‘There are thousands of them’: The invasive species that’s taking over northern Italy

An alien bird species has landed in large parts of northern Italy, putting local wildlife at risk.

The African sacred ibis is an invasive species that is thought to have invaded after it escaped or was released from captivity, with some zoo populations historically allowed to fly freely.  

The wading birds are native to Africa and Iraq, but are now proliferating "like wildfire" across northern Italy, causing ornithologists to sound the alarm over risks to local fauna.

The species’ natural habitat is marshy wetlands and mud flats, nesting on trees that are in or near water.

As the climate crisis begins to dramatically change weather patterns, causing droughts and floods, the birds are following the humidity to new habitats.

Sacred ibis are ‘prolific on a massive scale’ throughout northern Italy

“The phenomenon has spread to the whole of Emilia-Romagna,” Andrea Ravagnani, of the AsOER Ornithologists Association of Emilia-Romagna, told La Repubblica newspaper. 

“The sacred ibis has begun to nest massively in Bologna, Modena, especially Ferrara,” continued Ravagnani, who believes there could already be tens of thousands of the birds in the northern Italian region. 

“The sacred ibis is an alien species, which should not exist in Italy; it escaped, or was released, from farms in northern Italy. Its history is similar to that of the nutria,” said Ravagnani. Nutria, affectionately dubbed ‘little beavers’ in Italy, are native South American rodents that now proliferate across the country because they have no natural predators there.

“Like the nutria, [the sacred ibis] is extremely adaptable and prolific on a massive scale,” Ravagnani warned.

Why does the sacred ibis pose a problem?

In Europe, the African sacred ibis has been on the European Commission’s list of Invasive Alien Species of Union Concern for almost a decade. The birds are also listed in DAISIE, an inventory of alien invasive species in Europe compiled by the Research Institute for Nature and Forest and the Centre for Ecology and Hydrology.

The EU’s regulation on the prevention, management and spread of alien species states, “Invasive alien species represent one of the main threats to biodiversity and related ecosystem services… The risks such species pose may intensify due to increased global trade, transport, tourism and climate change.”

The sacred ibis preys on amphibians and on the eggs and chicks of other species, particularly tern and heron, risking harm to local biodiversity and threatening the survival of the young of native species.

Additionally, ibises feed on insect larvae at rubbish dumps and slurry pits, risking the spread of diseases transferring to pastures and poultry farms.

How was the sacred ibis introduced to Europe?

Native to Africa, Iraq and Yemen, a pair of sacred ibis were brought to France from Egypt in the 1700s. A century later, the bird species was spotted in the wild in Austria and Italy.

In France, free-flying populations from zoos in Brittany established themselves in the wild along the Atlantic coast in the 1980s and 1990s. In recent years, eradication programmes have reduced their numbers but they cannot be completely wiped out.

Spain has managed to cull all of its sacred ibis population and has a policy to shoot those birds that enter from France.

The Italian population is believed to originate from either migration of the French free-flying populations, or from the Italian zoo Le Cornelle in Lombardy, which once had a free-flying population of sacred ibis. A study in the Nature journal Scientific Reports suggested that the species began breeding from a single pair identified in north-western Italy in 1989 - 20 years later, more than 10,000 birds were documented in the region.