McHenry snowy owl: New report reveals what contributed to bird’s death

When a snowy owl captured McHenry hearts in December, many were amazed at how long the arctic species hung out in a field, allowing photographers and bird watchers an up-close look.

Killed in a vehicle strike overnight Dec. 17, the bird was collected by the Illinois Department of Natural Resources and a necropsy – an autopsy for animals – was performed.

[ Photos of the snowy owl that visited McHenry last year ]

According to the necropsy report made available this week, the bird was malnourished and the condition of its lungs suggested it had pneumonia when it died.

A lack of fatty tissue and digestive enzymes, along with an empty first stomach “suggest that the bird was severely malnourished and in a severely impoverished nutritional status prior to death,” said Brad Semel, a McHenry-based endangered species recovery specialist with the IDNR. Avian influenza was not detected in the owl.

“Taken together ... it is likely the bird was essentially starving to death prior to being struck and killed,” Semel said.

The carcass, now in storage at the University of Illinois, will be forwarded to Pennsylvania-based Project Snowstorm, a nonprofit organization that studies the owls and their migration.

It is not surprising that the bird did not make it, said Scott Weidensaul, one of the research group’s founders.

“This was a young bird and a lot don’t make it to their first birthday,” he said, adding that depending on the species, up to 70% of birds do not survive to be a year old.

“Survival means hunting skills, and not all of them are the sharpest knife in the drawer,” he said. “Some just don’t make it.”

It is unknown whether the bird remained in the area for as long as it did because it was undernourished and weak when it arrived, or if the attention it received while in McHenry County made it difficult to hunt, Weidensaul said.

“It could have been already weakened enough that it didn’t have the energy” to move on, he said.

Because the bird did not have avian flu when it died, the Project Snowstorm researchers will be able to do further tests on the carcass, including for rodenticides, heavy metals, mercury and for other toxins, Weidensaul said.

If it had tested positive for the avian flu, it would be incinerated, as other owls found this season were, he added.

“It will go to the Academy of Natural Sciences in Philadelphia. We will get as much scientific value out of the loss of the bird as possible. Nothing will go to waste,” he said.

The attention the bird received from visitors “was a double-edged sword,” Semel said. Residents “got to experience it. Maybe now they became bird watchers, or began to appreciate the open space. There as so many positive things about it, about appreciating the natural world.”

Originally, Semel and the IDNR had planned to send the bird to Chicago’s Field Museum, but decided instead to get it into Project Snowstorm’s hands.

“It seems more important to get it to Pennsylvania for the specialized collection” and study, Semel said.