More than 200 tarantula sightings have been reported across Austria since the start of September, according to records from the citizen-science platform naturbeobachtung.at, with experts confirming 175 of the reports.

The figures were published as autumn brings the spiders out in search of sheltered places to spend the winter, sometimes leading them into flats, houses and garages. The south-eastern state of Styria recorded the most reports, with 66, followed by Lower Austria with 49 and Burgenland with 43. Sightings were also recorded in Carinthia.

One recent encounter underlined how far the spiders are turning up from their usual areas. A jogger in Korneuburg, in Lower Austria, found a spider with a body estimated at five to six centimetres at the roadside in early November. Experts said there had previously been no reports from the neighbouring Tullnerfeld and Korneuburg areas.

Two native species, not exotic escapees

Despite their alarming size, the spiders are not exotic arrivals or escaped pets. Austria is home to two native tarantula species: the South Russian tarantula and the black-bellied tarantula. Both belong to the wolf spider family and are generally not considered dangerous to healthy people. The South Russian tarantula, which can reach a body length of around four centimetres, is the largest spider in Central Europe, while the black-bellied tarantula grows to about two and a half centimetres.

The two species are distributed differently across the country. Only black-bellied tarantulas have been reported in Styria and Carinthia this year, while Vienna and Lower Austria have recorded only South Russian tarantulas. Both species have been found in Burgenland.

Researchers have also noted unusual individual finds, including a South Russian tarantula in Tulln and a black-bellied tarantula in the lower Gail valley at Stossau in late August. The South Russian tarantula has been present in Austria for around a century, and a study published in 2025 showed the species had also returned to Czechia after decades of decline.

More reports do not mean a population explosion

Experts cautioned against reading the figures as proof that tarantula numbers have surged by the same amount. The count reflects reports submitted by the public through a website or mobile app, rather than a census of individual spiders, and the same animal could in theory be reported more than once.

Autumn is the peak season for sightings, because the spiders are especially active as they look for places to shelter from the cold, and people are more likely to notice them. Greater public awareness and the ease of reporting through the platform may also have contributed to the high number of records.

Carolina Trcka-Rojas, an expert at the Austrian nature conservation association Naturschutzbund Österreich, said the spread of reports into new areas was still significant, because it suggested the known boundaries of where the spiders live are shifting. Residents who find one are advised to leave it alone and, if it is indoors, to guide it outside rather than handle it.