Koalas were listed as endangered for the first time in Australian history.
A 57-year-old man received the first transplanted heart from a genetically modified pig.
Thousands of pigeons went missing after a freak weather incident.
The state of California became the first to ban fur products.
The UN reported that one million plant and animal species were at risk of extinction.
The World Economic Forum announced that there will be more plastic than fish in our oceans by as early as 2050.
A newly discovered water beetle was named after Leonardo DiCaprio.
Researchers identified the earliest known prehistoric ancestor of humans.
In San Diego, California, SeaWorld announced that it would phase out its orca shows following protests.
The Pyrenean ibex went extinct after the last surviving member of the species was killed by a falling branch.
The first cloned animal from an adult animal cell was announced.
The first killer whale calf was born in captivity at Marineland in Los Angeles, California.
President Richard Nixon signed the US Endangered Species Act into law.
A military dog 'Nemo' saved the life of his handler, Airman Robert A. Throneburg, during the Vietnam War.
The red robin was officially named Britain's National Bird.
Sputnik 2 soviet spacecraft burned up, returning through Earth's atmosphere.
The Soviet Union sent a dog into space aboard the spacecraft Sputnik II.
The famous elephant called Topsy was executed at Luna Park, Coney Island, in New York.
Julius Wolff supplied the first canned sardines from Maine, USA.
The Philadelphia Zoo opened. At the time, it was the only zoo in the 'New World.'
The Lake Merritt Wild Duck Refuge became the first US wildlife sanctuary.
The First Zoological Society in the US was formed in Philadelphia.
The United States received its first elephant.
The first polar bear in America was exhibited in Boston.
The United States exhibited the country's first-ever lion in Boston.
The first documented blood transfusion took place using sheep blood in a teenage boy.
Christopher Columbus sighted manatees for the first time ever.
