Last year a pair of house wrens used a hollow crevice in a juniper tree near Ash Creek Lower Campground (Lassen County CA) to nest. (See ‘House Wren Nest” o6-14-13) Leonard and I went back to check if house wrens were again using the cavity this season. New tenants, a pair of mountain chickadees (Poecile gambeli), are currently in residence and appear intent on raising a family in the house wrens’ hole.
Mountain chickadees prefer to nest inside tree cavities, but will also utilize natural crevices or nest boxes. Since they cannot excavate a hole, except in the softest wood, mountain chickadees use nest holes abandoned by other birds. The female mountain chickadee constructs a cup nest from grass, moss and other coarse materials and lines it with animal fur, hair and feathers. If the chosen cavity is too large or deep, the female will fill it with insulating materials before constructing her nest. To protect the eggs and nestlings when she is away, a female mountain chickadee also creates a soft “cap” to cover the nest.
A clutch consists of 5 to 12 small white eggs, sometimes speckled with reddish brown spots. The female mountain chickadee incubates her eggs for 12 to 15 days. At birth mountain chickadees are naked and blind with tufts of down on their heads and spines. After 17 to 23 additional days the young chickadees fledge. The young birds remain in their breeding territory for 2 to 3 more weeks before leaving the vicinity permanently. While the female mountain chickadee sits on the eggs, the male chickadee brings her food and continues to do so until the chicks are several days old, at which point both parents forage for their offspring.
Mountain chickadees are monogamous and form long-term pair bonds.
More information on mountain chickadees can be found in my previous post on 10-21-12 – “Mountain Chickadee”.
I wonder what happened to the house wrens, but am happy the mountain chickadees found a nest site.