Tag Archives: research

Why do guillemot chicks leap from the nest before they can fly?

(Aarhus University, Physorg; 24 March 2017)
It looks like a spooky suicide when small, fluffy guillemot chicks leap from the cliffs and fall several hundred metres towards the sea – long before they are fully fledged. But researchers have now discovered that there is good reason behind this seeming madness.

And you ask yourself why when you on a calm Arctic night watch the spectacular sight of dozens of young guillemots who leave their safe nests and flutter past the towering cliffs into nothingness.

What is it that drives these young birds into something that to the eye seems an impossible survival strategy for the species?

Food deep in the ocean

Researchers from, among others, Aarhus University, Denmark and Greenland Institute of Natural Resources, Greenland, have now discovered that there is good reason behind this seeming madness. They mounted small electronic loggers on the legs of a number of birds and recorded the birds’ flight and diving behaviour in detail.

The guillemot (or thick-billed murre) is a seabird with a long life span. The female lays only one egg and thus has no more than one chick per year. Guillemots nest on cliffs in the Arctic, often in very large colonies with up to hundreds of thousands of birds—including Saunders Island, Thule, Greenland, where researchers have now studied their behaviour.

The arctic summer is short and females must quickly produce an egg. After the chick is hatched and is still in the nest, both the mother and the father bring it food, which consists of small fish.

The small electronic dataloggers revealed that guillemots can dive very deep to find food—down to about 200 m. This is deeper than for any other flying bird.

Males ensure the growth of their offspring

The distance from good fishing spots to the colony may be long, and in late summer the female is exhausted. This is when the male steps into character and guides his offspring to the sea and the indispensable pantry. And the male stays with his offspring for five to seven weeks at sea.

“Our measurements show that the male feeds the chick twice as much as both parents could if the chick remained in the colony.

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Livestock grazing effects on sage-grouse

sage_grouse.jpg
(USGS; 21 March 2017)

Effects of livestock grazing on greater sage-grouse populations can be positive or negative depending on the amount of grazing and when grazing occurs, according to research published today in Ecological Applications. The research was conducted by scientists from the United States Geological Survey, Colorado State University and Utah State University.

Higher levels of grazing occurring early in the growing season – that is, before peak plant productivity – was associated with declining sage-grouse population trends, whereas similar levels of grazing that occurred later in the growing season corresponded with sage-grouse population increases. The study authors noted that this finding might reflect the sensitivity of some grass species to being grazed upon during their spring growing period, as well as the potential for additional plant growth if grazing later in the season removes dead vegetation.

“Increasing our understanding of how the amount of grazing and season of livestock use affect vegetation could help inform short-term modifications to livestock management to benefit sage-grouse populations and help sustain western ranching operations,” said Cameron Aldridge, a CSU professor, USGS collaborator and study coauthor.

Studies demonstrating a link between grazing and sage-grouse population trends have been lacking for this landscape species, which use vegetation consumed by livestock for food and shelter. In this new study, scientists analyzed grazing records from Bureau of Land Management allotments from 2002 to 2012 in sagebrush-dominated rangelands across Wyoming to determine the amount of grazing and when livestock graze in the plant-growth season. They then used annual counts of male sage-grouse from 743 breeding sites, known as leks, during the same period to evaluate whether livestock grazing management actions corresponded with sage-grouse population trends.

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Research work on peregrine falcons inspires future aircraft technologies

Research work on peregrine falcons inspires future aircraft technologies
(Physorg; 23 ;March 2017)

Scientists at BAE Systems and City, University of London have revealed how research work on how falcons fly is inspiring new technologies for aircraft that could contribute to their safety in the air, aerodynamics and fuel efficiency. The technologies could be applied within the next 20 years.

The scientists have developed several concepts following research into how the peregrine falcon – the world’s fastest bird – is able to stay in control and airborne at speeds of up to 200mph, even in high winds. The technologies being developed include ‘sensory feathers’ – 3-D-printed polymer ‘hair’ filaments which would act like sensors on the body of an aircraft, providing an early warning system if it began to stall. Similarly, more densely packed passive polymer filaments may also be capable of changing the airflow very close to the surface of the aircraft which could reduce ‘drag’ on the aircraft wing-skin. Aerodynamic drag ultimately slows aircraft in flight.

