We got a good demonstration of just how many tiny birds were present in the woods alongside roads in Sax-Zim bog, when our guide (Clinton Nienhaus, head naturalist at the bog) briefly played the call of a Screech Owl. Within a couple of minutes, dozens of Black-capped Chickadees and Red-breasted Nuthatches appeared, calling continuously to sound the alert of a predator’s presence.
Weighing in at a whopping 10 grams (less than a fast-food packet of ketchup), tiny Red-breasted Nuthatches are just a bit smaller than Chickadees, but even a small bird with that sharp-pointed beak could do some damage at close range. In any case, the point of the mob action is to pester the would-be predator enough that it eventually flies away. Mobs of small birds may also attract larger birds like jays and crows to help drive off the predator.
Red-breasted Nuthatches prefer coniferous woods, like the black spruce and tamarack of the bog. In the spring and summer, they are highly insectivorous, but like the chickadees, in the winter they love the peanuts and suet found at bird feeders. Even though they are one of the smaller birds at the feeder, their feisty, aggressive behavior often drives bigger birds away. Like their cousins, the White-breasted Nuthatch, they will store some of the feeder largesse in tree crevices for a snowy, cold day.
Sax-Zim bog is one of the premier birding areas in Minnesota, attractive to a number of Canadian breeding species like the Great Gray Owls and Hawk Owls, as well as northern breeding finches during the winter. The farm fields filled with hay bales seem to be filled with mice and voles, perfect for raptors, and the dense spruce-tamarack forest provides good cover. The Friends of Sax-Zim bog have established a welcome center where one can get a map, advice on where to search for some of the more exotic species, and even guided field trips to help you spot those elusive birds.
For more information about the bog, visit their website (link above) or check out the photos and commentary of one of the founders of the organization, Sparky Stensaas at The Photonaturalist.