Evidence from fossil records has suggested that a sixth mass extinction is underway due to a large number of species disappearing within a relatively short period of time.
Although extinction is a natural process which scientists suggests effects up to 98% of species., there is growing concern for the rate of modern extinction.
The dramatic increase in extinction rate due to human activities such as hunting, trade, development and pollution is 100-1000 times higher than the natural background rate and does not give ecosystems enough time to recover their populations, causing many species to be listed as endangered under the IUCN Red List of Threatened Species.
But are some species more prone to extinction than others?
New research published in the Proceedings of the National Academy of Sciences  which compared more than 27 000 vertebrates and analysed the relationship between body size and extinction risk found that of the 4000 species threatened with extinction both the heaviest and the smallest vertebrates had the highest risk of extinction, but for different reasons.
Larger animals such as elephants, lions, tigers and rhinos have low populations due to human activity such as hunting, trade, medicine and fishing, while smaller animal populations are often effected by pollution, farming, habitat degradation and development.
Most efforts to protect endangered species often focuses upon larger animals, while smaller animals are often neglected. Although different approaches are needed to conserve smaller and larger animals, there needs to be a step up to help protect smaller species and increase awareness.