Great horned owls take up residence at Jutila Center
Copper Country Audubon installed a Peregrine falcon nest box on the Finlandia Jutila Center in the spring of 2015 to provide the Portage Lake Lift Bridge falcons with an alternate nest site when the Michigan Department of Transportation was doing work on the bridge.
The falcons totally ignored the box, but last year a pair of great horned owls raised two young there.
The owls then disappeared about the time the falcons returned in mid-March.
Since it was pretty hard to view the owls in the Jutila nest box last year, the Copper Country Auduban Society worked with Finlandia to install a web cam on the nest box in case the owls returned. The camera and arm were installed in November 2018 last year.
We finished all this just about the time the early-winter cold and snow started. Almost immediately in late November the owls started to show up in and around the box every few days.
On Jan. 23 of this year, the female laid the first of two eggs in the nest box. We know the date because the camera has a rolling history and allows viewing video in five-day segments. This is a very useful feature as it allows us to scan the video from the previous night each morning to see what transpired at the box during the night. This provides a wonderful opportunity to closely monitor these nocturnal birds that people rarely even see in a completely non-invasive manner.
A couple of things that became apparent, especially after the eggs were laid. One was how dedicated the male was to providing food for the nesting female.
The Cornell birding site states the range for great horned owls varies from as little as 1/10 of a square mile to more than 1 square mile. Drawing a 1-square-mile circle on Google Earth centered on the Jutila Center shows the range would take in a good portion of Hancock but would be well short of extending to the lift bridge or the Hancock beach. It would also include a fair amount of waterfront on both the Houghton and Hancock sides of the canal and some of the Houghton subdivision behind Shopko.
It was surprising to me that the male consistently returned to the nest box most nights with a rabbit, squirrel, mouse, vole or weasel from a hunting territory that size. Although great horned owls have a very diverse diet, it appears that the Jutila birds’ diet is mostly ground-dwelling animals rather than birds, although it is sometimes hard to tell just what the prey was.
When the male returned with food he did not simply drop it off but rather brought it into the box and waited until the female took it from him. When she was sitting on the eggs, she would leave for 5-10 minutes to eat the food and return. The male sometimes would remain on the box perch and sometimes fly off while she was gone, but the male never sat on the eggs.
After the first chick hatched Feb. 27 and the second shortly after, she kept food in the box to tear into small pieces for the young. They seemed to be very neat housekeepers, unlike the falcons.
The male often stops by right around dusk and both birds “talk” to each other in low hoots and other chirping sounds. Maybe they are discussing where the male should hunt that night. Whenever they are together they “talk” to each other. The Cornell site also stated these owls are monogamous and will often stay in the same territory year-round which seems consistent with what we are seeing.
The range of the great horned owl covers most of north and central America, and they are extremely well adapted to cold weather. The Jutila owls seem to be totally unaffected by sub-zero temperatures, heavy snow and cold winds. The female even left the 5-day-old chicks unattended for 20 minutes in 8-degree temperature with no apparent ill effects.
Why they nest in the winter is not well understood. Possibly it is because when the juveniles are developing their hunting skills, prey is most abundant. Also, there is less competition from other raptors at that time and less chance other raptors would prey on the young.
You can watch the “action” by clicking on the Jutila web cam on the home page of the Copper Country Audubon web site at coppercountryaudubon.org. The bridge web cams are also there, and there may be peregrine falcons showing up there at this time of year.
Philip J. Quenzi is a member of the Copper Country Audubon Society.