Owl pair, offspring take up residence in Crystal Lake

Justine Neslund first spotted a pair of great horned owls in her Crystal Lake neighborhood in 2023, hearing them first, then finding them with her camera.

“Mom just looks mean and Dad is like, gorgeous, and his eyes are always giant and dilated,” said Neslund, a wedding photographer who does wildlife photography on the side.

She found the pair again as they made their nest and laid eggs in December.

“Mom was on the nest early and the babies hatched in early February,” Neslund said.

She never got too close. With a long telephoto lens and a bit of luck, she’s been able to capture and document the owl family using her car as a blind.

“I have photographed all stages of their nesting for 4½ months,” she said.

Once the owlets started to fly and learned to hunt, there were times Neslund couldn’t find them, until she finally saw the family of four hunting near a church a few blocks from her house.

“I was feeling good that they were still close, until I looked over and saw bait boxes,” Neslund said.

Loaded with anticoagulant rodenticides, bait boxes often are set out around large buildings in the suburbs to prevent mice from getting inside. The mice go inside the traps, eat the bait, wander away then die as their blood will not clot.

Then raptors including owls, red-tailed hawks, Cooper’s hawks and bald eagles, eat the dead or dying rodents. According to the National Audubon Society, “at a high enough concentration, anticoagulants can directly lead to birds’ deaths. But even at lower doses, they leave birds slow and disoriented.”

According to the Chicago Bird Alliance, an entire family of great horned owls at Chicago’s Lincoln Park were killed by rodenticide poisoning last year. California banned the use of the most popular rodenticides in September, and a similar law is being considered in Rhode Island.

Fearing for the Crystal Lake owls, Neslund contacted the church, asking if its leaders would consider removing the bait boxes until the the young owls leave the area to start a nest of their own.

The Northwest Herald is not identifying the church so as not to reveal the birds’ location to those who may want to look for them and get too close. In an email to Neslund, however, the church office manager thanked her for bringing it to their attention.

“Though our pest control representative says the bait boxes are not a threat, our custodian is removing them,” the emails reads.

“It is a no-brainer, that we would want to protect the owls,” the church office manager told the Northwest Herald. “I don’t think we plan to put them back,” and they will find another way to control mice.

It is common for both owners of large buildings and homeowners to turn to rodenticides, said Judy Pollock, a board member for the Chicago Bird Alliance. The new poisons, called second-generation anticoagulants, work faster than the previous versions.

“It used to be they had to feed on it a couple of times. Now they are designed to kill after just one feeding. If a hawk or an eagle or an owl eats the rat, they are also eating the poison,” Pollock said.

It isn’t just raptors getting a dose of the poison either. A Chicago-based study looked at trapped raccoons, skunks and possums taken by pest professionals. The researchers found 100% of the animals had at least one rodenticide in their liver, and 79% had multiple. In comparison, of the 101 rats trapped and tested, 74% had one compound in the liver and 32% had multiple.

Those skunks, raccoons and possums also are prey for the raptors.

“There are many raptors being killed in the Chicago area because of these rodenticides,” Pollock said.

The bird alliance is now working with the Lincoln Park Zoo on a study that uses birth control bait to reduce the rat population in Chicago. The group needs to raise another $8,000 for the study, Pollock said, most of which goes to buying the contraceptive-laced pellets. Donations can be made at the Chicago Bird Alliance website, chicagobirdalliance.org.

Last year, a snowy owl spotted in a field near McHenry attracted a lot of attention – including from the Northwest Herald – as it was the first confirmed sighting of that type of bird in McHenry County in several years. However, a short time later the snowy owl was hit by a car and killed, and some experts blamed the amount of attention the owl had received as a factor. It was later found to have been severely malnourished.