Vanishing rhinos, elephants and polar bears get a lot of press, but researchers warn that disappearing invertebrates like land snails reveal the extent to which the sixth mass extinction is underway. Nigel Stork from Griffith University in Australia estimates we are losing approximately 100 species a day as a result of habitat disruption, climate change, poaching and other human-influenced factors. New Scientist claims the evidence to support this is ‘thin’ since only 800 out of 1.9 million known species have been recorded as extinct – but Claire Régnier from the National Museum of Natural History in Paris says this is because few researchers are paying attention to invertebrates.
Invertebrates account for 99 percent of species diversity, according to New Scientist, so if we want to have a solid understanding of how quickly species are disappearing, we need to pay attention to them. Turns out that few scientists are counting ‘the little guys,’ which makes it difficult to understand how many species we’ve lost over the last few decades. One exception, however, is the land snail.
Régnier and her team scoured existing databases, museum collections and expert assessments to determine the status of land snails, New Scientist reports. They found that roughly one tenth of 200 recorded species are most likely extinct. While many endemic snails live on islands, where extinction occurs more rapidly, the researchers adjusted these numbers as a barometer to estimate total non-marine animal losses. They came up with 7 percent, or 130,000 recorded species that are now extinct.
This may not seem like an exact science, but other researchers believe the study is catalyzing a worthwhile discussion.
“This is an important paper,” Julian Caley of the Australian Institute of Marine Sciences in Townsville, Queensland told New Scientist. “It suggests that other invertebrate taxa are likely to have been experiencing extinction on higher levels than we know about.”
Ben Collen of University College London told the paper a similar approach may be useful for studying similarly unexplored invertebrate species as well.
Via New Scientist