GREY-HEADED WOODPECKER (Picus canus) - Pic cendré
SUMMARY
Closely related to the Green Woodpecker, and easily confused with that. The call has a more mournful, and squeaky timbre to it:
This bird is nowhere near as common as the Green Woodpecker to which it is closely related. In Switzerland it is found only below 600m and over the last 40 years the population has declined and retreated to the north and east of the country. The few times that I have encountered it has been on semi-degraded or abandoned agricultural land not too far from forest.
It could well be that it is overlooked because, not only is it rather similar in appearance to the Green Woodpecker (although slightly smaller and having a bland-looking grey head and face), but it also calls in a rather similar manner – a sort of semi-hysterical laugh.
Its basic call note is a penetrating cry at about 1.8 kHz. Here are three cuts of the same bird calling:
You can hear that the timing of the call is somewhat irregular and variable. In various accounts this is referred to as the “kuk” call, and is described as an alarm or anxiety or aggression call (Gorman 2004; Cramp etal 1989). I haven’t experienced it often enough to comment on this. But you will notice that in the third cut in the above sequence the call comes more quickly and regularly. So listen to this next piece where the delivery is longer and more frequent and I could certainly imagine a degree of excitement or alarm in this bird:
If you look carefully at the sonogram (and note the multiple harmonics in this), each note is rather like an inverted “U” and I think it is the sweep up and down that gives it a softer touch so that to my ears it sounds a bit more like a “whoop” than a “kuk”, but these things are probably in “the ear of the beholder” - so you decide for yourself:
The advertising call (song?) is a variant of this basic call but much more tuneful, and rather similar to a Green Woodpecker. If you listen carefully however there are differences - Grey-headed is slightly higher in pitch and with a squeakier timbre – rather like a Green with a sore throat, here are 4 cuts extracted from a longer recording:
Like the Green the Grey-headed Woodpecker calls like this intermittently over long intervals. The gaps between those four sets of calls were 20s, 50s, and 65s. In each set the number of calls was 10, 8, 10 and 8 with an average of 0.24 seconds per call. There is also a slight drop in pitch as each set progresses (clearly heard but only about 50 Hz), and there is also a slowing down in the rate of delivery of the last few notes.
Here are the two side by side for comparison three different Green calls separated by the same Grey-headed call:
And the sonogram for comparison of the two:
The differences that stand out to me are: the Green seems to give a “happier” more laughing note of a richer timbre, the Grey-headed is sharper, higher, more precise and slightly mournful. If we look at the sonograms of each in more detail we can see some features that perhaps create these impressions:
The Green starts at about 1.2kHz on a rising inflection, with energy (probably a harmonic) also between 2.5 – 3.2 kHz, this will make the richer sound and that rising inflection makes it more joyful in “feel”. The Grey-headed starts at 2.3 kHz and descends to about 1.7 kHz and the energy seems concentrated there – hence it sounds more squeaky (higher frequency) more precise (less dispersed energy) and I believe the downward inflection gives it a more mournful feel. You can find this mournful characteristic also in the Black Woodpecker.
Grey-headed Woodpecker in Asia: The Grey-headed Woodpecker has a very interesting global distribution (see map). There is debate over the taxonomy of the species, but its range extends from Europe all the way across to the Pacific coast, south into China and S.E.Asia, and with tongue that extends across the Himalayas into northern Pakistan. There are several sub-species forming this continuum. The European race is the nominate Picus canus canus.
I came across the Asian version when I was working on the Birds of Jabarkhet Nature Reserve . The Himalayan sub-species has a black nape and is referred to as P.c.sanguiniceps (I am not a taxonomist so I accept what the books tell me!). I was able to record one good sequence of the advertising call from there, and I thought it would be interesting to compare the calls of the two sub-species from such different locations. From the sonogram below it can be seen that the fundamental frequency of the two is the same, but the calls from the Garhwal Himalaya are shorter in each set (only 5 calls) and are delivered more slowly and deliberately (0.34s per call as against 0.24s). Listen to four calls from P.c.canus (Europe) followed by three from P.c. sanguiniceps (Western Himalayas):
Whether those differences are of any taxonomic significance I do not know, but it is interesting (to me!) to make the comparison.
Another interesting call that I heard from the same location were small chittering noises from two birds which were interacting close together in the same tree:
You can hear wings and feet scutterings in that recording as they hopped about on the tree trunk. Similar chittering sounds have been described from Europe (Gorman 2004; Cramp etal 1989) but I have not recorded them.