Kalin (Pyrrhula pyrrhula) is a bird the size of a ščinkavca, but of a sturdier build. Both sexes, the adult female and the male, have a strong short conical black beak, with a black cap drawn down from the head onto it. Juvenile individuals with black caps do not have it. The nape, shoulders and back are ash gray in individuals of both sexes, the tail and the ventral side behind the legs are snow-white. The tail is entirely black, and the color of the wings is interrupted only by a transverse white stripe. The male has a pinkish-red belly, hips, chest and cheeks, while the female along the ventral side of the body is pinkish gray.
Čeprav je kalin aktiven čez dan in ni boječ, ga le redko vidimo, saj je tih in nevsiljiv ptič. Še največkrat ga izda njegov nežni in melanholični phü ali phü-u. Hrani se pretežno s hrano rastlinskega izvora, raznimi semeni in poganjki, zato so mu včasih rekli tudi popkar. Poleti pa sebi in svojemu zarodu rad privošči tudi žuželke in druge drobne nevretenčarje.
Živi v mešanih gozdovih z bujno podrastjo, kulturni krajini z gostimi mejicami in osamljenimi drevesi, pa tudi v parkih, na pokopališčih in večjih vrtovih. Gnezdi aprila in maja v gostem grmu ali na veji drevesa do dva metra nad tlemi. Je stalnica. Seli se le izjemoma in na kratke razdalje; v dolgih in ostrih zimah se na primer z višje ležečih krajev spusti v nižine.
