Bermuda Cahows

Location: Nonsuch Island, Bermuda

Camera Host: Nonsuch Expeditions

May 18, 2017

Overnight Visit From Adult on Cahow Cam

It's a full-belly Friday for the Bermuda Petrel chick thanks to a late night visit from this adult cahow on Thursday. Watch here as the two birds congregate in the burrow after reuniting in the nest tunnel. Over the next two weeks, the larger-than-life cahow chick will begin to shed its downy plumage and its first fresh set of flight feathers. 

May 16, 2017

Leach's Storm-Petrel Vocalizations at the Bermuda Cahow Cam

A Leach's Storm-Petrel was heard vocalizing outside the entrance to the burrow of the Cahow nest. Last year, following the completion of the 2016 Cahow season, a Leach's Storm-Petrel spent time in the burrow, vocalizing and investigating the environment (see http://www.nonsuchisland.com/blog/storm-petrel for an account of that visit). Leach's Storm-Petrels aren't known to breed anywhere near Bermuda, and its presence is a very uncommon phenomenon! 

May 10, 2017

Feeding, Preening, and Cuddling Between Adult Cahow and Chick

On the Bermuda Cahow cam, the larger-than-life chick has received a visit from an adult on the past two consecutive nights. Last night's two-hour reunion showcased plenty of feedings, preening, cuddling, and wily activity by the young petrel. It's amazing to see the size comparison between a full grown adult Bermuda Petrel and its chick at this stage of development. Similarly to the Laysan Albatross, Bermuda Petrel chick's will often weigh more than an average adult during the pre-fledging period. 

May 18, 2017

Overnight Visit From Adult on Cahow Cam

It's a full-belly Friday for the Bermuda Petrel chick thanks to a late night visit from this adult cahow on Thursday. Watch here as the two birds congregate in the burrow after reuniting in the nest tunnel. Over the next two weeks, the larger-than-life cahow chick will begin to shed its downy plumage and its first fresh set of flight feathers. 

May 16, 2017

Leach's Storm-Petrel Vocalizations at the Bermuda Cahow Cam

A Leach's Storm-Petrel was heard vocalizing outside the entrance to the burrow of the Cahow nest. Last year, following the completion of the 2016 Cahow season, a Leach's Storm-Petrel spent time in the burrow, vocalizing and investigating the environment (see http://www.nonsuchisland.com/blog/storm-petrel for an account of that visit). Leach's Storm-Petrels aren't known to breed anywhere near Bermuda, and its presence is a very uncommon phenomenon! 

May 10, 2017

Feeding, Preening, and Cuddling Between Adult Cahow and Chick

On the Bermuda Cahow cam, the larger-than-life chick has received a visit from an adult on the past two consecutive nights. Last night's two-hour reunion showcased plenty of feedings, preening, cuddling, and wily activity by the young petrel. It's amazing to see the size comparison between a full grown adult Bermuda Petrel and its chick at this stage of development. Similarly to the Laysan Albatross, Bermuda Petrel chick's will often weigh more than an average adult during the pre-fledging period. 

March 02

Bermuda Petrel Egg Hatches!

The Bermuda Petrel chick emerged from it's shell during the late night hours of March 2nd! 

March 02

Bermuda Petrel Egg Shows First Signs of Pipping!

Hatching has begun in the Bermuda Petrel burrow on Nonesuch Island! The first pip on the egg surfaced early this morning after 51 days of painstaking incubation by the parents. Listen closely to hear the first peeps from the chick inside of the egg – which should hatch sometime in the next 24-48 hours.  

February 27

Another Nest Check as Hatch Date Inches Closer

Listen in on Bermuda Petrel expert Jeremy Madeiros as he makes a quick nest check on the incubating female. The female and egg both look healthy, and Madeiros expects the male to relieve the female of incubation duties within the next few days. If you listen closely, he also confirms that the first Cahow chick of 2017 has hatched in another burrow on Nonsuch Island, Bermuda! Assuming things go smoothly, the chick in this burrow is scheduled to hatch on the 5th of March, although a hatch is possible within a 1-2 day window around that date.  

Overview

Perhaps the world’s most storied seabird, Bermuda Petrel (Pterodroma cahow)—or Cahow, as it is called on Bermuda—was little more than legend until its rediscovery and description in the twentieth century, more than 300 years after it had vanished from human experience.(For a comprehensive overview of Bermuda Petrel ecology, check out their species account at Neotropical Birds Online.)


The Search & Rediscovery

At last, in January 1951, a scientific expedition was organized to search for the bird, led by Louis S. Mowbray (son of the 1906 discoverer) and by Robert Cushman Murphy and his wife, Grace E. B. Murphy. During a careful survey of the islets around Castle Harbor, they found seven nesting pairs of Bermuda Petrel, and the news of the discovery quickly spread around the world through the news media, with rare fanfare, at least for a seabird.


