An irruption has brought a wave of northern owls to Minnesota this winter. This great gray swoops in Feb. 19 on a photographer in Two Harbors. (Provided by Joe Gliozzo Photography)

The tremendous flow of northern owls into Minnesota this winter has brought flocks of birders to hotspots like the Sax-Zim Bog and the north shore of Lake Superior.

Last weekend, reports of a northern hawk owl had birders and vehicles stacked up in the bog, while reports of great grays owls hunting the waterfront sent droves of people to Two Harbors, hoping to snap a money shot.

Now a popular birding app is hiding Minnesota data on one of the species to help protect it from the human swarm.

Managed by the Cornell (Univ.) Lab of Ornithology, eBird is obscuring precise location data on boreal owl sightings. It regards the small raptor with piercing yellow eyes as a “regional sensitive species,” vulnerable to the type of public fervor witnessed this winter in Minnesota.

While winding down now, the irruption of boreals, great gray, snowy owls and other raptors has made it a winter to remember at the birding mecca of Sax-Zim Bog, northwest of Duluth, and areas up the North Shore. Coming off a productive breeding season, many are young owls flying south from Canada because they’re hungry. Food like the voles they find at the bog are scarce in their Canadian boreal habitat.

The interest in owls up north and even the metro has brought into sharper focus the use of technology to find birds, but also its use to shield them.

“A lot of us in the birding community were waiting for this next irruption and what would happen with the owl paparazzi. Because the forms of communication are so instantaneous these days,” said Bob Dunlap, a zoologist at the state’s Department of Natural Resources and former president of the Minnesota Ornithologists' Union, a statewide birding group.

Apps like Telegram, Discord and Facebook have made phones as important to some birders as spotting scopes. Birders receive and share exact location GPS pins to bird sightings. Some people quickly put up arresting photography.

Rich Hoeg relishes an owl sighting as much as the next birder and uses instant-messaging apps.

Still, the Duluth man has his limits.

Boreal owls are rarely seen in the numbers they were this winter in Minnesota. (Provided by Richard Hoeg, 365DaysofBirds.com)

The bird blogger and photographer was recently driving in the bog when he saw two separate groups and their vehicles stacked up off the road. He knew owls were the attractant.

Hoeg safely got off the road and posted a message to a Telegram app group named SZB Sightings — not to direct more birders to the gatherings but to tell them to steer clear of adding more cars and people to the road with no shoulders. The group has more than 3,600 members.

In a flash, Hoeg could have added to the numbers on an already crowded area of busy highway. But Hoeg is selective about what he shares — and he doesn’t share private locations on the back roads of the North Shore and other places.

Ebird’s selectivity with boreal locations is new to Minnesota, but managers began limiting data for other species beginning in 2017, even though conservationists and researchers value the database for its migratory and population trends.

The app managers had an initial list of 325 sensitive species. EBird defined them as birds that “face risks from humans of capture, targeted killing, or significant disturbance.”

Hoeg said he anticipated a boreal irruption. Normally, several of the owls might be banded at stations in northern Minnesota and Wisconsin for tracking. Last fall, reports were in the hundreds.

Their significant presence by early January moved eBird to act after consulting regional eBird reviewers and ornithologists, according to Michelle Terrell, an ornithologists' union past president. The boreal was added Jan. 10 as a regional sensitive species in Minnesota, joining the long-eared owl and black rail. As global sensitive species, the great gray owl, northern hawk owl and gyrfalcon also are on the state list.

EBird still records the birds’ sightings, but the data doesn’t appear on an eBirder’s checklist, and the locations won’t appear in detail on eBird maps. Instead, purple-shaded boxes will indicate a general area of sightings.

A great gray owl perches on the lens of Ryan Burg, left, of Boston, who was near the Two Harbors waterfront along with other wildlife photographers Feb. 19. Burg, who considers photography a hobby, said the experience "left me quite speechless." (Provided by Joe Gliozzo Photography)

While eBird still encourages users to submit sightings of sensitive species, it suggests they wait until a season has passed. Users also are encouraged to resist posting elsewhere on the web or asked to post without explicit details.

As executive director of the International Owl Center in Houston, Minn., Karla Bloem said she supports eBird’s initiative to limit the full-court press on some birds. She would like to limit the location-sharing of more owl species, including nesting data.

“EBird’s steps to start obscuring data are a significant step forward,” she added.

‘We aren’t the gatekeepers’

Sparky Stensaas, founder and director of Sax-Zim’s Friends group, said this winter there has been more pressure on the roads than on the birds — and that is a better issue to have.

He is quick to clarify that, while his group supports one of the best birding locations in the United States, it isn’t a birding organization.

“We are a land preservation group, with an emphasis on education,” he said of the 300-square-mile bog.

The group’s responsibility isn’t to enforce responsible behavior when the birding masses arrive, Stensaas added. He estimated a record 9,000 people will have visited the bog’s welcome center before it closes in March. The previous high was about 7,500.

“We are not the gatekeepers,” he added. “We try to hammer home the etiquette people have to have, to police themselves. We are not the police of the bog.”

Nevertheless, Stensaas said social media tools lead to “people chasing birds around the bog.”

Hoeg, who also is one of the Friends’ volunteer naturalists, said instant communication has its limits on the backroads of northern Minnesota.

Receiving an alert 10 miles from a bird sighting and then traveling over snow-covered dirt roads isn’t efficient or intelligent, he said. “The chance is that the bird has moved on you and you are never going to find it by the time you arrive.”

A better practice is to monitor where sightings have repeated over a previous run of days, mark those locations, and make them the focus of a search, he added.

Bloem, the owl center director, said owls “have the problem of being too popular for their good sometimes.

“In the days before eBird and social media and everyone having a camera with a big lens, they were pretty safe from mobs of people who wanted to see them or get a beautiful photo.”