Jizz is a term used by birders to describe the overall impression or appearance of a bird garnered from such features as shape, posture, flying style or other habitual movements, size and colouration combined with voice, habitat and location.
Sean Dooley described jizz as "the indefinable quality of a particular species, the 'vibe'g it gives off" and notes that although it is "dismissed by many as some kind of birding alchemy, there is some physical basis to the idea of jizz."
Experienced birders can often make reliable identifications in the field at a glance by utilising jizz. Often jizz is useful for identifying to the family or genus level, rather than the species level. For example, "It definitely had the jizz of a thrush, but I couldn't see what kind."
The word has been extended to refer to the impression of the general characteristics of other animals or plants.
The origin of the word is a mystery. There is a theory that it comes from the World War II air force acronym GISS for "General Impression of Size and Shape (of an aircraft)", but the birding term was first recorded earlier than that in 1920. More likely, jizz is a corruption of gestalt, a German word that roughly means form or shape, or more specifically from the word gist which has the same meaning.
- Texas Park and Wildlife Department - Project Prairie Birds - JIZZ Descriptions and Alpha Codes for Selected Species
- Veteran Naturalist - Jizz birding, and all that jazz
- uk.rec.birdwtching FAQ - What is jizz and where does the word come from?
- McDonald, D 1996, 'The etymology of jizz', Canberra Bird Notes, vol. 21, no. 1, pp. 2-11.