Bermuda Petrel

For the dedicated birdwatching and wildlife enthusiast based in the United States, few avian encounters rival the heart-pounding thrill of spotting a true pelagic rarity. Imagine standing on the wind-battered deck of a deep-sea charter off the coast of Cape Hatteras, North Carolina, scanning the endless, churning expanse of the Gulf Stream. Among the familiar shearwaters and storm-petrels, a medium-sized, long-winged seabird suddenly banks over the whitecaps. It arcs gracefully into the sky, revealing a crisp white underbelly and a striking, dark “M” pattern across its underwings. For North American birders, this is the holy grail of the Atlantic: the Bermuda Petrel, locally and affectionately known as the Cahow.

To understand the Bermuda Petrel is to dive into one of the most miraculous and harrowing narratives in the history of ornithology. This is a species that was literally erased from the scientific record—presumed globally extinct for over three centuries—only to reemerge from the shadows of history on a few jagged, storm-swept rocks in the mid-Atlantic. Today, it stands not just as a prized tick on a birder’s life list, but as a global beacon of hope for endangered species recovery. In this exhaustive, data-driven exploration, we will dissect the biology, ecology, and triumphant conservation story of the Bermuda Petrel, blending the precision of modern avian science with the vivid storytelling that makes birding such an enduring passion.

Description

To witness the Bermuda Petrel in its natural element is to observe a masterclass in aerodynamic evolution. Commanding the oceanic gales with a sweeping wingspan that ranges from 89 to 92 centimeters (roughly 35 to 36 inches), this medium-sized gadfly petrel is perfectly engineered for a life spent almost entirely in perpetual flight. With a body length averaging 35 to 38 centimeters and a mass fluctuating between 257 and 455 grams, the species exhibits a streamlined maritime silhouette that belies its robust endurance. The morphological design of the bird reflects the uncompromising demands of the open ocean, balancing lightweight agility with the muscular density required for traversing thousands of miles of tempestuous seas.

The plumage of the Bermuda Petrel is a striking study in high-contrast pelagic camouflage. The upper body is draped in a brownish-grey to dark grey mantle, merging seamlessly into an almost blackish hue across the upper wings and tail. This dark dorsal coloration provides excellent concealment against the dark, churning waters of the Atlantic when viewed from above by avian predators. The head is defined by a distinctive brownish-black cap, or “cowl,” that extends down to the eye, punctuated by a subtle pale eyebrow. A brownish nape reaches toward the upper breast to form a partial, elegant collar. Conversely, the underparts are brilliantly white, allowing the bird to blend into the bright sky when viewed from below by aquatic predators. A narrow white “U” shape—formed by the pale upper-tail coverts—bridges the dark rump and tail, serving as a critical field mark for identification. The underwings present a pristine white canvas bordered by a narrow black trailing edge and a broader black leading edge, culminating in a striking “M” pattern that becomes highly conspicuous during dynamic soaring. Physical features are finalized by a stout, black, hooked bill, alongside pink legs and feet that transition to black at their distal ends.

For USA-based pelagic birders, identification at sea requires a nuanced understanding of comparative morphology, particularly regarding the closely related Black-capped Petrel, which shares the same Gulf Stream foraging grounds off the North Carolina coast. Both species share a superficial resemblance, but precise observation reveals definitive structural and plumage divergences. The Bermuda Petrel is demonstrably smaller and slimmer than its Caribbean counterpart, possessing a noticeably smaller, less deep bill. Where the Black-capped Petrel brandishes an extensive white rump patch and a distinct white hindneck, the Bermuda Petrel features only the narrow white “U” on the rump and a dark cap that remains largely continuous with its dark upperparts.

Beyond its external plumage, the Bermuda Petrel harbors extraordinary anatomical and physiological adaptations tailored for marine survival. As a member of the tube-nosed seabirds, the species features specialized tubular nostrils atop its bill. This structure houses highly developed olfactory organs, granting the bird a phenomenal sense of smell used to navigate featureless oceans and locate patchily distributed prey over vast distances. More critically, these tube-like structures conceal specialized supraorbital salt glands. Because the bird spends its entire non-breeding life at sea, it must ingest seawater. These highly efficient glands extract excess sodium chloride from the bloodstream, excreting it as a highly concentrated, salty brine that the bird forcefully expels through vigorous sneezing.

