Weekend Birding: Nesting House Wrens
The House Wren is a tiny little bird commonly found in the northern two-thirds of the United States and parts of Canada. They don’t mind people and will readily nest in backyards.
They are migratory and head south of the frost line in winter but return to the same breeding grounds in the spring. The male arrives first and establishes his territory. He places sticks in multiple nesting cavities and then sings to attract a female. When a female arrives she chooses the nest site they will use and together they fill the box with sticks. The female will finish the nest cup with soft materials like feathers, hair, spider cocoons, moss and grass.
A few weeks ago a pair choose the nestbox on my back garage and worked non-stop for two days building the nest. I’m amazed at the size of the sticks they can carry and maneuver into the box.
Once the nest is finished the female lays an egg per day until the clutch is complete. After all the eggs are laid she will incubate them for 10 to 14 days. The eggs should hatch this weekend and both adults will then care for the young.
Inside the Nest
After the breeding season ends I clean out the nest boxes and get them ready for the next year. The photo on the right is a wren’s nest. The little box was stuffed so full of material I don’t know how they fit three baby birds in there. Click to enlarge and you can see the feathers and other soft materials that made up the nest cup.
Interesting Note on Behavior
While many birds are monogamous during the breeding season, and some mate for life, that is not true of the House Wren. Wrens can raise two or three broods per season and may mate with a different female for each brood. Males may also mate with two females simultaneously.
I monitor the nests for Project Nestwatch so I pay close attention to the bird’s behavior. Last year the male helped feed the young for the first week and then moved to a different nestbox ( I have four of them) and began singing to attract another female. I couldn’t believe what I was seeing. After a little research I discovered that this is not uncommon behavior. Needless to say the female, who was now a single parent, did not raise a second brood with this male, who I began referring to as the deadbeat dad.
Saturday Snapshot is hosted by Alyce at At Home With Books. Visit her blog to see more great photos or add your own.
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