Female bird songs have been underappreciated, study finds

Male birds may be better known for their singing, but female birds perform their own songs as well. Researchers are calling for more widespread documentation of the female birdsong, arguing that a better understanding of these vocalizations could lead to a better understanding of bird biology.

Karan Odom from Cornell University and Lauryn Benedict from the University of Northern Colorado have both independently studied female bird songs.

“I started studying California towhees 17 years ago, and I was fascinated by the duet vocalization given by females and males,” said Benedict.

“That led me to start looking for female song in other North American bird species, and I was surprised to learn that it was much more common than I expected. The reports of female song are buried in odd corners of the literature, but when you put them all together, you start to see some interesting patterns.”

The ancestors of modern birds most likely had many more females that sang. According to the experts, today’s female songs are not represented very well in collections of birdsong recordings and are also understudied.

The researchers believe that additional documentation of the female birdsong with more detailed descriptions of song structure and output could improve our understanding of birds on many levels, including their comparative physiology, neurobiology, behavioral ecology, evolution, and even conservation.

Endangered birds are frequently identified by their songs during surveys, but assumptions that all singing birds are male could misinform wildlife managers about the state of populations.

Odom and Benedict are asking both ornithologists and amateur bird lovers to share any resources they may have regarding the female birdsong. They have created a website where any birdwatcher can upload their observations.

“If you hear a bird singing, do not assume it’s a male,” said Odom. “If you observe a female bird singing, document it by uploading field notes, audio, or video to the collections on our website, femalebirdsong.org. Make sure to indicate how you recognized the bird was female.”

Zoology expert Katharina Riebel from Leiden University formerly collaborated with Odom.

“Odom and Benedict have written an excellent appeal to document and record more female bird song,” said Riebel.

“They rightly point out that the extent of female bird song has been starkly underestimated, as almost by default we assume that a singing bird must be the male of the species. As a consequence, we might have missed out many aspects and the dynamics of male and female vocal signaling in songbirds–clearly, there is still lots to discover! I am confident that ornithologists in the field can make substantial contributions toward these questions by sharing their observations and recordings, as I very much hope this article will encourage them to do.”

The study is published in in The Auk: Ornithological Advances.

By Chrissy Sexton, Earth.com Staff Writer

Image Credit: K. Thomas

Half of plant and animal species in diverse places face extinction risk

Researchers at the University of East Anglia are reporting that around half of plant and animal species in the world’s most diverse regions, such as the Amazon and the Galapagos, will face extinction by the end of this century if human-induced climate change continues at the current rate.

At this point, even if global warming is limited to 2 degrees Celsius, these regions are still likely to lose around 25 percent of their species.

“Our research quantifies the benefits of limiting global warming to 2°C for species in 35 of the world’s most wildlife-rich areas,” said study lead author Rachel Warren.

“We studied 80,000 species of plants, mammals, birds, reptiles and amphibians and found that 50% of species could be lost from these areas without climate policy. However, if global warming is limited to 2°C above pre-industrial levels, this could be reduced to 25%. Limiting warming to within 1.5°C was not explored, but would be expected to protect even more wildlife.”

The study was focused on 35 of the world’s most wildlife-rich areas. The researchers took into account a number of future climate scenarios that would result in a rise of global mean temperatures from 2 degrees Celsius to 4.5 degrees Celsius.

The experts identified the most vulnerable regions in the world, which include the Miombo Woodlands, southwest Australia, and the Amazon-Guianas. A global mean temperature rise of 4.5 degrees Celsius in these areas would make most habitats completely unsuitable to sustain life.

The study revealed that up to 90 percent of amphibians, 80 percent of mammals, and 86 percent of birds could become locally extinct in the Miombo Woodlands under these conditions.

In southwest Australia, 89 percent of amphibians could disappear, while 69 percent of plant species in the Amazon would likely vanish.

“Within our children’s lifetime, places like the Amazon and Galapagos Islands could become unrecognizable, with half the species that live there wiped out by human-caused climate change,” said WWF CEO Tanya Steele.

“Around the world, beautiful iconic animals like Amur tigers or Javan rhinos are at risk of disappearing, as well as tens of thousands plants and smaller creatures that are the foundation of all life on earth. That is why this Earth Hour we are asking everyone to make a promise for the planet and make the everyday changes to protect our planet.”

The study is published in the journal Climatic Change.

By Chrissy Sexton, Earth.com Staff Writer

Image Credit: WWF

Pterosaurs were still thriving just before mass extinction event

A research team led by the Milner Centre for Evolution has discovered the fossils of seven new species of pterosaurs. An analysis of the remains revealed that there was still exceptional diversity among the ancient reptiles at the time they were driven to extinction.

Pterosaurs are the largest known creatures to ever have the ability to fly. It was previously believed that these reptiles were already in a state of decline when they became a casualty of a mass extinction event that struck at the end of the Cretaceous period 66 million years ago.

