Great Tit (Parus major)

Dear Readers, my January edition of British Birds has come through, and while there are exciting articles on Common Nighthawks ( a rare vagrant nightjar that’s more often found in North America) and the breeding range expansion of the Caspian Gull (which will probably end up in the UK at the rate it’s going), I found myself drawn to the Letters section. In it, there was a response to an event that occurred back in 2023.

There was a report that, during a ringing session, a male Great Tit was briefly separated from its mate. The female started to sing, and the conclusion at the time was that she had taken over the defence of their joint territory. However, Richard Broughton, of the UK Centre for Ecology and Hydrology, had another explanation.

Many tits have a song that is used only when they are unable to locate their partner. . Known as a ‘mate-separation song’, it’s most commonly used when the female takes a brief break from incubating eggs, and can’t see her mate, but it can be used by either sex. Great tits are socially monogamous and they are totally dependent on one another to raise their broods, which can often comprise 12 chicks – that’s an awful lot of caterpillars. It’s no wonder that there are high levels of anxiety if one mate can’t see the other, so while the male was off being ringed the female would have been calling incessantly in the hope that he hadn’t been killed – the death of a partner invariably means the end of any eggs that haven’t hatched, and for most fledglings, especially as the remaining bird can’t both forage for food and either incubate her eggs, or defend her offspring from predators.

Great tits are not the only birds who have a mate-separation song – in North America, chickadees have a similar call, and in Europe the Marsh Tit also has one. But Great tits are renowned for the variation in their songs (up to 80 different variants have been recorded), and they were amongst the first bird species to have recognisable ‘accents’. This blog, by Sam Hardman, has a number of recordings of Great tits from different parts of the UK and Europe, and it’s fascinating to hear the differences, so do have a listen. I always think of the typical Great tit song as being a variation on ‘Tee-cher, Tee-cher’, but clearly I haven’t been paying enough attention. Hardman’s field of research was the great tit, and there is much to learn about these ubiquitous little birds – have a look at this post here, which mentions, amongst other things, that city great tits sing at a higher frequency than their country cousins, but are also duller in colour, probably due to the physical resources needed to combat city pollution.

And holy moly, Hardman reports that in times of food scarcity, a population of great tits in Hungary learned to feed on hibernating pipistrelle bats. They located the bats by their calls (even when hibernating, some bats will stir and call, which ist thought to deter mammalian predators by indicating that the bats are awake and will be difficult to catch). When the researchers provided sunflower seeds for the birds, the bat predation stopped, indicating that it is a last resort – bats have sharp teeth, and even a small bat would be a match for a great tit if it was fully awake. Furthermore, the behaviour was observed over a period of eight years – the lifespan of a typical great tit is only four years, so the behaviour is likely to have been taught to each generation by their parents. As Hardman says, there is clearly still much to discover about these unassuming little birds.