Parasites affect flight ability of wild seabirds, new study finds

Date:  May 30, 2018

Source:  University of Liverpool

A study led by the University of Liverpool and the Centre for Ecology & Hydrology (CEH) has found that parasites affect flight ability of wild seabirds, which may make it harder for them to raise chicks.

The researchers studied a population of European shags on the Isle of May National Nature Reserve, Scotland and measured how parasites affect energy levels and behaviour of individual birds, something which hasn't been done before in a wild population.

They used an endoscope to count individual worms in the birds' stomachs and miniaturised electronic tags recorded the movement and energy of the birds.

They then calculated the total energy used on each day, and the energy used for flying, diving and resting.

Researchers found that the total energy used per day did not depend on the amount of parasites, but females with higher levels of parasites had more costly flight and spent less time flying each day, presumably to avoid using too much energy.

Olivia Hicks, lead author of the study and a PhD candidate with the University's School of Environmental Sciences, said: "This is the first study to measure the impact of parasites on individual birds in this way

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The early bird got to fly: Archaeopteryx was an active flyer

Date:  March 13, 2018

Source:  European Synchrotron Radiation Facility

The question of whether the Late Jurassic dino-bird Archaeopteryx was an elaborately feathered ground dweller, a glider, or an active flyer has fascinated palaeontologists for decades. Valuable new information obtained with state-of-the-art synchrotron microtomography at the ESRF, the European Synchrotron (Grenoble, France), allowed an international team of scientists to answer this question in Nature Communications. The wing bones of Archaeopteryx were shaped for incidental active flight, but not for the advanced style of flying mastered by today's birds.

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Kestrels' strategies for flight and hunting vary with the weather

Even so, these small raptors expend a constant amount of energy per foraging trip

Date: June 7, 2017

Source: PLOS

Kestrels adapt their flight and hunting strategies to weather conditions, including solar radiation, wind speed, and air temperature, according to a study published June 7, 2017 in the open-access journal PLOS ONE by Jesús Hernández-Pliego from Estación Biológica de Doñana, Spain, and colleagues.

Theory predicts that to maximize fitness, foraging animals should gain the most energy for the least cost of time and energy. Hernández-Pliego and colleagues tested this theory in kestrels, small insectivorous falcons that return to their nest to feed their chicks after a foraging trip. Kestrels have the options of commuting via time-saving flapping flights or energy-saving soaring-gliding flights, and of capturing prey via time-saving active hovering flights or energy-saving perch-hunting.

To explore whether the birds' behavioral decisions reflect trade-offs during the commuting and searching parts of foraging trips, the researchers tracked lesser kestrels with GPS and tri-axial accelerometers, which provide data on energy and time budgets in wild animals. The study included six kestrels (four males and two females) from two breeding colonies with in the Guadalquivir river basin of southwestern Spain.

The researchers found that kestrels' behavioral decisions varied with weather conditions. When solar radiation increased -- which strengthens thermal updrafts -- commuting birds replaced flapping with soaring-gliding. When wind speed increased -- which provides a stronger lift -- searching birds replaced perch-hunting with hovering. But kestrels also hovered more when air temperature increased possibly as warmer weather boosts the activity of large grasshoppers, the birds' preferred prey. While flight and hunting strategies varied dramatically with the weather, the researchers also found that the energy expended per foraging trip remained constant. This suggests that the birds have a fixed energy budget per foraging trip and adjust their behavior accordingly when environmental conditions vary.

Read on

For the birds: New prediction method sheds brighter light on flight

Date: March 27, 2017
Source: Office of Naval Research

Resembling a feathered flying ace with his miniature protective goggles and chinstrap, the parrotlet named Obie stood ready to take off. On signal, Obie propelled into the air, flapped through a laser field infused with microparticles and landed on another perch three feet away.

The journey only lasted three seconds, but it challenged the accuracy of three aerodynamics models long used to predict animal flight. It also might impact future designs of bio-inspired drones, robots and unmanned aerial vehicles (UAVs), a topic of interest to the U.S. Navy and Marine Corps.

Sponsored by the Office of Naval Research (ONR), researchers at Stanford University found a new way to precisely measure the vortices -- circular patterns of rotating air -- created by birds' wings during flight. The results shed greater light on how these creatures produce enough lift to fly.