But now, hundreds of fossils found at dig sites in northern Morocco have been dated back to the end of the Cretaceous period. The researchers determined that the skeletal remains belonged to seven species of pterosaur from three different families.

The pterosaurs ranged in wingspan from 6 to 30 feet and weighed up to 440 pounds. The fossils from Morocco also contained evidence that the new species had distinguishable features from other groups, such as differences in beak shape, neck length, and wing proportions.

“To grow so large and still be able to fly, pterosaurs evolved incredibly lightweight skeletons, with the bones reduced to thin-walled, hollow tubes like the frame of a carbon-fiber racing bike,” explained lead author Dr. Nick Longrich. “But unfortunately, that means these bones are fragile, and so almost none survive as fossils.”

The newly discovered pterosaurs included Tethydraco, a family that was thought to have vanished fifteen million years earlier.

“Exciting discoveries are being made all the time, and sometimes, just the smallest of bones can radically change our perception of the history of life on Earth,” said study co-author David Martill.

Study co-author Dr. Brian Andres added: “The Moroccan fossils tell the last chapter of the pterosaurs’ story – and they tell us pterosaurs dominated the skies over the land and sea, as they had for the previous 150 million years.”

Moroccan paleontologist Professor Nour-Eddine Jalil said that the research shows the amazing diversity of pterosaurs at a time they were thought to be in a state of decline.

“The Moroccan phosphates are an open window on a key moment in the history of the Earth, one that shortly preceded the global crisis that swept away, among others, dinosaurs and marine reptiles,” said Professor Jalil.

The study is published in the journal PLOS Biology.

By Chrissy Sexton, Earth.com Staff Writer

A raven’s call tells its age, sex, and foraging opportunities

Ravens may be able to identify the age, sex, and specific details of a nearby foraging opportunity just by listening to another raven’s call, according to a new study.

Common ravens use calls to alert other ravens of available food, but these calls serve a range of purposes.

Researchers from the University of Vienna and the University of Cambridge say these calls are used as calling cards and nearby ravens can assess the specifics of a feeding situation.

Some feeding spots are dominated by competing ravens, or there may be predators nearby which poses an unnecessary risk.

The study, published in the journal Frontiers in Zoology, is the first of its kind to examine how raven food calls are interpreted by ravens who aren’t familiar with each other.

“The majority of previous research on call characteristics in ravens focused on recognition of known individuals,” said Markus Böckle, the corresponding author. “However, to our knowledge, no experiments have tested for features in food calls that might provide ravens with information about unknown individuals.”

The researchers studied a population of free-ranging common ravens that gathered for feedings on wild boar at the Cumberland Wildpark Grünau from 2009 to 2010.

The feeding sessions were videotaped, and audio recordings of 418 calls made by 12 different ravens were also analyzed.

The results showed that each raven’s call differed depending on age and sex, which could mean that the calls are a way to inform nearby strangers of more than just the specifics of foraging opportunities.

“Our results suggest that ravens have the necessary variation in their food calls and the cognitive means to distinguish between specific classes of sex and age (class-recognition),” said Böckle. “This gives ravens the opportunity to use information about the caller in decision-making processes, such as whether to join or avoid foraging groups.”

The calls could also be used to help ravens recruit allies to help them in tricky food situations such as dominant ravens competing for the same food source.

According to the researchers, the different calls may determine age and sex because of several factors such as size differences between sexes and age groups as well and hormones that create different resonances and timbres.

By Kay Vandette, Earth.com Staff Writer

Ancient fossil reveals first wave of dinosaur flight

The Late Jurassic dinosaur bird Archaeopteryx is the oldest known flying member of the avian lineage, which also includes modern birds. While it is well known that modern-day birds extended from extinct dinosaurs, scientists still have a lot to discover about their early evolution and the development of avian flight. One of the biggest remaining questions has been whether the Archaeopteryx was a feathered ground dweller, a glider, or an active flyer. Up until now, traditional research methods have been unable to answer this question.

New research published in Nature Communications by an international team of scientists shows how cutting-edge technology was used to answer this decades-old question. The researchers used synchrotron microtomography at the European Synchrotron (ESRF) to look inside Archaeopteryx fossils, an important technological breakthrough, as these fossils are among the most valuable in the world, and this technique limits invasive probing.

“Fortunately, today it is no longer necessary to damage precious fossils,” says Dr. Paul Tafforeau, beamline scientist at the ESRF. “The exceptional sensitivity of X-ray imaging techniques for investigating large specimens that is available at the ESRF offers harmless microscopic insight into fossil bones and allows virtual 3D reconstructions of extraordinary quality.”

The scanning data showed that the wing bones of Archaeopteryx shares important adaptations with those of flying birds. These sections of bone contain necessary flight-related signals in birds, such as thinner bone walls. “Data analysis furthermore demonstrated that the bones of Archaeopteryx plot closest to those of birds like pheasants that occasionally use active flight to cross barriers or dodge predators, but not to those of gliding and soaring forms such as many birds of prey and some seabirds that are optimized for enduring flight,” explains lead author Dennis Voeten of the ESRF.

