Reasons and the Future

First of all, thank you for reading my blog. I've enjoyed searching and reading through the possibilities and challenges ahead of the current ecosystem. My blog began with exploring previous extinction events and whether the 'Sixth Extinction' would happen. Currently, after all the fruitful readings on these topics, I would say humans have contributed greatly to the likelihood of the 'Sixth Extinction'. And this extinction would not be an abrupt event. Arguably, it would be gradual..

Previous mass extinctions gave us some insights into what might possibly be the underlying reasons to currently endangered or recently extinct species. Methane and climate threats are among those that are our current threats. But along the causes of climate change, I recognised that those related to humans are most influential in pushing towards the edge of a mass extinction event.  Their actions alter habitats and introduce invasive species. Specifically, hunting and poaching have been extremely destructive to animals, insects and marine species. Many species are threatened as a result of human practices.

Little egret

Climate change, as one of the hottest topics now in the world, is potentially the biggest concern to endangered species. The Little egret has now moved to Britain, where it was previously too cold for the species. The relocation of species has occurred two to three times faster than it was expected due to global warming. There are also campaigns raising awareness of the effects of global warming on species such as the donation to the survival of America Pika through National Wildlife Federation. As one can see in my earlier blogs, threats include non-human factors and therefore it is incorrect to direct the blame solely on human activities. However, the ever-increasing intensity of human activities is the key driver towards the possibility of the 'Sixth Extinction.' 

But in this last blog, I would like to share some alternative perspectives I came across that I found interesting. Perhaps extinction is just a process of evolution and therefore is inevitable? Just like mass extinctions in the past, current extinction of species might be part of the natural cycle on Earth. When humans are added to the equation, species that extinct are the ones which fail to negotiate with the changing environment. In other words, they are part of the evolutionary loss. Further, humans are not necessary a destructive force. Bringing about new species can be seen as increasing biodiversity overall (perhaps not locally..). 

Undoubtedly, there are still uncertainties about future extinctions. We see evidence of some species disappearing from the planet, but there is certainly not a mass extinction yet. I just hope to see greater effort in protecting endangered species, thereby minimising the amount of species reaching the edge of extinction.

Down to the Route of Extinction..

Towards the end of the blog, I would just like to mention some animals that are presumably extinct and perhaps critically endangered in the last decade.. 

Apart from Yangtze River dolphin that I previously mentioned, there are many other precious species slipped past us in the past decade. 

Mother Nature Network summarised 10 of them, some might sound familiar: 

Spix's macaws - Last known bird in the wild disappeared in 2000 due to hunting and trapping, destruction and the introduction of Africanized bees

West African black rhinoceros - Only around 10 rhinos left in 2000 due to poaching 

Golden toad - Species declared extinct in August 2007, airborne pollution and global warming are the main cause of extinction 

Apart from the Mother Nature Network, the powerful magazine TIME (click the link for the photos!) also identified 10 species near extinction..  

Bear in mind that, these just constitute the tip of the iceberg of endangered/extinct species.

As we can see, our development has led to the verge of extinction of many species. Ironically, humans have at the same time, attempted to preserve endangered species in different ways. Some of these methods are odd to say the least - spraying perfumes to spice up love lives of Sumatran tigers, cloning extinct species like Pyrenean ibex and freezing DNA of endangered species. Yet, it is still uncertain, almost unlikely, that these human efforts are sufficient to prevent the Sixth Extinction if it is approaching..

Relative Importance of Human Actions?

After several posts on how different human activities can alter both the environment and the ecosystem, I was just thinking which of those is/are relatively important. Today, endangered species have caught greater attention from conservationists, who often blame humans for it (Well, it is quite reasonable). Mace and Lande argued that habitat loss constitutes the most immediate threat. In fact, they even argued that hunting of species might not be a pressing problem, if the population did not experience fragmentation.

Summary of biodiversity and threat data in Asia and Australia. Shaded
and italicised countries were identified as global and continental areas
of critical concern respectively.

In many countries, deforestation is one of the requirements for urban development. Habitat loss is strongly correlated to rapid forest destruction and increasing pressure form human population. As shown on the left, a large proportion (14%) of countries were areas of critical concern in Australia-Asia. China, India, Philippines, Sri Lanka, Taiwan and Thailand were all among the top 20 countries of forest loss. At the same time, they were also countries that experienced high population pressure. For instance, Philippines ranked fifth for both forest loss and population pressure. In addition, human population pressure also poses threat on species richness. 

The relationship between biodiversity and the threat of habitat loss, as represented by indices developed for 135 continental and large island nations. Shaded regions represent areas of critical concern. 

Yangtze River dolphin

Of course, human population pressure does not only result in the form of habitat loss. Previously, I mentioned that the construction of dams and habitat alterations have affected freshwater species in my blog post Humans, Freshwater, Species. But they are not the main threats to Yangtze River dolphin in China. It was estimated that the species declined from 400 in 1979-1981 to only 13 of them during 1997-1999. By 2006, there was no evidence found on the survival of the dolphins. Unsustainable fishing of local fishers greatly increased by-catch. For example, the use of rolling hooks and nets and other fishing practices were considered to be the major extinction drivers. Again, human population pressure has increased the pressure on extinction through higher demand for local fisheries. Fishermen are anxious to catch more fish with different methods, some of which may involve ill practices. As the result, Yangtze River dolphin has become one of the victims.

It is difficult to decide what the dominant factor behind extinction is given the many facets of human activity. More importantly, it is even harder to discuss all the human practices that lead to the edge of extinction. So all I can do is to explore as many risks behind the Sixth Extinction as possible. Is it or is it not happening? If human population pressure is one of the key extinction drivers, I can foresee a bleak future for currently endangered species. Population will only continue to rise, especially how China, the country with the highest population on Earth, has just relaxed its one-child policy. Perhaps, the resolutions of NGOs and governments will now be to conserve endangered species by tackling the misbehaviours of humans instead (Carbon emission, forest destruction.. and more).