What is a native species?

A native species, also called autochthonous either indigenousis defined as a species that lives in a certain area naturally, that is, that their presence in that area is not due to human intervention, either direct or indirect. This definition does not exclude species that are found in different regions, even separated from each other, as long as they have been established in that region naturally, which differentiates it from an endemic species.

Over time, the native species that share an ecosystem evolve until they are perfectly adapted to each other and to the environment. Even subspecies adapted to small variations in similar habitats develop, which sometimes continue to evolve to give rise to new species.

Habitats and ecosystems with little interaction with other areas tend to have large numbers of native species and large numbers of endemic species. For example, it is common for numerous native plant and animal species to be found on islands that have evolved for a long time in an isolated environment, much more so the further away the island is from the mainland or from other islands. Species native to these isolated habitats are often more vulnerable to small changes in the environment as well as to the introduction of foreign species.

The expansion of native species

Native species may have evolved in a given habitat or may have been brought there by natural processes and events. This means that if the expansion of one species to colonize other areas occurs through natural phenomena, it is still considered a native species of the new colonized area. For example, the wind and animals transport plant seeds, which means that some plant species are native to a very large territory or can be found in distant regions.

Another example is animals that naturally expand their habitat as the population grows and need to search for new territories where they can find enough food. Many native animal species perform seasonal migrations and some of them travel long distances, especially birds and some insects.

Therefore, the ecosystem and geographical area of ​​distribution of a native species is not something static but changes over time. Evolutionary changes and environmental changes are the most influential factors that shape the region where a certain species lives. According to adaptive capacity and mobilityeach species colonizes different habitats and is distributed more or less widely.

The protection of native species

Native species are subject to numerous attacks on their survival, most as a result of human activity. Many biologists assure that we are at the gates of a human-caused mass extinction of species, the so-called Holocene mass extinction. The rate of extinction began to accelerate from the beginning of the 19th century and accelerated considerably from the 1950s. It is estimated that the current rate of extinction is 100 to 1,000 times higher than the natural average rate.

Currently the destruction of natural habitats continues to be one of the main reasons for the extinction of species and one of the main causes is deforestation, especially due to continuous increase of land dedicated to extensive agriculture. The International Union for Conservation of Nature (IUCN) estimates that 7 out of 10 plant species, 1 out of 4 mammals, 1 out of 3 amphibians and 1 out of 8 birds are endangered.

Recognition of the importance of native species and their ecosystems has led to the creation of organizations that promote the protection of native species. At the international level, the aforementioned IUCN, the World Wide Fund for Nature (WWF) and non-governmental organizations such as Green Peace stand out.

native vs endemic

By definition, an endemic species inhabits a limited and generally small geographic region and it is not found naturally in any other region of the planet. Therefore, an endemic species is a native species but a native species does not have to be an endemic species since a native species can be found naturally in different regions and can colonize large geographical areas.

Example: Marine iguana (Amblyrhynchus cristatus) is an endemic species of the Galapagos Islands.

Native vs Introduced

Unlike native species, introduced species, also called exotic species, are those that live in a certain habitat due to human intervention, either intentionally or accidentally. Introduced species often have a negative effect on native species by acting as an unbalancing element in the natural ecosystem, competing for space and resources. When an introduced species poses a threat to biodiversity, we speak of Invasive species.

Example: Gambusia affinis It is a freshwater fish native to the eastern and southern United States. Has been intentionally introduced into freshwater streams around the world as a method of mosquito control but it is a voracious predator that also feeds on other insects and invertebrates as well as the eggs of other fish and amphibians, posing a threat to many native species.

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