Great Tit mimicry of other bird species.

For several years, or perhaps most of my life, I've been trying to improve my knowledge of different bird's song and calls. Probably I learned Starlings and House Sparrows when I was a kid, as they were pretty much the most common of the birds that came to feed on kitchen scraps my mum put out for the birds (most people couldn't afford specially formulated bird food in those days!). At about the same time my copy of The Observer's Book of Birds told me that the Yellowhammer song says "a little bit of bread and no cheeeese" and, although we didn't get Yellowhammers in our garden, later on I did get a chance to hear that song on Barlaston Downs (a place I visited fairly frequently during my childhood and teenage years). I also remember from those days watching and listening to Skylarks displaying in the sky above the rough grassland on the upper end of Meir Aerodrome (near where I lived at the time). And I think I learned Robin's songs and calls as an adult as I was gardening. A more recent acquisition to my repertoire of call and song ID is the Chaffinch which I particularly recall learning as one year a male was often heard singing in a tree outside one of the numerous houses I have lived in. I was able clearly see that bird as it sang so I could relate that sound to that species, and I've remembered it ever since as the "chip-chip-cheereeo" bird because I've read somewhere it's song described like that! But in the last ten years or so I have made a determined effort to learn more bird calls and song. Now I am very familiar with many more species, particularly garden and woodland species, and less familiar with quite a few more.

A few years ago while out rehearsing my ability to remember bird calls and song I noticed a Wren and Great Tit within a few meters of each other in some lowish scrub along the disused railway line. Both birds were interacting with each other, as at times the Great Tit was perched above the Wren fidgeting and posturing on the branch and its actions appeared to be aimed at the Wren below. At the same time the tit was making the cross sounding rattle-type call which is made by Wrens (it sounds like a warning call - maybe to warn off a rival but I don't know if that is its function). I was fairly convinced that the Great Tit was mimicking the Wren call. Since then I have taken time to listen out for other examples of Great Tit mimicry - and I think I have heard it on several occasions. For example, when listening to a flock of mixed Blue and Great Tits I find it difficult to separate the calls of each species as to me it sounds as if the Great Tits are copying the Blue Tits.

This afternoon I got another opportunity to spend an extended period listening to Great Tits. There was about four of them initially alongside a couple of Blue Tits in Hawthorn trees near Stoke on Trent Boat Club. In the ten minutes or so that I watched and listened to these birds I heard sounds similar to Blackbirds, Blue Tits, Magpie and perhaps more. Judging by the width of the black band down the front of their breasts they were all males practicing this behaviour.

Wondering if I am correct in my interpretation of what I have been observing when I got home I looked in the classic British Tits by Christopher Perrins  (pub. by Collins in 1979) to see if there were any references to Great Tits mimicking other birds. However I can't find any. So, I resorted to the internet where the habit is mentioned on a couple of websites plus a scientific publication from which this is an extract.......Rather than attracting conspecific females, mimicry may be used to repel heterospecific competitors. For example, when great tits (Parus major) and blue tits (P. caeruleus) compete for food and nesting sites during the breeding season, great tits mimic blue tit song. As matching another individual's song is often used to signal aggression between conspecifics in many songbirds, it seems possible that the mimicking great tits are attempting to intimidate blue tits. Song sparrows, Melospiza melodia, may do something similar: their mimicry of white-crowned sparrow, Zonotrichia leucophrys, territorial song induces aggression in white-crowned sparrows although it is not clear to what effect. From http://www.sciencedirect.com/science/article/pii/S096098221001451X

So it seems that I am correct in my assumptions.

Great Tit Parus major male by Sławek Staszczuk This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.