Seabirds That Hunt Hurricanes

Riders of the Maelstrom: The Seabirds That Hunt Inside Hurricanes

As a powerful cyclone traverses the open water, its colossal power churns the sea into a frenzy. This violent upheaval brings organisms from the abyss towards the light, creating a fleeting opportunity. For most animals, this signals a time to flee or hide. Yet for a select few predators, the chaos offers a meal for those capable of enduring the tumultuous weather. On a high, rocky plateau on a remote Atlantic island, a small seabird that is active at night senses the distant tempest. It is a storm forming more than 1,600 kilometres away, yet it presents not a threat, but an invitation. This bird is the Desertas petrel, and it is about to fly towards the hurricane.

The Unseen Tempest

A tropical cyclone represents a vast engine of destruction. Fuelled by thermal energy from the sea's upper layer, it expands into a formidable spinning air column that travels over the planet. The weather system can be hundreds of kilometres wide, with external bands crackling with lightning. Underneath, gales reaching speeds of 240km/h whip the water into a chaotic state of gigantic swells. For most seabirds, this immense force is a clear signal to take evasive action. Many will abandon food-gathering excursions and stay on land. Others undertake huge detours, flying for vast distances to bypass the perilous high-velocity winds.

An Instinct for Avoidance

Different species have developed unique strategies to survive these meteorological titans. Frigatebirds, for example, ascend to very high elevations. They use the rapid air currents at the cyclone's edge to bypass it quickly. Even the mighty albatross, a bird renowned for its mastery of strong gales, will look for refuge. These expert gliders often find tranquility within the storm's calm center, waiting for the fury to pass. This avoidance instinct is a fundamental survival mechanism. The violent air currents and tumultuous seas are simply too perilous for most forms of life to endure, let alone exploit.

An Unlikely Hunter

However, not every creature views these storms as a direct menace. For a select few, the tempest's incredible force delivers a feast. Edible organisms such as octopus, squid, and cuttlefish are pulled from the ocean’s lower regions. This sudden bounty creates a banquet for any predator equipped to handle the conditions. One such animal is the Desertas petrel (Pterodroma deserta), a little, nimble seabird characterized by its long, thin wings. This particular bird actively pursues the strongest storms, viewing them as a chance to get a free ride and feed on the spoils.

The Scientific Quest

For years, the behaviour of the Desertas petrel remained a mystery. In 2015, a team of researchers led by Francesco Ventura, a biologist at the Woods Hole Oceanographic Institution, set out to investigate the secrets of their lives over the open ocean. Their work took them to the rugged and isolated island of Bugio in the Madeiran archipelago. This is the only known breeding colony for this species in the world, hosting fewer than 200 pairs. To reach the nesting sites, the scientists had to scale near-vertical cliffs to a high plateau covered with burrows, the birds’ homes.

Journey into the Storm

The team affixed extremely lightweight GPS devices to the petrels. When the birds came back to their nests weeks later, the scientists could retrieve the devices. The information they downloaded was astonishing. The trackers showed that the petrels embarked on some of the lengthiest food-seeking journeys ever documented for any animal. They covered distances as great as 12,000 kilometres over deep, open waters, journeying all the way from Africa to the New England shoreline and returning. Most remarkably, the information indicated the birds were not avoiding storms. Instead, they were deliberately flying into them.

A Calculated Interception

The study, published in the journal Current Biology, monitored 33 petrels across four breeding seasons. The information revealed a consistent and baffling strategy. Upon departing their colony, the birds would often select a route that would bring them nearer to a cyclone many hundreds of kilometres distant. Unlike other seabirds, this “hypermobile flier” did not circumnavigate the storm or seek the calm of its eye. On the contrary, they purposefully moved toward them, entered the storm's powerful wind fields, and then trailed its path for several days over vast distances.

The Hurricane’s Banquet

The reason for this perilous behaviour lies in the ocean's reaction to the storm. As a hurricane passes, its strong gales agitate the water. This process, known as upwelling, pushes cool, nutrient-rich water from the abyss up towards the light. This sudden nutrient injection fuels a massive bloom of phytoplankton, the microscopic algae at the base of the marine food web. Zooplankton arrive to consume the algae, and they are pursued by bigger hunters that normally reside in the ocean's deep “twilight zone.” This creates a rich, available meal for the petrels.

Masters of the Wind

Desertas petrels are exceptionally energy-efficient fliers. They use a technique known as dynamic soaring, which enables them to journey over great distances without flapping. By moving between air masses of different speeds—such as the slower air near the sea surface and the faster winds just above it—they harness power from the wind itself. Their extended, narrow wings provide superior lift and reduce drag, making them anatomically perfect for gliding with minimal effort. This skill allows them to navigate the turbulent conditions within a storm that would overwhelm other birds.

An Innate Weather Map

The petrels’ flight patterns indicate they possess an incredible, innate knowledge of the North Atlantic’s predictable wind systems. Caroline Ummenhofer, a scientist at Woods Hole and co-author of the study, noted the precision of their flights. The birds seem to predict and react to wind patterns on a scale that encompasses the entire ocean. They skillfully exploit the powerful tailwinds generated by cyclones to cover vast distances at high speed. This enables them to get to the productive feeding areas created in the storm’s wake with remarkable efficiency. None of the birds tracked by the team were harmed by the storms.

