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Butterfly numbers down by a quarter in annual Belgian census

05:02 09/08/2021

According to Natagora's annual butterfly census, there has been a substantial drop in Belgium since last year with 20,000 fewer butterflies seen this year - a total of 55,631.

Natagora carried out its butterfly census throughout the month of July. Entitled "Guess who flutters in the garden", it brought together more than 11,000 participants in 2,772 gardens.

Like last year, the pierids are ranked first. Some 17,052 butterflies of this species were observed, which represents an observation frequency of 78.1%.

The red admirals and the peacock butterflies rank just behind and thus confirm their second and third place. 9,854 red admirals were observed against 8,679 peacock butterflies. The decline in numbers translates into 20.1 per garden as opposed to 22.2 last year.

Philippe Frennet, who has been participating in the census for 16 years, said: "In the beginning, there were a lot of beautiful butterflies but unfortunately there are butterflies that we no longer see, and that’s very concerning because there were so many."

If the number of butterflies is decreasing, climate change is certainly one of the culprits.
"The decrease in butterflies is linked to meteorological effects such as periods of heatwaves or floods", explains Vincent Louwette, entomologist at Natagora.

But there are several other factors. "The main cause of the decline is habitat loss and fragmentation. There is also pesticide use, urbanisation, and intensive agriculture," he added.

"What we can do to alleviate the problem is to create some space for nature. If you leave more free areas, you will attract all sorts of flora and fauna. Developing your garden in favour of biodiversity will increase the likelihood of seeing butterflies in your garden."

Written by Richard Harris



I don't know what the forest workers are doing/spraying in the Forêt de Soignes in Watermael, but apart from the occasional fly, mosquito or slug, the forest seems to be dead. No birds can be heard, tree toads, mice, squirrels, rabbits have disappeared and the deer have tried to flee to safer parts. All this in just a couple of years. It's not just butterflies that are gone. Grasshoppers, crickets, ants -so many insects are missing. It's very sad and also very alarming.

Aug 10, 2021 13:16

I haven't seen a single butterfly this year. I had planted bee and insect friendly flowers in my courtyard and while there have been a lot of bees not a single butterfly has arrived this year.

Aug 18, 2021 13:12