Accompanying Mowbray and the Murphys on the expedition was a local Bermudian schoolboy, David B. Wingate, who was present when the first petrel was found, on 28 January 1951. Just two years later, the young Wingate acquired a specimen of Bermuda Petrel from an antique dealer; it proved to be from the 1800s, from the collection of John Tavernier Bartram, a naturalist who searched for the species without realizing he had a specimen in his possession. After graduating from Cornell University in 1957, Wingate returned to Bermuda to work on petrel conservation, under the auspices of the Bermuda Aquarium. He would become Bermuda’s Conservation Officer and the birds’ outspoken champion over the next five decades.


Conservation Risks and Successes

During that time, the tiny population of petrels was nearly lost again, first to terrible nest-site competition with another seabird, the White-tailed Tropicbird (Phaethon lepturus), first noted in 1951, then to egg-shell thinning caused by DDT. Wingate reduced, then eliminated the tropicbird problem by constructing tropicbird-excluding baffles at the entrances of active petrel burrows, which admit the petrels but keep out the larger-bodied tropicbirds. A successful, and ongoing campaign has also been carried out to supply tropicbirds with artificial nest “Igloos,” placed away from petrel nesting areas. The egg-shell thinning problem improved greatly following the banning of DDT in the early 1970s. In addition, a shortage of suitable deep nest burrows for the petrels on the rocky original nesting islands, which have little or no soil for them to burrow into, was solved by digging and constructing artificial concrete burrows, a program that continues to this day. These burrows have been so successful that they are now used by over 80% of the nesting population, enabling the petrel population to grow at an increasing rate.


In recent decades, there has been increasing overwashing and erosion of the original small nesting islands, which average only 0.5 to 1.0 acre in size each, during frequent episodes of hurricane surge. This has resulted in petrel mortality and the destruction of nest burrows, posing an urgent problem for Bermuda’s new Senior terrestrial conservation officer, Jeremy Madeiros, who has managed the Cahow Recovery Program since David Wingate’s retirement in 2000. Thus, Madeiros commenced a program in 2002 of translocating, or moving near-fledged young petrels from the original vulnerable nesting islands to artificial burrows on higher ground, on the nearby much larger Nonsuch Island Nature Reserve, which Wingate and Madeiros have reforested to its precolonial state over the past 56 years. By doing this, the fledgling petrels imprinted on the new site rather than the original tiny sub-optimal islands, which did not offer sufficient area for the species to completely recover. These translocated petrels returned when mature after several years at sea, and began nesting on Nonsuch in 2009 for the first time since the 1620s. As of early 2017, with a total of nearly 120 nesting pairs of Bermuda Petrel, there is guarded optimism for the survival of this striking seabird.

About the Site

The CahowCam is nestled in the side of a dome-shaped, manmade burrow constructed by the Bermuda Department of Environment and Natural Resources (DENR) on Nonsuch Island. These burrows are part of a larger translocation project that is essential to the long-term survival of the Bermuda Cahow, whereby juveniles from smaller, low-lying islets are translocated to Nonsuch Island, where there is ample habitat out of the reach of hurricanes and heavy surf. As of 2016, there are two translocated colonies on Nonsuch Island, and the DENR continues to work at establishing additional safe nesting spots for cahows to breed.

About the Petrels

Thanks to the efforts of the Bermuda DENR, both of the petrels nesting in the Cahow Cam burrow have been banded, and their individual histories have been recorded through prior nesting seasons. The breeding pair of Bermuda Petrels, or Cahows, that nest in the cam burrow (#R831) on Nonsuch Island, were both translocated in May 2006 as two-thirds fledged chicks from two separate nesting islets to artificial burrows on the larger and more elevated Nonsuch Island Nature Reserve. Once translocated, the chicks were hand-fed daily and monitored until they fledged out to sea. Both of our birds in the 831 nest then stayed out at sea for three years until they matured, and returned to pair up together in this nest in 2009. They have returned every year since to breed. Cahows produce only one egg each year, and are faithful partners, generally pairing up with the same mate for life, which may be over 30 years.

After colonizing this burrow in 2009, E0212 (the male) and E0197 (the female) nested unsuccessfully from 2010 through 2013. From 2014 to 2016, they were successful in fledging a chick each year, and we are hopeful for continued success this year.

The pair returned to the island in mid-November to court and mate, then disappeared out to sea for the month of December. On January 11, the female returned, and within an hour or so of arriving she laid a single egg that will be the singular focus of the pair’s efforts for the next 5-6 months (watch highlight). In the next 24-48 hours, the male should return to take over incubation duties for the next month while the female heads out to sea, and hatch won’t be for another 52-55 days—likely around the end of the first week of March. If the chick hatches successfully, fledging should occur around the first week of June.

About the Team

Multiple groups are working to raising awareness about the endangered Bermuda Cahow through the live CahowCam. LookBermuda and the Nonsuch Expeditions have collaborated with the Bermuda DENR since 2011 to bring the live cam to life, and have streamed live footage from burrows on Nonsuch since 2013. Continued support from Terrestrial Conservation Officer Jeremy Madeiros has been essential in arranging visits to Nonsuch, learning about cahow conservation, and the opportunity to share the ongoing work needed to safeguard the cahow’s future. Finally, a special thanks to the Government of Bermuda for prioritizing the ongoing conservation of this national treasure.