Kvakač (Nycticorax nycticorax) is a stocky night heron with a short, stout neck and relatively short legs. In size it is similar to the little white heron, but it is much stronger and less elegant. When stretched out it measures between 58 and 65 cm, and the wingspan of its wings is from 105 to 112 cm. The lower part of the adult bird's body is light gray; its head, nape, back and the strong long bill are black; the pupil of the eye is dark red. In spring, at the beginning of the breeding season, the legs of the night heron color raspberry red, and from the nape it grows a few long narrow white plumes. After breeding its white plumage gradually wears away, and the legs become yellowish. Juvenile individuals, aside from size, are not at all similar to adults. The plumage of a juvenile is dark brown and gray, speckled with whitish to brownish spots; its bill is yellowish with a black upper part and tip.
Kvakača ne vidimo pogosto, saj je aktiven ponoči. Na lov za žabami, ribami, raki, žuželkami in ostalim užitnim se odpravi zvečer, ko sonce zaide. Čez dan počiva v krošnji drevesa ali grma in odleti navadno šele, ko se mu zelo približamo.
Severne populacije kvakačev se v jesenskih nočeh na območja prezimovanja v tropski Afriki selijo v majhnih jatah, medtem ko se tropske populacije te vrste ne selijo. Kvakači navadno gnezdo v velikih kolonijah – evropske populacije raztreseno po vsej zahodni, južni in srednji Evropi. Gnezdi od aprila do junija v krošnjah dreves, v grmovju, trstičju, na skalnih stenah nad vodo, včasih pa kar na tle, a vedno v bližini vode. Na selitvi se lahko od obrečnih logov odmakne in ga imamo možnost opaziti tudi na bolj odprtih površinah, na primer na travnikih ali njivah.
