Where birds go in a hurricane

Faraaz Abdool is looking for the Abaco Parrot; and though the prognosis appears bleak, he is hoping that these ground-nesting birds found cover on other islands of the Bahamas during the long rain of Dorian. All photos by Faraaz Abdool

Hurricanes are massive rotating weather systems packed with howling winds and torrential rain. Birds are tiny, feathered creatures, some weighing no more than a few grams. It’s almost unfathomable that many birds are able to weather storms which flatten entire habitats. The truth is the ability of a bird to survive one of these mega-storms depends on a few factors.

Firstly, let’s consider how different birds deal with an approaching weather system. Some prefer to hunker down while others take to the sky in last-ditch attempts to escape. A particular species’ predisposition to stay or flee is crucial in determining how well it fares in extreme weather conditions. As a hurricane forms over the open ocean, seabirds are the first witnesses on the scene. Magnificent Frigatebirds, Sooty and Bridled Terns along with pelagic species like storm-petrels are often sucked into the storm as it develops over water.

Adept fliers, many of these birds ride the winds and harsh conditions until they reach a calmer area  – often a patch of open water which may eventually become the eye of the hurricane. Once this occurs, these birds are trapped within the eye of the storm, unable to escape through the violent vertical walls of the hurricane. So many birds were trapped within the eye of Hurricane Dorian a few weeks ago that Doppler Radar picked them up from space.

Royal Terns are sometimes forced inland due to slow moving hurricanes.

Sooty Terns, ocean-going birds, are among the most frequently trapped within hurricanes and are often deposited far inland after the storm dissipates.

Coastal birds such as Black Skimmers and Royal Terns may choose to stay close to ground while the storm passes, but this strategy is only effective when a hurricane passes quickly. Hurricane Dorian was an extremely slow-moving storm, causing many of these birds to be displaced far inland. Once birds become trapped within the hurricane, they tend to be pushed along even after the hurricane has weakened significantly.

Other species of birds that become trapped within a hurricane are migratory birds, escaping the approaching winter in the north. Their southward migration unfortunately coincides with the Atlantic hurricane season and they are very susceptible to being ‘entrained’ within storms. Birds which do not make it to the relative safety of the eye of the hurricane, tend to fly downwind to cover as much distance at the highest possible efficiency, making all efforts to avoid areas of torrential rain. Those that cannot avoid the areas of heaviest rainfall often perish as their waterlogged feathers are unable to keep them airborne for the length of time necessary to escape the storm. Some birds may not make it to the eye of the storm but manage to skirt around the hurricane. Tragically, this may result in the bird making landfall further north from where it was picked up!

Birds also must contend with the effects of storms on land. Even if they manage to survive the passage of the hurricane, they would still need to feed to ensure they can complete their southward journey. Relentless wind and rain wreak havoc on vegetation and insects, toppling trees and stripping them bare of leaves. Even storms with weaker winds can still suffocate vegetation and the entire leaf-litter ecosystem from widespread flooding. For birds that were displaced on their migration, this dearth of food can prove lethal.

 

Birds like this Gray Catbird pass over the Gulf of Mexico during their southbound migration, often having to dodge hurricanes at peak strength in the Gulf.

Small, migratory birds like the Northern Waterthrush depend on areas that are rich in invertebrate life for nutrition.

Species of birds that prefer to shelter in place fare quite differently. Their survival is often closely tied to the availability of appropriate shelter. Thick forests with large trees can protect some, buffering the high winds as the birds shelter closer to ground level. When faced with danger, birds do what provides the highest level of comfort to them – which may not always be what guarantees their survival.

The Abaco Parrot – also known as the Bahama Amazon Parrot – is one such unlucky example of where sheltering in a comfort zone turned out poorly. Abaco Parrots are found in the pine forest habitats of Abaco and Great Inagua islands in the Bahamas, and are unique among parrots found in the New World as they are the only species that has adapted to nesting in ground cavities. With the approach of Hurricane Dorian, it is likely that many of these parrots retreated to their underground cavities where they would be sheltered from the whipping winds of the hurricane. Heartbreakingly, these islands were largely inundated by a massive storm surge that likely flooded the Abaco Parrots’ hideouts. Conservationists will be on the look out for any survivors.

Other sedentary and endemic species also suffer in catastrophic storms. Without a natural wanderlust, these birds reliably choose to shelter in place – often with less-than-ideal consequences. Hurricane Matthew in 2016 absolutely ravaged the Bahamas, rendering one of its endemic species effectively extinct. It was only two years later after another frantic search that a single Bahama Nuthatch was found within the pine forest on Grand Bahama Island. Now, with the passage of Hurricane Dorian, odds are stacked higher than ever against the survival of this species.

The burning question must be addressed however: how is it that these birds that have endured hurricanes for millennia are suddenly disappearing? Within the Bahamas alone, much of the native pine forest has been removed for urbanization; introduced animals like dogs, hogs and cats decimate native wildlife, and human-ignited fires remain a constant occurrence. This situation is unfortunately mirrored in countless other territories, with frighteningly similar results. The Cozumel Thrasher is likely extinct due to invasive Boa Constrictors, the final nail in the coffin being a double hit by Hurricanes Emily and Wilma in 2005. 

  Shorebirds like this Whimbrel sometimes fly directly into hurricanes, many times emerging unscathed as they are powerful flying machines – a famous tagged Whimbrel called Goshen successfully navigated Hurricane Irene in 2011, deciding to rest on Guadeloupe before continuing her journey southward. She was shot and killed within a few hours of her arrival there.

We must all put a hand to help. Let’s replant and encourage the growth of native trees. Let’s avoid spraying pesticides in our gardens so that insects can begin to thrive. We need to ensure that the building blocks of the food chains are healthy, so that when migrants arrive in their seasons, they can find food reliably. Let’s make every effort to leave ancient forests undisturbed. Let’s avoid destroying habitats for birds; let’s avoid killing them for sport. Birds, majestic creatures that successfully navigated hurricane after hurricane in the past, should not be undone by the greedy hands of humans.

SOURCES

mnn.org
birdcast.info
orlandosentinel.com
forbes.com