Cicada Rhythms

Explanation: Amazing creatures, these are. Cicadas are amazingly diverse and nearly cosmopolitan, inhabiting tropical and temperate climates alike.

The star of this week's photo is a beauty I discovered after dark on the wall of my bamboo hut in south India next to Periyar Wildlife Sanctuary and Tiger Reserve.

Elsewhere in India, I was instructed how to capture cicadas for food. After dark, you stand on a high, open ridgetop in the forest, waving a burning torch. Cicadas are attracted to the light (and heat?) of the torch, and as they swoop up the hillside, two companions suddenly raise a net strung between two poles, thereby making the captures.

Cicadas have some of the loudest "songs" of all insects, produced not vocally but by muscular contractions and releases of specific membranes on the sides of their abdomen.

Here is a recording I made of a cicada (likely a different species than in the photo, above) from northeast India. Their sounds can be utterly deafening.

In the above recording, the cicada is singing across frequencies ranging from approximately 3 to 6 KHz. You can also hear a bird singing twice, at a lower frequency of about 0.8 to 1.5 KHz.

Here is a sound spectrogram of the above recording; see if you can identify the cicada hum and the bird song (click for larger version):

EPOW - Ecology Picture of the Week