Two loons with West Nile no concern for species

A loon with a chick on its back makes its way across a pond. Recently, two loons in Minnesota had been found to have contracted the West Nile virus. Despite this, state DNR officials say that they have no concerns about the loon population and that the population is healthy and large.

While the announcement of the discovery of two dead loons in the northeastern part of the state this summer due to the West Nile virus caused a bit of a stir in the media and online, officials from the Minnesota Department of Natural Resources – and those paying attention - have known about the effect of the mosquito-borne disease on the state bird since 2005.

And, despite some media reports that tried to paint a more drastic picture of what the recent findings could mean, agency officials aren’t overly concerned.

A press release from the DNR documenting the findings was sent out last week.

“The Minnesota loon population is healthy and large. We do not have concerns for any long-term impacts to the population from these deaths,” DNR nongame wildlife specialist Gaea Crozier said this week by email. “I am not sure why there was not much press in 2005. This year, I was getting quite a few calls about people seeing dead loons. As a way to help reduce public concern, we put out a press release and it took off like wildfire. So there is not more concern this year, just it became higher profile due to our press release.”

That’s good news for loon lovers, some of whom might have been a bit shocked when news outlets across the state ran the news release under big, bold, flashy headlines.

According to the release, University of Minnesota researchers identified WNV as the cause of death in two of three dead loons found locally and added that reports of dead loons have increased in the area.

The two loons confirmed to have WNV were from Arrowhead Lake near Britt and Bass Lake near Biwabik, according to Crozier.

“A group of concerned citizens collected the loons, let the DNR know, and arranged to have them tested. It is thanks to this group that we got West Nile virus diagnosis,” Crozier said. “I have since submitted more loons for testing to try to confirm that it is WNV in other lakes with dead loons in the area.”

The results of those tests are pending, she added.

According to the Centers for Disease Control and Prevention (CDC), West Nile virus is the leading cause of mosquito-borne disease in the continental United States.

First discovered in the U.S. in 1999 – and confirmed in Minnesota in 2002 - it is most commonly spread to people by the bite of an infected mosquito.

It is found in every state in the lower 48 and there are no vaccines to prevent or medications to treat WNV in people.

About one in five people who are infected develop a fever and other symptoms. About one out of 150 infected people develop a serious, sometimes fatal, illness.

When it comes to birds, according to the CDC, WNV is transmitted through the bite of infected mosquitoes and mosquitoes become infected by biting infected birds. Some birds that are predators (such as hawks and owls) or scavengers (such as crows) may become infected after eating sick or dead birds that were already infected with WNV.

The virus has been detected in over 300 species of dead birds. Although some infected birds, especially crows and jays, frequently die of infection, most birds survive.

In last week’s DNR news release, Crozier pointed out that Minnesotans love loons and it is a bit concerning for people to find them dead, adding that “when we start seeing multiple birds dying on a single lake, we want to know about it so we can start tracking the information and determine when further testing is warranted.”

She said this week that the DNR’s new release sparked an unexpected uptick in interest in the topic even though loon infection isn’t new news.

She added that loons are particularly susceptible to WNV and that she hasn’t received any reports of other species of wildlife dead in unusual numbers.

“The corvids like crows and jays are also very susceptible to WNA and we could potentially see increased in mortality in these species, although these species were hit hard by WNV about a decade ago and might be more immune to it now,” Crozier said. “We are asking that people report two or more dead loons on a lake (if cause of death is unknown) to the DNR nongame program. One loon is not too concerning as loons die from a variety of things, including lead poisoning from lead fishing tackle.”

Interestingly, one species of bird that DNR officials are concerned about when it comes to WNV, is grouse. Last year officials announced a plan to study the effect of the disease on one of the state’s most popular game birds.

Crozier said the results of that study aren’t in yet.

Participation in the study has involved hunters submitting hearts, a few feathers for sexing and aging and blood collected on filter strips from harvested birds for testing and providing officials with the location of harvest.

The research was partially funded by the Ruffed Grouse Society and the Game and Fish Fund.

At the time the study was announced, Charlotte Roy, Grouse Project Leader with the Minnesota DNR said, “Although the adult population has been cycling around a stable 10-year average, we don’t know if West Nile might be impacting the production of young birds, which make up a large portion of what hunters see in the fall.”


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