Enthusiastic wren is a one-bird choir
Each morning I wake to a blizzard of songs. I'm not referring to the dawn chorus whose medley of different voices makes it difficult to focus on a single singer. No. This bird is nearly a chorus of its own. The singer outside my window is the irrepressible house wren.
I like to describe the song of all wrens as a size-7 song packed into a size-4 body. The ultimate wren song is the song of the winter wren (now the Pacific wren). It carries on for 30 seconds or more, exhausting almost every possible combination of notes and phrases within its considerable repertoire. Certainly the wren sneaks breaths between notes to accomplish this feat, but just how is still a mystery to me.
Marsh wrens are equally enthusiastic but are noted for their diversity of song rather than length. A given male may have more than 80 different songs.
This winter I cleaned out some scrap wood in my garage and constructed a few more bird boxes for my yard. An entrance hole of 11/8 inches is perfect for these birds. Importantly, the entrance is not big enough to allow access by the house sparrows in the neighborhood. As a reward I now have two boxes bouncing with noisy young wrens, soon to fledge. The yard will be alive with little brown birds scurrying among the hellebore like so many mice. House wrens spend most of their time foraging on the ground, exploring every nook and cranny with their long, thin bill looking for spiders and other insects.
Both of the male house wrens in my yard have a single mate. On richer territories, males often entice more than one female, occasionally several. Polygamy is common among wrens.
With the arrival of male house wrens in late April, each male promptly sets out to claim all the bird boxes and natural hollows for its own.
Apparently, each aspires to assemble a sizable harem. To stake his claim he stuffs all potential home sites with sticks. When a female arrives, she usually has somewhat different ideas on the construction of a proper home and she proceeds to rebuild the nest to her own liking.
In the meantime, once a male finds a mate, he lets up a bit on the relentless stream of song.
House wren songs consist of two parts. The first is used to attract mates. The second is used to defend the territory.
Upon pairing, it's the first part of the song he softens, but only for a day or two. The honeymoon is short and soon he is in full voice again, tempting other passing females to join him. What the first female thinks of this is unknown. I'm sure it means less help when it comes time to feed the kids.
As much as I wish the house wrens would take short breaks so I could better appreciate the robins, house finches and spotted towhees singing in the yard, I know that one morning in July the singing will abruptly stop. The doldrums of summer will set in and I will have to wait until next April for the spring (wren) chorus to begin again.
Stewart Janes is a biology professor at Southern Oregon University. He can be reached at firstname.lastname@example.org.