The Netherlands: 84% less butterflies than a century ago

Palinurus

The Living Force
Source: Netherlands lost most of its butterflies in just over a century: research - DutchNews.nl

Netherlands lost most of its butterflies in just over a century: research

March 29, 2019

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Cabbage white butterfly

The Dutch butterfly population shrunk by at least 84% between 1890 and 2017, national statistics agency CBS [Dutch only] and the Vlinderstichting report.

The new figures are based on an analysis of long-term data resulting from a national measuring programme developed by the two organisations.

Three years ago scientists recorded a growth in some types of butterfly for the first time since monitoring began in the early 1990s, especially among rare species such as the dark green fritillary. However, the latest figures show that their number is declining again.

One of the main causes for the decimation of butterfly populations is intensive agriculture which has done away with the vegetation on which butterflies thrive. The figures show that where natural environments have been restored rare butterflies have returned.

According to this year’s red list [Dutch only] for butterflies in the Netherlands, 15 species have disappeared completely while 12 are critically endangered, 10 are endangered, seven vulnerable and three are near threatened. Only 29 species are not under threat at the moment.

However, a number of rare woodland butterfly species (wood white, white admiral, purple emperor, silver-washed fritillary) have profited from global warming and a greater variety in trees over the years, the organisations say.

Read the report (in English)
 

Maat

The Living Force
FOTCM Member
I'm in North-East of France, and a lot of years ago, I noticed that we don't see butterflies anymore. But maybe since a couple of years, they are much there again. That I noticed it because I was happy to see one, and then another, and another...

Like the poppy. When I was young, there were a lot, then they seemed to have disappeared. Nowadays, it's seems they are coming a little (yeah, a little) back. :-(:huh:
 

Palinurus

The Living Force
Source: Netherlands' animal populations halved since 1990; nitrogen the main culprit

Netherlands' animal populations halved since 1990; nitrogen the main culprit

By Janene Pieters on February 6, 2020 - 07:34

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Northern wheatear - imagebrokermicrostock/DepositPhotos - Deposit Photos

Wild animal populations in both the Netherlands' open natural areas and in the agricultural landscaped halved since 1990, according to the Living Planet Report Netherlands published by the World Wildlife Fund (WWF) [in Dutch and English; with PDF download links] on Thursday. According to the report, the high nitrogen precipitation - largely caused by livestock farming - is the main culprit behind the decline, NU.nl reports [in Dutch].

Due to too high nitrogen precipitation, special plant species that are important for butterflies and insects are overgrown by fast-growing grasses that like nitrogen. The insects that live off these plants disappear, which in turn has a negative influence on insect-eating animals, like birds and reptiles. The black grouse, northern wheatear and tree lark are among the bird species currently threatened in the Netherlands. The tawny pipit has completely disappeared.

The animal populations in the heathland saw the biggest decline over the past three decades. In certain heath areas, the size of the animal populations decreased by 70 percent. Animals in the agricultural areas halved due to intensive agriculture, desiccation, and the use of pesticides.

The WWF called the decline of the butterfly populations in agricultural areas particularly shocking. "Most species, including the wall brown butterfly and the small skipper, are now only found on dikes, roadsides and field hedges."

On the plus side, the WWF is optimistic about the animal populations in forests remaining stable on average. Existing forests are becoming increasingly varied, which is good for many animal species. Forests on high sandy soils affected by nitrogen also seem to be able to recover well - in forests where nitrogen precipitation has decreased over the past years, animal populations grew by 24 percent.

According to the WWF, this shows that biodiversity can be restored. But to achieve this, substantial investment will be needed and nitrogen emissions must be radically reduced.


Similar coverage:
Dutch wildlife population has halved in 30 years: WWF - DutchNews.nl
 

Palinurus

The Living Force
Some positive news for a change: Multiply butterfly: Increase in Dutch butterfly population - DutchNews.nl

Multiply butterfly: Increase in Dutch butterfly population

July 22, 2021

You are likely to see more butterflies floating around this summer, says butterfly protection organization the Butterfly Foundation. The group writes of an explosion in the butterfly population on biology website Nature Today (in Dutch; with additional graphs).

Every year, the foundation coordinates an annual butterfly count, where volunteers count every butterfly they see in their garden during a fifteen minute period. The organization collates the information into a report on the status of the butterfly population in the country.
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According to the findings, the count in the first two weeks of July was low but during the weekend of July 17 – 18th, the number of butterflies being seen increased sharply.

The group attributes the growth mostly to weather. ‘The explanation for this massive emergence can be found in the fact that there was much more rain this spring than in previous years,’ the organization writes. More rain is better for plants, and that provides an excellent food source for caterpillars.

These results are preliminary and the counting project will continue until the end of the month. If you want to help out, you can submit your count via the website.
 

Palinurus

The Living Force
Source: Rare moth not extinct, just hiding under cover of night - DutchNews.nl

Rare moth not extinct, just hiding under cover of night

July 29, 2021

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Photo: Ben Sale via Wikimedia Commons

A rare moth experts thought extinct has been spotted near Biervliet in Zeeland, 50 years after the last sighting.

Landscape preservation organisation Het Zeeuwse Landschap was sent a picture of the moth, a Dusky Sallow, on Facebook by a member of the public. ‘Two experts then went to the spot and found at least 30 [specimens],’ spokesman Marcel Klootwijk told local broadcaster Omroep Zeeland (in Dutch).

The organisation will keep an eye on the population to see if the congregation of moths is a fluke or whether the species is here to stay. If caterpillars appear at the end of the season, it means the animals are procreating.

If that is the case it may well mean the experts were hasty to declare the Dusky Sallow extinct. ‘People were probably just not looking for them. They are nocturnal after all,’ Klootwijk said.

Coverage in Dutch:
Gevlamde grasuil blijkt toch niet uitgestorven in Nederland
 

jsf

Jedi Master
Actually many moths are not so well researched because they live in certain areas, in certain times, and need certain plants.
This one is a widespread species in France as well.

For example we had this article about Idaea macilentaria, which is very common but the article says like, oh incredible, a species that was extinct for one century came back... haha

There are some species that are actually more frequent than expected, for example I recently found a Catocala diversa, which is very rarely observated in France ( instagram.com/p/CRo0sblCDWi/ ) but it's also probably because it's similar to other Catocala and not many people are searching for it.

The main problem I think is the destruction of habitats, for example old forests, wetlands, swamps, and widespread use of pesticides, monocultures. Probably also light pollution. Many species are in regression.

For example this document in french mentions Trichosea ludifica common in Rennes, but now it disappeared from this area. Many species were more common in plains, and now you have to search for them in mountains.

 

Palinurus

The Living Force
Thanks jsf for providing these details about France. This information isn't readily available to outsiders I'm afraid. In fact, other nations don't feature prominently neither here, a quick forum search with the term insect extinction revealed. That makes your contribution all the more precious; so thanks again. :thup:
 
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