What is actually taking place inthe researcher report, is that during the offloading of the nectar inside the bill, hummingbirds compress their tongues upon extrusion. In the past, scientists had attributed this ability more to the properties of liquids than to the bird’s behavior.

This view challenges an old notion of how hummingbirds sip – that nectar flows up open grooves in the tongue the way water rises inside thin capillary tubes, says functional morphologist Alejandro Rico-Guevara of the University of Connecticut in Storrs.

Those grooves drawn in nectar when they expand after having been squeezed by the beak, functioning as tiny pumps that draw rather than wick the liquid.

Researchers took measurements from seven countries throughout the Americas, where free-living, never handled hummingbirds were feeding at modified transparent feeders simulating nectar volumes and concentrations of hummingbird pollinated flowers.

The study has yielded the largest data set of any hummingbird study to date – the result of five years’ work. This occurred when, during initial tongue protrusion, one of the groove tips adhered to the feeder wall before the tip reached the surface of the nectar pool and the groove tip bent as the tongue continued to move forward.

The discovery of the micro-pump method of feeding may lead scientists to revisit previous hummingbird research, Rico-Guevara said.

In a study published Wednesday in the journal Proceedings of the Royal Society B: Biological Sciences, researchers uncovered the truth: Their tongues work like tiny mechanical pumps. It has recently been discovered that a hummingbird’s tongue uses pumping, not suction when drinking nectar, according to a number of tests and experiments conducted.

This new study shows how hummingbirds drink and feed on nectar with the first real mathematical model that can accurately depict their energy intake using these micro pumping actions that add to the better understanding of how hummingbirds forage for food and their overall ecology, adds Rico-Guevara.