About 90% of flowering plants require animals to pollinate them, and that includes about two-thirds of the world's crops. The extinction of pollinating organisms could spell disaster... but the very species that are killing them off could prove excellent substitutes.
The need for plants to be pollinated by insects and other creatures is one of nature's most basic and pervasive forms of symbiosis, and potentially losing huge swathes of pollinated plants has caused grave concerns about future food shortages. We need to know what happens when all the native pollinators in an ecosystem are killed off. That's why New Zealand, which has lost many of its native wildlife since the first humans arrived and brought new species with them roughly 800 years ago, is a crucial test case.
Princeton biologist David Wilcove explains:
"New Zealand offers a really interesting and rare opportunity to look at what the consequences of species extinction [are] for... pollination. We have this situation where almost all of the native vertebrates in New Zealand - birds, bats and reptiles - have disappeared from the North island... largely due to predation by rats."
During Wilcove and his team's recent investigations, they made a startling discovery - the very rats that had killed off the original pollinators were now filling in for two of the three plant species they were studying. Another non-native creature, a recently introduced bird species, was also helping out in the pollination process.
Wilcove says that this development is likely possible for plant species that are already pollinated by multiple animal species - those that rely on only a single type of pollinator are likely still doomed. Thankfully, many of the world's crops that rely on pollination fall into the first category, meaning other species could well step in to make sure they're pollinated. This hardly solves everything, but it is a bit of relief that the loss of pollinating species doesn't necessarily mean we're on the brink of global famine.