The Vanishing Mistle Thrush
David Attenborough describes the “wild, skirling song of the mistle thrush” singing from storm tossed tree- tops. Unperturbed the thrush can deliver its music through a lashing gale and this earns it the country name of storm cock. Sadly it has become an endangered species in the last few years and is rarely heard. It is our biggest thrush and from midsummer to early autumn family groups of mistle thrushes fly in flocks over open pasture and stubble fields searching out worms, slugs, beetles and berries. They are paler and more grey- brown than a song thrush with white tips to their outer tail feathers. The breast is boldly spotted with lovely, striated, diagonal dots on the neck and white feathering around the face. When on the ground, as I witnessed by a large manure heap in Forncett St Mary, it has a distinctive upright posture. The bird had descended from a hawthorn tree where ripe berries still clung to the February branches. It had a dashing, fearless air and as I learned it is a fierce defender of winter food in its territory. The mistle thrush flight has a bouncing motion as they give short flaps followed by a dip on closed wings. They are strong and good at aerial sallies on fruit that is inaccessible, such as berries at the end of fragile twigs of holly and yew where they cannot perch.
The Mistle Thrush. Photo: Yuriy75, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
As winter approaches the flocks separate and the birds forage singly or sometimes as a pair. In Norfolk there has been a very rapid decline in this species and winter survival has become a huge problem. The soil invertebrates important to them have reduced due to sprayed grassland and intensive farming. Pesticides kill birds and their insect food and can render eggs infertile. The mistle thrushes have to rely predominantly on wild berries that are less nutritious and are vulnerable to insensitive hedgerow management – hedges radically chopped back so the fruiting bows are struck away.
A few years ago a pair of mistle thrushes guarded clumps of mistletoe that are rampant on old apple boughs in my garden. The thrushes discard the sticky white seeds by wiping their beaks on a convenient branch or the excreted seed passes through them and is deposited on the tree. Most fascinating of all was a single thrush who one cold week in March defended a large slice of rich Easter or pashka cake stuffed with dried fruit and cream including raisins and figs dipped in brandy. I had enough to spare of this Russian dome-shaped confection, turned out from a large basin, and laid a slice as an Easter gift on the bird table. The mistle thrush hopped and sang, alternating a loud, fluting, joyous song with a harsh, triumphant rattling call ‘…like a comb scraped across wood.’ No other birds came near. The lovely Ukranian Easter bread, paska, is a sweet, rich cakey bread made with many eggs, butter, dried fruit and nuts. The inside of the long risen paska is a swirl of yellow and white said to represent the Resurrection. I am sure the mistle thrush would like that too. An old custom in some regions of Ukraine is to create dough ornaments for the paska connected to the spring reawakening of nature: leaves, flowers, larks. I will put a mistle thrush on mine, put out a slice on the bird table and wait.
Mistle thrushes not only defend their chosen, berried trees, but bravely defend their beautifully woven nests, chasing off much larger birds such as crows, magpies and buzzards. Naturalist, Mark Cocker refers to an extraordinary report of a peacock, knocked clean off its feet by a furious mistle thrush when it strayed too close to the tree in which the thrush was nesting.
How to help the Mistle Thrush
1. Don’t cut hedges back savagely. Make sure some berries can form for autumn and winter. The Norfolk Wildlife Trust suggest farmers could cut in a two or even three year rotation. Most hedgerow species only produce flowers and fruit on two tear old wood. Promote hedgerow trees in your hedge.
2. Keep your soil rich in invertebrates by mulching, manuring and never spraying with insecticides.
3. The NWT suggest encouraging mistletoe because of the mistle thrush’s partiality for the berries. It is best to collect berries in February or early March when they are ripe. Choose a young branch with thin, smooth bark on apple, lime, poplar, facing north, or on the shady side of the tree. There is no need to cut the bark with a knife just wipe the seed onto it as the thrush would wipe its beak. You need to be patient because often the first leaves do not appear for a couple of years!
July 2022
References:
Birds Britannica by Mark Cocker and Richard Mabey, Chatto & Windus , 2005.
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