The range and variety of plants and animals in the ecosystem we are part of is estimated to be the most diverse since life began about 3.5 billion year ago. Unfortunately, instead of celebrating and preserving this amazing world, we appear to be doing our level best to destroy the complex inter-dependent ecosystem we call home.
Since 1500, over 320 terrestrial vertebrates have disappeared and populations of the remainder show, on average, a 25% decline in abundance. The situation is just as bad for invertebrates and an international team of scientists believe we may be at the start of the planet’s 6th mass biological extinction event.
Unlike all previous extinctions – this one will have our sticky fingers all over it.
Mega-fauna, such as elephants, rhinos and polar bears, face the highest rates of decline and this trend repeats the process seen in previous extinction events. These creatures may only be a small percentage of the animals at risk but their loss could have trickle-down effects on other species, shaking their stability and tipping them over the edge into irreversible decline.
Experiments have shown that removing mega-fauna from an ecosystem leaves the area vulnerable to a population explosion of rodents as seeds and shelter become more available and the risk of predation drops. Rodents are carriers of ectoparasites which can then more easily spread into the wider ecosystem.
Rodents are a classic associate of humans – where there are people, there will be rodents, taking advantage of our food stores and wasteful habits. Our population has doubled over the last 35 years and in the same period the number of invertebrates – such as beetles, butterflies and worms – has fallen by an estimated 45%.
Do we want this planet, with all its astonishing diversity or one inhabited by little except rodents and scavenging invertebrates like cockroaches?