On the Wildside: Blue tits thriving on the winter feeders

Smaller birds (and mammals too) lose more heat proportionally the smaller they are – and this is a basic relationship between body weight or mass, and body surface area. To conserve heat and therefore body core temperature you want a large mass and small surface area!

For birds this relationship becomes more extreme the smaller they are, and the titmice, long-tailed tits, wrens, goldcrests and the like lose a considerable amount of heat on a chill winter night. So, maintaining the necessary body temperature means using up precious and limited stores of bodyfat, and again, this is much reduced in the smaller birds.

To make up for this situation, which can mean life or death, the more diminutive birds must feed voraciously during the hours of daylight in order to make up the deficit.

Following a few days of sub-zero night-time temperatures the early morning garden is busy with around 20 mixed blue tits, coal tits, and great tits all on the sunflower hearts and the peanuts, whilst a solitary robin, a wren and a couple of dunnocks scavenge on the ground. Dried mealworms and suet dumplings attract up to twenty starlings but also 10 or more magpies which vie with a few jackdaws and even a pair of carrion crows for the top spot in the pecking order.

Daily fluctuations in temperature can make a big difference to the numbers of the different species visiting, when they come, and how long for. Of course, if there is a hard frost then the birds need unfrozen water in order to drink, and so topping up a bird-bath or providing a shallow area of open water in a pond is essential.

The other trick with attracting birds to the garden is to provide a good range of foods and situated in different places and a variety of types of feeders. Hanging feeders are best if you want to minimise the risk of attracting rats.

Professor Ian D. Rotherham, researcher, writer & broadcaster on wildlife & environmental issues, is contactable on [email protected]; follow Ian’s blog (https://ianswalkonthewildside.wordpress.com/) and Twitter @IanThewildside