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Watch a parrot wearing goggles fly through a laser sheet

By Rachael LallensackDec. 5, 2016 , 7:15 PM

Thanks to a tiny goggle-wearing parrot named after Obi-Wan Kenobi, scientists have shown just how much we still don’t know about animal flight. The researchers set out to illustrate a problem that’s been warned of in their field of study, but never tested: The three most popular methods used to calculate lift, or how much force winged animals use to keep their bodies soaring, are frequently inconsistent and inaccurate. To do so, they spent months training Obi to fly from perch to perch through a flattened vertical laser projected through a cylindrical lens. Sound dangerous? Don’t worry; Obi had his own custommade pair of 3D-printed goggles as safety glasses, and the lasers themselves were harmless. Why lasers? Because the team needed a way to three-dimensionally observe the vortices—think miniature air tornadoes—birds create when they flap their wings. A total of 12 high-speed cameras surrounded the 1-meter-long flight path to capture Obi’s speed, wake flow, and path of the vortices. 

The scientists’ most surprising finding, published online today in Bioinspiration & Biomimetics, was that the vortices chaotically break down in the blink of an eye—literally, both take about 100 milliseconds. What they saw on video did not match what the three equations calculated. Two equations consistently underestimated the lift values. The other kept producing a zero value, which would imply free fall, at times when the footage clearly showed the bird still flapping through the air. The findings could help researchers develop better flying robots. In the meantime, Obi deserves a thank you—or perhaps an extra serving of his favorite treat: fresh broccoli. 

Source and watch video

First evidence birds nap in flight without dropping out of sky

3 August 2016

I only dropped off for a second…

Bryson Voirin, Max Planck Institute for Ornithology.

By Alice Klein

The debate has finally been put to bed. Wearable brainwave recorders confirm that birds do indeed sleep while flying, but only for brief periods and usually with one half of their brain.

We know several bird species can travel vast distances non-stop, prompting speculation that they must nap mid-flight. Great frigatebirds, for example, can fly continuously for up to two months. On the other hand, the male sandpiper, for one, can largely forgo sleep during the breeding season, hinting that it may also be possible for birds to stay awake during prolonged trips.

To settle this question, Niels Rattenborg at the Max Planck Institute for Ornithology in Seewiesen, Germany, and his colleagues fitted small brain activity monitors and movement trackers to 14 great frigatebirds.

12-second naps

During long flights, the birds slept for an average of 41 minutes per day, in short episodes of about 12 seconds each. By contrast, they slept for more than 12 hours per day on land. Frigatebirds in flight tend to use one hemisphere at a time to sleep, as do ducks and dolphins, but sometimes they used both.

“Some people thought that all their sleep would have to be unihemispheric otherwise they would drop from the sky,” says Rattenborg. “But that’s not the case – they can sleep with both hemispheres and they just continue soaring.”

Sleep typically took place as the birds were circling in rising air currents, when they did not need to flap their wings.

Weather eye

During this time, the brain hemisphere connected to the eye facing the direction of the turn was more likely to stay awake.

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A focus on flight: Birds use just two postures to avoid obstacles during flight

Date:

April 23, 2015

Source:

Harvard University

Summary:

A new study shows birds use two highly stereotyped postures to avoid obstacles in flight. The study could open the door to new ways to program drones and other unmanned aerial vehicles to avoid similar obstacles.

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Birdwatch: Bid to understand the flight of the starlings

By Bill Teale

Published on the 29 November 2014 

Every autumn and winter, thousands of starlings flock together and swirl across the sky in one of nature’s most dramatic spectacles.

Birders visiting the RSPB’s Blacktoft Sands reserve near Goole to watch marsh and hen harriers coming in towards dusk have been entertained by the spectacle of an estimated 170,000 starlings giving this flying display as they come in to roost a little further down river at Alkborough Flats.

Why starlings perform these displays is not fully understood.

This winter the Society of Biology and University of Gloucestershire have launched a national starling murmuration survey to try and find out why they form and how long they last before the birds plunge down to roost.

It’s also hoped that information can be provided to help stem the decline in starling numbers; 66 per cent since the mid-1970s.

Older readers will recall the huge numbers that used to gather in city centres, much to the ire of local councils, now these are a thing of the past and the remaining starling roosts are in woods and reed beds.

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Feathers in flight inspire anti-turbulence technology

Date:

October 27, 2014

Source:

RMIT University

Summary:

Inspired by nature’s own anti-turbulence devices – feathers – researchers have developed an innovative system that could spell the end of turbulence on flights.

Researchers from the Unmanned Systems Research Team at RMIT University in Melbourne, Australia, have lodged a provisional patent on the system, which mimics the way feathers help birds detect disturbances in the air.

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Peacock's train is not such a drag afterall: Flight unchanged with and without plumage

Date:

September 17, 2014

Source:

University of Leeds

Summary:

The magnificent plumage of the peacock may not be quite the sacrifice to love that it appears to be, researchers have discovered. "These feathers weigh about 300g and can exceed 1.5m, so it's expected that the male birds would be making a significant sacrifice in their flight performance for being attractive," one researcher said. However, experiments showed that in fact, the plumage made no difference to take-off and flight of the birds.

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