Yellow Wagtail (Motacilla flava flavissima) Photo by Natural England from https://www.flickr.com/photos/naturalengland/14335939742

Dear Readers, you might remember how fond I am of wagtails generally, but this bright yellow bird is such a delight. You might think that you’ve seen one, but what you’ve probably seen is the much commoner Grey Wagtail – I’ve spotted this species at the Barbican, and one even spent a few moments in my garden, drinking from the pond. As you can see, the Grey Wagtail does have a citrus yellow vent area, but the bird is mostly grey. In the summer, an adult breeding male (the one in the photo is a female) is a pale yellow all over, but nothing like the sunshine hue of the Yellow Wagtail.

Grey Wagtail in Coldfall Wood

Yellow Wagtails (Motacilla flava) are birds of grassland, and are completely dependent on invertebrate food throughout their life cycle. They winter in the Sahel, and spend summer in the UK, swapping the dusty fields of Africa for the potato and wheat fields of England, but they are under pressure at both ends of their migratory route. The basic reason for their decline in the UK is agricultural intensification, which has affected the availability of insects and nesting sites, plus, interestingly, soil degradation – the birds probe the soil for worms and grubs, and if they can’t penetrate rock-hard soil, they will find it difficult to locate their food. These are versatile little birds, who can cope with seasonal change – in Red List Sixty Seven, published by the British Trust for Ornithology, Juliet Vickery, who has studied the species extensively, describes how they move from winter wheat to potatoes and field beans, and change prey from flies and beetles to damselflies. Vickery also points out that where winter wheat predominates, it may affect late summer nesting sites – they also like to nest close to drainage ditches or bodies of water, probably because of all those hatching midges and mosquitoes.

Whatever the reason, the breeding population has decreased by 74% since 1967. What a shame. Fortunately, some farmers are trying to support the birds by introducing a mosaic of different crops so that they can raise broods in one sort of crop in the spring and then switch to another for a second and even third brood as the year goes on.

Yellow Wagtail – Blue-Headed Morph (Photo by Risto Silaste at https://www.flickr.com/photos/50677435@N00/512526045/)

In the summer we are also sometimes visited by the blue-headed variant of the Yellow Wagtail (Motacilla flava flava). In the Crossley Guide, it’s pointed out that the tail of the yellow wagtail is noticeably shorter than  that of other wagtail species, though the bird still bounces up and down in a most endearing fashion.

Crossley, I note, says that the Yellow Wagtail has a ‘truly terrible song, haphazard, jolting series of brief scratchy notes’. Having  listened to this, I note that the song does have a certain ‘fingernails scraping down a blackboard’ tone to it, though apparently the sound is a good way to spot the bird when it’s feeding in a grassy field.

For a bird that is so dependent on invertebrates, a clear win would be to reduce the amount of pesticides being used for agriculture. Insects are an essential part of the ecosystem as we all know, so helping them to thrive would help to support not only Yellow Wagtails, but innumerable other species. When will we wake up, I wonder?