Bats at Panama bird feeders


This video says about itself:

Bats Visit Panama Feeders in Middle of the Night – Nov. 13, 2018

Birds aren’t the only winged creatures you’ll find enjoying the offerings at the Panama fruit feeders. Watch here as a group of bats take turns foraging on sweet nectar in the middle of the night!

Watch LIVE 24/7 with highlights and viewing resources at http://allaboutbirds.org/panamafeeders

The Panama Fruit Feeder Cam is a collaboration between the Cornell Lab of Ornithology and the Canopy Family.

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How bats fly, unique new study


This 8 November 2018 video says about itself:

Unique study shows how bats manoeuvre

For the first time, researchers have succeeded in directly measuring the aerodynamics of flying animals as they manoeuvre in the air. Previously, the upstroke of the wings was considered relatively insignificant compared to the powerful downstroke but, in a new study, biologists at Lund University in Sweden have observed that it is on the upstroke of the wings that bats often turn.

From Lund University:

November 8, 2018

“Until now, we have not known very much about what animals actually do when they fly, since we have focused on steady flight. Steady flight is in fact not very common for animals flying out in the wild. We have now conducted direct aerodynamic measurements on bats and we can see how flexible they are. They turn in several different ways depending on where they are in the wing-beat”, explains Per Henningsson, a biologist at Lund University.

“It is really fascinating to see how complex and elegant the pattern of movement is, and how the bats choose the best solution just as they decide to start a manoeuvre,” he continues.

For the bats, flight technique with fast manoeuvres at high speed is important to successfully capture insects in flight, as well as to avoid collision with various obstacles such as trees and buildings.

The results could be significant in the development of the next generation of drones.

“One of the main challenges for the industry is about control and stability and enabling drones to avoid obstacles easily. In that context, our results are very relevant”, says Per Henningsson, who does not exclude the possibility of future drones being equipped with flapping wings.

The study was conducted on two [brown] long-eared bats that were trained to fly in a wind tunnel. As prey, the researchers used mealworms attached to a device that could be moved laterally. By moving the device to the right or to the left, the researchers made the bats turn to follow the direction of the prey. The researchers visualised the air flow and filmed the animals with high-speed cameras. This allowed them to link the aerodynamics to the movements.

The researchers behind the study are biologists from Lund University and the University of Southern Denmark.

How moths evade bats


This 5 July 2018 video says about itself:

Watch how battles with bats give moths such flashy tails

Long tails fool bats into striking in the wrong place.

Read more here and here.

From the Acoustical Society of America in the USA:

Moths survive bat predation through acoustic camouflage fur

November 6, 2018

Moths are a mainstay food source for bats, which use echolocation (biological sonar) to hunt their prey. Scientists such as Thomas Neil, from the University of Bristol in the U.K., are studying how moths have evolved passive defenses over millions of years to resist their primary predators.

While some moths have evolved ears that detect the ultrasonic calls of bats, many types of moths remain deaf. In those moths, Neil has found that the insects developed types of “stealth coating” that serve as acoustic camouflage to evade hungry bats.

Neil will describe his work during the Acoustical Society of America’s 176th Meeting, held in conjunction with the Canadian Acoustical Association’s 2018 Acoustics Week, Nov. 5-9 at the Victoria Conference Centre in Victoria, Canada.

In his presentation, Neil will focus on how fur on a moth’s thorax and wing joints provide acoustic stealth by reducing the echoes of these body parts from bat calls.

“Thoracic fur provides substantial acoustic stealth at all ecologically relevant ultrasonic frequencies,” said Neil, a researcher at Bristol University. “The thorax fur of moths acts as a lightweight porous sound absorber, facilitating acoustic camouflage and offering a significant survival advantage against bats.” Removing the fur from the moth’s thorax increased its detection risk by as much as 38 percent.

Neil used acoustic tomography to quantify echo strength in the spatial and frequency domains of two deaf moth species that are subject to bat predation and two butterfly species that are not.

In comparing the effects of removing thorax fur from insects that serve as food for bats to those that don’t, Neil’s research team found that thoracic fur determines acoustic camouflage of moths but not butterflies.

“We found that the fur on moths was both thicker and denser than that of the butterflies, and these parameters seem to be linked with the absorptive performance of their respective furs”, Neil said. “The thorax fur of the moths was able to absorb up to 85 percent of the impinging sound energy. The maximum absorption we found in butterflies was just 20 percent.”

Neil’s research could contribute to the development of biomimetic materials for ultrathin sound absorbers and other noise-control devices.

“Moth fur is thin and lightweight,” said Neil, “and acts as a broadband and multidirectional ultrasound absorber that is on par with the performance of current porous sound-absorbing foams.”

Bats wintering in snow, video


This video says about itself:

Watch Rare Video of Bats Hibernating in Snow Dens | National Geographic Wild

24 August 2018

Ussurian tube-nosed bats spend the coldest months in snow-covered dens—the only mammal species known to do so besides polar bears.

Evidence for Ussurian tube-nosed bats (Murina ussuriensis) hibernating in snow: here.

Vampire bats in Mexico, video


This 23 July 2018 video says about itself:

Follow Mexico’s ‘Bat Man’ on a Search for Vampire Bats | Short Film Showcase

University of Mexico Professor of Ecology Rodrigo Medellin travels deep into the Yucatan rainforest with National Geographic Photographer Anand Varma in an effort to research and photograph two rare carnivorous species of Vampire bat.