fauna

Fauna refers to all animal life of a particular region, habitat, or time period. The term is often paired with flora, the plant life of the same area, and is used in ecology, biogeography, and paleontology. Fauna encompasses all animal groups, from microscopic metazoans to the largest mammals. In practice, scientists classify fauna into major taxonomic groups such as invertebrates (arthropods, mollusks, annelids, echinoderms, cnidarians) and vertebrates (fish, amphibians, reptiles, birds, mammals). Within these groups, animals vary widely in size, mobility, and life history, and are further grouped into concepts such as microfauna, mesofauna, and macrofauna.

The composition of a region's fauna is shaped by geographic barriers, climate, habitat diversity, and evolutionary history. Island systems often harbor distinctive faunas with high endemism. Fossil faunas shed light on extinct lineages and past ecosystems, informing biogeography and climate research. Data on faunas are collected through field surveys, specimen collections, and biodiversity databases and inventories.

Fauna plays a central role in ecosystem processes, including pollination, seed dispersal, predation, decomposition, and nutrient cycling. Human activity affects fauna through habitat destruction, climate change, hunting and fishing, pollution, and the introduction of invasive species. Conservation aims to protect faunal diversity through protected areas, legal frameworks, habitat restoration, and, where needed, captive breeding or reintroduction programs.

Examples of faunal assemblages illustrate regional diversity, such as the diverse mammals and birds of temperate and tropical ecosystems, or island faunas with unique evolutionary lineages.