Bulgaria is great for birdwatching, being a nesting ground for most European species in spring (May-June) and on the migratory path of many Asian ones in autumn (Sept to mid-Oct) totaling around 400 species in all. There’s plenty to see at any time, owing to the diversity of ecological niches and the fact that farmers use less pesticides and insecticides than in Western Europe. Though birdlife can be seen anywhere, the richest concentrations are in  Rhodope Mountain, along the Black Sea Coast and the floodplain of Danube River.

     In the Rhodopes, Trigrad Gorge is notable for Pallid swifts, Crag martins, Pot-bellied dippers and above all, the rare, elusive Wallcreeper, while the local caves harbour six types of bat. Although eagles, hawks and falcons can be seen all over the highlands, the best sites for observation raptors are in Arda Gorge near Madzharovo, which boasts rare Eastern and Imperial eagles, Egyptian, Black and Griffon vultures, Black storks, Blue Rock thrushes, Chukars, Nurhatches and Barred, Orphean and Olivaceous warblers.

     Black Sea Coast has an even greater variety of birdlife, especially during the great autumn migration, when flocks of raptors fly over the lakes and marshes around Burgas, which teem with Black and White Storks, Marsh harriers and Mediterranean gulls, while Black-winged stilts and avocets feed in the lagoons and terns fish offshore. In spring, the salt-pans and reed-marshes sustain White and Dalmatian pelicans, Great White and Little egrets, Bearded and Penduline tits, Red-necked Phalarope and Broad-billes sand pipers.

     Cape Kaliakra is likewise good for observing birds of passage (larks, pipits, wagtails, wheaters and warblers besides larger migrants like storks and buzzards), while in spring you’ll see Alpine swifts, Pied wheaters and the rare Finch`s wheatear (found nowhere else in Europe). On Lake Durankulak, Spanish sparrows breed in the nests of storks and there’s a small nesting colony of Paddyfield warblers. Pygmy cormorants are also around in September, along with Ruddy and Ferruginous shelducks (the latter an endangered species).

     In spring, especially, another major site is Lake Srebarna on the Danube floodplain, which is frequented by around eighty migratory species and has a nesting colony of Dalmatian pelicans. Its rich variety of wildfowl includes "Wheezing" Penduline tits, egrets, several kinds of warblers, and seventy types of heron. Black-and Red-necked grebes attend their floating nests, and Whiskered and White-winged Black terns drift on the open water. Further west the lowlands are home to Pygmy cormorants, Glossy ibises and Marsh harriers.