Backyard Biology

Nature stories from my backyard and beyond

Nature Activities

Fishing for Fireflies

Tuesday, January 4, 2011


The winter seems like a strange time to be thinking about a summertime nature activity. But what better time to make your scientific equipment than when you are sitting at home waiting for the warm weather. So now is a fine time to make a firefly fishing rod.
In the eastern three thirds of the country, watching fireflies is a summertime ritual for many families. No other activity I know gets so many people outside in nature in the nighttime. So while you are outside enjoying the fireflies, why not talk to them in their language? You can do this with a firefly fishing rod.

Most people are surprised to find out that there are many different species of fireflies. On any given night, you may see five or more different kinds, while the ones you see early in the night may be different from the ones later in the night and those in the early part of the summer may be different from those at the end of the summer.
To eliminate confusion amongst themselves, each firefly has it’s own language - it’s own flash pattern. For instance, the male of one firefly may flash once every 5 seconds and the female may flash 4 seconds after the male flash, while another firefly species may flash once every two seconds with the female flashing one and a half seconds after the male. Typically, the male will flash while flying and the female, if she is interested in the male, responds while perched in the grass or on a bush.
Since it is dark out and the fireflies can’t see each other - only their flash - they can’t tell if the flash is coming from a firefly or other light source. As long as the flash is in the correct pattern, that is often good enough for them. It doesn’t matter if the flash is created by a penlight, a cigarette butt or even a lightning flash, they may respond to it.

A firefly fishing rod is a fishing rod with a LED or Christmas tree light on the end. A push-button switch on the handle of the fishing rod allows you to flash the light on and off - imitating the flash of a firefly. By imitating the flash of the flying male, you might get a response from the perched female, and by imitating the flash response from the female, you might get the male to fly down to her to investigate. While flashing my fishing rod from the grass, I have actually had male fireflies land on the flashing light of my fishing rod!

So how do you know the correct flash pattern to imitate? The best way to do this is to watch the fireflies as they do their thing and time the interval between their flashes. Then just imitate the pattern you observe.
Another way is to look at a firefly flash pattern chart. Firefly scientists have studied and recorded the flash patterns of many of our fireflies. In fact, since many firefly species look exactly alike, scientists most often identify firefly species by their flash patterns.
A chart of the flash pattern of many fireflies can be downloaded from the Firefly Watch Project* web site at https://www.mos.org/fireflywatch/flash_chart

Caution: Fireflies flash to each other as a way to find a mate. Each firefly only lives a few weeks as an adult and may be active for less than an hour each night, so their time for mating is brief. Use your firefly fishing rod sparingly, so as to disrupt their mating activity as little as possible. After all, firefly numbers appear to be declining, and we don' want to contribute to their demise.

fishing rod


Materials:

  • Fishing rod – the cheapest you can find
  • AA battery pack
  • Pushbutton switch - make sure to buy the “normally Open” switch
  • Bell wire - stereo wire can also be used
  • Christmas tree light – from a broken set of lights

Wiring Diagram:

wiring diagram

 

Directions:

  1. Use a wire stripper to strip the ends of all wires – including the switch, light, battery pack and bell wires.

  2. Tape the battery pack and switch to the handle of the fishing rod.
    battery pack

    switch









  3. Tape the light to the end of the fishing rod.
    light







  4. Connect one wire from the battery pack to one terminal on the switch by threading it through the hole in the terminal and twisting the wire so it makes good contact with the terminal.

    switch
  5. Connect a length of bell wire to the other wire of the battery pack by twisting the stripped ends together.
    Connect the other end of the bell wire to one of the wires on the Christmas tree light.

  6. Connect a length of bell wire to the second wire on the Christmas tree light.
    Connect the other end of the bell wire to the second terminal on the switch.

  7. Tape the wires to the fishing rod so they are securely out of the way.

Note: If you wish to be able to take your fishing rod apart for ease of transport, make sure you leave enough slack in the wire where the two halves of the fishing rod join.

fishing rod joint

*To learn more about fireflies and how you can participate in a scientific project to help protect them, check out the Firefly Watch Project at the Museum of Science in Boston
www.mos.org/fireflywatch