Marsh Wren

Photo by Stan Tekiela

by Stan Tekiela
© NatureSmart

August 14, 2017

Every now and then I'm surprised at something in nature. I get a little thrill when seeing something for the first time or learning something new. Recently I was out photographing Red-necked Grebes and their cute zebra-striped babies when I came across several very chatty Marsh Wrens (Cistothorus palustris) in a large cattail stand.

I’ve seen and photographed Marsh Wrens in the past so this wasn’t new but what I found interesting was the nests. The Marsh Wren is a small brown wren with darker wings and back. A dark cap on the head and a thin white line extending through their eye. They have a long thin bill which is slightly down-curved. They have a long tail which is often cocked upward pointing the tail straight upward or over their back.

The males claim a small territory (quarter acre) in a cattail stand and starts to build a nest. He weaves a very tightly woven nest made of a combination of dried and fresh cattail leaves. The nest is anchored at several points to a combination of last year’s dried cattail stems along with new shoots. The nest is not just a simple cup nest. No the Marsh Wren male constructs a nest with a full dome over the top and an entrance on the side. The entire nest is ball-shaped, about 12 inches tall with surprisingly thick and sturdy walls. The nest is well hidden inside the thick stand of cattails.

If that is not cool enough, the male will build five to six of these amazing nests within his territory. Each nest takes upwards of a week to complete. After constructing all of these marvelous nests, he starts to sing from the tops of the cattails to attract a female. The male sings a gurgling thrill that sounds more like an insect than a bird. It is a very unique call that once you hear it you won’t forget it.

If he attracts a female he will take her around to all of the different nests he has constructed. He will escort her to the entrance of each nest while she goes inside to inspect his construction skills. She will make the final decision on which nest she will use. Then she goes to work lining the interior of the nest cavity with soft warm plant material.

Sometimes the female doesn’t like any of the male’s nests so she will set out to build her own nest within his territory. Either way, once the female is settled into a nest and starts laying eggs, the male will continue singing his attractant song and try to persuade a second female to nest. The male may have upwards of three females in his territory using his domed nests all at the same time.

Before you start judging the male Marsh Wren and think that his is a no-good rotten scoundrel, recent studies show that only 30-40 percent of the female’s offspring in his territory are genetically related to the male that is holding the territory. After the female sets up her nest, she often goes outside of the male's territory and solicits copulations from neighboring males before returning to her nest. Seems that both sexes are promiscuous. 

So recently when I found an active Marsh Wren nest, I set up to photograph the female feeding the babies. It was so exciting to see the female hunting around the cattail stand snatching up all sorts of insects. She would stuff her beak full of all sorts of insects and come rushing back to the nest. She would approach the nest from the side and straddle two cattail stems before slipping inside the nest cavity to feed her babies.

When she emerged from the nest most times she was carrying a fecal sac. Yes, you read that right, a fecal sack. These white sacks which contain the baby’s feces are carried away by the female and deposited far from the nest. This keeps the interior of the nest clean and also doesn’t give away the nest location to any predators.

I never get tired of photographing the loving and caring actions of Mother Nature. Watching the female working non-stop to feed her babies inside one of the most amazing nest structures you will ever see in nature. Until next time…

Stan Tekiela is an author/naturalist and wildlife photographer who travels the U.S. to study and photograph wildlife. He can be followed on www.facebook.com and twitter.com. He can be reached at his web page at www.naturesmart.com.