#cahow

[na-bird-of-the-day]

BOTD: Bermuda Petrel

Photo: Miguel A Mejias, PhD.

"Endangered Atlantic Ocean seabird that nests on Bermuda and disperses widely when not breeding. When not nesting, it can only be seen far from land, where it often flies in swooping arcs with little flapping. Locally known as 'Cahow', it very nearly went extinct in the mid-twentieth century, but was returned from the brink largely due to the heroic efforts of local conservationists."

- eBird

[bermudianabroad]

Latest in Fluff Burd News:

142 breeding pairs of cahows! Whoop whoop!

[birdstudies]

February 4, 2020 - Bermuda Petrel or Cahow (Pterodroma cahow)

Breeding in Bermuda, these petrels spend the rest of their time at sea in parts of the western Atlantic Ocean. Thought to be extinct by 1620, after humans brought hogs, rats, cats, and dogs to their breeding islands and hunted them for food, they were officially rediscovered in 1951. Though little is known about their diet, they may eat squid, small shrimp, and small fish, probably capturing prey at or near the surface of the water like similar species of petrel. They nest colonially in burrows or crevices, where females lay a single egg in a scrape sometimes lined with plant materials. Classified as Endangered by the IUCN, their population is estimated at around 200 adult birds, but due to successful conservation efforts, it is predicted to continue to increase.

[virginiagreene]

Cahow cahow! #penandink #cahow #bird #art #illustration #wip (at Cornell Lab of Ornithology)

[bermudianabroad]

Since the last fluffy bird was such a big hit, here’s another.

Still from Bermuda, but this is a Cahow chick who was in the newspaper to celebrate the increase in breeding pairs!

Here’s a little historical background should you want to know more.

[bwabbitv3s]

Cahows break record with 134 breeding pairs | The Royal Gazette:Bermuda News

Bermuda’s cahows notched up a record 134 breeding pairs this year - and the chicks were at healthier weights than 2019.Jeremy Madeiros, the Government’s principal conservation officer, said that 68 of the endangered birds hatched in 2020.The number of breeding pairs topped last year’s figure of 131, although that season resulted in 73 fledged chicks.Mr Madeiros said: "All the chicks this year are at very good or above-average weights, with the exception of possibly two, which may nee

[neritic-by-nature]

Cahows! I drew them for my final exhibition piece in my “Transcultural Collaboration” class last semester. 

We all had to pick something important to our culture and make a piece about it. I chose the cahow, since they’re endemic to Bermuda and we thought that we had hunted them to extinction decades ago. There’s currently a big conservation/restoration project to help bring the population back up!

[ainawgsd]

Bermuda Petrel

The Bermuda petrel (Pterodroma cahow) is commonly known in Bermuda as the cahow, a name derived from its eerie cries. This nocturnal ground-nesting seabird is the national bird of Bermuda and can be found on Bermudian money. It is the second rarest seabird on the planet and a symbol of hope for nature conservation. For 300 years, it was thought to be extinct. The dramatic rediscovery in 1951 of eighteen nesting pairs made this a "Lazarus species", that is, a species found to be alive after having been considered extinct. A national program to preserve the bird and restore the species has helped increase its numbers, but scientists are still working to enlarge its nesting habitat on the restored Nonsuch Island.

The cahow is a slow breeder, but excellent flier. It visits land only to nest and spends most its adult life on the open seas ranging from the North Atlantic coastal United States and Canada to waters off western Europe. After 3–4 years at sea, males return to breeding islands to create nests. Females return after 4–6 years at open sea looking for a mate. Cahows mate for life and typically return to the same nest each year. They nest in underground burrows and only the ones that can be in complete darkness are chosen. Females lay one egg per season and 40% to 50% fail to hatch. 

The Spanish sailors of the 1500s used Bermuda and its surrounding islands as a waypoint for their raids against the Incas and other civilizations. At that time, cahows were abundant and formed dense, noisy colonies. These sailors, as Diego Ramirez writes in 1603, would take up to 400 birds a night for food. In addition to eating birds, conquistadors brought hogs to the island to sustain themselves over their voyage. These hogs decimated the ground-nesting cahow, rooting up their burrows, eating eggs, chicks and adults and disrupting their breeding cycle.

Bermuda's colonization by the English introduced species like rats, cats and dogs, and mass killings of the birds for food by these early colonists decimated the numbers of birds. The remaining cahow population also decreased due to widespread burning of vegetation and deforestation by the settlers during the first 20 years of settlement. Despite being protected by one of the world's earliest conservation decrees, the governor's proclamation "against the spoyle and havocke of the Cohowes", the birds were thought to have become extinct by the 1620s.

Cahows typically eat small fish, squid and shrimp-like crustaceans. Special glands in their tube-like nostrils allow them to ingest seawater. These glands filter out the salt and expel it through sneezing.

The Bermuda Petrel's re-population has explicitly increased and is approximated that the population doubles every 22 years, but there are still clear-cut inhibitors on its path to recovery. The Petrel's vulnerability has drastically increased because of substantial damage to its habitats and nesting sites by tropical storms and climate changes.  Its recovery has been hampered by competition from White-tailed Tropicbird (Phaethon lepturus) for nest-sites and subadult predation from a single snowy owl (the first ever recorded in Bermuda) on Nonsuch Island, which was eradicated, having eaten 5% of the population. Light pollution from a nearby airport and NASA tracking station adversely affects nocturnal aerial courtship.Another major issue with nests is competition with other birds in the area. To fix this issue, artificial dome nests were created for tropicbirds along areas, not used by the Bermuda Petrel, and by applying wooden baffles over the entrances of petrel burrows. These baffles only allow petrels to enter, keeping the competition of tropicbirds out.