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I was told a long time ago that having the weather radar turned on when at low altitudes helps to scare birds out of your way because the can sense/feel the radar. Casey also mentioned this in another answer of his.

Is there any evidence that weather radar actually scares off birds, or is this another "urban aviation legend"?

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My guess is it is an urban legend. Ground based weather radar have been used track and analyse behaviour of birds. Part of this research was done with the radar in fixed beam mode to record individual wing beat frequencies for species identification, keeping the bird in the radar beam. If the birds would be scared away by the beam this research would be almost impossible (and invalid as well). Of course, that's no hard evidence that the birds aren't scared. Also the distance between the bird and radar plays a role of course.

The radar used for that research was operating in the C-band, which is also the frequency band that most aircraft weather radars operate in. Newer aircraft weather radars operate in the X-band, which is a higher frequency band. My gut feeling is that the higher frequency is even less likely to bother birds, but then again, I am not a bird so what do I know?

jwenting suggested in a comment that this myth might have been started because of incidents where animals and humans have been harmed and killed by high power radar transmissions.

The FAA has published an Advisory Circular on recommended practices and precautions for operating weather radar on the ground. While not concerned with birds, it provides an example calculations of the output power and safe distance of a weather radar. It the example, the safe distance is less than 4.5 meter. That is too close for a bird to avoid a mid air collision. enter image description hereenter image description here

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  • $\begingroup$ might have been started because of incidents where birds and other animals (including humans) have been killed by high power radar transmissions (one reason why you're not allowed near a transmitting high power radar antenna). $\endgroup$ – jwenting Feb 21 '14 at 7:57
  • $\begingroup$ @jwenting Might be the source of the myth, but the distance at which a weather radar causes harm is too close for a bird to avoid a mid air collision. It's in the order of a couple of meters. $\endgroup$ – DeltaLima Feb 21 '14 at 9:29
  • $\begingroup$ yes, hence the myth... Unless the radar is malfunctioning and transmitting way more energy than it's rated for (and even then you'd possibly get hit by the cadaver, suffering a dented radome as well as a lump of molten electronics). $\endgroup$ – jwenting Feb 21 '14 at 9:31
  • $\begingroup$ ... or some animals are more sensitive than the regulatory panel took into consideration (gasp). Agree that likely this is a myth $\endgroup$ – New Alexandria Feb 21 '14 at 13:09

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