Description:

Among natural historians, the term 'jizz' refers to the characteristic impression given by an animal, plant, etc., that facilitates it recognition. The term is commonplace among experienced birders who can identify just which species of bird is seen from a glimpse, able to identify it from its jizz - a constellation of characteristics - rather then from individual identification features. People often ask about the origin of the term. I wrote this paper some years ago to record what I found about its origin.