Furthermore, the Bermuda Petrel shares a defining, unique physiological trait with other non-diving Procellariiformes: the production of stomach oil. Stored in the proventriculus, this complex biochemical mixture of neutral dietary lipids is synthesized from digested marine prey. This stomach oil serves a dual evolutionary purpose. Ecologically, it acts as an incredibly energy-dense food source—yielding approximately 16.1 kilojoules per gram—allowing adults to forage across thousands of miles and return to the nest with a lightweight, highly concentrated caloric payload for their slowly developing chicks. Behaviorally, this putrid, foul-smelling oil acts as a formidable defense mechanism; when threatened by nest predators, chicks and adults can projectile-vomit the oil, ruining the waterproofing of an avian predator’s feathers or repelling terrestrial mammals.

Taxonomy

The taxonomic classification of the Bermuda Petrel places it within an ancient lineage of highly specialized pelagic seabirds. The species was formally described to western science in 1916 by John Treadwell Nichols and Louis L. Mowbray, who granted it the binomial designation Pterodroma cahow.

The genus name Pterodroma translates elegantly from Ancient Greek as “winged runner,” a fitting moniker for seabirds that thrive in fierce oceanic gales and appear to run rapidly across the water’s surface before taking flight. The specific epithet cahow is an onomatopoeic adoption of the bird’s eerie, nocturnal vocalization, a haunting, drawn-out cry that echoed across the islands long before human settlement.

Taxonomic and phylogenetic analyses suggest that the Bermuda Petrel belongs to a widely distributed clade of gadfly petrels. Based on morphological characters and modern genetic evidence, the species is assumed to be most closely related to the Black-capped Petrel of the Caribbean, as well as Fea’s Petrel and Zino’s Petrel from the eastern Atlantic. Historically, some ornithological authorities, including earlier iterations of the American Ornithologists’ Union checklist, debated regarding the species as conspecific with other Atlantic and Pacific gadfly petrels. However, modern genetic consensus definitively recognizes the Bermuda Petrel as a distinct, genetically isolated species endemic to a single archipelago.

The evolutionary history of the Bermuda Petrel is forever intertwined with its status as a quintessential “Lazarus species.” In evolutionary biology, a Lazarus taxon is one that disappears from the observational record, presumed extinct, only to miraculously reappear centuries later—mirroring the biblical resurrection. For 330 years, the global scientific community mourned the Bermuda Petrel as a casualty of 17th-century colonial expansion. It was not until January 28, 1951, that an expedition led by Robert Cushman Murphy of the American Museum of Natural History and Louis Mowbray, curator of the Bermuda Aquarium, unearthed a handful of surviving nesting pairs clinging to existence on fragmented limestone rocks. This taxonomic resurrection ignited one of the most celebrated and protracted conservation narratives in the history of ornithology.

Distribution

The terrestrial distribution of the Bermuda Petrel represents one of the most restricted breeding ranges of any avian species on Earth. The bird is strictly endemic to the islands of Bermuda, an isolated archipelago situated at 32°N, 64°W in the western North Atlantic Ocean, roughly 650 miles east of North Carolina. Within this already diminutive 55-square-kilometer territory, the actual breeding range is localized to an unimaginably small fraction of land.

Historically, prior to the early 1500s, the species was superabundant, its distribution blanketing the entirety of the Bermuda archipelago. Coastal dunes, inland soils, and forested hillsides were honeycombed with their terrestrial burrows. However, centuries of ecological degradation, habitat destruction, and the introduction of invasive mammalian predators catastrophically contracted this distribution. By the time of the species’ rediscovery in 1951, its entire global breeding footprint had been reduced to a mere four jagged, low-lying rocky islets within Castle Harbour: Horn Rock, Inner Pear Rock, Green Island, and Long Rock.

These four islets encompass a combined area of less than one square kilometer. These fragmented, sheer limestone outcroppings were so inhospitable and difficult to land on that they managed to repel both human development and permanent populations of invasive rats, thereby serving as an accidental, last-stand fortress for the surviving birds.

