Research sheds light on great blue heron's shocking flight path

The great blue heron is an impressive-looking bird, and researchers are now finding its migratory flight is also remarkable.

'Two years ago, she flew 68 hours straight'

Great blue herons can fly astonishingly long distances over open ocean. (Submitted by Dwaine Oakley)

Her journey started in Maine with a plan to travel south. Unfortunately, a direct flight was out of the question this year. So instead, with just a small backpack in tow, Harper flew to Nova Scotia then non-stop for 40 hours to Bermuda. 

There she hung out for three days, fuelling up, before embarking on another journey — a 30-hour flight to the Bahamas. After an eight-hour layover, she finally headed to her final destination — Guajaca Uno, Cuba.

Although she travels frequently, Harper is not one of those adventure-seeking enthusiasts you find digging through social media for the world's top destinations. Harper is a great blue heron caught in 2019 and strapped snug with a solar-powered GPS. 

"We've seen the last three years in the fall that she's taken these long over-the-open-ocean flights down to Cuba," said Danielle D'Auria, a wildlife biologist with Maine's department of inland fisheries and wildlife.

The small GPS tracker has not affected Harper's behaviour. (Maine Inland Fisheries and Wildlife)

"Two years ago, she flew 68 hours straight."

D'Auria said over the years they have been watching her they have found the GPS tracker is not weighing her down or affecting her behaviour.

"It's only about one inch by two-and-a-half inches and then about one inch high," D'Auria told Island Morning host Mitch Cormier.

"It's relatively small compared to a great blue heron."

Flying fast and high

The goal was to understand what might be leading to the decline in Maine's coastal nesting population, said D'Auria. 

"We wanted to kind of examine some more closer movement information to see what they're doing, how far they're foraging their home range and maybe it would alert us to some problems," she said. 

"But one of the bonuses is that these transmitters, because they stay on them, we can also follow them when they leave the state and when they migrate."

Biologists prepare to release Harper, holding her bill to keep everyone safe. (Jen Nadeau/Maine Inland Fisheries and Wildlife)

It's created a whole new understanding about the graceful giant in the skies and also shed light on just how remarkable its migratory flight is. 

"She gets up to 60 to 70 miles per hour, and that's primarily with the help of some strong winds," said D'Auria.

"But they do go as high as about 4,000 feet, and sometimes they're right over the ocean." 

'Pretty remarkable'

The results were surprising to even D'Auria, who said she didn't expect the bird to be able to soar for so long without touching the ground. 

As Harper continues to help researchers understand more about her species, D'Auria said she hopes it can be used to help keep the population healthy for years to come.   

"It's pretty remarkable to think that these birds that you see just waiting around in the wetlands might be going as far as Cuba or Haiti and then coming back and doing these journeys repeatedly."

The GPS backpack is expected to stay with Harper for the rest of her life. 

"We don't want it to fall off partially, which could really cause trouble for the birds," said D'Auria.

"We want it to be secure. And so, therefore, we make it stay on for years."

With files from Island Morning


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