The Llobregat delta is very important for the bird fauna, since it is a strategic point inside the migratory route of the Western Mediterranean that joins Europe and Africa. More than 360 species of birds gather together in the Delta; this figure is one of the highest as far as Iberian Peninsula species are concerned.

The Delta is, for birds, an area of rest, moult, nourishment, nest building or hibernation. It is considered to be an area of global importance in scientific inventories, since it shelters species of priority conservation in our continent. For this reason, the Delta was declared Zone of Special Protection for Birds (ZEPA), because it has important birds’ populations of priority community interest.

Important populations of nest Black-winged Stilt, Kentish Plover, Little Ringed Plover and Little Grebe stand out. There are also other species that build their nests in this area of distribution which is very restricted to Catalonia, with one or two breeding areas in the country, like the Pied Avocet, the Collared Pratincole, the Little Tern and the Common Shelduck. The populations of hibernal birds are extremely significant and the ducks of different species stand out.

The Llobregat delta regularly shelters 3 out of the 15 endangered species in Spain: the Eurasian Bittern, the Balearic Shearwater and the fishing eagle Osprey. Out of these 15 species, 7 more have been mentioned or are in migration. Besides the endangered species, we can find endangered taxons, vulnerable and threatened birds.

There is also an outstanding autochthonous population of leprous freshwater turtles Spanish Pond Turtle and Spanish toothcarp, small endemic fishes that live in the Western Mediterranean coastal wetlands. The population of the scanty Spanish Psammodromus stands out in coastal sandbanks.

Among the mammals, the population of bats stands out, though it is not so numerous as it used to be a few years ago: migratory species like the Nathusius bat and other species that breed in the surrounding massifs and use the Delta as an area of nourishment.

The invertebrates are not so well-known. Yet, many scanty and endangered species inhabit the Delta.