Can birds scream as loud as a jet engine?

Question

I'm moving into an apartment with my cockatoo, and in thinking about sound level I realized I've never actually seen a source for the claim I've heard quite often and passively believed myself:

Cockatoos can scream as loud as a jet engine!

You can see this repeated over and over just by searching for "cockatoo scream jet engine".

The claim itself lacks any real units, but often recited in decibels. This site suggests in a comment:

Sun Conures are the loudest birds there is. Easily as loud as a jet engine. They scream at dawn and at dusk. It's instinct and they can't be trained out of it.

And this site says:

Most cockatoos will scream for about 20 to 40 minutes a day, for no reason. And, yes, they are very loud. The amount of decibels(unit of measurement for sound) their loudest scream has is greater than that of a jet engine.

My own original attempt at linking the two is noting that a jet engine (at 100 feet) is 140 dB (doubling the distance makes it about 134 dB, which would still be as "loud as a jet engine", to me), and (apparently) a Moluccan cockatoo can reach 135 dB. But how is the latter figure being measured? At what distance and with what reference level? Has it been measured at all or is it just a guess? Where's the source?

My cockatoo is not a Moluccan, but I can attest that at times he can be loud. I don't think, however, that the short-lived mid-to-high pitched screams of a bird can compare in loudness to the continuous rumbling of a jet engine.

Are there any studies regarding such comparisons, or the loudness of cockatoos, or is it bogus?

Answer 1

tl;dr: No, cockatoos output ~3000x less sound energy than jet engines, even taking claims of 135 dB at face value.

Loudness measurements are, broadly speaking, a mess when it comes to answering questions like these. Loudness is often measured for occupational health and safety reasons, and in these situations you put the microphone at the natural distance from the noise source. Here's a good reference on loudness; the writing quality is a little shaky but the technical data seems sound. As usual, Wikipedia has a decent article on sound pressure also. Unfortunately, decibel numbers for birds seem to be widely spread without distances or citations; there are YouTube videos of Moluccans which are incredibly loud but it's very difficult to estimate even orders of magnitude from that.

In any case, although I cannot find at what distance the Moluccan cockatoo was measured (or even if it really was), it is presumably in normal ranges for people who are around screeching cockatoos (a few meters). Also, note that jet engines do not radiate sound equally in all directions; they're a lot louder from the back than from the side. So this leaves us to conclude that the comparison is essentially meaningless.

However, one can as a closely related but sensible question: at the presumably loudest point around either a jet engine or cockatoo, how far away does each have to be for the two to sound comparably loud?

If we speculate that the 135 dB level is for about 3 meters, Wikipedia has a jet engine at 150 dB at 30 meters (which matches the top end of the 110-140 dB range at 100 meters). Another 5 dB is 3x more less power per unit area, or sqrt(3) ~= 1.7x more distance, so a jet engine at 170 meters is probably roughly comparable to a Moluccan cockatoo shriek at 3 meters. Since this is around 55x farther away, we can estimate that jet engines put out about 55² ~= 3000x more sound energy than the cockatoo. (Maybe somewhat less for the jet engine, given the reduced sound to the side.)

More relevant is probably that if you want your cockatoo to be only as loud as a rock concert (~110 dB; also about equal to a chainsaw that you're holding), you will probably have to be about 50 meters away from it*.

*^{25 dB drop is a decrease in power of 300 times, sqrt(300) = 17 times farther away; 3m*17 = 51m}