Why the clever coal tit is no ‘bird brain’

I got an email the other day, from a reader who carried out interesting experiments with his bird table.

He filled a standard, nine-inch feeder with sunflower seeds and was surprised to find it empty a couple of hours later, despite the fact there didn’t seem to be many birds around at the time. So, he filled it again and sat down to watch closely.

Within two hours, what he describes as “a family of four coal tits” emptied the feeder again. Before he refilled the feeder, for a third time, he counted the seeds. It held 3,600.