There is a large body of literature that examines the impact of human activity on biodiversity and climate change, but it is rarely considered that wildlife could be one of the most vulnerable species.
In a new study, researchers from the University of Cambridge have identified what species are most threatened by humans.
The study, published in the journal Nature Communications, found that the population of species with high populations of human-associated impacts is a relatively new phenomenon.
The authors say that this makes it difficult to quantify the impacts of these species.
“This is a new phenomenon in the field of wildlife management and is not expected to become a regular feature of future assessments of biodiversity,” said Professor David Sorensen, one of co-authors.
“It is very difficult to track the number of species impacted by human activities across the globe.
It is quite surprising that the number is so large, and the impact is so extreme.”
While the species most threatened were listed in the ‘Endangered’ and ‘Vulnerable’ sections of the International Union for Conservation of Nature’s Red List of Threatened Species, the number was considerably lower than the previous record of more than 5,000 species.
The authors say they were particularly concerned about the decline in the number and distribution of certain species, which they say may reflect a change in the nature of habitat use.
The new findings are based on analysis of data from the International Fund for Animal Welfare (IFAW) and the Zoological Society of London.
They found that, on average, there were around 100,000 known threatened species globally, of which nearly 10,000 were threatened.
These include birds, bats, reptiles, amphibians and mammals.
The majority of species are listed under the ‘Vulnerability’ or ‘Endangerment’ sections, meaning that they are considered to be ‘very’ or very seriously endangered.
In the past, the most threatened species were those that were at high risk of extinction, such as bats and the threatened coral reef turtle.
But, as the researchers point out, that changed dramatically after humans began their expansion into Asia in the early 20th century.
“We now have a much more sophisticated understanding of the effects of human activities on species and they have become less important in the analysis of threatened species,” Professor Sorenson said.
“The most important change in our knowledge of threats is that the most important species are now the ones that have become most vulnerable.”
The study looked at the number, distribution and abundance of a large number of animal species, including mammals, birds, reptiles and amphibians, as well as amphibians.
The researchers found that while the number fell dramatically over the past 20 years, the population density of these animals increased significantly.
“These species, and their close relatives, have been affected by a combination of human expansion, land use changes, industrial development, agricultural development, invasive species and habitat loss,” said the authors.
“They have also been affected in a way that is not readily apparent, as there has been very little information on impacts of human impacts on their habitat.”
The authors suggest that there are several possible reasons for this trend.
“There is the assumption that the impact from land use and agricultural expansion has been minimal or that the impacts on biodiversity have been small, and thus have not yet been considered,” said Prof Sorenesen.
“In reality, these effects are often very large, because of habitat fragmentation, pollution and human activities such as hunting and poaching.”
For example, there are a large variety of land uses in Indonesia that are now under pressure due to human activities, including urban development, logging, and over-grazing.
While these factors may be the cause, there is also the possibility that they could also have an indirect effect.
“Some of the impacts may be because of the activities of a few individual people, and other factors are the result of human action,” Professor Houghton said.
For example there may be an increase in agricultural productivity in areas where people have been encroaching on the land.
“If you look at how the rate of deforestation has been increasing over the last few decades, that is partly because of this over-harvesting of biodiversity, and partly because the deforestation is a result of agriculture,” he added.
“People are also doing things such as increasing the size of farms and the number that they have.
This leads to an increase of animals being killed, which is bad for biodiversity.”
There is also evidence that increased logging and farming can have a negative impact on wildlife.
“What we have seen in the past few decades is an increase and increase in habitat loss in areas of the world where human activities have been increasing,” Prof Sorys said.
While the authors say their findings provide insight into the impact humans have on wildlife, they do not make a judgement about whether or not humans should be banned altogether.
“I think that the scientific literature does show that this impacts