Veliki vranac (lat. Phalacrocorax carbo) (Veliki kormoran, Kormoran) su ptice koje su gosti svih većih bosanskohercegovačkih rijeka i jezera od oktobra do aprila. Odrasli kormorani su uglavnom crne boje, ponekad crne i bijele. U dužini mogu dostizati razmjere od 45 - 90 cm, a neke vrste i do jednog metra, i slični su dugovratim patkama. Kljun liči na oštru kuku, tanak je, i bočno sužen. Kratke, snažne noge nalaze se na zadnjem dijelu trupa i cetri prsta su spojena širokom plovnom kožicom. Veoma su društvene ptice, prilikom letenja prave "potkovicu". Kormoran leti brzinom od 60 kilometara na čas i roni na dubinu od 13 metara. Kormorani su najorganizovanije ptice u ptičjem svetu. Oni love u grupama, inteligentni su, lupaju krilima po vodi i tako natjeraju ribu na površinu.

Great Cormorant (lat. Phalacrocorax carbo) (Great Cormorant, Cormorant) are birds that have been hosted all the major Bosnian rivers and lakes from October to April. Adults cormorants are mostly black, sometimes black and white. The length may be proportions of 45-90 cm, and some types of up to one meter, they looks like long-necked ducks. Stem looks like a sharp hook, thin, and sideways narrowed. Short, strong legs are located on the rear parts of the fuselage and four fingers are connected wide webbed. They are very social birds, when flying they form "horseshoe". Cormorant can fly up to 60 kilometers per hour and diving to a depth of 13 meters. Cormorants are the most organized birds in the bird world. They hunt in groups, they are intelligent, they are banging wings on the water forcing the fish to the surface.