Western Yellow Wagtail

The western yellow wagtail (Motacilla flava) is a small passerine bird with a breeding range extending from Western Europe to Central Asia, and wintering in sub-Saharan Africa and South Asia. It measures about 15-16 cm (6-6.3 in) in length with a wingspan of 24-27 cm (9.4-10.6 in), and weighing between 15-25 grams (0.5-0.9 oz). Generally, males display vibrant yellow underparts and a greenish to olive back during the breeding season. They have a distinctive long, wagging tail, which is a key feature for identification.

There are several subspecies of the western yellow wagtail across its range, and they exhibit considerable variation in plumage color and pattern. The nominate subspecies, the blue-headed wagtail (Motacilla flava flava) has a paler blue-grey head with a white supercilium. Other subspecies, such as the grey-headed wagtail (Motacilla flava thunbergi) has a darker grey head and mostly missing white supercilium. Some have an all-yellow head (Motacilla flava lutea), and some an all-black head (Motacilla flava feldegg). The eastern yellow wagtail (Motacilla tschutschensis), found in East Asia, is often separated as a separate species.

Western yellow wagtails primarily inhabit open fields, wetlands, meadows, and agricultural lands, often near water bodies such as rivers, lakes, and marshes. This species can be found from coastal areas to high-altitude grasslands. They are ground foragers, feeding mainly on insects and other small invertebrates. Their diet includes flies, beetles, caterpillars, and spiders, which they catch by walking or running swiftly on the ground, often in a zigzag pattern. They may also catch insects mid-flight in a display of agile aerial maneuvers.

This species is a long-distance migrant, breeding in Europe and Central Asia and wintering in sub-Saharan Africa and South Asia. Migration occurs in large flocks, typically beginning in August and extending into October for southward journeys. The return migration to breeding grounds usually takes place from March to May. Western yellow wagtails undertake remarkable journeys, often covering thousands of kilometers between their breeding and wintering grounds. These wagtails often travel in conspicuous flocks that can include hundreds of individuals.

Western yellow wagtails breed from late April to August, with peak breeding occurring in May and June. They prefer nesting in open, grassy areas, often on the ground or in low vegetation. The nest, built primarily by the female, is a cup-shaped structure made of grass, roots, and moss, lined with softer materials such as hair and feathers. The female lays 4-6 eggs, which are incubated for about 11-14 days. Both parents participate in feeding the chicks. The fledglings leave the nest approximately 12-15 days after hatching but remain dependent on their parents for a few more weeks.

The western yellow wagtail is classified as least concern on the IUCN Red List, indicating that it is not currently at significant risk of extinction. Despite being widespread and relatively common, the species faces threats from habitat loss due to agricultural intensification and changes in land use. Conservation efforts focus on maintaining suitable breeding and wintering habitats to support stable populations.