Another bad year for butterflies in the Netherlands despite peak in September

The last year will be remembered as another bad year for the number of butterflies in the Netherlands, said the Dutch Butterfly Conservation on the nature website Nature Today. In both spring and summer, far fewer butterflies were counted than the average over the past 30 years. Although there was a peak in the counts in September, according to the foundation, this "did not save the butterfly year.”

The conservation based its findings on provisional figures from counts that have been conducted throughout the country since 1990 using a fixed method. These show a "clear pattern" that shows that butterflies are declining further and further.

Although species such as the peacock butterfly and the speckled wood "flew well" this year, many other species had a hard time, such as the heath butterfly, the small copper, the rare silver-washed blue, and the speckled blue.

"For these species, the hot and dry last few years have had a negative effect, and that is not compensated by a one-off wet year like 2024", according to Butterfly Conservation. The brown argus, which is always counted most often as these grassland butterflies occur together in groups, has also seen its numbers decline in recent years.

The Butterfly Conservation reported in August that the annual garden butterfly count had never counted so few butterflies as this year. However, many butterflies were seen a month later, including peacock butterflies, red admirals, and large cabbage whites.

"It led to optimistic reports that it was still a good butterfly year and that everything was just a bit later," according to the foundation. "Unfortunately, that is not the case."

The number of butterflies has more than halved between 1992 and 2023, it was announced earlier this year. According to the Butterfly Conservation, this is partly due to fertilization and desiccation, mainly as a result of the intensification of agriculture. Weather extremes due to climate change also have a negative impact on the butterfly population.