by Steve Westerman

Wharfedale Naturalists Society

AS we would expect in the spring, ground nesting birds have arrived on the upper levels of Ilkley Moor. Of course, ground nesting birds distribute themselves all over the moor – but some species have their own preferred areas (see Nature Notes 30th May, 2019). Over the last few weeks, I’ve been trying to photograph skylarks. Skylarks don’t like to nest near tall objects (such as trees) from which predators might launch attacks. This may be why they seem to prefer the open vistas of the higher slopes.

Skylarks also prefer grassy, rather than heather moorland; and moorland that is grazed, presumably because it reduces the height of the vegetation in some areas. Again, the upper slopes of the moor meet these criteria. Yes, there is heather, but there is also a good deal of grass, and some of the area has been grazed.

Skylarks can be quite elusive (not to be confused with the smaller and less melodious meadow pipits that are much more widespread on the moor). Amongst the heather and grasses they are well camouflaged and difficult to spot. Of course, periodically, males engage in song-flights, flying high above their territory, maintaining station for perhaps a couple of minutes or more, while emitting the burbling, complex song for which the species are well known. This may be a means of indicating ‘fitness’ to prospective mates or to signal territory ownership. However, they will often fly so high (perhaps 50m or more) that, although they can clearly be heard, locating the source of the sound in the sky is difficult.

The UK population of skylarks is fairly large (circa 1 million breeding pairs estimated in 1997). However, as with many species, changes to agricultural practices in the latter part of the 20th Century resulted in a very severe and worrying decline in numbers. It is thought that between 1975 and 1994 that 55% of the UK population was lost. Agricultural intensification, with the use of pesticides, inorganic fertilisers, and the change to autumn sowing (winter seeds) has produced an environment to which skylarks are not so well suited. Increased crop density during the breeding season seems to be a particular issue along with the availability of food in the winter months. It is somewhat ironic that a bird that has benefitted for centuries from human agricultural practices, with the creation of open arable spaces, is now in decline because of them.