Letter | Published:

Lack of Ultrasonic Components in the Flight Noise of Owls

Naturevolume 193pages594595 (1962) | Download Citation



DURING the course of some observations on the ultrasonic components of the songs and call notes of a number of species of birds1, we noticed to our surprise the extent to which the wing beats of small birds produced ultrasonic ‘noises’. This raised interesting problems as to how far the silent flight of the smaller and medium-sized owls is also ‘silent’ above the normal upper limit of the human ear: for if the owls' wings are noisy at the higher frequencies, then most of the supposed advantage to owls of this adaptation would be lost, since it is likely that the vast majority of small mammals on which these birds prey possess good hearing in the ultrasonic range2.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Thorpe, W. H., and Griffin, D. R., Ibis., 104 (in the press).

  2. 2

    Schleidt, W. M., Naturwiss., 39, 69 (1952).

  3. 3

    Thorpe, W. H., and Griffin, D. R., Ibis, 104 (in the press).

  4. 4

    Graham, R. R., J. Roy. Aeronaut. Soc., 38, 837 (1934).

Download references

Author information


  1. Sub-department of Animal Behaviour, Department of Zoology, Cambridge

    • W. H. THORPE
    •  & D. R. GRIFFIN


  1. Search for W. H. THORPE in:

  2. Search for D. R. GRIFFIN in:

About this article

Publication history

Issue Date




By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.