About 25 million birds are being unlawfully shot, trapped and glued in a Mediterranean crime wave that is even affecting birds vulnerable to extinction, according to the first report of its kind.

Conflict-hit countries such as Syria and Libya fare particularly badly in the study by BirdLife International, with Egypt the worst offender, with 5.7m birds killed each year.

An estimated 5.6m birds are killed in Italy – the second highest total – and Famagusta in Cyprus is the single most dangerous place in the Mediterranean for birds, totalling 689,000 deaths in one year, according to data gathered from 2014-15.

BirdLife’s chief executive, Patricia Zurita, said: “This review shows the gruesome extent to which birds are being killed illegally in the Mediterranean. Populations of some species that were once abundant in Europe are declining, with a number even in freefall and disappearing altogether.”

Birds such as the Eurasian chaffinch are being killed off at a horrifying rate according to the study, with an estimated 2.9m dying each year.

There are also 4.6m Eurasian blackcaps, quail and song thrushes suffering in a regional cull that extends to species listed as near-threatened on the International Union for the Conservation of Nature’s red list, such as the Eurasian curlew.

Populations of turtle doves, which migrate from Africa, have declined by 78% in Europe since 1980, partly as a result of illegal killings. Pallid harriers and Egyptian vultures are under threat, and the slaughter of even small numbers could have a serious effect on their numbers, the report warns.

Turtle doves have suffered a 78% drop in population since 1980. Photograph: Alamy

Gunshot is not the only cause of the bird deaths. Many are lured to traps by recordings of bird sounds, or snagged by lime sticks that glue them to branches and cause considerable suffering before death.

Tim Stowe, the director of RSPB International, described the decimation of bird numbers in the Mediterranean as “a source of lasting shame”.

“It’s time that action is taken to put an end to the killing, especially in the European Union where nature laws should be protecting vulnerable species,” he said.

The EU’s birds and habitats directives have overseen the recovery of more than half of the globally threatened birds targeted. But they are being reviewed in Brussels for cost-effectiveness, and to assess whether they pose an administrative burden to business, sparking protests from environmentalists.

“Our birds deserve safer flyways and we want conservation efforts to be increased now, before it’s too late,” Zurita said.