Today, thanks to visionary ecological intervention, the distribution is slowly expanding back onto larger landmasses within the territory. The cornerstone of this expansion is the Nonsuch Island Nature Reserve. Located adjacent to the original breeding islets, Nonsuch Island is a larger, significantly more elevated, and heavily protected island that has undergone decades of meticulous habitat restoration. Following intensive translocation efforts initiated in 2004, Nonsuch Island now hosts a thriving, rapidly expanding sub-colony, representing the first time the species has bred on a major Bermudian island since the 1620s. Recently, the birds have also naturally recolonized Southampton Island, further expanding their precarious terrestrial footprint within the harbor.

Range and Population

The demographic history of the Bermuda Petrel is a harrowing tale of apocalyptic decline followed by a slow, triumphant, mathematically exponential recovery. When Spanish sailors first navigated the waters around Bermuda in the 1500s, the population was estimated to exceed 500,000 birds. The sheer volume of their nocturnal flights was reported to darken the moonlit skies. However, by the early 1620s, hunting by early colonists and predation by introduced pigs, dogs, cats, and rats decimated the population to the point of presumed global extinction.

The modern baseline for the population begins at the 1951 rediscovery, where a profoundly bottlenecked population of just 17 to 18 breeding pairs was identified, collectively producing a mere 7 to 8 fledged chicks annually. Subjected to intensive, hands-on recovery actions—initially spearheaded by conservation pioneer Dr. David Wingate for 40 years, and subsequently by Jeremy Madeiros since 2000—the population was stabilized and eventually catalyzed into a steady pattern of growth. Demographic monitoring since 1961 indicates that the population has been increasing exponentially, doubling approximately every 22 years.

Between the 2000 and 2008 breeding seasons, comprehensive monitoring revealed steady incremental gains. Mean annual breeding success during this interval hovered at an impressive 62%, a rate considered exceptionally high for Procellariiformes, driven almost entirely by the provisioning of secure, artificial concrete nesting burrows that protected eggs from the elements and predators.

The momentum generated by these early interventions has yielded remarkable dividends in recent decades. The ambitious translocation project to Nonsuch Island further accelerated demographic security. By the 2010 season, the population had grown to 92 pairs producing 52 chicks. By 2019, the global census recorded 132 breeding pairs yielding 72 fledged chicks.

The most recent data from the 2024 and 2025 nesting seasons highlight record-breaking triumphs that thrill the global birding community. In 2024, the total global population was estimated at 425 to 450 individual birds, comprising 165 established breeding pairs that successfully produced 76 fledged chicks. Of these, 25 chicks fledged from the newly established, highly productive Nonsuch Island sub-colony, representing a 25% increase for that specific location over the previous year. The 2025 season concluded with even greater success, recording the second-highest fledging total in history with 78 chicks, falling just one shy of the all-time record of 79 chicks set in 2021.

Habitat

The habitat requirements of the Bermuda Petrel are distinctly bipartite, fiercely split between the microscopic terrestrial environments required for reproduction and the macroscopic oceanic realms required for foraging and long-term survival.

Terrestrially, the species is an obligate burrow-nester. Historically, they excavated deep nesting chambers into the soft coastal soils, sand dunes, and forested hillsides of Bermuda, shaded by native cedars and palmettos. Today, due to the severe restrictions of their remnant breeding grounds, their terrestrial habitat is almost entirely artificial. They currently inhabit hand-poured concrete burrows meticulously designed by conservationists to replicate the thermal and protective properties of natural soil burrows. These concrete domes are situated on small offshore rocky islets characterized by rugged limestone karst formations and sparse, salt-tolerant coastal vegetation. The environmental elevation of these current habitats is perilously low, making them exceptionally vulnerable to catastrophic saltwater inundation during severe hurricane events. The newly restored habitat on Nonsuch Island, characterized by higher elevations, deeper soils, and a restored native Bermudian forest canopy, represents a return to the ideal, historically accurate terrestrial habitat for the species.

Marine habitat usage is defined by cold, highly productive, deep-water pelagic zones. Through the deployment of modern GPS tags and archival geolocators, marine biologists have constructed comprehensive habitat suitability models. These models indicate that the Bermuda Petrel targets specific hydrographic features far beyond the territorial waters of Bermuda. Behaviorally deduced foraging habitat is best predicted by warmer sea surface temperatures interacting with deep ocean environments, explicitly pointing to the dynamic edges, eddies, and convergence zones of the Gulf Stream frontal system. These upwelling zones bring cold, nutrient-rich waters to the surface, creating massive blooms of phytoplankton that support the complex mesopelagic food webs upon which the petrels depend. During the non-breeding season, they prefer the cold, deep-sea waters located off the continental shelves of Nova Scotia and Newfoundland, as well as the deep oceanic basins northwest of the Azores.

