Colorado comes in 4th in the Mountain Chickadee population contest, with 8% of the US population. (CA wins hands-down with 22%, followed by OR with17% and AZ with 10%.) MOCHs have a strong preference for breeding in coniferous forests. Although their densities are highest in spruce/fir, lodgepole pine, and ponderosa pine woodlands, they also breed in pinyon/juniper habitats such as ours as well.
MOCHs here join the other small cavity nesters—Juniper Titmouse and White-breasted Nuthatch—in the first wave of breeding. This year, we had only 1 MOCH pair that nested–a rather low number for us. (For instance, in 2007, we had 3 pairs that fledged young.) Nesting began in mid-April; the first egg was laid on May 3; hatching began on May 23; and nestlings fledged in mid-June. More information on the natural history of MOCHs can be found at the Sialis Web site.
The MOCHs nested early in the season, before we got the hang of using a mirror to photograph the inside of the nest. And since we hosted only one breeding pair, we didn’t have several nests at each monitoring check to choose from. So this year’s photos are not the best. (Gives us a project for next breeding season!) However, here’s what we have for now.
This is the nest one week later. It’s now looking like a pretty typical MOCH nest, although you can see a layer of dead oak leaves at the bottom. I don’t recall seeing bird nests with oak leaves in any of the other boxes, which makes me think that the MOCHs took over a nest box that a chipmunk had started. (Starting in early March, one of our nest boxes was filled to the rim with dead oak leaves. No creature ever used it as a nest, so I’m not quite sure what was accomplished by what must have been a rather massive expenditure of energy.) If so, lucky for them that they could defend the nest. We had a White-breasted Nuthatch family that was not as lucky, laying 2 clutches of 6 eggs each that, I believe, a chipmunk depredated.
Here’s an interior view of the nest at week 2. Interesting clumps of fur or hair cover the nest. They feel rather like dryer lint. But since we don’t have a dryer, that seems unlikely. We never really figured out what they were (and from this photo, odds are you never will either).
The clutches are generally large—typically 6 or 7 eggs. Here’s a nest with 6 eggs (lurking blurrily there in the lower right corner). Until I see a parent, I often can’t tell MOCH eggs from Juniper Titmouse eggs—both are unmarked and of similar size. All of these eggs eventually hatched (and made for a very cramped nest box at the end). Below that is a side shot of the nest the same day. You can see the now-uniform layer of animal hair that was the final layer of the nest and nest cup.
These hatchlings are <1 day old. We were very lucky to happen on these guys at this moment. We had visitors—4 boys (ages 9, twins at 12, and 14) and their mothers—who had come to look at some of the boxes over Memorial Day weekend. I was a bit nervous, since I had never conducted a “tour” of the nest boxes before (although I had been writing to one of the mothers and sending her photos since nesting began in mid-April). And, having been a junior high school teacher in an earlier life, I knew what a tough crowd boys this age can be. But, with Zell carrying a small aluminum stepladder, we headed out for about a 1-mile loop to see what was going on. The first box we got to had these hatchling MOCHs and everyone got quick but terrific looks. SCORE!!! The oldest boy even took some photos to show his classmates the next week. Several other boxes had slightly older White-breasted Nuthatch nestlings and some had lovely MOBL eggs. But the luck of starting with the MOCH hatchlings really set the tone for the tour. I was greatly relieved that the kids thought it had been an interesting time. It can feel a bit scary to share something you love with kids—but this risk really paid off.
Here are the nestlings at about 10 days old. This is the last photo we took of the nestlings. At the next week’s check, the box was packed and the kids looked really mature–so much so that I considered giving them a tough-love lecture about getting the heck out of the box. When I opened the box at that time, one of the nestlings hissed at me, which certainly caught me off-guard (as the hiss call—often accompanied by the “snake display”—is meant to do, according to The Birds of North America Online). I assume it was a nestling; the box was so crowded that it’s hard to imagine that an adult would have wanted to be in there too. But with their being that old and so jammed in, I didn’t risk opening the box all the way even to get a good count—and opening it enough to get a photo was out of the question.
MOCHs tend to be non-migratory, so when I see a MOCH acting like a curious kid later in the season, I like to assume it’s from one of the local broods. (Since we’ll never know, what’s the harm?) In late September, I watched what was possibly one of these fledglings at our thistle feeder on a juniper tree just off the patio. I had never seen a MOCH at the thistle feeder before. For a grab-and-go eater like a chickadee, I wouldn’t think that a thistle seed would be worth the effort needed to fly in, grab a seed, fly off, and open it. But this dude was making a sort of yodel-y gargle-type call as it sat in the tree, eying the Pine Siskins and House Finches at the specialized feeder. (The call made it easy for me to track its movements.) It eventually flew to a perch below a port, pecking all around the hole until it got a seed, and then flew deeper into the juniper to eat the seed. Calling each time before it flew back, it found the port a bit more quickly with each visit, spending less time pecking at various parts of the feeder. After about the 6th time, it too seemed to have decided that it was a lot of work for very little pay-off and flew to the hopper feeder stocked with sunflower seeds. I haven’t seen a MOCH at the thistle feeder since. Lesson learned, I guess.
© 2008 Tina Mitchell