House Wren (Troglodytes aedon) by Philip English
I’m always on the lookout for something I didn’t already know.
How about you? Did you know that House Wrens keep pets of their own? I didn’t either, but while recently perusing Cornell University’s great bird knowledge site, allaboutbirds.org I learned that it’s a true, cool fact! These are not just any pets; House Wrens will actually raise spiders. By importing arachnids’ egg sacs into their boxes to hatch, the brilliant wrens rid their own hatch-lings of the body mites that plague the young birds, when the newly hatched spiders eat them! Smart. The next time someone calls you (or anyone else) a “bird brain” be sure to respond by saying you do hope they are not basing that slight remark on the wisdom of the House Wren.
Before we start examining Troglodytes aedon -House Wren (HOWR) in detail, let’s look at all of the Indiana wrens in general. Our Hoosier wrens total five in species (that number used to be six, but Bewick’s Wren (BEWR) has not been seen nor heard in the State since the 1980s). All wrens appear rather simple little songbirds although – in reality – while sharing a bevy of similarities, lead quite complex and differing little lives. From the wren who only overwinters here (the first bird discussed in this series, January 2019’s Bird of the Month, and champion of all North American songbirds for most complex of all songs: Troglodytes hiemalis – Winter Wren or, “WIWR,”) to the species who calls Indiana home year round, our February focus in this series,Thryothorus ludovicianus – Carolina Wren (CARW) they all share certain traits: Scientifically speaking, they’re in the order of Passeriformes and their family is that of the Troglodytidae. The more common ways in which we see them are as the tiny, extremely active, mostly plain, brown colored, birds with subtle markings, and BIG, BIG, voices.
Listen to the three links below, and compare the songs of House Wren with those of the Carolina Wren and the Winter Wren:
In the spring and summer, there are four species of wrens that the casual observer of birds might encounter in Indiana, but only two of those species is she actually likely to encounter, busy with their breeding activities not only in the woodlands, but are easily found around our own homes, for they are not quite so secretive as their cousins, Cistothorus palustris – Marsh Wren (MAWR) nor Cistothorus platensis – Sedge Wren (SEWR) two species considerably more difficult to locate in Indiana, and that is for a couple of reasons: First, they are species found in less traveled terrains, the marshy, reed-filled areas within our State, and the open grasslands, and secondly, migratory and behavioral peculiarities make them somewhat less easily found. The Marsh Wren is extraordinarily secretive, and tends to stay in reeds, closer to the ground, and the Sedge Wren – while often present in grasslands – is the most nomadic of all wrens, and simply cannot be counted upon to be at any known locale within the State on any given year. That leaves us with the two most common of our Hoosier dwelling wrens: the Carolina Wren and this writing’s focus: Troglodytes aedon – House Wren (HOWR). The name, Troglodytidae mean’s “cave dweller,” and sans nesting boxes being provided by humans, HOWR builds her nest in the cavities of trees in wooded areas, or any cavity-like spot around our homes (hence her common name) in potting sheds, garages or even taking possession of old boots or shoes left out. Smart.
Each species of wren seems to be unique where their own complex nature is concerned, and have qualities that make them stand out from the other species. Apart from being the most widely distributed bird in the entire northern hemisphere, the tiny House Wren is quite a paradox. In the world of songbirds, House Wren’s song is sweet to our human ears, and she is one of the plainest looking and smallest of songbirds, yet, what she lacks for in size (4.3 to 5.1 in long, with a 5.9 inch wingspan, and weighing in at only 10-12g) she certainly makes up for in tenacity and aggression; in spite of her diminutive size she remains one of the more aggressive songbird species. One might use the analogy of a feather-weight (no pun intended) boxer regularly going up against heavyweight contenders – and most times, winning. To illustrate by way of my own observations, I have watched a pair of HOWR clear whole gangs of House Sparrows from the feeders near their nest box territory.
However, before you haters of House Sparrows begin to plan your celebratory parties, consider that – conversely – the House Wren has also been known to be a significant enemy of and cause for nest failures in certain Eastern Bluebird (EABL) populations. One reason for this is that although the bluebird cannot fit through the opening into the House Wren’s box (if it is constructed properly) a HOWR can certainly fit through the EABL box’s entrance, and certainly will do so. There is nothing shy about the House Wren, nor anything milquetoast-like about their methods, and Eastern Bluebird tragedy will – and does – often ensue. A word of advice for those who love both Eastern Bluebirds and House Wrens: Along with your EABL boxes, put out correctly constructed HOWR boxes as well. The House Wrens actually favor the ones constructed specifically for them, because only their tiny bodies can fit into their specially fitted entrance openings, which gives their broods an edge against competition: an extra degree of protection from larger predators, and in this way, EABL might see less predation from the wrens (AND House Sparrows if the wrens run them off). Whatever box you decide to use for the wren, the key and simple trick for success is to make the entrance hole no larger than 1.25 inches (3.2 cm) in diameter. Even a tiny bit too large will allow the Black-capped chickadee (BLCH) or Carolina Chickadee (CACH) to build in them (although it is not likely the HOWR would stand for such a thing). Nature is indeed a mean mother.
Another thing all wrens have in common is their diet, and HOWR is no different from her wren cousins, foraging everywhere she goes for the insects that make up nearly all of her diet. This is one reason that although these birds are considered to be of “low concern” for endangerment when we look at their status strictly as a bird species, we have begun to take a more holistic view of the natural world, and have become worried for the well-being of all creatures; for the delicate and interdependent natural order of the food-chain is becoming more and more threatened by the alarming and rapid decline of all insect species, which is – in essence – to say that ALL species have become – by extension – threatened. Please take the time to read this powerful article which explains the frightening prospect:
This writer and bird advocate would consider himself remiss if failing to add here the thought that as if the above issue were in itself not a difficult enough obstacle for the lowly wren (and others) to endure in her fight to simply survive, it becomes a tragically compound problem: it has become coupled with glaring and undeniable changes in attitudes apparently aimed at diminishing or outright destroying any valuable environmental conservation policies already in place, through the recent and ongoing Administrative appointments to key offices, persons known to be opponents of true nature conservation policies and practices and through the wholesale disregard that seems to now prevail for public trust, and in blatant favor of financial interests.
The House Wren is a tough little bird, but she and all birds and nature can’t compete to survive against the worst humans can do; that is, without the help of the best humans can be.