Return of the Black-capped Chickadees

I put up a new chickadee box this year. It’s deeper than the previous one so the camera fits inside the box rather than a hole having to be cut through the roof of the box to accommodate it. Almost immediately after putting it up, a pair of Black-capped Chickadees started checking it out, so I’m glad I got it up before April!

Like with my flicker box, I put a handful of wood shavings in the chickadee box. This simulates a natural cavity. While they’re not nearly the pecking powerhouses that woodpeckers are, chickadees can and do excavate their own cavities if the wood is soft enough. However, chickadees are considered secondary cavity nesters, moving into cavities after the original tenants have moved on.

A Black-capped Chickadee dropping wood shavings away from its nest. Photo by Jamie Simo.

Much smaller than Northern Flickers, and more vulnerable to competition for nests and to predators, chickadees won’t just dump wood chips right outside their front door like a flicker will. Both male and female chickadees take a beakful of chips and fly a short distance away, scattering them. This prevents rivals/predators from following the wood chips like a trail of breadcrumbs straight to the nest site.

On March 31st, after they had “excavated” the wood chips, the female chickadee went to work building her nest. Only the female Black-capped Chickadee builds a nest, which she does starting with a thick layer of cushy moss. Following the moss, she began to bring in softer material. I recognized dog fur and, I believe, some leftover fluff from when my milkweed went to seed last year. With each new addition to the nest, mama chickadee would build up the nest cup and then wriggle her body down into it, conforming it to her body.

Like I mentioned, chickadees are small and vulnerable. They have little defense against the invasive House Sparrow, a species known to kill native birds and then take over their nest cavity. To combat that possibility, I put a metal 1 1/8 inch hole guard over the 1 1/4 inch box entrance. Black-capped Chickadees are small enough to still fit through the hole, but House Sparrows aren’t.

Check out this video of mama chickadee’s “snake display” warning away a (likely) House Sparrow intruder. Without the added protection of the hole guard, this display may not have been enough to deter a persistent nest parasite.

The literature I’ve read suggests that it can take up to 2 weeks for a Black-capped Chickadee to finish building her nest, with egg laying following 1-2 days later, but this particular female seemed to take a bit longer. It wasn’t until April 18th that she laid her first egg and, even then, she was still bringing in the occasional bit of fluff to pad out the nest.

Two Black-capped Chickadee eggs on April 19, 2019. Black-capped Chickadee eggs are white speckled with brown and just under an inch long.

I can only assume her first egg was laid on April 18th because Black-capped Chickadees, like many other songbirds, lay an egg a day and I noticed that there were 2 eggs in the nest on April 19th. As of April 21st, there are probably 4 eggs in the nest. Why can’t I tell for certain? Black-capped Chickadees tend to cover their eggs with fur nesting material when they leave the nest so, at the moment, I can only tell for sure that there are 3 eggs in the nest. Going by the fact that they lay 1 egg a day though, that means there should be 4 today.

Black-capped Chickadees, on average, lay between 6 and 8 eggs per clutch, so we could be could be close to incubation (mama chickadee will begin incubating the day before her last egg is laid), or we could still be a few days away. Personally, I hope she goes for a smaller clutch–it’s a pretty small box and I can’t imagine how crowded 8 babies would be–but we’ll soon find out!



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