- Mary K. Hanson
- Posted On
Tuleyome Tales: Tiny brown birds with very loud voices
NORTHERN CALIFORNIA – They’re tiny brown bird with very loud voices, and you can hear them this time of year in the forests and wetlands. They’re wrens!
A wren featured prominently in the old fable about how songs came to earth. According to the story, all of the birds of the world had gathered together to see which one could fly the highest and snatch the songs from the heavens.
One by one each bird species tried and failed, and then an eagle tried his hand (or wing) at reaching the heights. Eventually his stamina failed him, as well, and he started to fall back to earth.
But just then a tiny wren that had been hiding in the eagle’s neck feather burst out, flew up into the heavens, and brought the songs back to the planet with him. And that’s why his songs are some of the longest and loudest.
In California, we have several different species of wren, but for this article we’ll focus on two: the marsh wren (Cistothorus palustris) and the house wren (Troglodytes aedon).
The two species look very much alike: they’re small relatively drab birds that weigh less than half an ounce, and males and females both look pretty much the same.
The wrens have barring on their wings and tail, and the marsh wren usually holds its tail up behind it when it sings.
The two species also primarily eat insects and spiders, although the marsh wren will sometimes also eat vegetable matter and small water invertebrates, and the house Wren will sometimes eat the shells of snails for their calcium.
The greatest difference between the birds is where and how they build their nests.
When it comes to nest building, both the house wren and the marsh wren select several different nesting sites at the same time in the same general area.
Once they’re done, the male wrens then flit from nest to nest, singing their loud songs to attract females. It’s the female who selects which nesting spot she likes the best for her egg-laying purposes.
House wrens build their nests in the cavities of trees – or actually just about anywhere there’s a nook or cranny they can fit into. Some house wrens have been known to nest not only in nest boxes provided by humans, but also in buckets, boots and empty cans.
Aggressive little things when seeking a good nesting spot, house wrens will sometimes evict birds much larger than themselves, like wood ducks and flickers, and take over their nesting cavities.
The cavities are then lined with twigs; some of which are used like “guard rails” if the entrance hole is large enough to let in larger birds and other predators, while others are used as the base for the cup-shaped “mattress” on which the female will lay her eggs.
This cup inside the nesting cavity is lined with grass, feathers, animal (or human) hair, spider egg sacs (to feed the babies when they hatch), and other things.
Marsh wren nests are more elaborate. Rather than nesting in a cavity, the male marsh wren builds three or four intricately woven dome-shaped nests out of the “skin” of wet tules and cattails, dried grasses and other vegetation.
When building these nests, the male will start with a base in the shape of a cup that is woven between several upright branches or tules. Then he builds the roof, moving in and out of the nest as he works on it, taking breaks occasionally to sing or chase off rivals.
When the construction of all of the nests is finished, the male starts advertising his newly built homes by singing … sometimes for up to 18 hours a day.
Once a female has chosen a nest she likes the best, the other nests sit vacant, available to other birds, mice, wasps or anyone else who wants to move into them. The nests are not reused from season to season, so each year the males have to start from scratch.
When there is a lot of competition for space and food, the male marsh wren is known for going into the nests of other marsh wrens and breaking the eggs in them, so its competitor’s offspring don’t make it to the hatching stage.
Although one brood of three to 10 eggs is common, they can have up to two broods per year (especially if the first brood isn’t successful).
Tiny but loud, both species of wren are very visible (and audible) this time of year, so keep an ear and eye out for them.
Mary K. Hanson is a Certified California Naturalist, author and nature photographer. Tuleyome is a501(c)(3) nonprofit conservation organization based in Woodland, Calif. For more information, visit www.tuleyome.org.