Because Earth’s current extinction rate is 1,000 times the normal background rate, scientists believe we’re at the start of the sixth mass extinction.

What does extinction look like?   I visited a large display case at Carnegie Museum’s Bird Hall to find out.

In the case of extinct birds, each species has a story. The reason for extinction is often well known but the exact date of disappearance is usually obscure, though there are exceptions.

Take, for instance, the passenger pigeon (Ectopistes migratorius) shown above.  Native to eastern North America, we would have seen passenger pigeons in Pennsylvania if we’d lived 200 years ago but relentless uncontrolled hunting wiped out their population until it crashed.  The last passenger pigeon died in captivity on 1 September 1914 in the Cincinnati Zoo.  Extinction was caused by humans because we liked to eat them.

The Guadalupe storm-petrel (Oceanodroma macrodactyla) disappeared more quietly. Always hard to distinguish from its close relative, Leach’s storm-petrel, this bird nested only on Guadalupe Island off the coast of Mexico’s Baja California. Cats were introduced there in the late 19th century and by 1912 no storm-petrels could be found. According to Wikipedia, “Only old, abandoned burrows and the decayed remains of storm petrels killed by cats were found in the years thereafter.”  Extinction was caused by cats introduced by humans.

The Laysan crake or Laysan rail (Porzana palmeri) couldn’t fly but that didn’t matter because he lived on the remote island of Laysan. Unfortunately his population crashed due to habitat loss when humans introduced rabbits to his island home. The final blow came in 1944 when rats jumped ship onto Laysan.  Extinction was forced by two human-introduced species: rabbits and rats.

There are many stories in the case of extinct birds.  Learn why they disappeared at Carnegie Museum‘s Bird Hall.

(photos by Kate St. John)