Initially they were superabundant throughout the archipelago, but because of habitat degradation and invasion of mammals, the bird's suitable nesting areas have dwindled to four islets in Castle Harbor, Bermuda, in the warm waters of the Gulf Stream, some 650 miles east of North Carolina.

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.

In a first of its kind, a high school science project engaged in a remote study via live webcam using Cornell Lab's Cahowcam.

These hogs decimated the ground-nesting cahow, rooting up their burrows, eating eggs, chicks and adults and disrupting their breeding cycle.

Following the Spanish visits to Bermuda, the English ship Sea Venture was wrecked on the island in 1609, and the survivors culled the fattest individual petrels and harvested their eggs in abundance, especially in January when other food were scarce.

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 devastated their numbers.

Despite being protected by one of the world's earliest conservation decrees, the governor's proclamation "against the spoyle and havocke of the Cohowes",[citation needed] the birds were thought to have become extinct by the 1620s.

[6] Six years later, Bermudian naturalist Louis L. Mowbray received a live Bermuda petrel that had collided with a radio antenna tower.

He undertook work to address various threats to the Bermuda petrel, including the eradication of introduced rats on the nesting islands and nearby islands, and addressed nest-site competition with the more aggressive, native white-tailed tropicbird Phaethon lepturus catsbyii, which invaded petrel nest burrows and killed up to 75% of all chicks.

Following the design and installation of specially sized wooden "baffler" burrow entrance covers, which allowed the petrels to enter but excluded the larger tropicbirds, there has been essentially no further chick loss from this cause.

[citation needed] Wingate also initiated the ecological restoration of Nonsuch Island, located near the Bermuda petrel breeding islets.

Wingate's goal was to restore the habitat on Nonsuch Island so that it could eventually serve as a viable nesting site for the species.

Even since retirement, Wingate has esigned and donated artificial plastic nest boxes to the Cahow Recovery Project, funded by the Bermuda Audubon Society.

[12] David Wingate retired in 2000, after which Jeremy Madeiros became the Bermuda Government terrestrial conservation officer, taking over the management of the Cahow Recovery Program and the Nonsuch Island Living Museum Project.

[13] Madeiros carried out a review of the status of the Bermuda petrel, identifying erosion of the four small original nesting islets due to hurricane damage and sea level rise as the single largest threat facing the species.

Starting in 2011 the "CahowCam" project was launched by the Bermuda-based LookBermuda / Nonsuch Expeditions Team in partnership with the Department of the Environment and Natural Resources.

In 2016 they partnered with The Cornell Lab of Ornithology bird-cam team resulting in over 20 million minutes of CahowCam footage being watched in the following 3 seasons.

[5][21] Cahows, being a recovering Lazarus species, need special attention in order to support recovery and population growth.

The petrel's vulnerability has drastically increased due to substantial damage to its habitats and nesting sites by tropical storms and climate change.

The predicted future increase of category 4 and 5 tropical storms pose an imminent threat to the petrels' long-term survivability.

Its recovery has been hampered by competition from white-tailed tropicbird (Phaethon lepturus) for nest-sites[7] and predation of subadults by a single snowy owl (the first ever recorded in Bermuda) on Nonsuch Island, which was eradicated after having eaten 5% of the population.

Another factor may be that the cahow will have an increased risk of extinction because of restricted ranges, small population sizes, and lower genetic diversity.