Avian Meteorologists

The Desertas petrel is not the only bird with a mysterious connection to major storms. The Veery thrush, a diminutive songbird, has demonstrated an uncanny ability to predict the intensity of the Atlantic hurricane period. A study by Dr Christopher Heckscher of Delaware State University found that these birds adjust their breeding habits based on the forecast. In years destined for an intense hurricane season, the Veeries produce fewer sets of eggs and depart on their southern migration sooner. This lets them finish their journey before the most dangerous weather systems arrive.

A Mysterious Forecast

How the Veeries accomplish this forecast months in advance remains a puzzle. The birds’ migration from North America to Brazil coincides with peak hurricane season. One theory suggests they sense large-scale weather patterns forming over their South American wintering grounds. Changes in rainfall and food availability may provide cues that trigger a physiological response, which modifies their reproductive habits. This behaviour, observed over two decades, has proven to be a more accurate predictor of storm activity than many human-made meteorological models, highlighting a profound connection between animal behaviour and global climate systems.

The Perils of the Storm

While some birds have adapted to exploit storms, for many others, they represent a mortal danger. Less agile seabirds are frequently hit hard. Powerful gales can force them hundreds of kilometres off course, away from vital foraging areas. In the winter of 2013-2014, a series of severe Atlantic storms resulted in a mass mortality event. The bodies of almost 60,000 dead seabirds appeared on European coastlines. Most had perished from starvation, unable to find food in the turbulent waters. Such events demonstrate the fine line between opportunity and disaster.

A Changing Climate, A Shifting Sky

The growing threat of climate change adds a new layer of uncertainty. As global temperatures rise, hurricanes are projected to become more intense and possibly more frequent. This could have unpredictable consequences for avians such as the Desertas petrel. While stronger storms might create more abundant feeding opportunities, they also increase the risks. The delicate balance these birds have struck with one of nature's most powerful forces could be disrupted. The increased intensity of storms could push conditions beyond what even these expert storm-riders can endure.

The Toll on Marine Ecosystems

The impact of more frequent, powerful hurricanes extends deep below the surface. While upwelling can create temporary feeding hotspots, the overall effect of intense storms on marine ecosystems is often devastating. The sheer force of the waves can destroy fragile coral reefs, which can take decades to recover. It can decimate shellfish beds and disrupt the nesting sites of sea turtles. The massive influx of freshwater from rainfall can also alter the salinity of coastal waters, harming many species.

Conservation Concerns

The Desertas petrel is listed as a vulnerable species. The entire global population breeds on the single, precarious plateau of Bugio island. This situation renders them unusually vulnerable to threats. Historically, the birds faced pressure from human harvesting and introduced predators like cats and rats. While conservation efforts, including habitat restoration projects by organisations like LIFE Natura, have helped, new dangers are emerging. Marine pollution, particularly plastics, and the overarching threat of climate change pose significant risks to their long-term survival.

The Fragility of Bugio

Bugio island is a protected nature reserve, a critical sanctuary for the petrels and other wildlife, including a colony of Mediterranean monk seals. The island’s steep, crumbly cliffs make it naturally inaccessible, offering some protection. However, the plateau where the petrels dig their burrows is fragile. Soil erosion, exacerbated by past overgrazing from introduced goats and rabbits, threatens the stability of their nesting habitat. Ongoing conservation work is focused on restoring native vegetation to stabilise the soil and ensure the colony remains viable for future generations.

The Technology of Discovery

Our understanding of these incredible birds has been transformed by technology. The GPS trackers used by Ventura’s team are part of a revolution in wildlife monitoring. These devices have become progressively smaller, lighter, and more powerful. Modern tags, some weighing less than a gram, can now be fitted to even small birds without impeding their flight. Solar-powered trackers can collect and transmit data for years, providing an unprecedented window into the lives of migratory animals. This technology is crucial for understanding how animals respond to environmental changes.

A Window into a Secret World

The data from these trackers offers more than just location points on a map. Combined with accelerometers, they can reveal a bird’s behaviour—when it is flying, resting on the water, or actively foraging. By cross-referencing this information with environmental data on wind speed, ocean currents, and sea surface conditions, researchers can assemble a complete picture of an animal's life. This holistic view is essential for effective conservation. It allows researchers to identify critical habitats and understand the complex interplay between species and their dynamic environment.

The Future of Storm Riding

The remarkable story of the Desertas petrel's relationship with storms shows a remarkable element of adaptation. It demonstrates how a seemingly destructive force of nature can become an integral part of a species’ survival strategy. These birds have developed the ability to convert the turmoil of a hurricane into a predictable source of food, a testament to the resilience and ingenuity of life. As our planet’s climate continues to change, the fate of these storm-riding birds remains uncertain. Their continued existence depends not only on their extraordinary skills but on our ability to protect the fragile ocean world they call home.