Speckled Wood

Pararge aegeria

The speckled wood is a butterfly found in and on the borders of woodland areas throughout much of the Palearctic realm. The species is subdivided into multiple subspecies, including Pararge aegeria aegeria, Pararge aegeria tircis, Pararge aegeria oblita, and Pararge aegeria insula. The color of this butterfly varies between subspecies. The existence of these subspecies is due to variation in morphology down a gradient corresponding to a geographic cline. The background of the wings ranges from brown to orange, and the spots are either pale yellow, white, cream, or a tawny orange. The speckled wood feeds on a variety of grass species. The males of this species exhibit two types of mate locating behaviors: territorial defense and patrolling. The proportion of males exhibiting these two strategies changes based on ecological conditions. The monandrous female must choose which type of male can help her reproduce successfully. Her decision is heavily influenced by environmental conditions. Source

Where it is now

In the last 8 weeks this insect was recorded 380 times across 11 areas (each area is a 5 degree square).

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Movement and weather

Each season it is first heard regularly where daytime highs are around 12°C (typically 10 to 14°C, from 7 areas). That holds across 20° of latitude, which suggests its timing follows temperature more than the calendar.

Over the weeks it was present in the past year, its centre in Europe ranged from 43°N in October to 59°N in June, about 1,800 km apart.

Arrival dates

The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.

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Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.