KEEPING COOL

Birds possess a remarkable talent for regulating their body temperature. We have all seen them heading for a bird bath or garden spray to cool off in the water, but they also employ other means of beating the heat.

I have noticed an absence of birds during the hottest parts of the day – so, for example, if I put out seed once the sun is well up and the temperature is already high, few if any birds come to investigate it until the temperature begins to drop in the late afternoon. We have been experiencing temperatures in the high thirty degrees Celsius for most of summer. As birds do not sweat, some open their bills and flutter their throat membrane (called gular fluttering) to allow moisture to evaporate out of the mouth. Here you can see a Common Fiscal panting in this manner even while it is seeking shade in the dense undergrowth. This bird is ringed, making me suspect that it is the same Common Fiscal that I have been photographing in my garden over the past three years at least.

The other interesting aspect to observe is that this bird looks ‘thinner’ than usual. This is because it is holding its feathers more closely to its body – another means of keeping cool. Compare it with this one taken on a cooler day.

I am pleased to report that we have enjoyed a short period of light rain, which has cooled the temperature significantly. Instead of seeing the Common Fiscal hiding in the shade with its beak agape like this

I should see it looking for food like this: