Evolution of butterfly species populations in France - STERF

[wollastoni]

I have been authorized by Luc Manil (ALF President & STERF Manager) to illustrate on the forum some of the results of the STERF surveys, realized in France from 2005 to 2014, and to use some of the graphics of the STERF reports.
STERF means "Suivi Temporel des Rhopalocères de France"

The STERF is a national butterfly counting survey realized by hundreds of amateur entomologists in France and organized by ALF and MNHN.
You can find full reports (in French) on the ALF website

Having now 9 years of accurate data, we can now draw some first conclusions about the evolution of some species populations. We can see that trends differ highly per species and per habitat.

Generalist species :


Pelouse and meadows species :


Forest and bush species :



In the good news :
- explosion of Aglais urticae (which would be dued to several cold/humid summers in a raw), Gonepteryx rhamni, Pontia daplidice and Hipparchia fagi (maybe for the same reasons)
- generalist, forest and bush species are rather stable

In the bad news :
- meadow species are suffering, especially Lycaenidae year after year !
- confirmation of Nymphalis polychloros issue, Satyrium illicis, Fabricania adippe, Issoria lathonia evolution are frightening too !

- Southern migrants are in a bad trend too (Vanessa cardui, Colias crocea...) but that must be due to the succession of cold summers, more than a species issue

STERF is one perfect example on how much amateur entomologists can be useful to science when they unite and work together.
I recommend all French entomologist who would read this article to participate to it.

You will find contact on the ALF website.
Many thanks to Luc Manil for his kind authorization.

What do you think of those results ? Do you see the same trends in your countries ?

[nomad]

Very interesting report.

Aglais urticae is very abundant in my area of Wiltshire this year after a serve decline.

Gonepteryx rhamni is very common this year.

The last two years have seen few of the U.K immigrants Vanessa cardui and Colias Croceus, but there have been always good years and bad years in the U.K for these species.

Pontia daplidice and Issoria lathonia are very rare immigrants to our shores and not seen at all in most years.

Nymphalis polychloros is extinct here, the decline in France must be quite worrying.

Britain does not have the other some of the other species that you listed.

The biggest decline in a butterfly species that I noticed last year here, was in Lycaena phlaeas. Any other Brits noticed this?. Callophrys rubi did very well last year.

This spring there does not seem many Polygonia c-album around  and their numbers seem to be down.

[timmsyrj]

I've seen one c-album already this year in my garden, I usually get quite a few each year as I have a golden hop at the bottom of my garden that I can usually find their larvae on, inachus io everywhere today, what a lovely day it's been, my purging buckthorn buds are starting to open, this usually atracts a female G. rhamni to lay a few eggs.

Rich