Hull urban birds. 19. Willow Warbler

The Willow Warbler is a small warbler with olive brown upper parts and whitish underneath, with a yellow wash on the chest and pale eye stripe. Legs are orange. It is very similar to the Chiffchaff and most easily distinguished by their song. The young of the year, numerous during the autumn migration are noticeably yellower. It feeds on small flies, beetles, moths aphids, insect larvae and spiders, supplemented by berries in the autumn. The domed nests, with a side entrance are built on or near the ground amongst grass by a hedge or bramble.

Singing Willow Warbler by the Beverley and Barmston drain,  Bridlington Avenue Hull. 24th April 2021 (also top shot).

Habitat

Breeding habitat includes scrub and plantations, hedgerows and woodland edges and open woodland. It is more widespread during migration, when it can be found in Hull parks and gardens in small numbers.

Status and distribution in Hull

In his 'Birds of the Hull area (2002), Richard Broughton regarded the Willow Warbler "One of the more common summer migrants in the Hull area, the sweet tumbling verse of a Willow Warbler song may be heard in most outlying parts of the Hull area." The Chiffchaff and the Blackcap are now much more abundant species. Summer visitor and passage migrant. Winters in Subsaharan Africa. Birds migrate at night and start singing their characteristic warbling tune shortly after their arrival, often on the second or third week of April. Autumn passage in Hull peaks towards the end of August. The best chance for a Willow Warbler during the breeding season is at Noddle Hill and northern outskirts of the city.

Oak Road Lake. 27 April 2020.

An acrobatic Willow Warbler feeding on horse chestnut leaf miners. Pearson Park, 5 September 2019.

Young of the year Willow Warbler in my garden in Hull. 13 Aug 2010.

Conservation

Populations have undergone a moderate decline over recent decades and they are now Amber listed. This general trend masks considerable geographical variation in the UK, as the populations have been increasing in Scotland while markedly declining in the South East of England.

More information

Broughton, Richard K. Birds of the Hull Area.

Simms, Eric. 1985. British Warblers. New Naturalist n. 71.  432 pages.