Tag Archives: research

How migrating birds ‘run a marathon,’ burning muscles and organs in long flights

How migrating birds 'run a marathon,' burning muscles and organs in long flights

(Physorg, University of Massachusetts Amherst 12 July 2017)

Migrating birds complete long non-stop flights of many hours for songbirds and days for some shorebirds to reach breeding or wintering grounds. During such flights a bird’s metabolic rate is very high, fueled by stored fat, but also by burning the protein in musc

les and organs in a process that is not well understood, says eco-physiologist Alexander Gerson at the University of Massachusetts Amherst.

Now he has received a three-year, $756,000 National Science Foundation grant to thoroughly investigate the consequences and mechanisms of this phenomenon, which sometimes leads to dramatic reductions in migrating birds’ muscle mass and organs but may not result in significant loss of function.

As he explains, “There is evidence that some birds see a 20 percent reduction in muscle mass and up to 50 percent mass losses in the liver, intestine, kidneys and other organs except the brain and lungs. In one of the longest flights documented in this hemisphere, the blackpoll warbler during migration flies 22 hours over water, where they absolutely cannot stop. When you run a marathon like that, you either run out of fuel or water, but these birds can produce both by metabolizing their muscle and organ tissues.”

He adds, “We’re interested in what happens during flight, where the energy comes from, and how they maintain water balance. Water is produced from metabolism, and breaking down protein yields the most. But what happens when you lose 20 percent of your pectoralis muscles? Do you lose function or just size? These are a few of our questions.”

Gerson says this study will use two ultra-specialized tools not available to most researchers: a field-portable quantitative magnetic resonance imaging (QMRI) machine, and a wind tunnel specifically designed to study long duration flight in birds, one of just three in world, located at the Advanced Facility for Avian Research at Western University in London, Ontario.

The experimental series will look at body fat, lean mass and water content in one larger species, Swainson’s thrush, and one smaller, the yellow-rumped warbler, in the field and in wild birds flying in the climate-controlled wind tunnel. There, researchers can manipulate such factors as humidity and temperature to study the amount of water lost to respiration. This is relevant to climate change, Gerson notes, because flying in warmer air means more protein and water loss.

His research team will also look at water-loss rates in non-flight conditions, at rest, and look for differences among migrants and non-migrants. Further, Gerson and colleagues will conduct metabolic phenotyping and use transcriptomics to explore molecular mechanisms of protein breakdown and regeneration with UMass Amherst molecular biologists Courtney Babbitt and Larry Schwartz.

Gerson intends to engage many undergraduate and graduate students from diverse backgrounds in the research, training them in a range of cutting-edge techniques applicable to many science, technology, engineering and mathematics (STEM) fields. They will in turn develop and implement science communication and outreach programs for middle school students in a local low-income school district yet to be determined.

At the end of three years, Gerson says, “We hope to better understand the influence of climate on flight metabolism and have a better understanding of functional consequences of protein breakdown, which has the potential to be exciting because they burn a lot of muscles and don’t seem to show any dramatic functional loss. It may shed some really new light on questions that have been around for quite some time.”

Mystery of birds’ movements at sea solved

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RSPB 7 July 2017; Photo Chris Gomersall)

  • New research reveals where British and Irish seabirds go when they’re not on land.
  • The five year project GPS-tracked over 1,300 breeding seabirds and used computer models to predict where they go to find food.
  • Results reveal the majority of ‘hotspots’, where seabirds gather to feed, are concentrated in the coastal waters of Scotland, highlighting the need for robust conservation measures in this area.
  • The new maps will be used to protect threatened species by assessing potential impacts from offshore wind farms, pollution and other human activities on seabirds.  

New research has identified the most important areas for Britain and Ireland’s seabirds at sea, with the majority of ‘hotspots’ revealed in the coastal waters of Scotland.

Experts used GPS-tracking (1) and computer models on an unprecedented scale to map where breeding seabirds go when they leave land to feed, providing a unique insight into the lives of these enigmatic birds.