Behavior

The Bermuda Petrel leads a life shrouded in oceanic mystery, defined by highly specialized behavioral adaptations. Terrestrially, they are strictly nocturnal, a behavior likely evolved to evade diurnal avian predators such as gulls and birds of prey. They approach the nesting colonies only under the cover of darkness, performing complex, sweeping aerial courtship displays in the night sky above the islets. It is during these nocturnal gatherings that they emit their namesake vocalizations—a series of eerie, haunting, and drawn-out cries that peak in intensity during the autumn arrival and winter courtship phases.

At sea, their behavior is governed by the tireless demands of pelagic foraging. Recent deployments of miniaturized multi-sensor biologgers, including accelerometers and time-depth recorders, have unveiled the hidden behavioral states of the petrel. Accelerometry data identifies three distinct flying-related behaviors and three water-related behaviors. Consistent with their morphology, Bermuda Petrels employ “dynamic soaring,” an incredibly energy-efficient flight strategy that exploits wind gradients and updrafts generated by ocean waves to travel vast distances with minimal caloric expenditure. Consequently, “flying-non-flapping” is the most frequently recorded behavioral state across all conditions, accounting for more than three-quarters of their total time at sea.

However, they are not entirely reliant on passive soaring. Accelerometers detected an infrequent but critical “flying-intensive” state, which researchers interpret as “aerial dipping”—a specialized foraging technique utilized by gadfly petrels to snatch prey from the water’s surface without landing. Water-related behaviors include “active” swimming, “inactive” resting, and “intensive” behaviors associated with scavenging or aggressive prey seizing.

Interestingly, the biologging data highlights a distinct diel (24-hour) activity pattern. Flight-related behaviors sharply increase in correlation with negative sun elevation values, indicating that Bermuda Petrels are significantly more active in flight during the nighttime. Conversely, resting and water-related behaviors are more frequently observed during daylight hours. This nocturnal flight hyper-activity is a direct evolutionary response to their specific dietary targets.

Feeding

The dietary ecology of the Bermuda Petrel is fundamentally linked to the deep scattering layer and the phenomenon of diel vertical migration. Bermuda Petrels are specialized consumers of micronekton—small, actively swimming marine organisms ranging from one to ten centimeters in length. While comprehensive, invasive stomach content analyses are difficult to perform on such a critically endangered species, visual observations, guano analysis, and comparative studies of closely related gadfly petrels provide a robust picture of their diet. The primary diet consists of small fish, squids (cephalopods), and shrimp-like crustaceans.

Among the fish, they heavily target Myctophidae, commonly known as lanternfish. These bioluminescent mesopelagic fish spend their days at depths of hundreds of meters, safely beyond the reach of avian predators. However, under the cover of darkness, these organisms migrate in massive numbers to the upper echelons of the water column to feed. The cephalopod component of their diet is rich in deep-water families such as Cranchiidae (glass squids), Onychoteuthidae, and Histioteuthidae, alongside various decapod and isopod crustaceans.

To capture this prey, the Bermuda Petrel relies almost entirely on surface-skimming, aerial dipping, and extremely shallow dives. Time-depth recorder data unequivocally demonstrates their limited diving capacity, with 99.99% of recorded dives barely breaching 0.1 meters in depth. This confirms that the capture of meso-bathypelagic prey must occur exclusively at night when these organisms reach the uppermost surface layer of the ocean.

During the breeding season, foraging takes on critical urgency. Adults process captured prey in their proventriculus, converting the highly lipid-rich lanternfish and crustaceans into a partially digested, oily, vitamin-rich gruel and pure stomach oil. Upon returning to the dark nesting burrow, the adult regurgitates this energy-dense payload directly into the waiting chick’s beak. As the nestling matures, the diet transitions from pure oil and gruel to more solid, intact food items such as whole small squid. This biochemical conversion to stomach oil allows the adult petrels to forage over vast distances—often thousands of miles away near the North American shelf—without the food rotting, maximizing the caloric delivery to the solitary chick.

