DNR aids effort to study, help snowy owls
Jan. 28, 2016
From Saginaw Bay to Sault Ste. Marie and Kalamazoo to Escanaba, people across Michigan this winter have been reporting an influx of snowy owls from their Arctic tundra home territory.
These beautiful white birds, with piercing yellow eyes and a nearly 5-foot wingspan, are North America’s largest owls, by weight.
The reason the owls unpredictably travel so far south – sometimes in massive movements known as “irruptions” – is not well understood by biologists, but the behavior is linked to food supply, the number of chicks the owls produce in a given year and weather.
Snowy owls often arrive in Michigan weakened and starving, dehydrated and infested with mites. Others die along their extended flight paths, which have taken them as far south this winter as Kansas and all along the northern tier states, the Great Lakes and out east to the Gulf of St. Lawrence.
When the owls move south, Michigan Department of Natural Resources offices typically receive several phone calls reporting snowy owl sightings or birds appearing sick or injured.
Many of those calls were received in the Upper Peninsula, as an early, sudden arrival of numerous snowy owls was reported in mid-October.
Snowy owls are protected by federal law and it is illegal to possess an owl, its feathers or body parts without proper permits. Researchers suggest contacting the DNR if an owl is found injured, sick or dead.
“When we receive a call regarding an injured bird, we will either have the caller drop the bird off at the DNR office or, if feasible, we will pick up the bird,” said Erin Largent, a DNR research wildlife technician at Marquette. “We then take the injured bird to the Gwinn-Sawyer Veterinary Clinic.”
The vet will assess damage to the owl and either euthanize the bird if the injuries are too severe or treat the owl and transport it to a rehabilitator.
On Oct. 19, Jerry Maynard and Bob Jenson, co-founders of the Chocolay Raptor Center in Harvey, rescued a snowy owl from a municipal compost facility in Marquette. This owl was among those to arrive in the October influx.
“We got a call that it couldn’t fly and did not look healthy,” Maynard said. “Exam showed it to be seriously underweight and emaciated, and we could find no other injuries.”
The owl was heavily infested with mites. Maynard sprayed the bird to remove the mites and began treatments for dehydration.
During the first 24 hours, snowy owls being rehabilitated are tube-fed a special formula with easily digestible proteins and sugars. As owls recover, they eat frozen mice, rats, chicks and quail.
If all goes well, the owls are released back into the wild, often within a few weeks.
Of six owls brought to the Chocolay center from the original October influx, only two survived and were released Nov. 22 at a Marquette golf course. Maynard and Jenson use the releases as an opportunity to educate the public.
Meanwhile, sightings of owls continued throughout the state as 2015 came to a close, including a Nov. 23 report of a snowy owl sitting on the arm of a lamp post on the Mackinac Bridge.
On Dec. 17, the DNR's Newberry office got a call about a snowy owl west of the town of Curtis in Mackinac County.
“The caller moved it from the center of the road to the side of the road and called me at home, and other folks called the office, so we all heard about it pretty early,” said Sherry MacKinnon, a DNR wildlife ecologist at the Newberry office.
This was a young owl, starving and unable to leave the roadway on its own.
DNR staff fed the owl, dusted it for biting lice and brought it to the Chocolay Raptor Center.
Snowy owls hunt over open territory and often will sit on telephone poles, light standards, buildings or even small knolls or dirt berms.
Largent got a call about a dead snowy owl under a light post at a lakefront hotel in Marquette.
“I picked up the carcass, which was still warm, and put a necropsy tag on it with all the pertinent information and sent it down to the lab for necropsy,” Largent said.
The DNR’s Wildlife Disease Laboratory is located in Lansing. Personnel there are helping researchers with “Project SNOWstorm” determine the potential environmental effects of the owls’ southward journeys.
Partners in the international project are studying snowy owls, alive and dead, to determine more about their behavior, potential effects from chemicals, causes of death and genetics.
Some live owls are being tracked with solar-powered GPS transmitters. Owls are nicknamed and their movements are plotted on maps on the project website. In January and February 2015, four snowy owls in Michigan – captured in Detroit, Saginaw, Grand Rapids and Pickford – were fitted with tracking devices.
When a dead owl is sent to the DNR lab, personnel routinely perform a gross necropsy (animal autopsy) to determine or confirm the cause of death and, if warranted, perform a microscopic examination (histopathological) of fixed tissue sections to look for evidence of disease.
“We generally submit a piece of every organ (brain, heart, lungs, liver, spleen and kidneys) when we are requesting this (histopathological) testing,” said DNR lab technician Julie Melotti. “Since this examination is at the cellular level, it allows the pathologist to see something that might not be evident on just a gross examination and can help determine if there is a disease process at work and can aid in our diagnosis.”
Thomas Cooley, a DNR wildlife biologist and pathologist at the lab, said several tasks are performed on snowy owls with the lab’s participation in Project SNOWstorm.
“We are doing a series of measurements, taking a series of photos, taking tissues for histopathological examination, taking tissues for West Nile Virus, taking fat and muscle tissue samples, evaluating the physical condition of the animal by the gross appearance of the breast musculature and taking livers for metals analysis,” Cooley said.
The lab began participating in the project in January 2015.
Melotti said feathers also are sampled from various parts of the owl’s body and any feather lice on the carcass are collected.
“We also give a score (1-5) on the general condition of the carcass and on the physical condition of the bird,” Melotti said. “All of these samples will then be shipped to the coordinators of Project SNOWstorm.”
Since the concentrated snowy owl irruption in October, the DNR lab has received two dozen snowy owls for necropsy – 14 from the U.P. and 10 from the northern Lower Peninsula.
“The main cause of death has been starvation or malnutrition and dehydration (17 owls), followed by vehicular traumas (4 owls), one electrocution and one diagnosed with a herpesvirus causing hepatitis and splenitis,” Melotti said. “One of these owls was sent out to be skinned for a study skin and we will perform our necropsy and get a diagnosis on it once we get the carcass back.”
Most of the owls are incinerated after necropsy. Several have been saved as study skins for education purposes.
Project SNOWstorm and some other snowy owl research efforts emerged over the past few years, beginning during a massive, perhaps once-in-a-century irruption in the winter of 2013-14, when snowy owls were recorded as far south as Florida and as far west as Hawaii.
A smaller, though still substantial, irruption followed the next winter. Even in non-irruptive years, some snowy owls generally wing their way to Michigan.
“While it might be the case that a small proportion of the owls that disperse are underweight or malnourished, the researchers who study these irruptions actually report that the birds that come south during major irruptions are fatter and healthier than birds that wander during non-irruptive years,” Maynard said.
Maynard encourages using caution before judging an owl to be too weak to fly or to be incapacitated in some way.
“Please resist the urge to try to catch these birds or to approach them too closely,” Maynard said. “It is far more likely that a quiet, unassuming snowy owl is just being a normal snowy owl.”
Since the initial snowy owl arrival in October, birds have continued to be reported across Michigan, but this winter so far does not appear to be a season of massive owl irruption.
Earlier this month, a snowy owl found emaciated near Deer Park in northern Luce County was brought to the DNR office in Newberry and then to the Chocolay rehab facility.
Maynard said the bird is recovering well after initially consuming the formula, has gained weight, was recently moved to an outdoor cage and is expected to be released in a public event sometime over the next several weeks.
As spring arrives, the snowy owls will make their way back north to the Arctic.
Watch a video of Maynard and Jensen releasing two rehabilitated snowy owls at a golf course in Marquette County.
See a DNR list of licensed Michigan wildlife rehabilitators.
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