The study (2), headed by the RSPB in partnership with over a dozen scientists from leading research institutes (3), used five years of tracking data to estimate the areas used by four species: kittiwakes, shags, razorbills and guillemots.

This comes as the Scottish Government considers the creation of Special Protection Areas at sea to safeguard key seabird feeding areas, as well as planning future management of marine activities in Scottish waters outside of the EU and the Common Fisheries Policy.

During the project, lightweight GPS tags were fitted to over 1,300 adult birds from 29 different colonies. The tracking data was then used to create a computer model for each species, so that all of the important areas at sea could be predicted.

The results (see study maps attached) show the extent to which birds travel to find food. The majority of seabird ‘hotspots’, where different species gather to feed, are concentrated in the coastal waters of Scotland, highlighting the need for robust conservation measures to protect these areas. Overall, the four species use at least 1.5 million square km of sea around Britain and Ireland – an area three times the size of Spain.

This is a major step forward in our understanding of seabirds and is a powerful tool to help protect birds from potentially harmful activities at sea, including helping to make better decisions about where those activities can be undertaken to limit their impacts on seabirds.

Understanding more about our seabirds is vital because they are one of the most endangered groups of birds in the world. Over the last 30 years, kittiwake and shag numbers have declined by 72% and 68% respectively in Scotland. This is partly due to the impacts of climate change and fishing, and a new OSPAR report (4) underlines this trend, highlighting widespread seabird breeding failures in the North and Celtic Seas. Scotland is also home to internationally important populations of breeding seabirds so we have a global responsibility to safeguard them.

Dr Mark Bolton, RSPB Principle Conservation Scientist, said: “Our rich and diverse marine environment makes Britain and Ireland one of the greatest areas in the world for seabirds and this new research is further evidence of just how important our seas are for seabirds and their chicks during the breeding season. In order to strengthen this research and our predictions, there is an urgent need for a complete seabird census which will provide an accurate and up-to-date estimate of the size of our seabirds breeding colonies.”

Dr Ellie Owen, who led on the tracking work, said: “The sight and sound of hundreds of thousands of seabirds flocking to our shores is an amazing natural spectacle and something that we must help protect for future generations to enjoy. The methods used in this study could be applied to other seabird species, to show where they go at sea. This will be an invaluable tool in helping to protect seabirds, as it will greatly improve our ability to assess the likely impacts on breeding seabirds of offshore wind farms, oil spills and other potentially harmful activities in our increasingly industrialised seas.”

Dr Ewan Wakefield, lead author of the research, said: “Many seabirds are at the top of the marine food web. They feed on sandeels and other small fish but that prey is declining because of human pressures, including climate change. The result is that thousands of seabird chicks are dying each year because their parents can’t feed them. For the first time, this study provides us with a full map for each breeding colony of the feeding areas for some of our most important seabird species. That means we can now protect the places these birds catch the fish they need to feed their hungry chicks, securing the fate of future generations of these amazing creatures.”

Dance Moves Support Evidence for New Bird-of-Paradise Species

Western New Guinea form of the Superb Bird-of-Paradise

(Cornell LoO 29 June 2017; Photo Tim Laman)

Ithaca, NY—The Superb Bird-of-Paradise—the shape-shifting black bird of central New Guinea that woos its mate with an iridescent blue “smiley-face” dance—has an equally superb cousin in the isolated mountains of Indonesia’s Bird’s Head Peninsula in the island’s far west. Scientist Ed Scholes and photographer Tim Laman, with the Cornell Lab of Ornithology’s Birds-of-Paradise Project, have now visually documented the distinct differences between the western population in the Arfak Mountains and the more common form found elsewhere on the island. Both believe the western form should be considered a new species.

