Loyd CZISMADIA
Special to Tribune
As members of the Williams Lake Field Naturalists, my wife and I have maintained a mountain bluebird route on Becher’s Prairie for about thirty-six years.
The original purpose of the route was to offer a biological alternative to the spraying of pesticides. Today, this route and others like it provide a valuable boost to the flagging songbird populations and give naturalists like me another reason to be outdoors.
The Riske Creek wildfire in 2017 greatly improved the grassland habitat for the mountain bluebirds of Becher’s Prairie by removing many small trees. At the same time, however, it wiped out the fence lines on which we had 50 plus nest boxes. Happily, the government reconstructed most of the fences in 2020, just before COVID-19.
I am truly grateful to our government for funding the reconstruction, not just at Becher’s, but on other bluebird routes as well. Fences are critical for the success of the Field Naturalist’s Mountain Bluebird Program.
Rebuilding the Becher’s bluebird route in March of 2020 required 40 new nest boxes. Ten older bird houses had survived the fire, so I left these in place on their askew, charred, random posts.
Two of the surviving houses date back to the late 1970s, which is when the Williams Lake Field Naturalists initiated the Bluebird Program. I never liked these first houses. They were difficult to clean, the roof often flew off on a gusty day, and the cavity was so dark and narrow that I needed a flashlight to count eggs and young. I was tempted to retire these last two veterans, but the birds really like them. And when I considered that each box potentially fledged at least 10 birds per year over 42 years…well wow, that adds up to 840 birds by 2020! Since 2020, these two boxes have likely fledged 60 more birds.
That being said, the current design takes into account both the bird and the birder. The front of the box opens like a drawbridge, giving ready access to a gloved hand or a scraper. This ensures speedy and hygienic removal of the old nests. The open front also offers a clear view, so the route manager can collect breeding data with minimal disturbance to the mother and young.
Back in 2020, it took me two full afternoons in March to rebuild the Becher’s route. Because my wife had mapped the GPS location of each house on the old fence lines, I was able to reconstruct the route almost as it was before the fire.
This is important for comparing breeding data from year to year.
On the first afternoon of reconstruction, while carrying eight houses at a time in my wheelbarrow, I bounced over the stony grassland from station to station. The distance between stations is mainly determined by how well the habitat meets the mountain bluebird’s requirements for food. Like most hatchlings, bluebird babies have insatiable appetites. For 17-21 days, the parents must feed each of the four to six nestlings about three times per hour from sunrise to sunset, and much of this food comes from the soft and hard-bodied insects that live or hide on the ground.
If the vegetation is too thick or tall, as it eventually would be in a hay field, the insects are more difficult to find. Bunchgrass ecosystems like Becher’s Prairie are ideal. Taking advantage of this, I spaced my stations closer together, about 50 to 75 meters apart (@ 150 – 200 feet). The recommended average is 100 meters (@ 330 feet).
In 2020, I re-established 20 stations. Each station required two nest boxes spaced approximately 6 to 8 metres (20 to 25 feet) apart. Two boxes are necessary because tree swallows compete aggressively for every box, even if it is occupied. The theory is that tree swallows won’t evict a mountain bluebird if another box is handy.
In my experience, this usually works. On average, mountain bluebirds return mid-March, whereas tree swallows return in late March or early April. So, it is likely that mountain bluebirds have established territories and built nests before the tree swallows arrive.
During that first sunny afternoon, I observed neither swallows nor bluebirds. I did, however, spook a ruffed grouse. Four more grouse could be heard drumming nearby. In fact, each island of aspens seemed to have a grouse of some type. The profusion of yellow-rumped warblers was an unexpected pleasure. They filled the nearby fields with clouds of activity. vesper sparrows were also abundant, but not unusually so. I don’t remember if I spied any horned larks, another common inhabitant of Becher’s Prairie. With so many distractions, work felt like play.
During the second afternoon, I completed the remaining stations. The afternoon slipped by so peacefully that I was reluctant to hang the final box.
As my empty wheelbarrow and I trundled our way across the prairie, I observed tree swallows congregating around the newly erected boxes.
Two bald eagles soared overhead, winging their way toward the Separating Lakes.
An unexpected cliff swallow fluttered by, its orange rump catching my eye. As I passed the last nest-box station, a pair of bluebirds landed on the shiny new wire next one of the houses. I watched as the female peeked inside. Then the pair flew off. “No point settling on the first house,” I thought. “There are 49 more to choose from.”
And I left, satisfied with my day.
READ MORE: Williams Lake Field Naturalists’ Bluebird Program going 47 years
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