Autumn is perhaps the best time of year. A true masterpiece of nature: colours and shades fit for any art gallery. Golden browns, sunset oranges and fiery reds paint a glorious mosaic across the landscape. In numbers unmatched, leaves descend in their masses. Numerically, only the overuse of the term ‘autumnal’ can compare…
Many of our greatest wildlife spectacles occur at this time of year – geese, ducks, swans and waders touch down on our shores, escaping their northern homelands before winter. Other migrants join the rush. Redwings, fieldfares and bramblings come to enjoy the banquet on offer. A-listers like waxwing are always popular - their unique style an attraction to any nature lover. Wars are waged in the countryside as red deer fight for dominance whilst grey seals give birth on the coast, providing the chance to see their pure white pups.
It's hard to complain about such an exciting season! Well one aspect of nature that is sorely missing at this time of year is insects, in particular Lepidoptera. Understandably, as the weather grows colder and days shorter, insects have found strategies to maximise their survival. Creatures such as butterflies and moths are mostly designed to thrive in our warmer months and to avoid our cooler and wetter seasons, leaving a Lepidoptera shaped hole in our fauna for the next 6 months or so.
Yet for the last few years I have discovered a way to extend my insect interests into the autumn whilst also contributing to important science. The herald moth (Scoliopteryx libatrix) is a fascinating species that survives the cold British winters by hibernating in its adult form (a fairly rare strategy for moths in the UK). Unlike many other moths and butterflies, autumn and winter are probably the easiest time to find heralds. Outbuildings, sheds, caves, ruins or anywhere offering some cool shelter and protection from the elements could well be occupied by heralds.
My job as a ranger with Historic Environment Scotland offers me the chance to visit some of the country’s most important and valued historic properties. Yet these ancient castles, abbeys and monuments are also perfect winter holiday homes for heralds. Hiding away in the darkest and dampest corners, a herald hunt is certainly an enjoyable and novel way to experience any castle! Of course, like any good accommodation, such prime real estate is in high demand. If you don’t find any heralds you may spot some butterflies. Species such as small tortoiseshells and peacocks also hibernate and serve as a good consolation prize!
Surveying for heralds is a lot fun, but finding out exactly where the moths are hibernating is the real goal. The distribution map of the herald across Scotland is slowly improving thanks to the great work carried out by a few dedicated volunteers. By regularly checking sites across years (and finding new ones!) our understanding of this species in Scotland is gathering momentum.
If you are interested in searching for heralds, please remember some of these locations can be dangerous and you should take appropriate precautions. These conditions are often favoured by bats. If you plan to investigate these types of locations then please contact your local bat group. Otherwise, also contact the Butterfly Conservation Scotland Office for guidance about best practice in this area. You must be careful not to disturb any bats. Disturbance during their hibernation can affect the survival chances of these protected species. If you do inadvertently find any bats then you should leave promptly and contact your local bat group who would be delighted to know they are there!
I hope you find some hibernating heralds!
Gordon Smith is an Assistant Ranger with Historic Environment Scotland, based at Holyrood Park. He has a BSc in Zoology from Aberdeen University. Whether at work or in his free time he enjoys exploring the great outdoors.