately built and installed a smaller baffle, but this demonstrates the fact that if management of the Cahow population was reduced, that the population would immediately plunge again, possibly to the point of extinction.

At this time, there appear to be a total of 57 or 58 chicks for 2015, which are now reaching between 4 and 6 weeks of age. It normally takes 12 to 14 weeks (84 to 98 days) after hatching for a chick to fully develop, fledge and leave the nest. After flying out to sea, the chicks will not return to the nesting islands to choose mates and nesting burrows until they are 3 to 5 years old.

Our video star chick, “rainbow”, hatched on the 4th March, 2015, and weighed only 46 grams at its first weighing 2 days later. By the 15th April, its weight had already reached 324 grams, and should continue to increase until it reaches its peak weight in another month or so. During the last two to three weeks, chicks actually loose weight again as  they convert fat reserves to bones, muscles and feathers before flying out to sea.

Rainbow the Cahow Chick

Sophie & Jeremy with Rainbow.

Sophie & Jeremy with Rainbow.

The 2015 CahowCam Chick named: Rainbow

For the third year in a row our Junior Explorer: Sophie has named the star Cahow chick that is being filmed by our CahowCam in burrow #831 from Translocation Colony A on Nonsuch Island . This year it was named "Rainbow" following "Lightning" in 2014 and "Backson" in 2013.

Sophie Names the Cahow Chick

Sophie names the Cahow Chick from burrow #831 on Nonsuch Island, Bermuda, the star of the 2015 CahowCam LiveStream.

Posted by Nonsuch Island Project - Bermuda on Monday, March 30, 2015

Rainbow was filmed hatching on March 4th, the first time this has ever been observed or filmed!

Cahow Chick Filmed Hatching

March 4th 2015, 1.40pm, live from burrow # 831 on Nonsuch Island, Bermuda.

For the first time ever, a Cahow chick hatching has been caught on film!

The award winning CahowCam developed by LookBermuda and now operating for its third year on Nonsuch Island, enabled the team at the Department of Conservation Services to watch this never before seen event from their offices on the mainland along with all of the other followers who were watching the live video stream on the internet.

The video clip below is an archived version of the actual stream, to see ongoing LIVE activity from this nest, please visit the Live CahowCam here.


Airport Art Nonsuch Branding

Here are samples of the Nonsuch Expedition AirportArt installation highlighting the new branding and  "collection tags":


Nonsuch Island Hurricane Gonzalo slideshow

On the whole Nonsuch Island faired well during Faye and Gonzalo. There was a great deal of wind damage to vegetation however the island structures held up quite well. Thankfully there was far less wave damage and coastal erosion than was expected, which was much worse in Fabian and Igor.

All photos by Jean-Pierre Rouja for LookBermuda

Nonsuch Island Hurricane Gonzalo Update #1

Gonzalo eye passing over Bermuda

Gonzalo eye passing over Bermuda

We are happy to report that despite a direct hit by Hurricane Gonzalo, in the initial surveys it does not appear that Nonsuch Island suffered any major damage to it's Infrastructure or Geology.

Despite fears of the island being cut in two by the waves, the beach and costal areas suffered far less than during hurricanes Fabian and Igor.

It has however suffered substantial damage to the vegetation with some of the larger cedars and bay-grapes being uprooted or broken. The Bermuda Palmettos and Olive Woods however appear to have little or no damage.

This week the priority will be to get the Cahow nesting sites and manmade burrows ready, including diving up the concrete lids that will have been blown overboard on the outer islands, as the Cahows should be returning this week for their mating rituals. Fortunately the translocation site on Nonsuch Island where our cameras are located suffered virtually no damage.

It should be noted that the Ascendant supplied solar power system withstood the winds and  there is still power on the island which will be very helpful as we prepare to start streaming live from the Cahow nesting sites for the next season.

Please stay tuned for further reports, Follow our Group on Facebook Like us below and sign up for the newsletter to receive updates.

Hurricane Gonzalo

Below is the post we made to our companion Facebook page during the Hurricane:

Nonsuch Island Photography Expeditions

LookBermuda has just completed the second phase of its Biodiversity Survey Photography Expeditions focused on the Nonsuch Island Nature Reserve and surrounding waters.

In these expeditions,  the LookBermuda team led by photographer & filmmaker Jean-Pierre Rouja are collaborating with world renowned photographer David Liittschwager to produce a series of unique images to showcase the biodiversity of this unique island habitat.

View Gallery

The resulting imagery is being used to enhance local curriculums, to obtain international exposure and to highlight Bermuda’s Eco Tourism assets in part via the nonsuchisland.com website, allowing users to virtually visit the island which is otherwise too sensitive to accommodate the masses.

To reach a wider audience a Nonsuch Island themed exhibit is being created for LookBermuda’s AirportArt project. For this project LookBermuda has secured the rights to install large scale art installations throughout the Bermuda International Airport to educate, entertain and enhance the travelers experience and the Nonsuch Expeditions will be the first of the themed installations.

To reach the non-traveling public, a MobileArt exhibit mirroring the airport installation will be shown in public popup art exhibits throughout the island and also throughout the island’s public and private schools. In the schools it will be accompanied by curriculum content developed by the LookBermuda Foundation.

 

These expeditions would not be possible without the support and assistance of: 

Senior Terrestrial Conservation Officer (Cahow Recovery Program manager): Jeremey Madeiros

Marine Species Collector: Chris Flook

Sponsors: Jim Butterfield, Richard Rockefeller

 

Virtual Tour of Nesting Site | Last visit with "Lightning"

Above is an Interactive Video Virtual Tour of the nesting site.

For the full immersive experience please visit this page with a flash enabled browser. Click and drag the image to change your point of view and use the the thumbnails in the top left corner to change between still and video mode.

This Tour was created on the growth assessment on May the 27th with "Lightning" the Cahow chick that we have been following from burrow # 831. He (or she) departed around 11pm on May 28th and is expected to return in 3 to 5 years.

We will be moving this CahowCam to another active nest in the next few days and are preparing to live stream the nocturnal outdoor exercising of the remaining chicks starting next week, please sign up to the Newsletter for alerts.

Lightning Exercising, will fledge in next few days.

Above film recorded at 5pm on May 25th, *chick did NOT depart night of the 25th

This years CahowCam star: "Lighting" has had the benefit of both parents feeding him (or her) regularly and has therefore been one of the fastest growing chicks this year and now appears ready to fledge earlier than expected, possibly in the next few nights.

Last night our equipment suffered (but survived) the second lightning strike in the past 2 weeks and I have asked my daughter to more careful when picking a name next season.

j-p