The birds that fly into hurricanes
When hurricanes pass over the ocean they churn up creatures from the deep – a chance to feast for predators brave enough to weather the storm.
High on a rocky plateau, one small nocturnal seabird is nestled in its burrow, where far below waves lap gently against the cliffs. In the blackness of night, it senses a storm brewing 1,000 miles (1609km) from the coast of Morocco.
Drawing energy from the warmth of the ocean's surface, a tropical cyclone begins to form until a powerful column of rotating air is marching across the globe. The cyclone the bird senses is hundreds of miles wide, and lightning strikes speckle its outer bands, while 150mph (240km/h) winds churn the ocean waters below.
Hurricanes are known for their destructive force. Seabirds will often forgo foraging trips and stay ashore when they sense a storm is coming, or they'll fly hundreds of miles to circumnavigate the dangerously strong winds. Frigatebirds climb to extreme altitudes to quickly bypass a cyclone at high speeds, and even albatrosses – known for their ability to fly in high winds – seek calm in the eye of the storm.
But not all animals see them as a threat. For some, the fearsome energy of the storm provides a banquet, as delicacies from the ocean depths – like squid, octopus and cuttlefish – are dragged up to the surface.
One such predator is the Desertas petrel, a small agile seabird with long slender wings. This petrel seeks out the most powerful storms, seeing an opportunity to hitch a lift. It darts straight into the bands of spinning air, reaching areas within 200km (124 miles) of the eye of the storm.
"Honestly, I cannot imagine what the conditions would be like," says Francesco Ventura, a biologist and postdoctoral investigator at US ocean research organisation Woods Hole Oceanographic Institution. "They're pigeon-sized, just a few hundred grams, experiencing winds up to 100km/h [62mph] – most likely much more than that – and gigantic waves, with ocean swells up to 8m [26ft]. They're really amidst the madness of the storm."
When the tropical cyclone passes, continues Ventura, "the birds align their movement trajectory along the wake of the hurricane". Now, this delicate little bird rides on the tail of the storm, foraging on creatures churned up from the twilight zone.
We're all too familiar with the human tales of devastation associated with hurricanes, from lives and homes lost, to flattened and drowned cities. But these mega-storms also impact the oceans – turning life upside-down for the myriad creatures that live beneath the waves.
Tropical cyclones – otherwise known as hurricanes or typhoons, depending on where they crop up in the world – churn the ocean as they travel, thrusting warm surface water into the depths where it is trapped and can travel for thousands of miles before resurfacing. Meanwhile cool water wells up from the deep.
This underwater turmoil can have a profound negative impact on oceanic and coastal ecosystems, stirring up the seabed, destroying turtle nesting sites and decimating shellfish beds, sending migrating animals miles off-course, and smashing through delicate coral reefs.
However, this ocean churning can also kickstart phytoplankton blooms as the nutrient-rich waters rise to the upper layers of the water column.........
© BBC
