Species of the day: Goldcrest

By James Duncan

Learning and Engagement Officer

The Goldcrest (Regulus regulus) is simply tiny, just 9cm long and weighing between five to ten times less than a Starling, the same as a 20 pence coin. This diminutive species is not just Britain's smallest bird, it's one of the very tiniest in the whole of the northern hemisphere. Though remarkably 'tit-like' in its behaviour, it is in fact very much more similar in look to some of the smaller Leaf Warblers (Phylloscopus), though it's taxonomically distinct and has its own family, Regulidae, the 'Crests' or 'Kinglets.' If it weren't for the fiery golden stripe atop its head, the Goldcrest may be considered a somewhat plain looking bird, with olive-buff plumage and a couple of distinct wing bars. Without the eye stripe and supercillium of the more exotic looking Firecrest, the Goldcrest, with its beady eye, may almost appear to display a blank 'expression of surprise.' The black-bordered 'flame' is substantially more orange in the male and during mating displays may become surprisingly prominent as it's raised in an effort to attract a female. For such a tiny bird, the Goldcrest shows surprising bravery, frequently allowing observers to get remarkably close.

In line with its size, the Goldcrest also packs a tiny voice. Unfortunately, its high-pitched nature makes it one of the very first bird songs that become lost in old age - an avian hearing test of sorts. It's a tinkling little ditty, see-sawing from one note to another, with a little flourish at the end. Owing to the bird's unobtrusive habits,  both the song and its thin hissing contact calls are often the very first sign of its presence. Up until the early twentieth century, the Goldcrest was misleadingly known as the 'Golden Crested Wren', a taxonomic inaccuracy as it bears no relation to the Wrens. However, this may date to a time when there was much interchangeability between the Greek words for both wren and crest. Both Aristotle and Pliny wrote of a contest to determine the 'King of the Birds', the one who could fly the highest. A small bird cunningly hid in an Eagle's plumage and emerged upon the Eagle tiring, awarding it the win. Though the title of King has been associated with both Wren and Goldcrest, the Latin name of Regulus refers to a 'petty king', suggesting relevance to perhaps more than just its crown.

The Goldcrest is a widely distributed species, showing a preference for coniferous habitat, certainly within the breeding season. The nest itself is a tiny cup of moss, lichen, spider silk and feathers and is truly a thing of beauty, sometimes containing up to twelve eggs. Goldcrest's truly are serial nesters, as they'll often begin a second clutch before the first brood has even fledged. This is particularly important as the Goldcrest's tiny size makes it extremely vulnerable to the cold. They may, in fact, lose up to 20% of their fat reserves overnight in an effort to stay alive. If the winter is truly brutal, only around a quarter of the previous year's birds may survive to breed, creating continual fluctuations in population. It would therefore seem the Goldcrest is a vulnerable species, an unsuitable candidate for migration. Surprisingly this is not the case as it's a tough, resilient little bird, one that's impressively able to withstand Arctic conditions. Though most of the British birds are sedentary, our population may be bolstered by more than four million individuals travelling across the North Sea in autumn. The feat of endurance required to complete this return journey is clearly absolutely phenomenal, though many may rest on route with boats and oil rigs providing suitable respite. Despite this, they're ultimately one of the very lightest birds that undertake and complete a migration over the sea.

Goldcrest © Dave Kilbey