The wren is one of Britain’s most abundant birds, with over eight million breeding pairs found in a large range of habitats. What strikes me most is the impressive volume to their song, so loud that it is often one of the first songs I hear when I approach woodland. I have often wondered how a bird that weighs the same as a pound coin can produce such an impressively strong song, louder than birds much larger than itself. The feat is achieved by a specialised vocal organ near the wren’s lungs called a syrinx, which amplifies sound in an echoey chamber.
As well as being the loudspeaker of nature the male wren is also known for a bizarre mating behaviour. When nest building season arrives the male becomes very busy, dedicating a large proportion of his time to gathering materials to make as many as twelve nests. Once nests are completed he attracts the attention of a female (through his loud song) and then proceeds to give her a tour of his property portfolio. If she’s impressed, she will choose the nest most suited to her tastes; one that is well concealed from predators and close to places to gather food. Once the perfect nest is chosen she will line the nest shell with her feathers, moss and other soft materials, proceed to mate with the male then later lay her eggs and bring up her chicks.
But what about the other nests the male wren has built? All is not lost as he will repeat the same process with other females, until all nests are occupied with females that will raise his offspring. By building so many nests and mating with the occupants he massively increases his reproductive success. This means that there will be more chicks that will grow up and pass his DNA onto future generations, the aim of most males of all species of animal.
What the wren lacks in size it certainly makes up for in hard work and sound! You can hear our wren recording on our SoundCloud page here.