Breeding

The reproductive strategy of the Bermuda Petrel is characterized by extreme K-selection: a slow, meticulously extended breeding cycle defined by high parental investment, high adult survivorship, and very low fecundity. Bermuda Petrels mate for life, forming intense, long-lasting pair bonds, and exhibit profound philopatry, returning year after year to the exact same nesting burrow to breed. They are slow to mature, not reaching sexual maturity until they are at least five years old.

The breeding phenology operates on a rigid, highly synchronized annual calendar during the northern winter. Following the oceanic non-breeding season, adults begin to arrive in Bermuda around mid-October, reclaiming their burrows and engaging in nocturnal courtship flights. By mid-November, the pairs depart the islands entirely on a crucial “pre-breeding exodus.” This oceanic exodus lasts between 32 and 56 days (averaging 42 days), ending roughly between late November and mid-December. The purpose of this massive foraging trip is to build up the extensive fat and lipid reserves required for the grueling incubation period to come.

Upon returning from the exodus, the female lays a single, irreplaceable egg—typically between December 31 and January 31, with a mean lay date of January 10. If this egg is lost, predated, or broken, it is not replaced that season. Incubation duties are shared symmetrically between the male and female in alternating, multi-day shifts that demand immense fasting capabilities while the partner is at sea. The incubation period is exceptionally long, spanning a mean of 53 days, with hatching occurring between February 16 and March 26.

Once hatched, the chick requires an extraordinarily long fledging period, averaging 91 days. Initially brooded continuously, the chick is soon left alone in the dark burrow while both parents embark on long-distance foraging trips to harvest micronekton. The young birds, fattened on a diet of regurgitated squid, fish, and stomach oil, rapidly gain mass, often outweighing their parents before a slimming period. Finally, under the dark skies of late May or June, the fully feathered chicks emerge from the burrows, exercise their flight muscles on the rocks, and launch themselves out to the open sea, not to return to land for several years.

Threats

The existential struggle of the Bermuda Petrel is defined by a gauntlet of historical tragedies and modern environmental pressures. The initial collapse of the species in the early 17th century was swift and merciless. When early Spanish seafarers avoided the islands due to the eerie cries of the “devils,” they nonetheless left behind a catastrophic ecological legacy: feral hogs, introduced to breed as living food stores for passing ships. These boars systematically rooted up the fragile terrestrial burrows, consuming eggs, chicks, and vulnerable adults. Following English colonization in 1609, the introduction of black and brown rats, feral cats, and domestic dogs further accelerated the slaughter. Despite one of the world’s earliest known environmental protection laws—a 1620 proclamation by the Bermudian Governor “against the spoyle and havocke of the Cohowes”—the species was effectively extirpated from the main islands.

In the modern era, having retreated to four tiny, rat-free rocky islets, the species faces an entirely different suite of threats. One of the most immediate biological pressures comes from a native species: the White-tailed Tropicbird, locally known as the Longtail. Tropicbirds, which breed slightly later in the spring, continually target the petrels’ nest sites. Being heavier and more aggressive, prospecting Tropicbirds frequently entered Cahow burrows, resulting in the brutal death of the smaller, defenseless petrel chicks. This nest-site competition was brilliantly mitigated by Dr. David Wingate through the invention of the “baffler”—a specialized wooden plate fitted over the burrow entrance. The baffler features an elliptical entry hole precisely measured at 127 millimeters wide by 57 millimeters high. This exact dimension takes advantage of physiological differences; it allows the flatter, slimmer Bermuda Petrel to slip through, but physically blocks the rounder, bulkier bodies of the Tropicbirds.

Today, the preeminent threat is anthropogenic climate change, specifically the escalating intensity of tropical cyclones and accelerating sea-level rise. The low-lying limestone rocks are actively crumbling into the sea. In 2003, Hurricane Fabian struck Bermuda with devastating force, pushing 35-foot waves completely over three of the breeding islets. The storm surge swept away established concrete burrows and eroded the rock face, “melting away like sugar cubes” in the words of conservationist Jeremy Madeiros. Furthermore, coastal light pollution from the Bermuda International Airport and surrounding infrastructure poses a navigational hazard; intense point light sources can disorient the nocturnal petrels during misty or rainy conditions, drawing them in like moths to collide with structures. Industrial fishing operations in the distant North Atlantic, particularly squid nets and long-lines, also present a looming threat of bycatch and resource depletion within their oceanic foraging grounds.

