Sunday 14 January 2018

Why Firehawks carry flames in their beaks

Australia's indigenous peoples have long observed "firehawks" spreading wildfires throughout the country's tropical savannas.

Australia is no stranger to fire: The hardy landscape is adapted to blazes, enduring many thanks to humans and lightning. But Australia’s Aboriginal peoples have long identified a third cause: birds.

In interviews, observations, and ceremonies dating back more than a century, the indigenous peoples of Australia's Northern Territory maintain that a collective group of birds they call “firehawks” can control fire by carrying burning sticks to new locations in their beaks or talons.

The idea is that these birds of prey use fires to help find food—making easy meals out of insects and other small animals trying to flee the blaze.

The anecdotes, compiled in a recent study published in the Journal of Ethnobiology, may lead some to rethink how fires spread through tropical savannas like those in northern Australia.

"We're not discovering anything," cautions co-author Mark Bonta, a National Geographic grantee and geographer at Penn State University. "Most of the data that we've worked with is collaborative with Aboriginal peoples... They've known this for probably 40,000 years or more."
The black kite (pictured, an animal at Madagascar's Tsimbazaza Zoo) is one of the birds thought to spread fire in Australia. 
For decades, people in northern Australia have considered firehawks—the black kite (Milvus migrans), whistling kite (Haliastur sphenurus), and the brown falcon (Falco berigora)—part of the natural order.

According to co-author Bob Gosford, an Australian indigenous-rights lawyer and ornithologist, these birds of prey thrive in wildfires, soaring and perching near the fire fronts that rage in Australia’s tropical savannas.

“Black kites and brown falcons come to these fronts because it is just literally a killing frenzy,” he said in a 2016 interview with the Australian Broadcasting Corporation. “It's a feeding frenzy, because out of these grasslands come small birds, lizards, insects, everything fleeing the front of the fire."

Each year, up to 75 percent of Earth’s tropical savannas burn—accounting for about half of the biomass that burns each year worldwide, according to one 2015 review.

Australia is no exception to this rule. From 1997 to 2011, some 18 percent of Australia’s 730,000 square miles of savanna were affected by fire each year, on average. Some regions see fires once every two years.

“I have seen a hawk pick up a smouldering stick in its claws and drop it in a fresh patch of dry grass half a mile away, then wait with its mates for the mad exodus of scorched and frightened rodents and reptiles,” wrote Waipuldanya Phillip Roberts in I, the Aboriginal, a 1964 autobiography of Roberts compiled by Australian journalist Douglas Lockwood.

“When that area was burnt out, the process was repeated elsewhere.”

When Gosford first stumbled across this passage, it later inspired him to collect firsthand accounts of the behavior, which he has doggedly pursued since 2011. Though he hasn’t witnessed it firsthand yet, some of his firefighter co-authors have.

Previously, some local experts had been skeptical of whether hawks were setting fires intentionally—or were merely doing so unintentionally.

“If [hawks] have missed the prey and perhaps grabbed a stick... they will then drop that stick or rock,” wrote Anthony Molyneux of the Alice Springs Desert Park in 2011. “If the stick is smoldering or on fire, it will then start another fire.”

The new study's sweep has impressed outside ornithologists, but more details will surely come to light.

Though Gosford and his colleagues solicited photos and videos of the behavior, they haven’t yet received any usable footage. They hope to document the behavior in the field later this year, by closely studying a series of controlled burns administered by local firefighters.

"The more word gets out on this, the better," says Bonta. "It's only a matter of time."

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