This invasion that reached the British Islands has been large-scale. As a consequence of the fact, that we have the race (P. p. pyrrhula) normally appearing in our area, it might be so that not all birdwatchers have reacted on the unusual call. One bird, ringed at Stora Fjäderägg has been controlled on Fair Isle, Shetland. Biometric measurements have shown that the wings are longer than the migrators that pass St. Fjäderägg a normal autumn. Birds have been observed in considerable parts of Great Britain, in the Switzerland, Germany and Bulgaria, as well as on Iceland.

On the British Isles this invasion has been lively debated (http://www.birdforum.net/showthread.php?t=24605&page=1&pp=25), but here in Sweden the invasion did not seem to have been noticed at once by all bird watchers.

A good article is found here: http://www.birdsireland.com/pages/site_pages/features/bullfinch.html.

Parts of the discussion on the message board "Brevduvan" (“the Carrier Pigeon") of Club300 regarding trumpeting bullfinches is found on Gebbe Björkman's home page [in Swedish though].

Is it possible to divide between the trumpeting and the whistling bullfinches? The opinion on that seems to differ between bird watchers. As said, biometric analyses have shown that the wings are longer among the trumpeters. Some birdwatchers have claimed that the trumpeters are bigger that the normal population, but probably this is depending on ornithologists in western and southern Europe who compare with their local races. Other distinguishing characteristiscs discussed are: 1. males of the trumpeting population has a stronger red colour on the breast, females sometimes a more grayish rose colour compared with whistling bullfinch. 2. Trumpeters have more evident and broader wing bars than the whistlers. 3. The outer tail feathers have a white longitudinal mark (evidently this is also true for the western population, but the frequency increases towards east). See a picture of this link 4. The red colour of the male trumpeter goes further back on the underparts than in whistling males (WRONG! this is a characteristic of the race (P. p. rossikowski) found in for example Caucasus). 5. The white rump is larger among trumpeters. 6. Other ideas on plumage charcteristics are: the black on the head goes unevenly far in the neck in the two populations, the border between the black on the head and the side of the head forms an even curve in some birds whereas there is a tendency toward an angle behind the eye in others (this is maybe an effect of the eye extending somewhat into the red/grey on the side of the head, see this link), a number of specimens have a white line under the eye. But proofs of different characteristics are still to be proven, maybe the differences listed here are just a normal variation within the race.

Both trumpeting and whistling northern bullfinches have been singing in February trough April 2005. Both males and females sing. It seems to me that the song of the trumpeter is more "squeeky" that the song of the whistler, but there is for shure considerable individual variation also by "our own", whistling bullfinch.

In the garden the trumpeters were more hesitant to come down to the feeders compared with the whistlers. Can this depend on that they were used to other types of feed than the whistlers? From February on it changed in that way that also the trumpeters came down to the feeders.

The home range of these birds has been unclear. However, on the British site I found a link to recordings of northern bullfinches made in Syktyvkar in the Komi Republic in the NE part of European Russia, that have the same call as the invaders (examples presented below). The recordings are made by Annika Forstén and Antero Lindholm. I have taken some small samples from these files and added a whistling bullfinch for comparison (Stieg Carlsson and Per-Erik Gydemo): bullfinches. Starting from that we could say that the trumpeting bullfinches are probably coming from the European part of the Russian taiga, or even more far away. However, in the Dutch equivalent to ”Vår fågelvärld” a reference to a letter is given indicating that trumpeting northen bullfinches were found breeding so far west as in Utsjoki in northern Finland, near the Norwegian border. The population is not, in fact, brand new to western Europe, there are Swedish records from a number of winters and a number of Finnish birdwatchers claim that they are heard in eastern Finland in winter.

An idea came to my head: might it be so, that the Siberian Tits (Parus cinctus) observed in the district of Uppland during the winter of 2004/2005 are part of the same invasion? Read about siberian tits in our own home area!! Maybe are the Waxwings (Bombycilla garrulus) and the Pine Grosbeak (Pinicola enucleator) also part of the same invasion? And if so, what has happened in their home area during late summer or autumn 2004? According to a message from somewhere in Europe the snow had come one month earlier than normal in the Caucasus, but this is probably not the breeding area for the ”trumpeters” – maybe a few observations from SE Europe concerns the race breeding in this area?

Calls from The Komi Republic, NE European Russia
Calls from the Netherlands and Iceland
Calls from Shetland
Whistling northern bullfinch from Svista, Össeby-Garn, municipality of Vallentuna February 4th 2005
Trumpeting northen bullfinch from Svista, Össeby-Garn, municipality of Vallentuna January 31st 2005

An analysis of the call of whistling and trumpeting northern bullfinches displays totally separate structures. The whistling population displays a pure tone somewhat sinking in pitch (see figure below). This makes the call sorrowful. At the beginning of the call the pitch goes up considerably, but this is made within hundreds of a second so a human ear cannot hear that.

The trumpeting bullfinches have a call built in quite another way, it is even difficult to imagine that it is the same species. These bullfinches have two or three tones simultaneously. It is these two – three tones, sounding with a difference in pitch of c. 500 Hz (Hertz) that makes the call sound like a toy trumpet (the Trumpeter Finch that displays a similar call has 5-10 parallel tones). Unlike the indigenous bullfinches the tones are constant in pitch, but a similarity is that they have a starting sequence with increasing pitch and the sonogram indicates a very characteristic hook within the first two hundreds of a second. The call is also somewhat longer than the call of the whistling bullfinch.

