Willow tit

The willow tit (Parus or Poecile montanus) breeds throughout northern Europe and across Asia to Japan. It is also found in North America. It is resident in England and Wales, and southern Scotland, with the greatest concentrations being in central England and Wales. There is some movement of populations in mainland Europe between the seasons, but these are not considered to constitute full migrations.

Appearance

At about 11.5-13 centimetres (4.5-5 inches) in length, the willow tit is similar to the blue tit in size. It has a large head and thick neck. The colouring is very similar to that of the marsh tit, with which it is easily confused. It is grey-brown above and off-white below. The head has a black cap that extends all the way down the nape of the neck, white cheeks and a black bib. Males and females have similar plumage.

The differences in plumage between marsh tits and willow tits are not easy to spot. The white cheeks are less extensive in the willow tit but the black bib is larger. The willow tit’s crown is duller, and its plumage in general is less sleek. It has a pale patch on the secondary feathers of the wings that is absent in the marsh tit. However, the two species would need to be seen side by side for most people to be certain which was which.

There are also slight variations in appearance as between willow tits in different areas. For example, those breeding in northern and eastern Europe have whiter cheeks and paler underparts than do the willow tits found in Great Britain.

Habitat

In the east of its range the willow tit is a bird of coniferous and birch forests, particularly at higher elevations. Further west it is found at lower levels in mixed woods of birch, willow and alder. It particularly favours environments where there is plenty of water, such as alongside rivers and streams, flooded gravel pits and reservoirs.

Behaviour and feeding

Willow tits feed on invertebrates in spring and summer and plant material in autumn and winter. Differently from the marsh tit, the willow tit’s bill is not strong enough for it to tackle hard seeds and nuts, so it concentrates on the softer seeds of alder and birch. Willow tits hoard food when it is plentiful in order to build up a winter store.

A very clear difference between marsh tits and willow tits is in their voice. Whereas the marsh tit’s call is loud and clear, that of the willow tit is distinctly nasal in tone. It also has a harsh “chay” call that the marsh tit does not have.

The willow tit has two distinctive songs, a series of “sad” notes that resemble the song of the wood warbler, and a variable high-pitched warble and trill.

After the breeding season willow tits form flocks to roam the countryside, often together with other small birds, but they are reluctant to wander far from their own territory.

Breeding

Willow tits pair for life. The task of nest building falls to the hen bird, and she will sometimes excavate a cavity in a rotting tree stump for this purpose. Depending on the state of the wood being tackled, this can be a lengthy process of up to three weeks. The willow tit’s preference is to find an existing natural cavity rather than create a new one, but the nest will not be the same as the one that was used in the previous year. The nest cavity is lined with plant material and chips of wood.

A clutch of six to eight eggs is laid in May and these are incubated for up to 14 days by the female alone.

Both parent birds feed the young, for up to 18 days in the nest and a further two weeks after the chicks have fledged. During this period the parents will have to bring food to the young about once every three minutes throughout the hours of daylight in order for them all to survive.

Conservation

The willow tit is regarded as a species of “least concern” by BirdLife International due to its wide range and large numbers across much of that range. However, it does have red status in the United Kingdom because of steadily declining numbers since about 1970. The causes of this decline are not fully understood, but probably have to do with loss of habitat due to higher standards of woodland management that have reduced the scrubby, unkempt conditions that are preferred by willow tits.

© John Welford