Sunbirds use their tongues as straws
The team took high-speed video of sunbirds drinking from transparent artificial flowers. Shown here are two views — a macro video of the sunbird drinking (top) and a close-up of its tongue inside the “flower” (bottom). The nectar in these flowers is dyed red so that it’s easy to see it going into the birds’ tongues. Credit: Cuban et al./Current Biology
Sunbirds may look similar to hummingbirds — small, iridescent birds with thin bills — but it turns out the two are only distantly related. Sunbirds live primarily in Africa, Asia and Australia, and have a unique way to slurp up nectar. Unlike hummingbirds, which use minute movements in their bills to sip nectar, sunbirds use their tongues as a straw. In a recent paper published in Current Biology, a team led by researchers at the University of Washington showed that these long-billed birds can change the pressure at the base of their tongues to create suction that moves nectar through their tongues and into their mouths, a novel mechanism never before seen in vertebrates. The researchers used multiple techniques — including high-speed video of sunbirds drinking red-dyed nectar from transparent artificial flowers — to demonstrate this phenomenon across multiple sunbird species as well as build a mathematical model that describes how it works. Sunbirds pollinate the flowers they drink from, and researchers are interested in understanding how different sunbird species’ plant preferences affect the plant-pollinator networks across continents.
For more information, contact lead author David Cuban, who completed this research as a UW doctoral student in biology, at david_cuban@brown.edu.
The other UW co-author is Alejandro Rico-Guevara. A full list of co-authors and funding is included in the paper. Related stories in Science and Nautilus.
Seattle Fault gets 5,000 more years of sleep
Just over 1,100 years ago an earthquake on the Seattle fault rocked — and reshaped — the Puget Sound region. It lifted the sea floor and sent a powerful tsunami through the sound. Researchers have estimated that this fault, which runs east to west beneath the middle of the city, will produce a large earthquake every 5,000 years or so. However, a UW analysis, recently published in Geology, pushes that estimate back to 11,000 years. The researchers extended this window by scouring submerged shorelines for evidence of significant elevation changes. The geological record at these sites dates back 11,000 years, but they only found evidence of one major earthquake. This information could be useful to those making seismic hazard maps, which help people understand the risks associated with different regions. Although other regional faults and the imposing Cascadia Subduction Zone pose more imminent risks to residents, the main Seattle fault doesn’t appear to be ready for rupture anytime soon.
For more information, contact lead author Elizabeth Davis, UW research scientist of Earth and space sciences, at edav@uw.edu.
The other UW co-author is Juliet Crider. A full list of co-authors and funding is included in the paper. Related story in Eos.
The PNW has many rivers, but no system for gauging landslide dam risk
Scientists have a new tool for estimating lesser known hazards in the Pacific Northwest: landslide dams and outburst floods. Landslides along rivers can block the flow of water downstream, creating a lake just above the slide area. Most landslide dams fail within 10 days, releasing trapped water in an outburst flood, which can be devastating. Last fall, 20 people died after a landslide dam failed in Taiwan. In a new study published in Natural Hazards and Earth System Sciences, UW researchers debut a mathematical approach to mapping landslide dam hazards based on valley width and projected slide size. When they applied the tool to a mountain range in Oregon, they found that roughly one-third of rivers in the study area were susceptible to landslide dams, with risk increasing in mountainous areas. If a landslide dam does form, alleviating pressure by digging a channel for water to escape can help prevent flooding. Identifying high risk areas can help guide emergency response efforts following storms, earthquakes and other events that increase landslide risk.
For more information, contact lead author Paul Morgan, UW doctoral student of Earth and space sciences, at pmmorgan@uw.edu.
The other UW co-author is Alison Duvall. A full list of co-authors and funding is included in the paper.
Rubin observatory expected to spot many ‘imminent impactor’ asteroids
Small asteroids — those 1 to 20 meters in diameter — hit the Earth 35-40 times per year, though they’re very rarely spotted by telescopes before impact. That could soon change: According to new research published in The Astrophysical Journal, UW astronomers calculate that the Simonyi Survey Telescope at the NSF-DOE Vera C. Rubin Observatory could discover one to two Earth-impacting asteroids annually once it begins full operations later this year, roughly doubling the number currently logged. The researchers expect Rubin to discover these asteroids an average of 1.5 days before impact, which is more warning time than ever before. Advance notice is extremely valuable in the case of larger asteroids that could be a threat to people or infrastructure. Because the Rubin Observatory is located in the Southern Hemisphere, it will likely discover many Earth impactors that existing asteroid surveys — concentrated in the Northern Hemisphere — miss.
For more information, contact lead author Ian Chow, a UW graduate student of astronomy, at chowian@uw.edu.
Other UW co-authors are Mario Jurić, Joachim Moeyens, Aren N. Heinze and Jacob A. Kurlander. A full list of co-authors is included in the paper.
Many marine microbes share a genetic toolbox for fixing supper at sea
Researchers have now identified a set of genes that allow some bacteria to process a compound, called homarine, that is abundant in the ocean and appears to play a key role in nutrient cycling. Phytoplankton produce loads of homarine, but scientists weren’t sure what became of it until now. In a recent study published in Nature Microbiology, researchers found a set of genes present in common and far-flung bacteria that convert homarine into glutamic acid, an essential building block for life. This suggests that homarine may be a vital and overlooked resource and highlights the importance of bacteria in stabilizing marine ecosystems. Previous studies also found that homarine serves as an indicator of whale health and helps small crabs evade predation by bigger crabs. The UW team will continue studying homarine to better understand how it fits into the broader ecological landscape.
For more information, contact senior author Anitra Ingalls, a UW professor of oceanography, at aingalls@uw.edu.
The other UW co-authors are Frank Ferrer-González, Katherine Heal, Joshua Sacks, Laura Carlson, Zinka Bartolek, Claudia Luthy and Virginia Armbrust A full list of co-authors and funding is included in the paper.