DNR photo Michigan DNR wildlife biologist Christie Sitar holds an injured bald eagle in her arms. The bird, which was struck by a vehicle at the Schoolcraft-Luce County border, was taken to a wildlife rehabilitator last week.

By John Pepin

Michigan Department of Natural Resources

Earlier this week, along a snow-covered highway near the Schoolcraft-Luce County line, Michigan Department of Natural Resources Conservation Officer Jason Ruth pulled his vehicle over to the side of the road.

DNR wildlife biologist Kristie Sitar had arrived there in her truck too.

Sometime over the past few days, a vehicle passing the area had struck and killed a white-tailed deer. Crows, ravens and at least one bald eagle had found the carcass and began scavenging meat from the roadkill.

At some point, when a vehicle or vehicles sped past, the adult eagle flushed from the carcass and tried to fly away — likely to a branch in a nearby tree where it could overlook the scene.

But the tremendous bird, with a wingspan of nearly 7 feet, couldn t gain enough altitude on take-off before it too was struck by passing traffic and thrown down to the side of the road with the force of the impact.

Sitar and Ruth were now trying to recover the injured bird in hopes of getting it to a bird rehabilitation facility.

Slowly, but deliberately, Sitar approached the eagle that was downed in the snow away from the highway. She was able to capture the bird in her hands.

She and Ruth rolled a tarp around the eagle for the safety of the bird and its would-be rescuers. The eagle was taken to the Skegemog Raptor Center in Traverse City to be assessed further and treated.

Sitar said the prognosis for recovery is not good.

The eagle is being treated, with recovery possible, but it is a very slim chance due to severe paralysis, she said.

Metal bands are shown attached to the yellow legs of an injured bald eagle.

The eagle was determined to be a female that was wearing metal leg bands indicating it was banded as a juvenile 20 years ago.

Unfortunately, these eagle-vehicle collision incidents and outcomes are not as rare as one might hope especially along highways with higher speed limits, where roadkill and scavenging eagles frequently occur.

Ravens can get out of the way easily, but eagles are much bigger, and it often takes them five or more wing strokes to get out of the way of oncoming traffic, and since they are big and need a lot of room, they fly into the open area over the road to do so, Sitar said. A bird’s chances of a full recovery from this type of accident are very small, so we really want to avoid hitting them.

According to the website World Population Review, Michigan is home to about 800 breeding pairs of bald eagles, ranking seventh-highest among U.S. states, behind Alaska with 30,000 breeding pairs, Minnesota (9,800), Florida (1,500), Wisconsin (1,500), Virginia (1,100) and Washington (900).

In all, the U.S. has about 55,630 breeding pairs. Rhode Island, Utah and New Mexico each have less than 10 pairs.

Among large North American birds of prey, only golden eagles and California condors have larger wingspans than bald eagles.

A study on golden eagle collisions with vehicles at highway roadkill sites in Wyoming cited several factors affecting a higher number of eagle-vehicle collisions in fall and wintertime.

An adult bald eagle is shown flying from a branch against a clear, blue sky in Marquette County.

Vehicle collisions are a recurrent source of golden eagle deaths that cause an estimated 1% annual mortality in the western United States. Much of this mortality and the opportunities for mitigation occur in fall and winter when more typical eagle prey is hibernating or less available, which may increase scavenging by eagles the Modeling Golden Eagle-Vehicle Collisions to Design Mitigation Strategies research article read.

At the same time, roadkill of ungulates (hoofed mammals) typically peaks in winter, and cooler temperatures facilitate longer persistence of carcasses. Together, these factors make it more likely that golden eagle collisions with vehicles occur in the fall and winter…

Another research study, Golden Eagle Use of Winter Roadkill and Response to Vehicles in the Western United States, said vehicle collisions are a significant source of wildlife mortality worldwide, but less attention has been given to secondary mortality of roadkill scavengers, such as the golden eagle.

Primary mortality refers to the original vehicle collision with a white-tailed deer, for example. Secondary mortality would be eagle deaths at roadkill scavenging sites.

Researchers in the study sought to quantify golden eagle winter use of roadkill mammal carcasses and eagle flushing from vehicles in Oregon, Utah and Wyoming, as proxies for strike risk, using motion-sensitive cameras.

They monitored 160 carcasses and captured 2,146 eagle-vehicle interactions at 58 carcasses (one to 240 observations per carcass) during winters of 2016-2017, 2017-2018 and 2018-2019.

