Coincidentally, I just did a partial count of world human population and came up with "2"

The Associated Press: Partial walrus estimate alarms conservation group

ANCHORAGE, Alaska (AP) — A partial federal assessment of Pacific walruses estimates their minimum population at just 15,164 but says the count likely missed a number of animals.

The estimate released Thursday only represents animals counted in about half of walrus habitats in the Bering and Chukchi seas and does not account for animals that were in water rather than on ice.
...
Wildlife biologist Doug Burn said agency officials had hoped to have a firm walrus population count by now but experienced problems with the thermal imaging methodology.

A method that counts walruses using body heat was tested near St. Lawrence Island during a relatively warm winter but did not prove reliable during a colder winter in 2006, Burn said.

"We realized we were missing a lot of walrus groups," he said.

Dec '07: National Geographic says lots of walruses still around

...The loss of 4,000 or more Pacific walruses is not a major blow to its population, wildlife service experts say.

While scientists lack a firm population estimate for the species, researchers have encountered herds as large as 100,000 in recent years, Woods said.