Feathered Joy: Bremer Boxes Result In Hatches

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Amidst a chaotic time due to the Covid 19 pandemic, two little owls made their way into this world, thanks to the new owl nest boxes at Bremer Sanctuary in Hillsboro.

Little did they know, they would be part of a state-wide study and would be monitored once a week for five weeks.  Their postings received the most “likes, loves, comments and shares” in the history of the Bremer Sanctuary’s Facebook page.  Their initial story was included in the Illinois Audubon Society’s spring magazine, their photos featured on the 4-H Barred Owl Nest Box Challenge Facebook page, local news media and countless other places that their “Shares” on Facebook took them. Here is their story.

It started as an observation by Jacques Nuzzo of Illinois Raptor Center in Decatur, who noticed from field studies that Barred Owls seemed to prefer an open top nest site. The idea of a modified nest box was born and Nuzzo made a blueprint of his thoughts (available for download at illinoisraptorcenter.org).   

A traditional nest box design is a box with a hole in one side and a roof overhead to keep occupants shielded from the elements. The modified box consists of a partial open top which provides a natural setting for nesting Barred Owls.  A modified nest box was constructed and installed late last year and paired with an existing traditional box. The University of Illinois 4-H made plans to conduct a study comparing the two nest box styles with the idea of placing a pair of nest boxes in each county of Illinois and to be monitored by local 4-H groups. 

Then, the Coronavirus came into play shutting down many of the nature parks where the boxes were installed.  Luckily, two Bremer volunteers were able to access the nest box site and made a remarkable discovery on March 26–an adult Barred Owl peering out of the modified nest box.

On March 27, a reach pole was constructed and with a cell phone attached to the top, the first video was obtained of the nest box contents. 

Two Barred Owlets approximately one week old and an unhatched egg were discovered.  Since the incubation period for Barred Owls is 28-33 days, the eggs were probably laid around Feb. 17 and began to hatch around March 20.  Barred Owls lay one egg every two-to-three days and incubation begins with the first egg laid, then the eggs will hatch in the order they were laid. Upon hatching, the owlets are helpless and covered in white down with their eyes closed.

Subsequent monitoring on April 4 and 11 found that the third egg did not hatch and was discarded. The two remaining owlets were growing at an astounding rate and were already displaying adult behaviors like hissing and bill clapping when they perceived a threat approaching.  They had lost the down fluff and were growing feathers.  

Also, noted in the nest box was a large cache of small rodents brought in by the parents.  In the first weeks, the female was in the nest box but would flush when we approached and remained in the immediate area, returning as soon as observers exited.

April 16 was the last monitoring done with the reach pole as the owlets were moving about the box with ease and observers didn’t want to spook them into an early fledge. The parents remained in the area and were calling from 20 yards away as they typically do not stay in the nest box at this stage but merely bring in food.   

The box was scoped from a distance on April 24 and found only one owlet remained while the other had entered the branching phase. The second owlet left the nest the next day.  When the young leave the nest–at about four weeks–they are not able to fly, but crawl out of the nest using their beak and talons to sit on branches. This branching phase is when they obtain the skills to fly by hopping short distances while flapping their wings. They are considered fledged at 35 to 40 days.  Once they leave the nest box, they do not return to it but stay in the nearby vicinity.

Two months later, on the eve of June 27, one of the owlets was spotted about 50 yards from the modified nest box. It was identified by the fledgling’s begging call to the parents for food. Two other Barred Owls were also seen in the vicinity; possibly it was both parents or one parent and the sibling.  

Parents care for the young for at least four months, much longer than most other owls. Young tend to disperse very short distances–usually less than six miles–before settling. Pairs mate for life and territories and nest sites are maintained for many years.

The story’s author and photographcer, Nancy Redman is education chairperson at Bremer Sanctuary in Hillsboro.

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