It happens countless times a day. A flower's bright color and the smell of sweet nectar (花蜜) attract a bee. The bee stops by for a quick taste and small grains of pollen (the powder produced by a flower) stick to its body. The bee then travels to another flower of the same type and leaves the pollen as it has another meal. This is an example of animal pollination (授粉) — a process extremely important to plant reproduction.
It's not only plants that depend on animal pollination — humans do, too. Worldwide, nearly a thousand plants that we grow for food, spices, clothing fibers, and medicine depend on it. If pollination suddenly stopped, we would have no apples, tomatoes, coffee, and many other goods.
This important process is carried out by more than 200,000 different animal species known as pollinators. Flies and beetles - the original pollinators - date back 130 million years to the first flowering plants. Birds, butterflies, and ants also do their part. Even nonflying mammals help out: monkeys tear open flowers with their hands, accidentally spreading pollen into the air and onto their fur.
Pollinators are therefore important, but they are also at risk. Climate change, habitat loss, and invasive predators (入侵捕食者) all threaten them. The United States, for example, has lost over 50 percent of its honeybees over the past ten years. A serious threat facing bees is colony collapse disorder, when worker bees mysteriously disappear from their colony. Scientists are still trying to identify its cause.
There is a quote attributed to Einstein that if bees ever disappeared, man would only have four years left to live. Whether that's true or not does not really matter, says wildlife photographer Louie Schwartzberg: the key point is that there is a real danger. "The healthiest food we need to eat," he says, "would disappear without pollinating plants. It's pretty serious. "