Migration

The concept of migration for the Bermuda Petrel is intrinsically linked to its dual-foraging strategy and vast pelagic wandering. Rather than a linear point-A-to-point-B journey typical of songbirds, their movement is a dynamic, continuous oceanic patrol covering staggering distances across the northern Atlantic. For USA birders, understanding this migration is key to knowing when and where to look for them off the eastern seaboard.

During the breeding and chick-rearing season, the species employs a dual foraging strategy designed to balance the energetic demands of the chick with the survival of the adult. Utilizing archival geolocators and highly precise GPS tags deployed on chick-rearing adults, researchers have mapped two distinct types of trips. Short foraging excursions are concentrated relatively close to the colony, optimizing rapid food delivery to the rapidly growing nestling. Conversely, adults will periodically abandon the chick for extended “long trips” dedicated to self-maintenance. These long-haul journeys take the birds far beyond the core home range, maximizing their own fat reserves before returning to the grueling demands of parental care.

When the breeding season concludes in June, the entire population initiates a massive, ocean-wide dispersal for the five-month non-breeding season. Geolocator tracks recovered between 2009 and 2011 confirmed that the birds do not remain in the warm Caribbean or Sargasso Sea. Instead, they migrate extensively to colder, highly productive waters, following the abundant micronekton of the Gulf Stream frontal system.

The tracking data reveals two core, widely separated epicenters of activity during the summer and autumn months (July to October): the first lies beyond the continental shelf of the eastern United States coast, stretching up to the deep-sea waters between Bermuda, the Nova Scotia shelf, and Newfoundland, Canada. This is precisely why pelagic birding trips out of North Carolina occasionally strike gold with a Cahow sighting. The second core area sits far to the east, in the deep mid-Atlantic to the north and northwest of the Azores archipelago in European waters. In these desolate, turbulent regions, the petrels undergo their annual molt, regenerating their flight feathers while wandering endlessly over the abyssal plains until the biological clock summons them back to the limestone rocks of Castle Harbour.

Conservation Efforts

The survival of this species is the result of what is universally recognized as one of the most successful, hands-on, long-term conservation projects in history. Following the foundational work of Dr. David Wingate, who spent 40 years fighting off rats, building concrete burrows, and planting the seeds of restoration, Senior Terrestrial Conservation Officer Jeremy Madeiros recognized that passive protection was insufficient against the looming specter of climate change.

Inspired by techniques used on the Gould’s Petrel in Australia, Madeiros initiated a daring translocation project. Between 2004 and 2008, 175 near-fledged chicks were extracted from their vulnerable burrows on the rocky islets, tucked securely into modified tomato boxes, and transported by boat to the elevated, restored habitat of Nonsuch Island. In the artificial burrows of Nonsuch, these chicks were hand-fed daily on fresh squid and anchovies, ensuring they imprinted on the new, higher-elevation location before fledging.

To encourage their return from the open ocean years later, researchers deployed solar-powered sound systems that broadcasted the petrel’s nocturnal courtship cries over the island, creating an acoustic beacon—what Madeiros humorously termed “the hottest cahow nightclub in the island.” The strategy was a masterstroke of ecological engineering. By 2009, the first translocated birds returned to breed, producing the first chick hatched on Nonsuch Island in nearly 400 years. With returning translocation rates hitting an astonishing 49%, the Nonsuch colony has rapidly expanded, driving the record-breaking population numbers we see today.

Cultural Significance

The spectacular resurrection of the Bermuda Petrel from the ashes of extinction has cemented the species not merely as an ornithological marvel, but as an emblem of Bermudian cultural identity and a testament to natural resilience. In 2003, acknowledging its profound historical legacy, unparalleled endemism, and the sheer grit required to save it, the Bermuda government officially declared the Cahow as the National Bird of Bermuda.

The cultural reverence for this resilient seabird is prominently displayed in the nation’s pocketbooks. The Bermuda Petrel has been a fixture on Bermudian currency for decades. The bird’s image has graced various iterations of the country’s beautifully designed banknotes, most recently featured alongside King Charles III on the vibrant, high-security $2 and $5 bills issued by the Bermuda Monetary Authority. The $5 note, known for its eye-pleasing design, even won the Banknote of the Year award from the International Bank Note Society. The petrel is also engraved on the reverse of the ubiquitous 1-dollar coin, reinforcing its daily presence in the lives of Bermudians.