Human activities in Asia have reduced elephant habitat by nearly two-thirds since 1700
Despite their iconic status and long association with humans, Asian elephants are one of the most endangered large mammals, Down to Earth reported.Believed to number between 45,000 and 50,000 individuals worldwide, they are at risk throughout Asia due to human activities, such as deforestation, mining, dam building and road construction, which have damaged numerous ecosystems.
My colleagues and I wanted to know when human actions started to fragment wildlife habitats and populations to the degree seen today. We quantified these impacts by considering them through the needs of this species.
In a newly published study, we examined the centuries-long history of Asian landscapes that once were suitable elephant habitat and often were managed by local communities, prior to the colonial era.In our view, understanding this history and restoring some of these relationships may be the key to living with elephants, and other large wild animals, in the future.
How have humans affected wildlife?
It isn’t easy to measure human impacts on wildlife across a region as large and diverse as Asia and more than a century ago. Historical data for many species is sparse. Museums, for instance, only contain specimens collected from certain locations.
Many animals also have very specific ecological requirements, and there often isn’t sufficient data on these features, at a fine scale, going far into the past. For instance, a species might prefer particular microclimates or vegetation types that occur only at particular elevations.
For nearly two decades, I’ve been studying Asian elephants. As a species, these animals are breathtakingly adaptable: They can live in seasonally dry forests, grasslands or the densest of rain forests.
If we could match the habitat requirements of elephants to data sets showing how these habitats changed over time, we knew that we could understand how land-use changes have affected elephants and other wildlife in these environments.
Dramatic declines
Land-use patterns changed significantly on every continent, starting with the Industrial Revolution in the 1700s, and extending through the colonial era into the mid-20th century. Asia was no exception.
For most areas, we found that suitable elephant habitat took a steep dive around this time. We estimated that from 1700 through 2015 the total amount of suitable habitat decreased by 64 percent.
More than 1.2 million square miles (three million square kilometers) of land were converted for plantations, industry and urban development. With respect to potential elephant habitat, most of the change occurred in India and China, each of which saw conversion in more than 80 percent of these landscapes.
In other areas of Southeast Asia — such as a large hot spot of elephant habitat in central Thailand, which was never colonized — habitat loss happened more recently, in the mid-20th century. This timing corresponds to logging concurrent with the so-called Green Revolution, which introduced industrial agriculture to many parts of the world.
Could the past be the key to the future?
Looking back at land-use change over centuries makes it clear just how drastically human actions have reduced habitat for Asian elephants. The losses that we measured greatly exceed estimates of “catastrophic” human impacts on so-called wilderness or forests within recent decades.
Our analysis shows that if you were an elephant in the 1700s, you might have been able to range across 40 per cent of the available habitat in Asia with no problem, because it was one large, contiguous area that contained many ecosystems where you could live. This enabled gene flow among many elephant populations. But by 2015, human activities had so drastically fragmented the total suitable area for elephants that the largest patch of good habitat represented less than 7 per cent of it.
Sri Lanka and peninsular Malaysia have a disproportionately high share of Asia’s wild elephant population, relative to available elephant habitat area. Thailand and Myanmar have smaller populations relative to area. Interestingly, the latter are countries known for their large captive or semi-captive elephant populations.
Less than half of the areas that contain wild elephants today have adequate habitat for them. Elephants’ resulting use of increasingly human-dominated landscapes leads to confrontations that are harmful for both elephants and people.
However, this long view of history reminds us that protected areas alone are not the answer, since they simply cannot be large enough to support elephant populations. Indeed, human societies have shaped these very landscapes for millennia.
Today there is a pressing challenge to balance human subsistence and livelihood requirements with the needs of wildlife. Restoring traditional forms of land management and local stewardship of these landscapes can be an essential part of protecting and recovering ecosystems that serve both people and wildlife in the future.The Conversation. Down to Earth
