Now mathematicians at MIT have found that efficient feeding depends on how sugary a flower’s nectar is, and whether an animal dips or sucks the nectar out. The researchers found that animals such as bees, which probe with their tongues, are “viscous dippers,” and are most efficient when feeding on more sugary, or viscous, nectar. Suction feeders, such as birds and butterflies that draw nectar up through tubes, do their best when sucking up thinner, less sugary nectar.
The difference, says John Bush, a professor of applied mathematics, may point to a co-evolutionary process between flowers and their pollinators.
“Do the flowers want a certain type of bug or bird to pollinate them? And are they offering up the nectar of their preferred pollinator?” Bush asks. “It’s an interesting question whether there’s a correlation between the morphology of the plant and the morphology of the insect.”
The researchers published their results in a recent issue of the Proceedings of the National Academy of Sciences.
While Bush is not a biologist, he says curiosities in nature, including nectar feeding, pose fascinating challenges for mathematicians. As he sees it, nectar feeding is a classic example of optimization in nature: The sweeter the nectar, the more energy it delivers, but the more energy it takes to transport. The optimal sugar concentration shifts according to how the fluid is taken up.
As a large-scale analogy, Bush says it’s more efficient to suck up sugar water than molasses through a straw. Conversely, it’s more effective to dip a spoon in and out of honey versus juice. There’s an ideal viscosity for a given uptake mechanism, an optimization puzzle that Bush says is tailored for mathematics.
The birds and the bees
To get at this puzzle, Bush and his colleagues analyzed data from previous papers on nectar-feeding species, which include bats, birds, bees and butterflies. Most papers described two kinds of nectar-drinking mechanisms: active suction, whereby butterflies and moths suck nectar up through long, narrow tubes, or probosci; and passive suction, in which hummingbirds and sunbirds draw nectar up in their tongues via capillary action.
The team compiled the papers’ data and found that both groups of suction feeders were most efficient at taking up the same concentration — 33 percent — of sugar in nectar.Video: Watch the animals feed on the PNAS website
Going a step further, Wonjung Kim, a graduate student of mechanical engineering and lead author of the paper, took an experimental approach, studying live bees in the lab. Kim collected several bees from around MIT and kept them in a box lined with paper towels soaked in a sugar solution. Kim filmed the bees with a high-speed camera, confirming that the insects did indeed dip their tongues in the syrupy surface.
Going with the flow
Bush and Kim plan to examine the ways in which other species drink, in order to model more small-scale fluid dynamics. One target, Bush says, is a certain desert lizard that “drinks” through its skin. The lizard simply has to step in a puddle of water, and an intricate system of cracks in its skin soaks up moisture — a useful trait in extremely dry environments.
“People are now interested in moving around small volumes of fluid for microfluidic applications,” Bush says. “It’s clear that nature has been solving these problems for millions of years. Animals have learned how to efficiently navigate, transport and manipulate water. So there’s clearly much to learn from them in terms of mechanisms.”
Written by: Jennifer Chu, MIT News Office
Caroline McCall | EurekAlert!
When fat cells change their colour
28.10.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau
Aquaculture: Clear Water Thanks to Cork
28.10.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH
Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.
So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
28.10.2016 | Power and Electrical Engineering
28.10.2016 | Physics and Astronomy
28.10.2016 | Life Sciences