For as long as there has been life on earth, there have been new species arising and others disappearing. A handful of times, the rate of disappearances has temporarily skyrocketed during what scientists call mass extinction events. Scientists say we’re in the midst of the planet’s sixth such event – this one of our own making.
Note: A longer version of this interview originally aired on August 17, 2015.
With animals going extinct at one thousand times the natural rate, it can be easy to lose track of any individual species. Understandably, most attention gets focused on species that are either lovable or critically important to human survival, like the bees that pollinate most of our food plants.
So, here are three extinction crises you’ve probably never heard of.
Mollusks, like snails, clams, and mussels, are going extinct at an even faster pace than the global average.
“In terms of the continental United States, by far the greatest extinction spasm we’ve had is of freshwater mussels in the southeast,” says Kieran Suckling, executive director of the Center for Biological Diversity.
The top culprits in the loss of mussels are water pollution, and damming and other development of waterways. Generally speaking, habitat loss and invasive species are the leading causes of extinction.
Islands, in general, are more susceptible to both. There’s nowhere else to go, if habitat is destroyed. And many island species have evolved in the absence of predators. The American boring beetle faces a different threat.
“It competes, oddly, with coyotes,” says Suckling. “The coyotes like to eat small mammals and medium-sized birds, like pigeons. And that’s exactly what a burying beetle seeks out.”
The endangered red and black beetle eats and nests in dead birds and mammals. As humans killed off larger predators, like bears, coyote populations soared, and burying beetles were starved out.
The last natural population east of the Mississippi River is on Block Island. Burying beetles have been reintroduced to Nantucket, but there doesn’t appear to be enough food to support them. They’re currently being supported by “quail hand-outs” from a project of the Maria Mitchell Association.
Last, but certainly not least, are the lowly bacteria and other microbes. They produce half the air we breathe, digest our food, provide antibiotics, and so much more. Suckling says they’re almost certainly impacted by human activities, but we don’t have any good information on extinction rates.
“We know so little about the microbial world that they’re not even counted in the surveys, and they’re incredibly important,” says Suckling. “We don’t have a clue.”