Whooping cranes arrive a month early for winter vacation

Whooping cranes arrive a month early for winter vacation
Two of the four whooping crane early birds that landed a month ahead of schedule at their wintering grounds at Aransas, Texas stretch their wings following their 4,000 km flight.Photo: US Fish and Wildlife Service Southwest Region.

With their babies now schooled on how to make their wings work, the flock of endangered whooping cranes from Wood Buffalo National Park (WBNP) is making its way south for the winter.

Four of the big white birds have already been spotted at their wintering grounds in Aransas, Texas, their presence confirmed by the U.S. Fish and Wildlife Service (USFWS) a full month ahead of their average arrival date.

“Oct. 15 is typically when we see the first whooping cranes arrive,” said Wade Harrell, the whooping crane recovery coordinator for USFWS. “These are probably what we call sub-adults; they’re not paired yet because they’re not breeding age. They’re sort of teenagers, two or three year-olds, and they usually come down first.”

How exactly do these magnificent birds complete their 4,000-km journey every fall? According to one biologist, migration is more of a marathon than a race, with the cranes taking their sweet time.

“They’re capable of completing the entire migration in about a week, but they usually complete fall migration over several weeks,” said Mark Bidwell, a species at risk biologist with the Canadian Wildlife Service. “In fall, most cranes depart the breeding grounds and fly over northeastern Alberta, crossing into Saskatchewan, and then they spend up to six weeks doing what we call staging in central Saskatchewan.”

According to Bidwell, staging is a period of time where the birds stop for several weeks to stock up on energy by feeding on fallen grain in agricultural areas once the local farmers are done harvesting for the season. During this time they will spend their evenings sleeping at night in shallow wetlands and lakes surrounded by agricultural fields.

Once they’ve had their fill, the birds will cross over the border into North Dakota, making their way through South Dakota, Kansas and Oklahoma before reaching the wintering grounds in Texas. They follow a similar route during spring migration.

A lot of what scientists know about the bird’s migration route comes from pioneering research conducted between the 1960s and 1980s, when the late Ernie Kuyt and his team of biologists from Environment Canada followed the cranes as they completed their journey.

Bidwell said modern studies on the whooping crane involve a more technological approach. Satellite transmitters are attached to the crane’s lanky legs, pinging off location signals as it heads south.

Should a fatality occur, biologists will notice a stationary signal. If they act quickly enough, the body can be collected for research.

Over 60 birds have been tracked this way since 2009. Further studies on the whooping crane’s movements are pending within the next few years, according to Bidwell.

Hazards on the route

Migratory birds might not have to deal with the inconvenience of checked bag fees or cramped seating when they fly south, but there are certainly challenges that can make their journey difficult and sometimes hazardous.

Weather and predators are always a threat, but it is the human factors that really pose a danger to the species, Bidwell said.

Though more research needs to be collected, Bidwell said power lines are a known danger for the cranes. When one of these large birds collides with the line, they can break their bones. Barbed wire fences pose a similar threat. Due to informative campaigns, hunters have become less of an issue over the years, but some birds are still shot.

As the cranes fly over northeastern Alberta, there are also concerns of the impact of oilsands and tailings ponds on the species’ health.

“Using the satellite transmitters, we are learning about their migration through the oilsands region,” Bidwell said. “Information that we obtain via the study with both government and industry will be used in mitigating risks and also implementing improved monitoring and deterrent programs in these areas.”

Luckily, Bidwell said, the crane often prefers natural landscapes like wetlands and marshes, rather than those modified by man – a preference that might be life-saving.

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