Chiffchaff: A Summer Visitor to Britain

Chiffchaffs, Phylloscopus collybita, are small olive-green warblers who arrive from their wintering grounds in the Mediterranean and West Africa in the spring. Their arrival is one of the earliest of all the summer visitor that fly to Britain to breed.

Happily, the Chiffchaff population has shown a strong increase since the 1990s because of milder winter weather.

The Chiffchaff is also known as the Common Chiffchaff.

Adults are alike and about the size of a blue tit. The upper body is a dull olive or brown-green during the spring and summer. The lower body is yellowish with a pale rump. There are yellow lines on the short wings. Adults are duller in the autumn and winter.

Chiffchaffs are small, hyperactive birds who arrive in Britain from their wintering grounds in the Mediterranean (Iberia and North Africa) and West Africa between March and April.

Over a million Chiffchaffs arrived on the shores of Britain in the early spring. They leave during the last 20 days of September.

”Growing numbers of chiffchaffs are wintering in the British Isles where, if the weather stays mild, they can find enough insect food to sustain them during the coldest months.

If they survive, they will have less distance to travel to their breeding grounds and can secure the best territories” ( BBC - http://www.bbc.com/earth/story/20150223-singing-chiffchaffs-in-winter ).

A few wintering Chiffchaffs from Germany leave Britain in the spring.

Wintering Scandinavian Chiffchaffs pass over Britain in the autumn with some also staying until the spring.

The huge numbers of  Chiffchaffs that arrive in the spring ensure they are the most abundant species of warbler that breed in Britain.

Chiffchaffs live and breed among shrubs and trees in woods, scrub, parks, cemeteries and gardens. Conifers are generally avoided.

They enjoy constantly flicking their wings and wagging their tails as they forage for food in shrubs, bushes and trees.

The diet of the Chiffchaff is a wide variety of insects and spiders. The most common insects eaten include flies, aphids, moths and caterpillars. They sometimes eat seeds and berries.

Foraging Chiffchaffs often leave the safety of shrubs and trees to catch insects by hovering in the air or picking them from a leaf.

Chiffchaffs are one of the few birds which sing their name loudly from a perch in a tree. Their repetitive “chiff-chaff” call makes them easily recognisable in the spring.

Pairs breed among the dense shrubs understorey of mature deciduous woodland and places where there are dense low-lying shrubs and a few tall trees such as rough areas of gardens.

The nest is hidden low down among the dense foliage of shrubs, bushes and bramble thickets.

The female builds a domed nest of grasses and leaves with a small entrance at the side.

Five to six eggs are laid between April and May which hatch after 2 weeks.

The chicks are fed mostly by the female in the nest for another 12 to 15 days.

Each parent often rears half the brood until they become independent after between 10 and 19 days. Both parents look after the young and raise 2 broods a year.

Weasels are among the predators who prey on eggs and chicks.

The Common Chiffchaff is classified as of Least Concern by IUCN.

The population of Chiffchaffs in Europe has shown a “moderate increase” between 1980 and 2013.

The Chiffchaff is a green-listed species of bird in Britain.

The population declined during the 1960s and 1970s but later made a strong recovery. There has been a widespread increase in the Chiffchaff population in Britain since the 1990s except for the eastern areas of Northern Ireland.

A shallow increase was recorded in England since 1994. The number of Chiffchaffs in Wales has also risen.

Milder winters due to climate change may be a reason for the increase in Chiffchaff numbers.

A “widespread moderate increase” was recorded in the number of Chiffchaffs in Europe

(BTO - https://app.bto.org/birdtrends/species.jsp?&s=chiff ).

The British Trust for Ornithology said the number of Chiffchaffs in Scotland has risen by “an amazing 550% since 1994“ (BTO - https://twitter.com/_bto/status/750992808668868608 ).

The RSPB said in 2017 that “chiffchaffs have increased by …104% …since 1970. Milder winters in the UK and Europe, where increasing numbers of both species stay for the winter, boost overwinter survival”.

“chiffchaffs are expanding their breeding range northwards and into higher altitudes, as the climatic conditions become more favourable” (RSPB – State of the Birds – page 15 -

https://www.bto.org/sites/default/files/publications/state-of-uk-birds-_2017.pdf ).

The main threat to the Chiffchaff is stormy and unsettled weather during migration.

For more information on the birds of the countryside and gardens of Britain and Ireland, please visit

http://bird4u.mzzhost.com/index.html

Difference Between Chiffchaffs and Willow Warblers

Willow Warblers and Chiffchaffs are very similar in appearance, possibly because they belong to the warbler family of birds. Chiffchaffs have black legs and a pale eye-stripe.