The table below indicates the construction of the call of a whistling bullfinch. The pitch of the typical call has (after the first two hundreds of a second) a frequency (pitch) of 2,650 Hz and is after c. 0.13 seconds ending at a frequency of 2,400 Hz.

Time (sec.)	0	0.01	0.017	0.025	0.135
Frequency (Hz)	2,400	2,600	2,650	2,650	2,400

The trumpeting bullfinches have the following construction. They have always at least two tones at a time. From the start at a frequency of 2,000 Hz and 2,500 Hz resp. the pitch of the call rises rapidly to 2,350 and 2,850-3,000 resp. (differs between different birds) and there it stays for c. 0.15 seconds. Sometimes a third tone is seen with a frequency around 3,200 Hz. In recordings made from a distance the uppermost tone is often drowned and the second highest appears a little weaker than the lowest. This was the case when recording trumpeting bullfinches in my garden, where the same bird displayed this variation with distance. However, the individual variation is considerable.

Time (sec.)	0	0.012	0.154
Lowest tone (Hz)	2,000	2,350	2,300
Middle tone(Hz)	2,500	2,850/3,000	2,850/3,000
Uppermost tone (Hz)	2,900	3,250	3,150

Sonograms of these two populations are indicated in the figures below. The vertical axis indicates pitch (frequency) in Hertz and the horizontal axis time in seconds. The trumpeting bullfinch is recorded in Shetland by Mike Pennington, the whistling bullfinch by Stieg Carlsson and Per-Erik Gydemo (from the CD "Tättingläten" [“Passerine calls”], see reference at the end of this page). NOTE that the scales are not the same in the figures!!

The left recording is made in mono, the right in stereo. In the case of the whistling bullfinch the keynote is seen (the light part) but also two overtones where the first has double the frequency of the keynote and the second the triple of the keynote. The overtones indicate very neatly how the pitch is sinking through the call. The strong part of the tone is followed by a tail that is probably the echo of the call. In the right figure the hooks in the beginning of the call are clearly seen (especially in the upper part of the figure) and that the call after that has a constant pitch. There is an indication of a very weak third tone above the two strong bands.

The third tone is very clear in the left figure below. The recording is made in the Russian republic of Komi in Russia west of the Ural mountains (Forstén & Lindholm). A large number of echoes and overtones are also seen. The Two-barred Crossbill (Loxia leucoptera) has a trumpeting call similar to the trumpeting bullfinches. The right figure below shows a sonogram of the trumpet call of a Two-barred Crossbill (from Carlsson and Gydemo). There is a large number of disturbances in the recording but it is evident that there are many similarities between the two calls. An important difference is, however, that the call of the Two-barred Crossbill is higher in pitch that that of the bullfinches. The keynote has a frequency of c. 2,700 Hz, the second and strongest of c. 3,600 Hz and the highest of c. 4,500 Hz. In addition to that the first overtone of the keynote is visible having a frequency of c. 5,400 Hz. An effect of the strongest tone to be 3,600 Hz the call is apprehended as higher in pitch. The echo remains for a long time also in this recording. The length of the call is around 1/10 of a second, i.e. it is a little shorter than the call of the trumpeting bullfinch. If you now of a recording of the call of the Two-barred Crossbill that is not affected by so much disturbance it would be interesting to get a chance to make an analysis of the recording.

In a paper by Patricia M. Gray et al.: "The Music of Nature and the Nature of Music" (Science, vol 291, 5 Jan, 2001, pp. 52-54) Bullfinch is mentioned as a species having “vertical learning” of the call. According to the authors this means that the young learn from their parents. At the same time this means that the call is nothing inherited and this opens up for local dialects. This is something we know from for example the Redwing (Turdus iliacus). It will be interesting to see during breeding time 2005 if any trumpeting bullfinches will remain in Sweden to breed, if there will be “mixed marriages” and, above all, what call the young will learn.

On January 31st 2005 I was able to record the call of a trumpeting bullfinch in my garden. The call is in principle the same as in the recordings from Shetland, but the third tone is weaker than in the Komi birds. Recording distance was merely ten meters so the risk that the tone has not reached the equipment is small. Maybe we can see different “accents” also among the trumpeters. If somebody has recordings of trumpeting bullfinches it would be very interesting to see if there is a difference between different birds. For example “my” bullfinch has a shorter call than the Komi Bullfinch and it is also a little lower in pitch (2,250, 2,800 and 3,250 plus a large number of “unsorted” overtones).

On August 11th I heard - to my surprise - a group of four bullfinches using both whistling and trumpeting. A difference from the trumpeters in winter was that this trumpet call was more subdued. In August bullfinches are not often seen in our area at all, and four birds is a record so far for August 2005. The rested too short time for me to find out whether different birds used different calls or if they mixed the calls. Anyhow the birds must have been breeding in Sweden, maybe it is a cross-breeding between a whistling and a trumpeting bullfinch. But more information is needed to make clear what I heard.

Hans-Georg Wallentinus