News in Brief: Life
Hummingbird tongue is a trap
Shaking up nearly two centuries of thinking about hummingbird
tongues, new high-speed video shows that nectar actually does not
fill a pair of grooves at the tip the same way any liquid rises
through tiny capillaries. Instead, the tongues grooves change shape
as the tongue pulls out of the nectar and traps the sip. Both
living birds and tongues salvaged from carcasses showed the same
groove changes, suggesting birds dont need to exert energy with
this efficient system. Rethinking hummingbird tongues could affect
studies of foraging and the evolution of nectar feeding, University
of Connecticut researchers report online May 2 in the
Proceedings of the National Academy of Sciences. Susan
Milius
Rethinking foot-and-mouth
The drastic culling of animals without symptoms of the dreaded
foot-and-mouth disease might become a thing of the past if
scientists can develop ways to test large numbers of cattle
quickly, say researchers in the United Kingdom. Their experiments
show that cattle were unlikely to transmit the disease until half a
day after showing symptoms. Also, cattle on average could
transmit the virus for only 1.7 days, a shorter period than
pathologists routinely expect, the team reports in the May 6
Science. That short window raises hopes that refining
tests for foot-and-mouth in large numbers of cattle could reduce
the need for controversial and expensive measures. Susan
Milius
Leeches get warmer, then colder
Leeches like it hot n cold, changing up their temperatures before
and after eating, researchers from Wellesley College in
Massachusetts report online May 3 in Biology Letters.
Medicinal leeches seek out hot hiding spots after gorging on blood.
Between meals and the critters can go months without eating leeches
stick to the cold. Hot habitats may give these slimy creatures more
energy for digesting and excreting their bloat-inducing feasts.
Cold water, on the other hand, may be ideal for saving energy,
researchers say. Daniel Strain