by Steve Westerman

Wharfedale Naturalists Society

I’VE started to visit the River Wharfe more frequently once again. It has been nice to get back and see what is going on with regard to wildlife. The level of the river has a lot to do with how much is on view. If it is too high, and the water is too fast-flowing and murky, the feeding opportunities for many birds are limited. Similarly, if the level is very low many shallow areas and pools dry up.

Along one of my favourite parts of the river, two kingfishers have been disputing territorial rights. This isn’t so unusual (see Nature Notes, 1/11/2018). Both of these birds are juveniles – one female and one male. I don’t think this section of the river has been used for nesting for the last couple of years, so I suspect these youngsters are looking for their own space, having been chased off from their parents’ territory at the end of the breeding season.

From time to time this pair have been engaging in high speed chases up and down the river. Occasionally these have included what seems to be the kingfisher equivalent of a handbrake turn. This involves the leading kingfisher (the one being pursued) briefly splashing into the water from full-speed flight – leaving the pursuer to fly over their head – presumably cursing under their breath!

For a while, the female seemed to have the upper hand. She was the one that I saw most frequently - often calling as she flew along the river – apparently patrolling. However, on a recent morning the male arrived at the edge of the territory with an accompanying series of ‘peeps’ to announce his presence. He perched, for some time, high in a willow – perhaps to see if there was any reaction. When there was none, he ventured further upstream and spent half an hour or so fishing.

Another impressive in-flight ‘trick’ that the kingfisher has at its disposal is hovering, motionless, above the river, while looking for prey. Unlike the Kestrel, that I mentioned in a recent Nature Notes (6/8/20), they can only sustain this for a few seconds at a time. The photograph shows the female doing this. From a low perch she took off, faced into the breeze, and maintained position in the air for a few seconds, before heading off. Presumably there were no fish to dive for. The literature suggests that Kingfishers need a slight headwind to do this. However, just recently I have seen the male hover, three times in quick succession, on a very calm morning.

www.wharfedale-nats.org.uk