The Spanish word 'avifauna' is a compound word formed from two Latin elements: 'avis' meaning 'bird' and 'fauna' meaning 'animals' (originally from Fauna, a Roman fertility goddess). The term literally combines these concepts to refer to all the bird species of a particular region or area.

In Spanish, you might recognize related words like 'ave' (bird) and 'aviario' (aviary), which also come from the Latin 'avis'. The 'fauna' element appears independently in Spanish with the same meaning as in English, referring to animal life.

English speakers will find this word quite familiar as it exists in English with the exact same meaning and spelling: 'avifauna'. Other related English words include 'avian' (relating to birds), 'aviation' (from the same Latin root 'avis'), and 'fauna' (animal life). The word 'faunal' is also used in English to describe things relating to animals of a particular region or time.