Černý orel

Černý orel is a natural monument straddling the border of the Prague-East and Mladá Boleslav districts, within the cadastral territories of Káraný, Otradovice, and Sojovice, roughly a kilometer from Stará Boleslav. The site protects a stretch of lowland floodplain landscape along the Elbe, combining old deciduous forest with damp meadows that shelter a rare butterfly.

What is this protected area?

Černý orel is a small but ecologically valuable enclave covering a total of 226.7 hectares, of which the core reserve within the protective zone spans 9.259 hectares. Protection of the site dates back to 1933, when it was first declared by the then Ministry of Education and National Enlightenment. Its current legal status was established by a regulation of the Central Bohemian Region on 15 April 2013 — a history of nearly a century of conservation on this ground.

What does the site protect?

The main purpose of protection is to preserve the original habitat of oak-hornbeam deciduous forest, characteristic of the lowland areas of central Bohemia. An equally important reason for establishing the protected area is safeguarding the dusky large blue (modrásek bahenní) — a small, dark-colored butterfly with a wingspan of up to 4 centimeters and distinctive markings on its wings. The species depends closely on damp meadows where great burnet grows, the host plant its larvae rely on.

What is the life cycle of the protected butterfly?

The dusky large blue appears on the meadows only in July and August. Females lay their eggs in the flower heads of great burnet, and the hatched caterpillars feed there for a time before dropping to the ground. From that point, the larvae develop in symbiosis with ants, which carry them into their nests — a dependency that makes the species highly sensitive to environmental change and requires active protection of both the meadow habitat and the ant population it relies on.

Why is preserving a site like this important?

The combination of old oak-hornbeam forest and damp riverside meadows makes Černý orel a mosaic of habitats rarely found so concentrated in the lowlands of Bohemia. The presence of an indicator species like the dusky large blue signals the good ecological condition of the meadows — the butterfly needs specific, undisturbed moisture conditions and carefully managed mowing so that the great burnet population, and the ants tied to it, can persist.

Frequently asked questions

Where exactly is Černý orel located? The site lies on the border of the Prague-East and Mladá Boleslav districts, within the cadastral areas of Káraný, Otradovice, and Sojovice, about a kilometer from Stará Boleslav.

How large is this protected area? The total area is 226.7 hectares, while the core of the reserve within the protective zone covers 9.259 hectares.

Since when has the area been protected? Protection dates back to 1933, and the current legal status was granted by a regulation issued on 15 April 2013.

Which species receives special protection here? The dusky large blue (modrásek bahenní), a rare butterfly tied to damp meadows overgrown with great burnet.