The high frequency part of bird calls

[GrahameNZ]

Hi folks,
Can someone point me in the direction of research or general info about the high frequency part of Harrier, Falcon and I guess Kea calls.
Possibly even Owls.
I'm interested in birds that would be called a "predator" and NZ.
I'm thinking above 20 kHz, for those that don't know that's above the top range of what a decent set of human ears can hear.
Recordings of the high frequency component would be interesting or just a time / freq waveform.
Thanks
Grahame

[Davidthomas]

The only birds i know of to have calls above 20kHz are Kea and Rock Wren, with a Notornis paper by my friend on Otira Rock Wren showing a harmonic above 20kHz. While Kea calls appear to have a large number of harmonics from quite low kHz to in excess of 24kHz aka higher than microphones will normally go! Theres a paper by R. Schwing and Dr. Ximena Nelson (My old supervisor) in the NZ Journal of Ecology (I think?) regarding kea calls and their harmonics/audio dynamics.

Can probably find both of the above papers if you'd like Grahame so just let me know.

Cheers

[GrahameNZ]

Thanks David,
You were the person I thought most likely to be able to answer this ??
My question then becomes
Why do "bird scarers" that work in the 20 - 30 kHz range work ?
I had assumed that there was a high freq component part to predator / general bird call that we don't hear and is part of the id of that bird.
Something that aids the prey along with the visual and below 20 kHz to id what they are "seeing"
And of course the birds to communicate with each other.
I'd be interested in the Kea paper if it has some spectrograms in it.
An interesting project I'm working on, just wanting to see some "proper" data to try and give me a rough idea as to where to start some rough field trials.

[GrahameNZ]

Found it
Here
http://ximenanelson.weebly.com/publications--all.html
Got me here
Vocal repertoire of the New Zealand kea parrot Nestor notabilis
http://ximenanelson.weebly.com/uploads/ ... _small.pdf
She has an interesting collection of papers she has collaborated on.
Some interesting reading coming me thinks.
Thanks David

[Davidthomas]

Sorry about not replying with the papers sooner Grahame, but glad you were able to find the ones you were after. Shes certainly very talented and switched on thats for sure! A lot of her spider cognition stuff is amazingly interesting, certainly blew my mind and im a birdy person!

[GrahameNZ]

Believe me David my palps are waving with anticipation