Imperialism, Globalisation and the Spread of Invasive Species

In a famous speech at Oxford in 2015, Shashi Tharoor expressed how Britain owed India reparations due to the exploitation of their colonial past. He spoke of how they plundered India’s resources, causing economic downfall, famines, and several other disasters whose repercussions are still felt today.

But he seemed to have left out one point. 

There is another colonial relic that the British gave India, which rests neither in museums nor history textbooks. Instead, it endures in the countryside, hidden in plain sight. It lives in the invasive shrubs that Britishers brought as ornamental plants when they took over this vast land.

What are Invasive Species?

To answer this, we must look at what a stable ecosystem looks like.

Evolution occurs when nature weeds out organisms that are too weak. The best live on and reproduce, passing on traits that aid survival. Over time, these characteristics add up, and a species evolves.

Within an ecosystem, species evolve in conjunction. So when prey animals become harder to catch, predators evolve and become better hunters. It is a never-ending cycle of one group trying to outdo another via natural selection. Since these evolutionary processes occur under the same environmental conditions, each organism’s population remains balanced. You never find an overabundance of prey or predator—they eventually even each other out.

Photo by Hung Tran on

When the British ruled over India, several foreigners brought decorative shrubs to grace their new homes. Plants like Lantana, Eupatorium, Water Hyacinth, Japanese Honeysuckle, and even some species of eucalyptus entered India through the British. They have taken over the landscape, starving native vegetation of nutrients and menacing local wildlife.

The Spread of Invasive Species

Invasive species have circulated around the globe primarily due to human activities. Some of these actions have been accidental, some intentional, and all have had devastating consequences.

Take rabbits in New Zealand. European settlers took them there so that they could hunt them. But soon, rabbits wrecked the ecosystem, eating up all the vegetation. Attempting to tackle this, ferrets were introduced, which further added insult to injury. These tiny carnivores ignored the rabbits and began eating native wildlife, like the now-endangered kakapo. 

Or consider the introduction of earthworms on the American continent. While done in the hope of improving crop yields, these annelids dispersed across the continent, changing coil composition and thus altering native vegetation. Scientists suspect that if left unchecked, America’s forests could turn into grasslands. 

Photo by Karolina Grabowska on

Some species seemed to have spread by accident, like the zebra mussels in America’s great lakes. They came as larvae in the ballast tanks of ships from Europe. Ships take in seawater to control their buoyancy as it travels long distances. When it reaches its destination, it releases this water and the organisms in it. This is how zebra mussels took over American waters.

Now, countries spend billions of dollars in controlling the spread of invasive species. They try culling them, sterilising them, and even physically removing them. It is hard work because it’s like trying to fight a superorganism. Every organism must be incapacitated to ensure an invasive species is wiped out. Because if a few individuals survive, they can rebound. There is no way of getting rid of the biological advantage they had in the first place.

I have worked in this space. I was involved in the lantana removal project at Bandipur Tiger Reserve. Being one of India’s prime tiger habitats, it is disheartening to drive through and see nothing but lantana enveloping the forest. Cutting up this weed is back-breaking work, not to mention painful (their thorns are really sharp). If you are interested, you can read up about the project here.

Female Asian elephant. Shot in Wayanad Wildlife Sanctuary, Kerala, India by Ishan Shanavas
Female Asian elephant surrounded by Latana

Some scientists say that invasive species are an evil that we cannot escape. We must live with them and hope that nature can cope too. There is much debate about whether we need to focus on invasive species or not. 

The Threats with Globalisation

Invasive species were the reality of the colonial experience and are a terrifying threat to our globalised world. Now, it has never been easier for an organism to spread around the planet. 

Just consider the Covid-19 pandemic, for instance. A tiny viroid particle in a remote corner of China harnessed a bipedal primate’s (humans) weak immunity and spread around the globe. With flights and ships departing every second from every city in the world, just imagine what havoc one stray animal could cause.

Photo by CDC on

Learnings from this disaster

One lesson we need to learn is that any natural revival process must be done through a scientific lens. Flights and ships now have procedures that check for the presence of stray organisms. We cannot afford to have more invasive species take over ecosystems to which they don’t belong.

We must do most research into how invasive species take over new environments. This will better efforts to control their populations. Identifying the anatomical, biological, or environmental factors of an invasive species’ success is crucial in tackling the problem.

An Interesting Thought Experiment

I came across an interesting idea in an ASAP Science video about what could happen if all humans suddenly disappeared. I wondered, would nature take its course and, after millions of years, would organisms adapt to deal with invasive species? Let me know your thoughts by commenting or sending me an email.

So, returning to Shashi Tharoor and his species, I pose another question. Do colonist nations owe reparations for the ecological damage they have caused by spreading invasive species?

(I must mention that this article is not intended to point fingers and shame the British or other colonist nations. I am just intent on shining more light on the subject and instigating more conversations around it)

PS. A related series of facts:

  • In Florida, Burmese pythons have taken over the local ecosystem, eating up alligators, deer and so on. Scientists speculate that they entered the peninsular state as pets, which owners carelessly released into the surrounding wilderness. Local organisations consulted the help of the Irula people, a tribe from Tamil Nadu, India, who are expert snake trackers. (More about them here)
  • Lionfish are plaguing the local waters in Miami, USA. So divers have taken it upon themselves to try to deal with the problem. They regularly spearfish on their dives in an attempt to curb their population (More about them here)

More resources

The threat of invasive species – Jennifer Klos

Invasion of the Yellow Crazy Ants!

Invasion Of The Earthworms!


Invasive Species 101 | National Geographic

Divers Fight the Invasive Lionfish | National Geographic

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Published by Ishan Shanavas

I am a young adult, interested in nature, photography, art and culture. An aspiring polymath, I share my learnings through my blog. I also include insights from my favourite books.

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