WASHINGTON, June 4 (UPI) -- Hummingbirds migrating north from Central America may be finding the flowers they depend on for nectar unavailable because of climate change, scientists say.
The glacier lily that graces mountain meadows throughout western North America flowers early in spring, when the first bumblebees and hummingbirds appear -- or it used to, researchers said.
The problem, they said, is that they are blooming earlier with warming temperatures and are no longer synchronized with the arrival of broad-tailed hummingbirds, who are finding many of the flowers withered away and their nectar-laden blooms gone with them.
The first blooms have been appearing about 17 days earlier than they did in the 1970s, a release from the National Science Foundation reported.
"In some years," Amy McKinney of the University of Maryland said, "the lilies have already bloomed by the time the first hummingbird lands."
Higher latitudes may be more likely to get out of sync ecologically because global warming is happening fastest there, researchers said.
"Northern species, such as the broad-tailed hummingbird, are most at risk of arriving at their breeding sites after their key food resources are no longer available, yet ecologists predict that species will move northward as climate warms," said Saran Twombly, program director in the National Science Foundation's Division of Environmental Biology, which funded the research.
"These conflicting pressures challenge society to ensure that species don't soon find themselves without a suitable place to live."