The danger of invasive species
Invasive species are one of the main causes of biodiversity loss on the planet. These animals come from different countries or continents, and are accidentally, intentionally or artificially introduced into ecosystems. Over time, they end up displacing or extinguishing the native species.
The Spanish catalog of invaders is currently made up of 205 species, including fungi, algae, flora, non-arthropod invertebrates, non-crustacean arthropods, crustaceans, fish, amphibians, reptiles, birds and mammals.
Why are they a threat?
This type of specimen can cause serious damage to biodiversity due to its way of acting in the territories that are introduced. In this way, many native species are in danger of extinction, since they cannot compete with the invasive ones as they have not grown together with them. In addition, according to the World Wide Fund for Nature, this problem represents an investment of 12,500 million euros per year for the European Union.
One of the main threats attributed to them is their performance as predators, habitat alteration, hybridization with native species, and introduction of new parasites and diseases.
How to control invasive species
You must inform yourself before acquiring an animal, since many of them need different care than you can imagine, grow more than necessary or have an origin that is detrimental to our biodiversity.
Do not abandon animals, and even less, in natural spaces, it is really a big problem for ecosystems. A clear example is the Florida turtle, when people get tired of it or it has grown too big, they release it into reservoirs or rivers. This species has adapted very well to our biodiversity, it eats the food of the native breeds or the eggs and tadpoles.
Do not acquire foreign species, if you go on a trip do not bring souvenir plants, seeds or animals. The Pampas feather duster is one of those invasive plants that reproduces at an unusual speed and over long distances. It was common to find it adorning the highways and it has ended up becoming a real plague. It displaces native species and decreases the quality of pastures for cattle, in addition to increasing allergies in humans and increasing the risk of fire wherever it is found.
Five invasive species in Spain
The zebra mussel was detected in the Iberian Peninsula in 2001, specifically in the Lower Ebro, and is considered one of the most harmful pests worldwide. It is a bivalve native to the Caspian and Black Sea, very similar to the marine mussel, but with black and white stripes that give it its name.
It has a great capacity for reproduction and dispersion and adapts very well to all kinds of situations, this makes it very difficult to control. It creates colonies of great densities, causing serious economic and ecological damage. It clogs pipes and water passage networks and causes damage to boats when it enters their pipes. Ecologically speaking, it displaces communities of fish and other bivalves, impoverishes the river system, and competes for phytoplankton.
It all started in the early 2000s in Madrid, some residents of Rivas Vaciamadrid decided to import specimens from North America to try to domesticate them and acquire them as pets. This went wrong, we do not know if due to abandonment or escape of the animal, since its tracks were found in the Southeast Regional Park of Madrid. In 2018, only in the Community, 814 specimens were captured and since they do not have direct predators, they can cause irreparable damage to ecosystems. In fact, that is what they have been doing for years in those places where they are beginning to expand, such as Madrid, Castilla La Mancha, Galicia, the Valencian Community, the Basque Country, Andalusia (near Doñana) and even in Mallorca, on the islands Balearics.
Raccoons can transmit rabies, distemper, toxoplasmosis, or tuberculosis to people, livestock, and pets. They also have a very aggressive character and are nocturnal, a fact that complicates their population control. It is capable of displacing, consuming and, in some cases, compromising the conservation of numerous taxonomic groups. Despite being omnivorous, it is considered a potential hunter of small and medium-sized mammals and birds and a nest predator, which is why it has a significant impact on many species, including hunting ones, such as the red partridge.
It is a clear example that animal abandonment can cause great havoc, since the Argentine parrot has proliferated thanks to its release. Spain, due to its climatic conditions, is a propitious and favorable place for its reproduction. Only in the country there are more than 20,000 specimens, about 85% of the population of Argentine parrots in Europe.
It is a bird that especially damages crops of pears, quinces, tomatoes and vegetable species in gardens or home gardens, such as fig trees or strawberries. Exotic species, such as the Argentine parrot, become a lurking danger for the local flora and fauna. They consume the same resources as native animals, considerably reducing the existence of other birds due to lack of food or changes in their habitat. An Argentine parrot nest can weigh up to 200 kilos, the danger of one of them detaching and falling is too serious not to act. The health authorities assure that the nests and droppings of the Argentine Parrot are a risk to general health and environmental hygiene.
The catfish is a species introduced by humans, which has been made with the Spanish river network. It was released in the Mequinenza reservoir in 1974, by a German biologist, who cleared customs with 32 fingerlings of this species without problems, justifying that they were to be used as bait to fish for pike. It is true that the catfish has managed to attract thousands of people each year in search of its fishing, since specimens weighing more than 100 kilos have been caught, which are very attractive to fishermen from all over the world.
Despite the economic value, the invasive species in the Ebro river basin, such as the American crab, have managed to displace the native ones. This has been to such an extent that it is difficult to find barbels and madrillas, but it is easy to see American carp or catfish.
The corn snake is an invasive exotic species that is traded as a companion animal; in fact, it is the most popular colubrid acquired as a pet worldwide. It can also be accidentally introduced into containers coming mainly from America (where it originates from). It is called the corn snake because of the pattern that is drawn on the part of the belly that is reminiscent of that of an ancestral ear of corn. It is a solitary snake and does not live in holes but on the plain and the fields.
It is a great threat to small mammals, insects, birds or small reptiles, which are the basis of its diet. It is also a carrier of numerous pests that can affect the native fauna.
If you like this blog and want to know more about hunting and conservation, I invite you to read this blog about 5 types of hunting that you may not have known about at the following link: https://www.youngwildhunters.com/blogs/noticias/cinco- modalities-of-hunting-that-perhaps-you-didn't-know
Author: María Balletbó