Skip to content
- This butterfly is easily spotted on Cowbar and is one of the first butterflies to be seen in the spring. (It can be seen almost any time of the year in urban areas but many hibernate over the winter.)
- They often hibernate in groups and need to put on 20% of their bodyweight before they do this.
- This butterfly used to be low priority as a threatened species but there has been more concern about it in recent years. Populations are declining because of the habitat conditions brought about by global heating.
- The caterpillars emerge from eggs usually laid in sets of 60 to 100 on small nettles and common nettles, which the caterpillars then eat.
- If the summer is hot and dry, there can be less water and less nitrogen in nettle leaves so fewer caterpillars survive.
- Caterpillars are dark and tufty with yellow stripes down each side.
- Male tortoiseshells are very territorial and will chase other butterflies and anything else that appears in their space.
- The dark undersides of the wings make them look like leaves when wings are closed, and difficult to spot. They sometimes flick their wings open at a predator, creating a warning flash of red to show they are not good to eat.
- They will also escape capture by flying away in a straight line.
- A male will drum his antennae on the female’s hind wings to court her.
- The large tortoiseshell, which has similar markings, used to be very common in Victorian times but is now extinct. This partly due to climate change and to Dutch elm disease, which destroyed one of their main food plants.
