Bird feeder pecking order
Size matters when it comes to getting a fair share of food
Spend any time now watching the comings and goings at a well-filled bird feeder and you’ll see plenty of interaction between the birds that visit.
And lots of it involves friction – mostly posturing and body language – but some low-level violence, too. Who gets what of what’s on offer is certainly not decided on a fair-share basis. There’s a pecking order, literally.
It means that some visitors can take their time, eating their fill of the best, while others get less than they would like. What you’ll see at feeders has recently been studied by ornithologists, who spent time watching feeders to throw light on how the pecking order operates.
When two birds clashed they’d rate the one that stayed put as more dominant, and the one that backed off as less so. And, no surprise, it was the bigger species that monopolised feeders at the expense of the smaller ones.
Big species took their time while smaller ones would feed in a hurry and concentrate on food that the scientists classed as of lower value. Size matters.
The average sparrow weighs three times the weight of the average coal tit. So it’s heavyweight versus featherweight, and the outcome comes as little surprise.
The researchers came up with a ranking of 10 garden birds from one (most dominant) to 10 (least dominant). The house sparrow tops that list, with the greenfinch at number two.
At the other end of the scale, number nine is the blue tit (average weight, 10.9g), and at 10 is the coal tit (a tiny 9.1g). But weight isn’t the whole story, because the average house sparrow weighs in at 27.3g while the average greenfinch is a little bulkier at 27.7g.
And somewhere in the middle the robin (number four and 19g in weight) sees off the chaffinch (number eight, 21.8g). So some of it is, presumably, about attitude.