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WILDLIFE
Let’s not talk about Christmas robins
IF you’re like me, December 21st feels like a turning point, the shortest day of the year followed by a minuscule increase in day length that heralds the beginning of the long path towards spring. For some small birds weighing only a few grammes, these long winter nights By CHRIS can mean the difference between life and SPERRING MBE death. Take, for example, a wren: weighing in at just ten grammes it potentially loses around ten per cent of body weight in one night. Long-tailed tits weigh even less than wrens, at around 8.5 grammes. However, they do fly around in groups. I have seen 17 in my garden – a record for me. This bonding – helping each other look for food during the daylight – continues at night whilst roosting so they are better equipped to survive even the harshest of winters. They literally roost together. Finding a branch in dense scrub they will line up. Clearly the birds at either end of this feathery line-up are the ones most vulnerable to succumbing to the cold of the night, but they have a brilliant strategy for this also. As the night progresses the birds at each end gradually and carefully shuffle into the middle of the group, whilst those from the warm middle gradually move out towards the ends. If you could run a time-lapse camera on the group all night what you would see is a constantly shifting line of longtailed tits with each one being aided by the rest of the group. Back to the wrens and our first observations find a bird that seems quite unlike long tailed tits because it seems more territorial. Easily observable, even in winter a wren will very vocally defend its territory using its song. But that’s not the whole picture. When conditions in winter deteriorate into a North Easterly-backed freeze it seems even wrens will forget about their daytime squabbles and come together en-masse and create a wren roosting “ball”. A good farmer friend of mine
high up at Priddy witnesses this most winters. This farmer has great tit nesting boxes around the farm and during one winter, just prior to a mid-winter frosty sun rise, he saw more than over 20 wrens emerging from one single small nesting box. What a great strategy. I bet, like the longtailed tits, this cramped, tight ball of wrens will be constantly moving around ensuring everyone enjoys the warmth from the middle of the ball. Both these birds are insectivores, so you can imagine at this time of the year the pressure is really on them; they can, and do, feed on other things and both will, for example, take fat and mealworms provided by people feeding birds in their gardens. But for those that live away from gardens, both have incredibly good eyesight for finding food. If you’ve got a garden and have spiders’ webs showing well on frosty mornings, then look to see if there’s a hole in the web which is about spider sized. If there is, then this is a sign that the wren has removed the spider delicately enough to leave the rest of the web intact. Long-tailed tits will fly around woodland and forest in extended groups and can find even the smallest moth larvae or other insect buried deep in the cracks of the bark of trees. Indeed, their skill must be known well throughout the bird world. If, during the holiday break, you are walking in woodland and find a group of long-tailed tits searching for food, just stop and watch the number of other species that follow them. Many other birds will watch where they are feeding and join them using the skill of the long-tailed tits to their advantage. Isn’t nature just brilliant! Thank you to everyone throughout 2021 who has contacted me regarding these articles; I’m glad so many of you enjoy them. Nature isn’t all about doom and gloom: there are some amazing successes and of course an endless list of incredible species to watch, to learn from, and to enjoy. I wish all of you a super “wild” Christmas and healthy New Year.
Wrens will put aside their territorial instincts to keep warm
Strength in numbers: long-tailed tits will feed and roost together
Contact me on 07799 413918 or email me at: Chris.Sperring@hawkandowltrust.org.uk
MENDIP TIMES • DECEMBER 2021 • PAGE 57
