Climate Change Threatens Rare Orchid’s Survival Strategy

A rare orchid's unique pollination strategy could be imperiled by climate change in Britain, The Guardian reported Thursday.

The early spider orchid, or Ophrys sphegodes, imitates the scent of the female mining bee, or Andrena nigroaenea. This confuses male mining bees, who attempt to mate with the orchids and spread their pollen in the process.

This only works, however, if the orchid blooms before the female mining bee emerges from hibernation. If the male bee picks up the scent of actual females, he won't fall for the orchid's trick.

A study conducted by the University of Kent, the University of East Anglia, Kew and the University of Sussex and published in the April issue of the Botanical Journal of the Linnaen Society found that, as springs get warmer, the female bee emerges earlier, beating the orchids to male attention.

Researchers looked at data for temperatures and orchid populations covering 356 years in central England. They found that mean spring temperatures had gone up from 7.68 degrees Celsius to 8.64 degrees Celsius from 1659 to 2014 and that the female bee emerged before the orchid bloomed for 80 percent of the years between 1961 and 2014. This is an increasing problem: In 26 of the last 28 years, the female bee emerged first.

Lead author and University of Sussex ecology professor Michael Hutchings told The Guardian that the orchid's range has shrunk in Britain and that it could become extinct in the country.

But the study has implications beyond one orchid.

"Ecologists have been saying for a long time that if phenologies (seasonally-impacted life cycles) are changed by changing climate this might disrupt important interactions in communities of species. This study provides the strongest evidence we have that something nasty is happening. There are probably lots of other undocumented cases where similar detrimental effects on species are occurring," Hutchings said.

Indeed, The New York Times ran a story this week highlighting other examples of this growing phenomenon.

For example, the European pied flycatcher usually migrates from Africa to Europe in order to lay eggs before winter moth caterpillars emerge so that their chicks can feed on them. But warmer temperatures in Europe mean that the caterpillars are emerging up to two weeks earlier in some places, and the birds, who leave based on the length of days in Africa, are not arriving in time. Researchers in the Netherlands found that, in the parts of the country where the caterpillars emerged the earliest, flycatcher populations were declining.

Caribou face a similar problem. In Greenland, they winter along the coasts then move inland to give birth and eat Arctic plants. But as temperatures warm, those plants are greening earlier and earlier, and the caribou are not changing their habits. Researchers have found that caribou calves die earlier in years when the plants green before their inland calving season, suggesting that the young caribou need the nutritious, early growth that they are missing as the Arctic warms.