Surplus killing seems to occur when prey are vulnerable and easy to catch - in winter, for instance, when there is deep snow.

“有剩余的捕杀”只是发生在那些在冬季很容易捕食的小动物身上。

youdao

Killing mechanism: volcanic winter.

杀伤机制：火山冬季。

youdao

In rough winter seas, a smuggler's speedboat broke apart, killing 14 people.

CNN: Smuggling of Cubans into U.S. reported on rise

One of those arrested, a Yemeni who has not been named, is suspected of having been part of the three-man execution squad responsible for killing the Wall Street Journal reporter, Daniel Pearl, last winter.

ECONOMIST: A breakthrough