Jackdaw of Britain and Ireland

The Jackdaw, Corvus monedula, is a fairly common and familiar bird in the woods, farmland and towns of Britain and Ireland.

The population of Jackdaws has been increasing in Britain since the 1960s. Their numbers have also risen in Ireland where they are one of the commonest garden birds.

Jackdaws are the smallest members of the crow family. Adults are all black from head to claw with a purple sheen on the back and a grey neck. Juveniles resembled adults although brown eyes which are blue-grey in adults.

Adults begin breeding when they are 2 years of age. The typical lifespan of Jackdaws is 5 years although they can live longer.

“It’s not too unusual for some birds to start going grey in old age” ( Discover Wildlife – see below).

Jawdaws are sociable birds who are usually seen in pairs or large flocks throughout the year. They have adapted to living in a wide range of habitats

Typical haunts include open woodland, farmland, the sides of mountains and sea cliffs, pastures, parks, gardens, towns and villages.

Gardens are mostly used as foraging areas during the breeding season, particularly in June. “Almost half of garden birdwatchers in Wales report seeing Jackdaws, compared to only 23% in England" 
(BTO - https://www.bto.org/sites/default/files/u23/images/Ambassadors/amanda_skull/14-06%20Jackdaw.pdf ).

Jackdaws will scavenge anything edible. Their diet includes carrions, seeds, berries, insects, earthworms, invertebrates, small mammals and the eggs and young of other birds.

Thrown away food on the streets of towns, villages and city centres are a valuable source of nourishment. Some tear open rubbish bags or raid bins. Scraps left on garden tables are also eaten.

Foraging takes place on the ground where they can be seen walking rapidly and running, or sometimes hopping.

Jackdaws are often found on grassland and pastures where sheep and cattle are grazing. Some Jackdaws search for food along the seashore.

Jackdaws are resident birds in Britain and Ireland who form communal roosts during the year. They are fairly common birds who are found in most areas throughout the year.

The Scottish Highlands and the mountainous regions of the west of Ireland have fewer Jackdaws.
Jackdaws tend to stay near their breeding colonies during the winter and regularly visit their nest sites.

Those living in southern Britain rarely move 40 kilometres or 25 miles from their colonies.

Northern Jackdaws leave higher ground between September and November and often travel 100 kilometres, or 62 miles, from their breeding grounds.

Some wintering Jackdaws from Europe and Scandinavia arrive in Britain in the autumn. The wintering movements of European Jackdaws is generally unknown.

Research from Exeter University found Jackdaws join together to drive away predators by “mobbing” them  (Irish News: https://www.irishnews.com/magazine/science/2019/10/01/news/-mob-mentality-rules-jackdaw-flocks–1727613/ ).

Pairs form lifelong bonds who often join flocks of Rooks, Carrion Crows and Starlings in the winter.
Jackdaws are an abundant breeding species in Britain and Ireland. Pair nest in small colonies during the breeding season which begins in late April.

They are noisy birds, particularly around their breeding colonies. Their call is a harsh-sounding “jack-jack”.

Nests are built in holes in trees, crevices in cliffs or man-made buildings. Some pairs use large nest boxes, chimneys and church towers.

Pairs make a nest of sticks lined with wool, hair and softer material.

Four or five pale blue eggs are laid in April and take between 18 and 20 days to hatch. The young stay in the nest and learn to fly after 30 days. Sadly, the smallest of the chicks rarely survive.

Jackdaws are dedicated parents who continue to care for their young for another week after leaving the nest.
The Jackdaw is classified as of Least Concern by IUCN.

The Jackdaw is a green-listed species of bird in Britain and the Republic of Ireland.

The population of Jackdaws has been increasing since the 1960s. Their numbers increased steadily in all parts of Britain between 1994 and 2009 except for eastern Scotland.

The population is continuing to rise in Britain in recent years except for Wales.

The European population of Jackdaws has remained stable since the 1980s (BTO – species: https://app.bto.org/birdtrends/species.jsp?year=2018&s=jackd ).

Woodland populations of Jackdaws in Britain have shown better breeding performance with larger broods being reared (RSPB Handbook of British Birds).

However, some research has shown Jackdaws “declined in woodland but increased slightly in farmland over the last 30 years” (R.D. Gregory and J.H. Marchant – page 10: https://www.tandfonline.com/doi/pdf/10.1080/00063659609460993 ).

There are approximately 1.4 million pairs of Jackdaws in Britain and 210,000 in the Republic of Ireland.

Jackdaws are one of the top-twenty garden birds in Ireland.

The main threat to Jackdaws is persecution. However, the increase in their population is due primarily to their adaptability and generalist diet.

For more information on the birds of the gardens and countryside of Britain and Ireland, please visit,
http://bird4u.mzzhost.com/index.html

Interesting Articles 
Discover Wildlife - https://www.discoverwildlife.com/animal-facts/birds/facts-about-jackdaws/

BTO - The crow next ‘daw’:Jackdaw: 
https://www.bto.org/sites/default/files/shared_documents/gbw/associated_files/bird-table-70-jackdaw-article.pdf