“The courtship dance is different. The vocalizations are different. Even the shape of the displaying male is different,” says Scholes. “For centuries, people thought the Superb Bird-of-Paradise in the mountains of the Bird’s Head region was a little different from the other populations throughout the rest of New Guinea, but no one had ever documented its display in the 200 plus years this bird has been known to occur there.”

“Even after many trips to the region, we’d never seen the Arfak birds do their courtship display,” says Birds-of-Paradise Project co-leader Tim Laman. “When we finally located a display site and saw a male open his cape for the first time, what we saw was a complete surprise!”

When expanded for courtship display, the western male’s raised cape creates a completely different appearance—crescent-shaped with pointed tips rather than the oval shape of the widespread form of the species. The way the western male dances for the female is also is distinctive, being smooth instead of bouncy.

           
The raised cape of the western male (left) is crescent shaped and unlike the oval shape of the widespread Superb Bird-of-Paradise (right) found throughout most of New Guinea. Left image by Tim Laman/Macaulay Library. Image on right is from video by Ed Scholes/Macaulay Library.

Scholes and Laman have been studying and filming birds-of-paradise behavior in the Arfak Mountains for the past 13 years. They first uncovered this population’s unique courtship behaviors in June 2016 and returned again this year to gather additional documentation for a forthcoming scientific paper.

A recently published independent genetic study confirms the visual and behavioral evidence collected by Scholes and Laman. A team of researchers from Sweden and Australia used DNA samples from museum specimens to examine the evolutionary relationships among Superb Bird-of-Paradise forms throughout New Guinea. Their research, published online in the Zoological Journal of the Linnean Society, found that the western form is more genetically distinct from the widespread form than previously thought. They, too, say the western population should be recognized as a full species called Lophorina neidda inopinata. 

“The timing of this DNA-based study is perfect,” said Ed Scholes, “because it is great to have our field observations supported by solid genetic evidence. We really appreciate this in-depth study of the evolutionary relationships among the different forms of Superb Bird-of-Paradise.”

The Cornell Lab’s Birds-of-Paradise Project (birdsofparadiseproject.org) is a research and education initiative to document, interpret, and protect the birds-of-paradise, their native environments, and the other biodiversity of the New Guinea region—one of the largest remaining tropical wildernesses on the planet.

Touchscreen test reveals why some birds are quicker to explore than others

(Science Daily 10 July 2017)

Birds such as parrots and crows have been using touchscreen technology as part of an international research study examining whether the ways in which animals respond to new things influences how eager they are to explore.

The new research, involving scientists from across Europe, looks at how a number of factors affect the speed and frequency with which the birds investigate new objects that they have never seen before.

The study was carried out by researchers from the Messerli Research Institute (University of Veterinary Medicine Vienna) and the University of Vienna in Austria, the Max Planck Institute for Ornithology in Germany and University of Lincoln, UK.

It has generally been assumed that neophobic species (species that do not like new things) have a tendency to explore less than those that do (referred to as neophilic). For example, kea parrots in New Zealand have been known to destroy cars because they are so interested in new things.

The research results reveal that the neotic style of a bird (how neophobic or neophilic an animal is) has an impact on when they choose to explore new objects, but not on their level of exploration. Those who are more neophobic carry out the same amount of exploration, but simply make the approach much later. The results also show that juvenile animals explore more quickly than adults do.

Significantly, the scientists found that individual differences and characteristics seem to be much more important than species-level differences in determining how eager a bird is to explore. This suggests that neotic style is not, as is frequently assumed, a result of the challenges faced by an entire species, but instead appears to differ depending on the individual bird.

As part of the investigation, the parrots and crows were introduced to a touchscreen which revealed two different coloured shapes on a regular basis, and they were trained to understand that choosing one of the shapes (by pecking it) could result in a food reward. The researchers showed each bird 16 pairs of shapes, and throughout the task introduced a few novel stimuli that they had never seen before. The researchers measured how quickly they responded to the new shapes, and at which point in the test they chose to investigate them.

