Marsh Tit - Distribution and Habitat

Distribution and Habitat

The Marsh Tit has a worldwide Extent of Occurrence of around 10 million square kilometres. The global population includes between 6.1 million and 12 million birds in Europe alone. The species is classified as Least Concern, though there is some evidence of a decline in numbers. For example, between the 1970s and 2007, Marsh Tit numbers declined in the United Kingdom by more than 50% and consequently it is on the Red List of species compiled by the UK's Joint Nature Conservation Committee. Research suggests that the cause may be low survival rates from year to year, though the nest failure rate has fallen during the decline. Other studies have shown that reduced diversity of woodland structure and plant species, partly because of the impact of deer browsing, is the cause of the bird's decline.

Data from 157 woodlands covered by the RSPB/BTO Repeat Woodland Bird Survey showed that the abundance of Marsh Tits in 2003-2004 corresponded with the vegetation present 2–4 metres above the ground, the shrub layer. Data from the 1980s did not show the same results, but Marsh Tit numbers had increased by 2003-2004 in woods with the most shrub cover. The study concluded that damage to the shrub layer, caused by overgrazing by deer, for example, may make woodland less suitable for Marsh Tits.

It is a widespread and common resident breeder throughout temperate Europe and northern Asia. It occurs from northern Spain north to south-eastern Scotland and east to western Russia, with a broad gap in western Asia and present again in eastern Asia from the Altai Mountains east to northern Japan and northern and western China.

This species is sedentary, making short post-breeding movements in most of its range, but in northern Europe some move southward in winter. However, Marsh Tits seem not to perform the occasional irruptions that other members of the tit family do. Most Marsh Tits stay in their breeding territories year-round; presumably this is related to their food-storing strategy. Analysis of UK ringing data showed that of 108 recoveries (when a ringed bird is found dead or caught by another ringer), 85% were less than 5 km from where the bird was originally caught, and only 1% further than 20 km. Young birds join mixed roaming flocks; adults also join the flocks when they pass through, but do not stray from their territory.

Marsh Tits breed mostly in lowland areas, but can reach altitudes of up to 1,300 m. They prefer large areas of moist, broadleaved woodland, often oak or beech, though they can occupy wet alder woodland, riverside trees, parks and gardens or orchards. A study at Monks Wood, Cambridgeshire, England, found that Marsh Tits required mature trees with a shrub layer below the canopy, but that they avoided parts of the wood with lots of young trees. Another study in the United Kingdom found that during winter and while foraging, Marsh Tits spent more time than Blue Tits in the wood's understorey, and more time lower in the woodland canopy and understorey. Trees and shrubs in 10 breeding territories were also compared. The trees varied significantly between territories, but the shrub characteristics did not, suggesting that the shrubs were more important to the birds. In Wytham Woods, Oxfordshire, Marsh Tits were "largely absent" from parts of the wood with a dense canopy but poor shrub cover.