Could I see a butterfly in the depths of winter?

With the arrival of the winter solstice daylight is at its shortest and the nights their longest. Many of us feel hemmed in by this increasing darkness and yearn for the longer days of spring and summer. 

Withdrawing indoors, one can be forgiven for thinking that the butterfly season has already come to an end, but there are a few species that overwinter as adults in the UK and some individuals can and will take advantage of the occasional mild, sunny day to top up on any available nectar. These hardy annuals are the Brimstone, Comma, Peacock, Red Admiral and the Small Tortoiseshell butterflies.

The Brimstone.

The Brimstone can have a life-cycle that reaches up to 10 months long, with new adults emerging from late June to early August, and thus over-wintering as adults. Favoured haunts for hibernation are dense bushes of Holly, Ivy or Bramble where they can shelter amongst the foliage, and it is imperative that any pruning or tidying up of these shrubs should be left until late winter or early spring when the adults are on the wing. Adults that do emerge during the winter months will look for early flowers on Dandelion, Primrose, Cowslip or Bugle, and may even look at garden plants such as Hyacinths.

               The Comma.         

                           

The Comma also has a lengthy life-cycle similar to that of the Brimstone. Adults can often be seen in late autumn and even early winter taking advantage of late season flowers and fallen fruits such as blackberries, grapes and plums. They will then move to nearby wooded areas to seek out hollow trees, fissures in bark and sheltered branches where they will hibernate for the winter. The butterfly can be encouraged to over-winter in gardens by creating log-piles in a dry, sheltered spot protected from cold winter winds. Adults can often be seen basking in the winter sunshine on favourable sunny days.

                                                                          The Peacock

The Peacock also over-winters as an adult, with the breeding period usually running from early May to late June, and adults emerging from late June to late July. This species has to be one of the most easily identifiable of all our native butterflies with the prominent eye markings on the upper wings. The underside of the wings is, in complete contrast, almost jet black and this helps prevent predation in the winter months as the butterfly will hibernate is outbuildings, underpasses and even hollow trees. Like the previous species, Peacocks can often be seen basking on sunny winter days. Adults will generally emerge from hibernation in March.

                                                                    The Red Admiral

The Red Admiral has generally been regarded as a migrant butterfly with just a few adults over-wintering in the UK. It is now thought that more adults are spending the winter months here as a result of the warming climate. The main breeding period begins in late spring, but numbers are supplemented by migrants from mainland Europe, with adults emerging throughout August and September. My findings have led me to conclude that this species is probably the hardiest of the five. My last butterfly sighting of this year is of a single Red Admiral in our front garden on the 23rd of November. My latest ever sighting was of another singleton on the 30th of December in 2014.

                                                                 The Small Tortoiseshell

The Small Tortoiseshell butterfly could, and sometimes does, out-compete the Red Admiral for the crown of either last or first butterfly of the year, especially if the temperature is warm enough to wake them from hibernation. The butterflies usually emerge towards the end of March or in early April depending on the weather. Adults will often hibernate in nooks and crannies in garden sheds, garages and outbuildings, and may occasionally be found waking up inside the home. If one is found indoors, avoid the temptation to place is directly outdoors unless it is a warm sunny day. It would also be a good idea to leave a door or window of a shed or garage open to allow the butterfly to find a suitable spot to go back into hibernation. 

There is a saying that the only thing that is predictable about our weather is that it is unpredictable. All five of the above species are opportunists and you could see any one of them on a warmer, sunny winter's day. If the weather is favourable, then do keep yours eyes peeled because you may be lucky enough to spot one. 

Could I see a butterfly in the depths of winter? There is every chance that you could. If you do, then please let me know.

Richard M. Jeffery

Butterfly Recorder for Leicestershire & Rutland