[7] Romania is also home to the asprete, a critically endangered species described by the media as a living fossil and "Europe's rarest fish".
The six species that are the most commercially viable today are all small-sized fish: the red mullet, the sand smelt, the round goby, the European anchovy, the merling and the sprat.
An entire stable population of the species was discovered by experts in 2014 along the banks of the Danube, with the exact location being kept a secret to avoid trophy hunting.
[21] Romania is home to roughly two-dozen species of raptors (Accipitriformes), the order which includes the hawks, eagles, kites, and Old World vultures.
[1] The adjacent bird-of-prey groups, the falcons and kestrels (Falconiformes) and the owls (Strigiformes) each have about ten species represented in the country.
These include numerous species of Anseriformes, such as ducks, geese, and swans, as well as cormorants, shags, herons, storks, ibises, pelicans and, seasonally, greater flamingos.
[27][28] The great white pelican is sometimes mentioned in the media as being the national bird of Romania, despite the lack of any official decision in this regard.
[31] The great bustard, the world's largest extant flying animal,[32][33] was once common in Central and Southeast Romania until the early 20th century, when agrarian reform severely restricted its habitat.
[34] They were considered extinct in Romania, with no sightings between 1981 and 2002, but can now be found in two small, isolated groups in Bihor and Timiș counties, near the border with Hungary.
[54][55] After collective farms were closed in the 1990s, the population was supplanted by freed horses and by the beginning of the 21st century, it increased to around 4,000 individuals, turning them into a threat to the protected flora of the region.
[56][57] Following media and public outrage in 2011, authorities walked back on the initial plan of killing the horses and the population is now controlled through birth-control vaccines.
[58] The large carnivores living in Romania are the European wildcat, the Eurasian lynx, the red fox, the golden jackal, the grey wolf and the brown bear.
[1][61] While the endangered Mediterranean monk seal still appears in the Black Sea, it has not been recorded in Romanian waters for several decades.
Among these the most notable are the East-Asian raccoon dog, which spread to Europe through the USSR and was first seen in Romania in 1951,[62] the European mouflon, which was introduces starting with 1966 in game reserves and later in the wilderness,[63] and the North-American muskrat, which was introduced to Romania accidentally, after individuals which escaped captivity in Czech and Russian farms spread across the continent around the middle of the century.
Despite being a signatory of the Berne Convention on the Conservation of European Wildlife and Natural Habitats, Romania is behind many other countries when it comes to protecting its ecosystems from invasive alien species.