Electronic circuit to keep Kingfishers away of your pond
"Why all of the birds chirp loudly in the morning..?" Still it retains in my memory, as a six or seven years old kid holding father's finger and walking in the garden, asked this question. He took almost no time at all to explain the reason of bird chirping at dawn.
A long long ago, when the great great ancestor of all kind of the present birds had been living on earth, this incredible incident happened. By that time, the earth had been fully occupied by ruthless creatures. Very powerful hungry souls dominated on ground. So bird's great great ancestors, having light and weak bodies, had been chased up to tree tops and sky. One day, all of a sudden the sun disappeared. The whole world fell in darkness and this continued long. The giants which dominated on ground died quickly and the rest faced the same fate sooner or later. At last, seldom falling of sun rays on earth occurred place to place. The bird's ancestors used each and every of these occasions to eat and mate. Thus, whenever they saw the first sunlight, started informing and calling others with a loud chirp. So even today, the birds chirp altogether whenever they see sunlight after darkness. (Even after solar eclipse). Being older and learning the Theory of Evolution I really admired his explanation.
As you see the birds express their presence and dominating power with the chirp. Using this biological fact, you can keep kingfishers away of your pond. I have been using the following electronic circuit successfully for that purpose. Make a PIR (Passive Infrared) sensor as per the schematic diagram fig.1 and mount it facing the Fresnel lens towards the pond. The second circuit "the bird chirp" can be connected to the relay out-put of the PIR detector.Whenever someone moves near the pond, the sensor get triggered and a loud bird chirping sound which is similar to kingfisher's is generated. The electrolythic capacitor values may be changed in order to match the frequencies of the local Kingfishers in your area.
Fig 2
