This 2016 video is about large copper butterflies.
Translated from Dutch NOS TV today:
Conservationists surprised by resurrection of large large copper butterfly
Things are wonderful for the rare large copper butterfly in the Netherlands. In the Frisian nature reserve Brandemeer, between Wolvega and Tjeukemeer lake, the animal is currently flying in large numbers.
That’s noteworthy, because at the end of last year all seemed to be over for the large copper butterfly in the region. The Butterfly Foundation sounded the alarm because a contractor had dredged the ditches in the Brandemeer too rigorously.
The contractor had scrapped all water plants from the ditch; including the protected butterfly’s caterpillars wintering there. The foundation feared that almost ninety percent of the eggs had disappeared.
More robust than thought
It turned out that was not true. “The large copper butterfly, a rare butterfly of peat marshes, appears to be more robust than thought”, the Butterfly Foundation says. There are many butterflies and even more eggs than last year. According to Omrop Fryslân broadcasting organisation, it is not clear why. It may be that in the ditches young plants have come up where the butterflies could deposit the eggs. It may also be that there were enough caterpillars in the vicinity of the dredged ditches.
A third possibility, according to the Butterfly Foundation, is that a small number of butterflies has flown very well because of the good butterfly weather [warm summer] of the past few weeks, and has deposited a lot of eggs.
Not only for the Butterfly Foundation, but also for Staatsbosbeheer [Forestry Department], this is a “great relief”, according to the Nature Today website. Staatsbosbeheer has done much in the Brandemeer in recent years to create a nice habitat for the large copper butterfly and other marsh inhabitants such as the bittern, the otter and whiteface dragonflies.