Dr Anna Wilkinson, a specialist in animal cognition from the School of Life Sciences at the University of Lincoln, explained: “Rather than its species, we found that individual differences have a significant impact upon how quickly a bird begins to explore. This is likely to be due to a combination of the bird’s age, its individual position in the social hierarchy, and its own previous experiences.”

The birds that featured in the study were from nine different species of parrots and corvids — also known as the crow family. They were selected to represent different ecological backgrounds so that factors such as the likelihood of pressure from predators could also be taken into account. For example, species originating from islands such as Goffin’s cockatoos and vasa parrots are less likely to face pressure from predators than those such as ravens, jackdaws and African grey parrots, which are much more widely distributed.

As part of the study, researchers worked with Eclectus parrots from the Lincolnshire Wildlife Park to assess their reactions.

The first author of the study, Dr Mark O’Hara from the Messerli Research Institute and the University of Vienna, said: “Our findings allow for a more accurate interpretation of behaviour and the processes which control responses to changes in the environment.”

The full paper, The temporal dependence of exploration on noetic style in birds, is published in Scientific Reports.

Decline in hummingbird population linked to insecticide

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(Terri Theodore 9 July 2017; Photo Darryl Dyck)

VANCOUVER — Some species of North American hummingbirds are in severe decline and a British Columbia research scientist says one possible cause might be the same insecticide affecting honey bees.

Christine Bishop with Environment and Climate Change Canada said researchers started looking at a variety of factors that may be responsible, ranging from habitat loss to changes when plants bloom.

To try and find some answers, researchers began collecting urine and feces from the birds for testing.

“No one has ever measured pesticides in hummingbirds before. So we decided to try it,” she said in an interview. “It turns out, to our surprise actually, that the birds are obviously picking up pesticides in their food, which can be nectar and also insects.”

Bishop said the concentration found in the urine is relatively high at three parts per billion.

“Now what does it mean? Right now we’re just understanding what the level of exposure is, and then how is it affecting the population, well that’s part of the population dynamics,” she said.

Her research is focused in the agricultural regions in the Fraser Valley and southern B.C. — the core area for the rufous hummingbird.

The rufous is a feisty, red-throated bird that weighs about as much as a nickel and spends its summers in B.C., Alaska and the Pacific Northwest states, then migrates to the southern United States and Mexico.

The testing doesn’t harm the birds. Researchers hang a net over a feeder and then lower it like a drape when the bird comes to feed.

Because the hummingbird is constantly processing nectar, it is also constantly expelling it, and Bishop said by the time they are banded the bird has likely expelled urine and feces to test.

The annual breeding bird survey shows that between 1966 and 2013, the rufous population on the Pacific Coast dropped an average of 2.67 per cent per year. The survey says the Allen’s and broad-tailed hummingbirds were also in decline.

Health Canada is re-evaluating the use of imidacloprid, a neonicotinoid insecticide used in on a large number of agricultural crops and at home on fleas or ticks on cats and dogs.

Health Canada says they are aware of Bishop’s work and will consider information she passed on during a consultation period as part of its re-evaluation. Health Canada says in its statement it expects to publish its findings in 2018.

A separate Health Canada preliminary report issued in 2013 says imidacloprid has potential for short-and long-term effects on bees, including a change in behaviour and mortality.

Bishop is two years into a five-year study and said the next question that needs to be answered is whether pesticides could be a factor in the decline of hummingbirds.

“We can’t rule it out,” she said.

Like bees, hummingbirds return to the same place to find food and they remember where certain flowers are, said Bishop, adding there are concerns pesticides might disrupt their memory.

But researchers don’t think the decline is strictly an agricultural issue.

It could be habitat loss, or seasonal plants blooming at the wrong time of year, or even an increase in the deer population with the animals eating the same flowers the hummingbirds need for their food source, Bishop said.

The population of the Anna’s hummingbird is also increasing in the area as the birds move north. Bishop said given the bird’s territorial and aggressive nature, it’s possible they are forcing the rufous out.

