Tuesday 24 November 2015

Butterflies in November and British Butterflies that hibernate

The Red Admiral

The only butterfly you are likely to see flying in November in the UK is the Red Admiral (Vanessa atalanta). Conspicuous, not only because it is the only butterfly you are likely to see at the time of year, but also because of its bold colours of red, black and white.

Red Admiral (Photo: Public Domain)

The Red Admiral can still be seen flying on sunny days late in the autumn and will feed from rotting fruit, such as windfall apples and pears, and on ivy blossoms. It is the last butterfly to be seen in many parts of northern Europe too. It is also found in Asia and North America.

The Red Admiral is actually a migrant butterfly that arrives in Britain in varying numbers each year but it also hibernates and thus maintains a resident population.  Hibernating individuals emerge in spring and start the cycle again by laying eggs on the food-plants, which for this species, is mainly the Stinging Nettle (Urtica dioica).

British butterflies that overwinter by hibernating

There are four more butterflies found in the UK, that although they are not seen flying as butterflies in November,  hibernate as adult butterflies. They are the Small Tortoiseshell (Aglais urticae), the Peacock (Aglais io), the Comma (Polygonia c-album) and the Brimstone (Gonepteryx rhamni).  Actually, of these, the Comma can still be seen in early November in very mild autumns but usually it will be tucked away somewhere hibernating.

Small Tortoiseshell

Small Tortoiseshell (Photo: Public Domain)

The Small Tortoiseshell was once one of the most common British butterflies but has sadly been in serious decline in recent years, although the exact cause remains unknown.  It is thought to be susceptible to Climate Change, though pesticides and parasites are likely to have killed many as well. This pretty butterfly has caterpillars that, like the Red Admiral, feed on Stinging Nettles. 

Adult Small Tortoiseshells hibernate under cover and often enter buildings, including sheds and outhouses. If you find one in your house it is best to gently move it into a shed if you have one because the temperature inside a house is likely to waken the butterfly from its sleep too early, and it will waste its stored energy fluttering about.

This species, the Red Admiral, Peacock and Comma are all often seen feeding from the Butterfly Bush (Buddleia davidii) in late summer.

Peacock Butterfly

Peacock (Photo: Public Domain)

The unmistakeable Peacock butterfly is one of the most beautiful insects in the world with its four eye-spots displayed against its dark red wings. This common butterfly has caterpillars that also feed on nettles. Like the Small Tortoiseshell it will enter buildings to hibernate and also go into hollows in trees to pass the winter months in a dormant state.

The Comma

Comma (Photo: Public Domain)

The Comma has a ragged edge to its wings and from the underside, which is a mottled brown, it can look like a dead leaf.  There is a white comma-shaped mark that gives the butterfly its name. It is a common species too and its caterpillar feeds on nettles, Gooseberry (Ribes grossularia) and Hops (Humulus lupulus).  When it is small the caterpillar of this species is dark grey and whitish and looks like a bird-dropping. 

The Brimstone

Brimstone (Photo: Public Domain)

The Brimstone male is a bright yellow and the female is a paler creamy yellow with a greenish tinge.  This insect was once known as the "Butter-coloured fly" and is said to have been the origin of the term butterfly.  It has a very long life for a butterfly, though much of its time alive is spent in hibernation. 

The caterpillar will only feed on the two types of buckthorn - Common Buckthorn (Rhamnus cathartica) and the Alder Buckthorn (R. frangula). This limits the distribution of the species to areas in which the females can find these shrubs. 

The adult butterflies hibernate in ivy and evergreen vegetation and are usually the first species to emerge in spring, and can be seen flying as early as January in mild winters. 

The other species of butterflies found in Britain all spend the winter months as eggs, chrysalises or as larvae. 


Simon Snake said...

I was in my garden moving things about yesterday (1st November) and found a Small Tortiseshell butterfly on the ground. It flapped its wings a few times but stayed on the ground, so I took a couple of photographs of it, then had to come into the house briefly, forgot all about it, then went back outside but haven't seen it since. I was surprised to see any butterfly at all this time of year, but then again, the weather has been warm enough for me to be outside in just a shirt and shorts. I'm not sure where I ought to report my sighting though.

Unknown said...

I have a butterfly flying around my Lounge at the moment. What should I do?