Geoffrey’s photo shows cranial kinesis, which is something that allows the bird’s upper mandible to hinge at the base and thus move upwards. Most obviously
shown in parrots. So birds can open their beak by moving either or both mandibles (unlike mammals for example, that can only lower the lower jaw). This is done by moving the quadrate bone forward and the jugal bone slides forwards (and backwards) against the
palatine bone. Only a few birds (such as this godwit) go even further with a hinge in the middle of the upper mandible that allows it to also bend upwards.
I am thinking this zirkelning is something else again, from what these waders do, involving the opening of the lower mandible whilst pushing against the soil.
Or maybe it is a combination of both. I am wondering if this is a German word.
Philip
From: Canberrabirds [
On Behalf Of Geoffrey Dabb
Sent: Tuesday, 29 August, 2023 6:27 PM
To: 'Wallaces'; 'Canberra birds'
Subject: Re: [Canberrabirds] Zirkelning - word of the day!
Excellent, Steve.
From: Canberrabirds <>
On Behalf Of Wallaces via Canberrabirds
Sent: Tuesday, August 29, 2023 5:22 PM
To: Canberra birds <>
Subject: [Canberrabirds] Zirkelning - word of the day!
While going through entries in HANZAB online today (yes HANZAB online is still alive!), I came across the word
'zirkelning', a term I was not familiar with. It is described in the text but not defined in the HANZAB glossary. Googling it returned two source which used the similar words to HANZAB. It is also not in The
Ornithologists Dictionary (Lynx).
It turns out that most of us have probably seen starlings zirkelning – probing with the bill open.
From HANZAB Common Starling entry:
“Probe ground for invertebrates (Phillipps & Lindsay 1948; Badman 1979; Wilson 1979). Single probes can sometimes
comprise several thrusts of bill (East & Pottinger 1975), and often accompanied by bill gaping (‘zirkelning’), birds opening bill c. 2 cm while embedded in earth to enlarge openings; technique
appears to be learnt when young (Gannon 1932; Thomas 1957; East & Pottinger 1975; Martin 1987; Kloot 1993); also use zirkelning action to separate grass (Terrill 1946).”
The search facility of HANZAB online returned four species in which zirkelning has been observed: Common Starling, South Island Saddleback, Victoria’s Riflebird and Grey Currawong.
I have added zirkelning to the HANZAB Glossary.
Cheers
Steve
