On a sunny – or at least dry – moment count butterflies for fifteen minutes on the balcony or in the garden. You can do that this weekend during the annual garden butterfly count of The Butterfly Foundation. With the counting data, researchers hope to be able to answer that one but important question: what about garden butterflies?
According to Nora Thierry of De Vlinderstichting, the butterflies in the west, including in North Holland, are doing worse than in the rest of the Netherlands. “But we don’t know exactly what causes this and it also differs per species.” Thierry explains that butterfly pupae hatch when the weather is good. “It could just have been colder in North Holland than in other provinces or less dry, so that dolls could survive longer.”
So far, the peacock’s eye has been most commonly seen in the Netherlands. “Remarkably, your number two is different from other provinces. Your number two is the atalanta, while in other provinces it is the whites.”
Thierry explains that butterflies are pollinators and are therefore very important for the development of new plants. “In addition,” she continues, “butterflies play a major role in the food web, but people always don’t like to hear that. Butterflies and caterpillars are often eaten by birds and dragonflies.”
Finally, the butterfly population is an important indicator for the larger natural problems such as drought and nitrogen. “We can calculate nitrogen figures on the basis of butterfly numbers. For example, we know that a common, general species such as whites can live well on plants with nitrogen. More specialized species, such as nacres, can live less well on them.”
What can you do for garden butterflies?
According to De Vlinderstichting, you can attract more butterflies to your garden by planting nectar-rich flowers for butterflies and providing food plants for caterpillars. Marjan Minnesma is a North Holland woman who is taking part in the annual garden butterfly count for the third time.
“In my garden I have paid a lot of attention to what butterflies and caterpillars love. For example, the atalanta and the little fox lay eggs on nettles, and hatched caterpillars eat nettles.” Minnesma’s garden is also full of cow’s eyes, butterfly bushes and thistles. “I keep looking at what the butterflies are on, and I leave them alone. I also don’t use poison. I’ve lived here for twenty years and every year I have more butterflies.”
Count in?
Minnesma counted yesterday afternoon, and plans to do the same today and tomorrow. “The idea is that you count all the butterflies you see for 15 minutes. You can count several times during the weekend, but every 15 minutes counts as one count.” According to Thierry, sunny weather, no clouds and a temperature above 17 degrees are the best conditions for counting butterflies.
According to Thierry, Noord-Holland is currently at number 4 of all provinces in terms of counters. Everyone can pass on their observations of butterflies in the garden directly via Garden Count’s website. Even if you don’t see any butterflies, that is important information to pass on, says Thierry.