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The UK glories in 59 different species of this brightly coloured insect. Fifty-seven are resident species, and two are migratory species (the painted lady and clouded yellow butterflies).

A common blue butterfly perches on a yellow flower. The common blue butterfly is bright blue and widespread throughout the UK.

Butterfly facts

Scientific name: Lepidoptera

Family: Papilionoidea

Diet: Nectar

Predators: Mammals, birds, spiders, and other insects

Size: 2-9cm wingspan

Lifespan: Depending on the species, anywhere between two weeks to a year

Winged wonders of nature

Butterflies have existed for at least 50 million years and probably evolved around 150 million years ago. Their magical transformation from egg to caterpillar to chrysalis is one of nature's wonders.

Butterflies are important indicators of biodiversity and environmental health. Across the world, there are over 250,000 species, making up a quarter of all named species. Despite over 50 butterfly species residing in the UK, five kinds have gone extinct in the last 150 years.

Butterflies and our canals

To help combat populations declining, we've been working in partnership with Butterfly Conservation and local volunteers to improve habitats.

At places like Fenny Compton, on the Oxford Canal, and Napton Reservoir, we've planted banks with kidney vetch and creeping cinquefoil. This is an important food source for the grizzled skipper butterfly and the rare small blue butterfly.

How to identify a butterfly

Butterflies in the UK range in colour, size, and markings. From bright red peacock butterflies to leaf-like brimstone butterflies, which have you spotted?

  • Peacock butterfly

    Peacock butterflies have bright red colouring with black markings. They have blue spots on the forewings and hindwings, resembling the 'eyes' of peacock feathers. The underside of their wings is dark and dull.

    Females are larger than males. With a wingspan of 6-7cm, these are distinctive butterflies. Widespread throughout the UK, you're likely to spot peacock butterflies all year round.

    As caterpillars, they're jet black with small white spots.

  • Red admiral butterfly

    Red admiral butterflies are black with red stripes on the wings and white spots towards the tips of the forewings. They're large butterflies and strong fliers. Females are slightly bigger and can measure up to 7.8cm across the wings.

    Widespread throughout the UK, you might spot a red admiral anytime during the year. They're most common from spring through to November.

    As caterpillars, red admiral butterflies are black and spiny with fine hairs and a yellow stripe along its underside.

  • Small tortoiseshell butterfly

    Small tortoiseshell butterflies are a reddish-orange colour with black and yellow markings. They have a ring of blue spots lining the wing tips. Its wingspan ranges from 4.5-6.2cm, and females are slightly larger than males.

    Small tortoiseshell butterflies are one of the UK's most widespread butterflies. However, populations have noticeably declined in recent years. You might catch sight of small tortoiseshell butterflies all year round.

  • Common blue butterfly

    The most widespread blue butterfly, the common blue is active between April and October. They're found in heathland, woodland, grassland, parks, gardens, and waste ground.

    Males are bright blue with brown lining around the wingtips and a white fringe. Females are a light brown colour, with blue dusting close to the body and a white fringe. Common blue butterflies have orange spots under the wings. They have a 2.9-3.6cm wingspan.

  • Large white butterfly

    Large white butterflies have brilliant white wings with one or two black spots. They have a wingspan of 5.8-6.3cm and are, as the name suggests, larger than other white butterflies.

    They're widespread from April to October, flying across allotments, farms, and gardens.

What do butterflies eat?

While each species has a slightly different diet – some unsavoury, like the holly blue eating the juices of rotting fruits – most prefer sweet nectar from flowers. Butterflies have straw-like mouths (called proboscis), meaning they're mostly restricted to liquids.

They use their proboscis to reach nectar deep in the flower. Some butterflies aren't fussy about the flowers they feed from. Others prefer specific plants.

Nectar-rich flowers like bluebells, lavender, red campion, cornflowers, primrose, and clover are all butterfly favourites. Spring blossom, ivy, hawthorn, holly, bramble, and nettles also attract butterflies. The abundance of wildflowers and vegetation is one of the reasons we see so many along our canals.

How do butterflies breed?

Butterflies have a unique four-stage life cycle. They start as tiny eggs laid on leaves in which the larvae (or caterpillars) form. Eggs can hatch after a few weeks or remain dormant for over winter before emerging.

Once hatched, caterpillars vary in size, shape, and colour depending on the species. Some are furry, some spiky, some camouflaged, some smooth. All caterpillars love to eat. They munch their way through large amounts of green leaves to store energy for their next phase: the chrysalis.

The chrysalis (or pupa) stage of a butterfly's life cycle sees it transformed from a shuffling caterpillar to a free-flying butterfly. The caterpillar surrounds itself with a protective case, anchoring itself to a plant.

Finally, the insects emerge from their cocoon as fully formed butterflies. They're ready to find a mate and start the process all over again. At this stage, some butterflies will travel thousands of miles to breed.

Where do butterflies live?

Butterflies make their homes anywhere from woodlands and grasslands to hedgerows and scrubland. Sunny sheltered areas are good places to find butterflies. You might also see them feeding on brambles in the summer.

Tips to spot butterflies

Choose an overcast day to see them up close as they're less active and stay still for longer. Head to your local canal or river and keep an eye on their favourite flowers or watch the bramble and nettles.

Threats to butterflies

It's always a pleasure to see different and vibrant butterflies feeding along our towpaths. Butterflies inspire images of sunshine and flowery gardens. However, many species are under threat from habitat loss and degradation.

In fact, one in ten species of butterfly faces extinction in Europe. Over a third have declining populations. Several UK species are now listed in the UK Biodiversity Action Plan. Butterflies are fragile creatures and react quickly to change. Their decline is more serious than a loss of colour in the countryside.

Other species to look out for

Family nature guide 2019

Download your free nature guide

Identify footprints and read fascinating facts about the creatures who make their homes along our canals and rivers

Last Edited: 24 May 2024

photo of a location on the canals
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