Beavers, Castor canadensis, are semi-aquatic rodents who build dams. They are also the national animal of Canada. Beavers occur naturally in North America, where they have predators, including wolves and coyotes. And also, rodents were heavily hunted for their fur, which caused their number to dwindle rapidly. To prevent this, there was a ban imposed on hunting these creatures. Their number grew back to normal, but the fur industry took a big hit. In 1948, there was a need to boost the fur industry. So ten pairs were brought to Argentina and set free in Lake Fagnano. From there, they spread along the Beagle Channel, and now, a voracious beaver colony has been established on the Brunswick Peninsula in Chile, South America. While the pelt project for spurring trade never really took off, the beavers did. Since they were protected from hunting for the last 35 years and there were also no natural predators in South America, they sprouted rapidly. And the results are disastrous.
Beavers are the keystone species in South America
There are two types of beavers, one is present in Eurasia, Castor fiber, and the second the Castor canadensis, which is in North America was introduced in Canada in the 1940s. Beavers have been roaming North America for over 7 million years, a period long enough for native flora and fauna to know their teeth. Willow can now resprout its stems successfully, and Cottonwoods produce distasteful tannins to deter chewing.
In South America, beavers act as the keystone species, an organism that sustains the entire ecosystem. And, the presence or absence of that particular species would dramatically alter the food webs and affect the ecosystem.
Florida has been grappling with invasive species like Burmese Pythons, which wreak havoc on native wildlife for decades. Silver Spring State Park in Florida, previously well-known for its pristine forests and wetlands with a spring-fed river flowing right through it & exotic native wildlife, is now home to over 1,000 rhesus macaques.
Native to south and southeast Asia, these monkeys are prolific breeders and consumers. They’re herbivores but also feed on small insects, invertebrates, and bird eggs. This diverse diet combined with occasional feeding by humans has helped them habituate and thrive outside their native range. “A recipe for trouble,” as anthropologist Erin Riley, studying human-animal interactions from San Diego State University, had described.
The Silver Spring primates aren’t as afraid of humans as other animals. Though they are skittish around people, their aggressive behavior led to the partial closure of two State parks in 2016 & 2017. A prime reason why a growing population could lead to the increased human-macaques interactions and conflicts.
A new study published in the journal Wildlife Management suggests that their population will double by 2022 unless controlled. This ballooning population is a threat to park management and visitors. This is because the macaques carry a rare and deadly form of Herpes virus, Herpes B virus. Though it is extremely rare for Herpes B to spread from a monkey to a human, it can be fatal when it does
California is home to the Californian tiger salamander, which has a scientific name Ambystoma californiense. It is an amphibian that has large round snouts and has small eyes with black iris. They are called tigers because of the yellow bars on their skin.
The males of species can be distinguished from the females by the presence of swollen cloacae during the mating season. An adult male of the species can be up to 8 inches, and females are smaller in size, and can be about 7 inches. They eat insects and larvae of other species.
Every month, several alien species are introduced in new ecosystems where they threaten biodiversity. Non-native, exotic species, be it a giant Hippopotamus or an amphibian Cane Toad, can wreak havoc on the environment, ecology, and economy in their new homes.
Alien species may alter habitats, predate on or compete with native fauna or be important vectors of diseases and parasites. The hardy, fast-growing creatures with few or no natural predators in the new home bully the native flora and fauna to the point of extinction. Several carnivore species like the American mink, raccoon, and raccoon dog were brought to Europe for their valuable fur or to become pets in the black market.
Though the raccoon dog (Nyctereutes procyonoides) resembles North American raccoons, it is the closest relative of the Canidae family’s true foxes. The stumpy grayish-black raccoon dog, indigenous to East Asia, has established itself in sub-tropical regions of Northern and Eastern Europe.
The cane toad, exotically known as Rhinella marina, is a large, non-native amphibian introduced into Australia in 1935. Native to South and Central America, Giant toads are viewed as invasive species in Florida and Australia. They are poisonous to animals that try to devour them.
Not every non-native species introduced in a new region is invasive. They are labeled as invasive only when they compete with native flora and fauna for resources and alter or damage the ecosystem. Cane toads are invasive as they outnumber the native fauna with their breeding and insatiable appetite.
Columbia is worth seeing for its golden, palm-fringed beaches, lofty, snow-covered mountains, dense tropical rainforests, and scenic lakes. However, wild hippos are now a sight for sore eyes in the Magdalena River of Columbia, thanks to notorious camel Pablo Escobar.
From Burmese Python in Florida to wild boars in Texas, European Starlings of the U.S to wild hippos of Colombia; invasive species have made whole ecosystems go haywire.
“An invasive species is a non-native organism that causes ecological or socio-economic damage in a new environment”.
These species muscle out native flora and fauna, competing for resources and territories and thus reducing biodiversity and altering habitats.
Of the invasive species introduced by humans, Columbian hippopotamuses (Hippopotamus amphibius) date back to their exporter, cocaine kingpin Pablo Escobar. Native to Sub-Saharan Africa, these third-largest land mammals are not only relocating native Colombian animals but also altering the water channels and water quality.