e and tame.

    tion t arises is  times are in effect part of a single extinction event— we may well be.

    According to ty of Cologist David Raup, te ofextinction on Eart biological ory  every four yearson average. According to one recent calculation, inction no level.

    In tralian naturalist tim Flannery, noruck by tle o kno manyextinctions, including relatively recent ones. “o be gapsin t recorded at all,” old me w him in Melbourne a year or so ago.

    Flannery recruited er Scen, an artist and felloralian, and togetly obsessive quest to scour tions to find out, , and  four yearspicking ty specimens, old draten descriptions—ings of every animal te, and Flannery e t raordinary bookcalled A Gap in Nature, constituting t complete—and, it must be said, moving—catalog of animal extinctions from t three hundred years.

    For some animals, records  nobody imes for years, sometimes forever. Steller’s sea coure related tot really big animals to go extinct. It ruly enormous—anadult could reacy feet and ons—but ed  only because in 1741 a Russian expedition o be sures still survived in any numbers, te and foggy Commander Islandsin the Bering Sea.

    ion uralist, Georg Steller, he animal.

    “ook t copious notes,” says Flannery. “er of itsals—to do ts texture. e  always so lucky.”

    teller couldn’t do self. Already ed to tinction, it ogety-seven years of Steller’s discovery ofit. Many ot be included because too little is kno them.

    tless crake,at l