Friday, June 15, 2012

Marsh Wrens at the Utica Marsh and the Ninebark Bush - an Unrivaled Bug Magnet

Marsh Wren singing
At the Utica Marsh the Marsh Wrens have been very active in the cattail beds. Marsh Wrens have a close association with cattails and are seldom found very far from them. The invasive plant, Purple Loosestrife, has taken over much of the wetland habitat at the Utica Marsh. In fact, cattails now only cover a relatively small portion of its acreage. This means that the Marsh Wren and many of the other Marsh specialty species are forced to make do with an ever decreasing amount of viable habitat.

A well concealed Marsh Wren nest

Male Marsh Wren build nests mostly out of cattail leaves. They create oval-shaped, domed nests which are placed about 1 or 2 feet above the ground (or water). Most often the nests are well hidden in the reeds, and difficult to pick out unless you know what to look for. Like the House Wren, the males usually make several “dummy” nests that will never be used. Sometimes as many as 6 nests will be built for every one that is actually used to raise young. It’s up to the female wren to decide which nest to finally lay eggs into.

The Marsh Wren male is often polygamous, so perhaps when he is making all of these nests he’s being optimistic that he’ll be able to secure enough wives to fill them all with eggs. I think that it’s more likely that nest building is a constructive outlet for all of the surplus energy that wrens seem to possess.

The Wren himself often stays hidden from view

Looking out at their breeding grounds at the Marsh, I can see 2 new Wren nests built only 10 feet apart from each other. The builder sings a rapid bubbling (or clicking) song that’s similar but not as musical as the House Wren’s song. It has been shown that a young male Marsh Wren learns between 50 and 200 different song types, but discerning the subtle differences between most of these similar sounding songs takes keener ears than mine.

Found nearby the Wrens, a Red-winged Blackbird nest with eggs
For the other resident birds of the marsh, Marsh Wrens can be antisocial neighbors. Apparently, when given the opportunity, they will sometimes peck holes in other birds’ eggs –thus destroying them. I however, found my Marsh Wren neighbor to be quite amiable. I spend a few hours in his territory observing a Least Bittern nest, and he never tried to peck at my head once! In fact he flitted about the marsh grasses, collecting materials for a nest, and pretty much behaved as if I wasn’t there. Getting pictures of him when he was singing was difficult. For the most part, he liked to sing low down in the cattail leaves, and so it was hard to get a clear view of him. He wasn’t on the best terms with the other male Marsh Wrens nesting nearby and they’d engage in singing duels at irregular intervals. However, no actual physical fighting was observed.

Nesting nearby is the rare and colorful Least Bittern

Like all of the other wren species that I know, Marsh Wrens are excellent hunters and so any insects that share a habitat with them had better beware.

Ninebark is a trurly massive native bush that grows at our nature preserve

Ninebark is in full bloom at the nature preserve. The profusion of flowers on this large native bush attract more pollinating insects than any other plant on the property. Moths and Butterflies appreciate this bush, but bees, wasps, beetles and flies seem to be its real devotees. If anyone ever wants to study the diversity of bee and fly species in this region, my advice is to stake out a Ninebark Bush. Every spring, I’m guaranteed to find several species that I’ve never seen before.

Ninebark flowers are busy with pollinating insects of all kinds

We started these bushes by seed originally, and they grew pretty quickly. Now the largest of them is over 8 feet tall and is covered with thousands of blossoms.

No comments:

Post a Comment