The researchers discovered that roadkill distance from the road is the easiest factor to manipulate,

with the dual benefits of increasing food availability to golden eagles and decreasing flush-related vehicle strike risk.

A technician looks inside the beak of a dead bald eagle during a lab examination.

“We recommend that roadkill be moved at least 12 meters (40 feet) from the road to increase eagle use and decrease flushing four-fold relative to behavior observed at the road edge,” the study read. “Because flushing from roadkill is believed to be the primary cause of eagle-vehicle strikes, informed roadkill management has the potential to reduce human-caused mortality of golden eagles.”

It stands to reason that the same logic pertains to bald eagles.

The DNR tries to safely pull deer carcasses farther off the road to help avoid eagles getting hit when feeding on road-killed deer, Sitar said.

DNR wildlife biologists suggest slowing down when approaching an area where scavengers are feeding on roadkill.

If you accidentally strike an eagle with your vehicle, or you see one hit, report it as soon as possible to a local DNR office. For incidents that occur after business hours, call or text the DNR s Report All Poaching hotline at 1-800-292-7800.

The sooner an injured bird can be recovered, the more likely help might be effective.

A conservation letter published in the Journal of Raptor Research earlier this year said that raptor (carnivorous birds of prey) interactions with landscapes modified by humans, including structures and infrastructure systems like highways have the potential to negatively affect individual birds, populations, and species, often in the form of collisions with human-made structures and vehicles.

Many raptors are attracted to built environments because of high availability of prey and carrion, and novel perches and nest sites, yet living in such environments puts raptors at risk of collisions, according to the letter. Raptors are vulnerable to collisions with stationary and mobile human-made objects, which frequently result in traumatic injuries or death. Globally, collisions are consistently reported among the top causes of raptor admissions to rehabilitation centers.

An immature bald eagle is being examined in a laboratory to determine cause of death.

The letter said these admission records represent only a fraction of all raptor collisions, with many occurring in places with limited accessibility. Raptors found dead are often unreported.

Multiple collision risks pose threats to raptors in urban and rural areas alike, though some have been better studied than others, the letter s authors stated. Most studies on raptor collisions focus on vehicles, wind turbines, or to a lesser degree, windows and buildings. Numerous other collision risks in built environments remain under-studied, such as aircraft, overhead power lines, communication towers and fences.

Vehicle collisions with nocturnal owls blinded by headlights represent a substantial threat to wild populations and are a major cause of owl mortality, according to the letter.

Within the last month, a barred owl that flew in front of a vehicle and was struck along a city street in the darkness of early morning was brought to the DNR s customer service center in Marquette. The bird was released later that day and, after resting in a pine tree for a couple hours, flew away.

The conservation letter said raptor-vehicle collisions are dependent on many factors including:

– Traffic volume and prey availability.

– Speed limits, road width and surrounding landscapes.

– Vehicle collisions affect urban and exurban raptors, indicating patterns likely differ across species and landscapes.

– Human-related mortality is a major limiting factor for some raptor populations, with human-caused raptor mortality increasing over the past century.

– Raptors that collide with vehicles experience higher mortality rates than those impacted by other human-generated factors.

Across 15 raptor species in the United Kingdom, vehicle collisions were the cause of death in 28% of recovered banded birds between 2002 and 2019, the letter states. Similarly, approximately 11% of raptor band recoveries in the USA from (the) 1920s-2000s were due to vehicle collisions, a percentage that increased markedly over time.

On the afternoon after Ruth and Sitar recovered the female bald eagle from the snow along the highway, another eagle-vehicle collision was reported.

This one was from neighboring Mackinac County, near Gould City, along U.S. Highway 2 near the Lake Michigan shoreline another highway with a 65-mph speed limit.

That’s two in two days, Sitar said.

In this case, Sitar retrieved the adult eagle, but it had died.

The eagle will be shipped to the DNR s disease lab in East Lansing for an examination and then shipped to the National Eagle Repository in Colorado for redistribution to Native American tribes.

It is illegal for any individual to possess a bald or golden

eagle, including its parts (feathers, feet, etc.). The distribution of bald and golden eagles and their parts to Native Americans is authorized by the Bald and Golden Eagle Protection Act and provisions found in the Code of Federal Regulations.

For hundreds of years, Native Americans and Alaska Natives have used eagle feathers for religious and cultural purposes. In recognition of the significance of these feathers to Native Americans, the U.S. Fish and Wildlife Service established the National Eagle Repository in the early 1970’s.