A further technology has been inspired by the falcon’s ability to stabilise itself after swooping or landing by ruffling its feathers. Small flexible or hinged flaps on an aircraft could allow the wing to manoeuvre quickly and land more safely at lower speeds. The added safety margin gained using this approach could allow future aircraft of a more compact design or to carry more fuel. In addition, the research so far has shown that the flaps could potentially lower aircraft noise pollution.

Professor Christoph Bruecker from City’s Aeronautical Engineering department, said: “The peregrine falcon is the world’s fastest bird, able to dive for prey at incredibly steep angles and high velocities. The research work has been truly fascinating and I am sure it will deliver some real innovation and benefits for the aerospace sector.”

Professor Clyde Warsop, a specialist in Aerodynamic Flow Control from our military aircraft business based at Filton in Bristol and Warton in Lancashire added: “Working with Professor Christoph Bruecker and his team at City, we’ve investigated how we could apply the unique abilities of the peregrine falcon to aircraft. Bio-inspiration is not a new concept; many technologies that we use every day are increasingly inspired by animals and nature.”

Research teaches machines to decipher the dawn chorus

(Author: Physorg; Photo: Wikipedia; 20 March 2017)

Innovative research looking at the timing and sequence of bird calls could provide new insight into the social interaction that goes on between birds. It will also help teach machines to differentiate between man-made and natural sounds and to understand the world around them.

The work is being led by Dr Dan Stowell, a research fellow in machine listening at Queen Mary University of London (QMUL). It is supported through an Early Career Fellowship from the Engineering and Physical Sciences Research Council (EPSRC). An audio slide-show Deciphering the dawn chorus on this research is available on YouTube with examples of the bird recordings.

In August 2015, Dr Stowell’s technology was released to the public in a smartphone app called Warblr. Users record the sound of a bird on their mobile device and the app analyses the sound, matches it with patterns of bird calls in its dataset and provides a list of possible species that the recording matches.

Dr Stowell is now building on this work to take the computer analysis of the sounds that birds make to a new level, to discover more about what messages are being communicated and who is dominating the conversations that are going on.

“Traditionally you would take explicit measures of things like how long is this sound, what frequency is that sound?” says Dr Stowell. “To go beyond this we use modern machine-learning methods where you don’t necessarily know how a computer has made a decision about a particular sound, but by training it, which means showing it lots of previous examples, we can encourage a computer algorithm to generalise from those.”

At the University’s laboratory aviary, female zebra finches provide Dr Stowell with plenty of audio examples for his work.

“We have put the timing of the calls together with acoustic analysis of the content of the call, for instance whether it is a short or long call. We examine factors such as does the probability of one bird calling increase or decrease after another bird calls or is there a more subtle interaction going on? Working out how strongly each bird influences another helps us to build a picture of the communication network that is going on in that group of birds.”

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Antarctic penguin numbers double previous estimates: scientists

(Physorg; 15 March 2017)

Almost six million Adelie penguins are living in East Antarctica, more than double the number previously thought, scientists said Wednesday in findings that have implications for conservation.

Research by an Australian, French and Japanese team used aerial and ground surveys, tagging and resighting data and automated camera images over several breeding seasons, which allowed them to come up with the new figure.

They focused on a 5,000 kilometre (3,100 mile) stretch of coastline, estimating it was home to 5.9 million birds—some 3.6 million more than previously thought. On this basis, they estimate a likely global population of 14 to 16 million.

Before, population estimates only took into account breeding pairs, said Australian Antarctic Division seabird ecologist Louise Emmerson.

“Non-breeding birds are harder to count because they are out foraging at sea, rather than nesting in colonies on land,” she said.

“However, our study in East Antarctica has shown that non-breeding Adelie penguins may be as, or more, abundant than the breeders.

“These birds are an important reservoir of future breeders and estimating their numbers ensures we better understand the entire population’s foraging needs.”

Adelie penguins, slick and efficient swimmers, live on the Antarctic continent and on many small, surrounding coastal islands. They spend the winter offshore in the seas surrounding the pack ice.

Seabird ecologist Colin Southwell said the research had implications for conservation, with more birds potentially interacting with humans in Antarctica and the Southern Ocean than previously thought.