“But what’s interesting about this is … more and more people are putting out feeders, yet the population is still declining.”

Skeptics Poke Holes in Claim That Birds Mistake Plastic for Food

Tabitha Watson 6 July 2017;Photo Joe McDonald)

Idea was that birds are drawn to smell of plastic garbage, but research may have looked at the wrong birds

Recent research suggested that marine birds such as albatrosses and petrels are attracted to the smell of dimethyl sulfide (DMS), a compound produced by phytoplankton but also by plastic debris. Matthew Savoca and his colleagues at the University of California, Davis claimed that there was evidence that certain seabirds use DMS as an olfactory cue to identify sources of food, resulting in them eating plastic waste.1 But this finding has now been challenged by another team.2

Gaia Dell’Ariccia of the University of Montpellier and her team claim that the original paper was based on questionable data, the use of which resulted in the misclassification of the DMS-responsiveness of species. According to them, the original authors included three species of bird among the DMS-responders that have been shown not to respond to DMS (Pachptila belcheri, Ardenna tenuirostris and Ardenna grisea). It was also suggested that as Savoca and his team had placed undue focus on the nesting habits of the birds – a lifestyle trait of ‘dubious relevance’ in the context of plastic consumption – there was insufficient ecological insight to definitively link DMS to plastic consumption.

Further, several flaws in the overall method were detected, including the way that the oceans were divided and how the data was pooled over 50 years. The team led by Dell’Ariccia argue that splitting the world’s oceans into nine overlapping regions was likely to ‘severely reduce statistical power’, and the pooled data would ‘obscure biologically meaningful patterns among taxa’.

The solution suggested by the original paper was an ‘increase in the antifouling properties of consumer plastics’. In other words, manufacturing plastics differently. This is entirely unpalatable to Dell’Ariccia. She and her colleagues believe that this conclusion presents a ‘substantial environmental risk’ by delivering the ‘wrong message’ to policymakers – instead of altering the composition of the plastics, the priority should be to cut plastic waste and prevent it ending up in the seas.

Birds’ migration genes are conditioned by geography

(Lund University 6 July 2017; Photo Max Lundberg)

The genetic make-up of a willow warbler determines where it will migrate when winter comes. Studies of willow warblers in Sweden, Finland and the Baltic States show that “migration genes” differ — depending on where the birds breed in the summer. The willow warblers that breed in southern Sweden migrate to West Africa, while those in northern Sweden, Finland and the Baltic States fly to southern or eastern Africa.

According to a new study led by biologists at Lund University, the key to the willow warblers’ differing migration patterns probably lies in their genes.

The researchers studied the entire genetic make-up of willow warblers that breed in southern and northern Sweden, Finland and the Baltic States. The comparison shows that the genomes are almost completely identical, but there are significant differences between the birds that breed in southern Sweden and those that breed in the northern parts of the country and east of the Baltic.

The differences are restricted to two regions in the genome, where the comparison shows extensive differences in over 200 genes.

“Of these 200 or so genes, there are several that can be considered to be important for migration-related physiological adaptations and others that, according to our present knowledge, have a poorly characterized or unknown function,” says Max Lundberg, researcher at Lund University.

According to him and his colleagues, the genetic differences are probably decisive in determining that willow warblers in southern Sweden migrate to West Africa, whereas the more northerly willow warblers head for the south-east of Africa.

Researchers have previously known that the migration behaviour of many birds is strongly determined by genetics. Inherited information in the genes determines the direction of migration and a schedule that contains information about when and how far the birds are to migrate. The migration over thousands of kilometres also requires inherited physiological adaptations, for example to store and use fat and energy as efficiently as possible. Up to now, however, very little has been known about the specific changes in the genetic make-up that underlie where birds, in this case willow warblers, migrate.

“Our results represent an important addition to the understanding of migration-related genetics and will guide future studies in the subject,” says Staffan Bensch, a professor at Lund University.