A male Allen’s hummingbird (Selasphorus sasin) near Santa Cruz, CA. Image credit: Shravans14 / CC BY-SA 4.0.
Since the 1830s, ornithologists have assumed that hummingbirds drink by capillary action (wicking), the passive process of a fluid rising into a narrow tube because of forces attracting the liquid to the tube’s solid internal surface.
A new study, led by Dr Alejandro Rico-Guevara from the University of Connecticut, debunks the ‘wicking theory’ and shows that the hummingbird’s tongue actually works as an elastic micropump.
Using high-speed cameras, Dr Rico-Guevara and co-authors filmed the tongue-nectar interaction in 18 hummingbird species, from seven of the nine main hummingbird groups throughout the Americas.
The results were published online today in the journal Proceedings of the Royal Society B: Biological Sciences.
“A hummingbird’s tongue, which can be stuck out about the same length as its beak, is tipped with two long skinny tubes, or grooves,” Dr Rico-Guevara explained.
“Rather than wicking, the nectar is drawn into the tongue by the elastic expansion of the grooves after they are squeezed flat by the beak.”
The tongue structure is collapsed during the time it crosses the space between the bill tip and the nectar pool, but once the tip contacts the nectar surface, the supply of fluid allows the collapsed groove to gradually recover to a relaxed cylindrical shape as the nectar fills it.
Young people run amidst fireworks exploding off of a wheeled paper bull rigged with pyrotechnics, during the annual pyrotechnics fair in Tultepec, on the outskirts of Mexico City.
It was two months after an explosion tore through the Tultepec fireworks market, killing 42, the town honoured its patron saint San Juan de Dios in its usual exuberant style, by exploding hundreds of colourful bulls elaborately rigged with fireworks in a field and the packed town square.
Image Credit: Photograph by Rebecca Blackwell / AP
Scudder’s American Museum, in the former NYC poor house (via NYPL)
One of the first museums to draw the crowds in Manhattan was Scudder’s American Museum, which ran from 1810 to 1841.
First lodged in the city’s former almshouse, it was started by John Scudder with the acquisition of some smaller museum collections, including the Baker’s American Museum.
Eventually it relocated to a five-story building at Broadway and Ann Street, where patrons could pay a small price to see an 18-foot live snake, taxidermy dioramas, a two-headed lamb, magic lantern slides, bed sheets from Mary, Queen of Scots, and some macabre curios like a wax figure cut by a guillotine.
It was even open until 9 pm, to wander by candlelight.
As P. T. Barnum wrote in 1869: “People in all parts of the country had sent in relics and rare curiosities; sea captains, for years, had brought and deposited strange things from foreign lands; and besides all these gifts, I have no doubt that the previous proprietor had actually expended, as was stated, $50,000 in making the collection.”
In fact, Barnum was so impressed with the museum, he decided to buy it and transform it into the greatest spectacle the city had known.