MISTLE THRUSH
DURING the winter our native thrushes are joined by their Scandinavian cousins, redwings and fieldfares.
As the cold weather sets in, flocks of redwings and fieldfares can be seen in our gardens and parks feeding on various berries.
However, one of our native thrushes, the Mistle Thrush can take particular exception to sharing its favourite food sources with these “foreigners”.
In particular when times are hard, they will defend their food sources, typically isolated fruiting holly bushes, becoming very aggressive towards other avian interlopers looking to steal a quick meal.
The mistle thrush gets its name from the fact that it will feed on mistletoe berries and its Latin name, Turdus viscivorus, means devourer of mistletoe.
Mistletoe berries are an important food source for thrushes in mainland Europe but in the UK, mistletoe is not so abundant, and they prefer holly and hawthorn berries.
Mistle thrushes are noticeably larger than song thrushes and have a longer tail. They have pale grey-brown upperparts, and their white underparts are heavily spotted with thorn-like spots which often coalesce to form darker patches on the sides of the breast – becoming more rounded on the belly and flanks.
The Song Thrush has more brownish upperparts and its upper breast spots are shaped like upside-down hearts or arrowheads - becoming more elongated on the rest of the belly and flanks.
In 2015 both mistle and song thrushes were classed as Red-listed Birds of Conservation Concern in the UK due to the recent decline in both breeding population and breeding range.
The British Trust for Ornithology (BTO) reports that there has been a 58% decrease in the population of UK mistle thrush between 1967 and 2020 with a current population estimate of 165,000 breeding territories.
he cause of the decline for both species is not fully understood, but may be linked to degradation of farmland habitat.
The mistle thrush is also known as the “storm cock” as it was thought that their singing was to warn of an approaching storm.
Males will sing as part of their defence of their territories and do this from the top of the tallest tree, or television aerials on houses even if it is windy and rainy.
As Spring approaches, they are one of the earliest birds to sing and will start as early as late January. They will often lay eggs by the end of February and continue to breed through to the end of June. Its main call sounds very similar to a football rattle whilst its song is like that of a Blackbird, but not as mellow and fluty and tends to be more monotonous.