It didn't appear to be common behaviour amongst the many Long-tailed Tits visiting the garden back then and although I observed this feeding behaviour on more than one occasion later that winter it may have been limited to just one individual. This was one of those situations when it would have been really informative if the Long-tailed Tits were colour-ringed as I would have been able to establish how many individuals were involved but what I can say is I didn't see more than one bird feeding in this manner at the same time.
I have seen and photographed Long-tailed Tits using this feeding method each winter since that first encounter and it has gradually become more common amongst the birds that visit the garden. I haven't started colour-ringing my Long-tailed Tits (yet) so it is still not possible to be certain of the number of individuals involved but last weekend (13th & 14th Jan) at least 4 were using the 'hanging and holding' feeding method simultaneously out of a total of ten or so that were in the garden at that time. Establishing numbers is further complicated by the fact that more than one Long-tailed Tit flock may visit the garden over the course of a day and birds from the same flock may switch between feeding on sunflower hearts and fat cakes but there is no doubt it has become more prevalent amongst the the birds that visit my garden. This also begs the question as to what extent it is an innate skill as opposed to having to be learned. Again colour-ring could help answer that as it could show if there are any differences between age groups (potentially a nice line of research for someone).
There is a bit more to it than just hanging upside down and eating - a Long-tailed Tit will take a sunflower heart from the feeder and carry it in its bill to a suitable twig and then hang upside down before transferring the seed to one of its feet. Now I don't know if individuals have a preference over which foot they hang from and which foot they hold the seed in or if they can be ambipedal but I have seen individuals hang from either foot and photos in this post show that (now there is another research project for someone). The twig that an individual chooses to hang from may be near the feeder but is often one or two metres away, presumably to avoid disturbance from larger species that may come to use the feeder. The twig selected obviously has to be a suitable diameter to enable the bird to get a good grip and the way the tendons work in the birds leg and foot probably allows it to hang with little or no effort.
There are a couple of aspects of this feeding behaviour that I find really interesting, one is that they seem to be increasingly taking advantage of a relatively new food source in the form of sunflower hearts and the other is the question of how common and widespread it has become. With that in mind I contacted Kate Risely, who runs the BTO Garden Birdwatch project, to see if it was something she was aware of and if had been reported before. Kate wasn't aware of any reports of this behaviour and thought it was interesting enough to try and find out how common and widespread it is by putting a request out on Twitter (link here).
Kate also did a little digging and kindly pointed me to some references in the literature on Long-tailed Tits feeding whilst holding food items in one foot and hanging from the other. Two of them were notes in British Birds, one from 1959 and the other from 1989, and related to food items that had been provided. Ornithologist Derek Goodwin commented on the latter report saying: 'this is normal and usual behaviour if a Long-tailed Tit finds an insect too big to be swallowed immediately'. This shows the feeding method itself is not that unusual, although I would say I think it is one that is easily missed or overlooked in anything other than a garden or feeding station setting as Long-tailed Tit flocks are usually always on the move. However, the use of this feeding method to exploit sunflower hearts taken from feeders does appear to be relatively new. It remains to be seen how common and widespread it is or if it is an increasing trend as has been the experience in my garden. Early replies to the BTO tweet show it has been noted elsewhere but none make comment on how long it has been happening or if it is increasing at the locations concerned.
Hall-Craggs, J (1959) British Birds 52, 21-2.
Shackleton, K (1989) British Birds 82, 373-4.
Thanks for sharing your photos of this fascinating behaviour! We've recently noticed the ones in our garden (nr Glasgow) also do this with seeds they take out of the tube feeder. :-)
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