Friday 18 March 2022

Butterflies flying in March in Portugal

Butterflies flying in March in Portugal

There are many butterfly species currently flying in the area of Portugal I live in. They are enjoying the warm spring sunshine. I saw several Green Hairstreaks (Callophrys rubi), two Clouded Yellows (Colias crocea) , two Red Admirals (Vanessa atalanta),

lots of Speckled Woods (Pararge aegeria aegeria) and several Large Whites (Pieris brassicae) on a short walk today. As well as these butterflies, I spotted two Spanish Festoons (Zerynthia rumina). I live in Quinta do Conde and like to walk through some forest and scrub on my way to the local supermarket and back. I usually see butterflies unless it is very cold, wet or windy. There are plenty of plants the Green Hairstreak butterflies can lay their eggs on here. They have a choice of Gorse (Ulex) or the Rockrose (Cistus) species. I was watching a Clouded Yellow female carefully searching in a short grassy area for Clovers and Medicks that are sprouting after some recent rains. Like all butterflies, the success of a species is very much linked to the distribution of plants they need for their caterpillars, and how well these plants are growing at the right season. Even if the correct plants are available in a given area, heat and drought can shrivel them up or prevent them growing at all. This is a disaster for a female butterfly. Every year we get several months in the summer period when the vegetation mainly goes brown or dies back to the ground. It can even be difficult finding some green blades of grass.

This is a big problem for the butterflies, like the Speckled Wood and Meadow Brown (
Maniola jurtina), that have larvae that feed on grasses. The latter butterfly flies later in the year and does surprisingly well here, though I have seen them sheltering in the shade of trees when it is very hot. I always wonder how they find enough grass to lay their eggs on. For the Speckled Wood in February and March this is not a problem because the grass species grow back after the winter rains. This year there has been a terrible winter drought so the land is very dry. Nevertheless many plants, including grass species, have survived, though they are nowhere near the usual size. I have been especially glad to see the small colony of the Spanish Festoon is still thriving. Last year, I didn’t see any of this species and feared that the brutal cold of the winter of 2020-2021 had wiped them out. I was obviously wrong because I have seen several of this species in the area they are found in here. Speaking of the Spanish Festoon, and its potential problems, it took me years to find the food-plant they are using in my locality. The Spanish Festoon needs any of the species of Birthwort (Aristolochia).
The species that grows here is the Round-leaved Birthwort (
A. rotunda). It is a delicate plant that winds its way amongst bushes and undergrowth so is not that easy to spot, especially in shaded areas. It only grows in one part here, where it is found in a lightly wooded area with a pathway and a bank. I can see for myself how this species is bound to stay where its food-plant grows because every year this location is the only place I can find this spectacular butterfly. I say spectacular because its wings are marked with darker zigzags and red dots on a yellow background. I am a migraine sufferer and the jagged lines remind me of the aura formation many people who get migraines are used to seeing.
Horrible as migraines are, the Spanish Festoon is a truly beautiful species of butterfly.

All photos by Steve Andrews

Thursday 3 March 2022

Helping the Red Admiral Butterflies

Red Admirals need Nettles

Red Admiral Photo: Steve Andrews

The Red Admiral (Vanessa atalanta) is a very pretty butterfly you are probably familiar with. You can’t miss it with its striking red, black and white wings, and in the UK, it is one of the last butterflies to be seen in late autumn. We all love to see butterflies but many people don’t realise how important the plants the caterpillars need to feed on are. In the case of the Red Admiral, the main food-plants are Nettle species. The Stinging Nettle (Urtica dioica) is the most commonly used plant but here in Portugal where I live, the Annual Nettle (U. urens) is the species they use.

Annual Nettles Photo: Steve Andrews
These nettles spring up as a garden weed and on waste ground in the autumn and winter when rains fall. Sadly because they are regarded as a weed, many people destroy them, either manually with care, due to the stinging threat from the plant, or with herbicide, and any Red Admiral eggs, caterpillars or chrysalises, get destroyed too. 
I saw a large patch of Small Nettles growing on some rough ground in a shortcut between two roads in my neighbourhood. I checked for Red Admiral caterpillars and soon found some, which I took into care, just in case anyone came along and killed the plants. I am very glad I did because some council workers turned up and removed all the vegetation that was growing there.
There is a skill to finding Red Admiral caterpillars, but it is very easy to learn. The caterpillars are usually found towards the top of a nettle stem and they fold leaves around themselves as shelters. The leaves are held with a small amount of caterpillar silk. They eat surrounding leaves and you can spot the holes in these leaves and their ragged appearance where they have been eaten away.

Sometimes the Red Admiral caterpillar will pupate inside their shelters too, but not always, because they will also transform into chrysalises that hang suspended from nettle stalks or possibly on a wall, fence or other object near where the caterpillar has been feeding.
I keep the caterpillars in sandwich boxes with a paper towel on the bottom to help absorb any dampness and to make it easier when cleaning out the container and providing new food. Often I find that the caterpillars will choose to pupate after spinning a pad of silk on the plastic top of the sandwich box. The chrysalises are brown but some are speckled with gold. As the butterfly inside becomes more developed and nears the time for emergence it becomes much darker and you can see the wings colouring up in the wing-case on each side of the chrysalis.

When the Red Admirals finally emerge, or eclose, as lepidopterists would say, they need to dry their wings thoroughly before they take their first flight. It is very important at this stage that they are not disturbed and that they don’t fall off whatever they are clinging to. This can be a problem for all species of butterflies at this stage of their life-cycles. Fallen butterflies can become cripples if they fail to expand and dry their wings properly. Usually all goes well, though, and the Red Admiral is all set to fly away. This butterfly can fly a long way. Many of those seen in the UK are migrants, though this species can hibernate in Britain too. In Portugal they have more than one generation but need nettles. I usually see them in autumn, winter and spring. In summer it is too hot and dry. There is a place in some woodland near where I live that I can almost guarantee I will be able to find a male Red Admiral every year in the right seasons. Of course, it isn’t the same butterfly but is obviously an ideal spot for a male of this species to create a territory he can patrol.

All photos by Steve Andrews