He said the rocky, ice-free areas preferred by penguins for nesting were also favoured by research stations due to ease of resupply.

“There are currently nine permanently occupied research stations in the ice-free areas of East Antarctica and we found over one million birds breed within 10 kilometres of a station,” he said.

“By identifying significant penguin breeding populations near stations we can better identify which areas may need enhanced protection into the future.”

The study also estimated the amount of krill and fish needed to support the Adelie penguin population, prey that is also sought after by seals and whales.

“An estimated 193,500 tonnes of krill and 18,800 tonnes of fish are eaten during the breeding season by Adelie penguins breeding in East Antarctica,” Emmerson said.

This information will now be used by the Commission for the Conservation of Antarctic Marine Living Resources to set sustainable krill fishery catch limits.

Scientists analyze dispersal of parasites by birds in the Americas

(Physorg; 15 March 2017)

Monitoring and understanding the dispersal of potentially pathological microorganisms are constant concerns for sanitary and epidemiological authorities worldwide. The risks involved are evident, given the possibility of outbreaks of emerging diseases in humans or in domestic animals and livestock.

Cross-border transfer of pathological agents can occur not only through human mobility but also through the movement of wild animals. Among the leading suspects to be monitored are migratory birds, which transport parasites over long distances, but little is known about how parasites are transferred by flocks of birds in wintering or breeding sites.

A pioneering study was based on an analysis of malaria parasites in blood samples taken from more than 24,000 migratory and resident birds in 23 countries throughout the Americas.

“It’s the largest study ever performed on the parasitology of migratory birds in the Americas,” said biologist Maria Svensson-Coelho, researcher at the Federal University of São Paulo’s Environmental, Chemical & Pharmaceutical Science Institute (ICAQF-UNIFESP) in Brazil, where was responsible for processing some of the samples.

“Hundreds of species of birds leave their tropical or subtropical wintering ranges every year to spend the summer in high-latitude breeding ranges, returning to low latitudes at the end of the mating season,” Svensson-Coelho said. “These species are exposed to different parasites in their boreal or temperate breeding areas and subtropical or tropical wintering areas. They may disperse parasites between these areas.”

Illegal bird trapping levels remain tragically high

(Birdlife Cyprus, 16 March 2017)

With 2.3 million birds estimated to have been killed in Cyprus in autumn 2016, BirdLife Cyprus highlights the urgent need for action by both the Cyprus Government and the SBA Administration.

The latest findings of the BirdLife Cyprus surveillance programme show that 21km of mist net rides were active during autumn 2016 within the survey area, which covers the Larnaka-Famagusta and the Ayios Theodoros-Maroni areas. Based on the data gathered systematically in the field, BirdLife Cyprus estimates that nearly 2.3 million birds could have been killed across the whole of Cyprus in autumn 2016. Illegal bird trapping is a serious and persistent problem both in the Republic of Cyprus and the SBAs. In the Republic, the use of limesticks is widespread and there are restaurants illegally offering ambelopoulia, while in the SBAs there is extensive mist netting activity and widespread use of calling devices to draw in birds to their death.

The extensive and widespread use of mist nets is further verified by enforcement statistics, where for the months August to October 2016 more than 850 mist nets were confiscated by the competent authorities, the highest number confiscated in the last 6 years. With regards to limesticks, more than 3,500 were confiscated by enforcement agencies.

This wildlife crime is taking place both in the Republic of Cyprus and the SBAs, making it very clear that a joint effort is necessary to address this persistent issue. In particular, within the Dhekelia SBA area, mist netting activity remained around record levels last autumn, with Cape Pyla recorded as the worst trapping location for mist nets in Cyprus. Furthermore, other developments highlight the lack of political will on the part of  the Republic of Cyprus to take serious action to tackle this persistent problem. In addition to the inclusion of the ‘alternative plan’ to the Strategic Plan for the ‘selective hunting of blackcaps by derogation’ in 2015, the Game and Fauna Service has proposed a catastrophic law amendment, introducing a series of relaxations and loopholes in the existing legislative framework.

Martin Hellicar, Director of BirdLife Cyprus, stated: “The proposals included in the amendment would be completely counterproductive to anti poaching and illegal bird trapping efforts and we call the plenary of the Cyprus Parliament to vote against this bill.

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