The fossils analyzed were found in the Late Jurassic sediments of southeastern Germany. “We know that the region around Solnhofen in southeastern Germany was a tropical archipelago, and such an environment appears highly suitable for island hopping or escape flight,” says Dr. Martin Röper, Archaeopteryx curator and co-author of the report.

These findings illustrate that Archaeopteryx is part of the first wave of dinosaurian flight strategies, which eventually went extinct, leaving behind the modern avian flight anatomy and physiology that we see in birds today.

“Indeed, we now know that Archaeopteryx was already actively flying around 150 million years ago, which implies that active dinosaurian flight had evolved even earlier!” exclaims Stanislav Bureš of Palacký University in Olomouc. “However, because Archaeopteryx lacked the pectoral adaptations to fly like modern birds, the way it achieved powered flight must also have been different. We will need to return to the fossils to answer the question on exactly how this Bavarian icon of evolution used its wings.”

By Connor Ertz, Earth.com Staff Writer

Image Credit: ESRF/Pascal Goetgheluck

AI machines can detect illegal wildlife trade on social media

The illegal wildlife trade, which poses a major threat to biodiversity conservation, has now become more easily accessible through the use of social media. Some scientists believe that this illegal industry can be effectively monitored on social media platforms using artificial intelligence.

Dr. Enrico Di Minin is a conservation scientist at the University of Helsinki who leads a team in the school’s Digital Geography Lab. The researchers are developing artificial intelligence methods to detect illegal wildlife trade activity on social media.

“Currently, the lack of tools for efficient monitoring of high-volume social media data limits the capability of law enforcement agencies to curb illegal wildlife trade,” said Dr. Di Minin.

“Processing such data manually is inefficient and time consuming, but methods from artificial intelligence, such as machine-learning algorithms, can be used to automatically identify relevant information.”

Dr. Di Minin pointed out that artificial intelligence methods are rarely used as tools to prevent biodiversity loss, despite their great potential to do so.

Many social media platforms have an interface that allows access to user-generated text, images, and videos. The researchers can also access information such as connections between the users and the time or date when specific content was uploaded.

The team is applying machine learning techniques to automatically identify content that relates to the illegal wildlife trade.

“Machine learning algorithms can be trained to detect which species or wildlife products, such as rhino horns, appear in an image or video contained in social media posts, while also classifying their setting, such as a natural habitat or a marketplace,” said co-author Christoph Fink.

According to study co-author Tuomo Hiippala, machine learning methods can be used to interpret the language of social media posts.

“Natural language processing can be used to infer the meaning of a sentence and to classify the sentiment of social media users towards illegal wildlife trade,” said Hiippala. “Most importantly, machine learning algorithms can process combinations of verbal, visual and audio-visual content.”

The study authors emphasized the importance of collaborating with law enforcement agencies and social media companies to further improve the effectiveness of their strategy.

The research is published in the journal Conservation Biology.

By Chrissy Sexton, Earth.com Staff Writer

Image Credit: Enrico Di Minin

West coast marine ecosystems recovering from 2 year heatwave

California’s Current Ecosystem, which includes marine life off the Pacific coast, is now just beginning to recover from a two-year marine heatwave that caused population declines in many species including salmon.

The recent recovery rates were reported by the Southwest Fisheries and Northwest Fisheries Science Centers, two marine laboratories that are part of the National Oceanic and Atmospheric Administration (NOAA).

The annual “California Current Ecosystem Status Report” is important to the Pacific Fishery Management Council for making informed decisions about ecosystem management and preservation.

“The report gives us an important glimpse at what the science is saying about the species and resources that we manage and rely on regarding our West Coast economy,” said Phil Anderson, the Council Chair. “The point is that we want to be as informed as we can be when we make decisions that affect those species, and this report helps us do that.”

The report discussed the two-year extreme heat wave that lasted from 2014 to 2016, starting with warm ocean temperatures called “the Blob” that covered a lot of the west coast.

These temperatures combined with a strong El Nino pattern in 2015 caused many species to travel outside of their traditional range to feed.

Although the report notes that some areas and species are recovering, the impact of “the Blob” will still be felt, particularly among salmon populations, in the coming years.

Some of the other highlights of the report include improved feeding conditions for California sea lions and seabirds, and vital plankton species shifting back to fat-rich, cool-water species that help aid in the survival of salmon.

The report also notes that even though areas are recovering, adult salmon populations will still be lower than normal for the next few years, and whale entanglements are becoming increasingly common as the whales have been forced closer to shore to follow prey.

In 2017, parts of the west coast had low snowpack levels, indicating possible future drought conditions for 2018. This would pose further risk to salmon populations as they rely on river systems to spawn.

All in all, the California Current Ecosystem is slowly recovering from the extreme rise in marine temperatures, but it will be a few years before some species’ populations, such as salmon, completely bounce back.

“These changes occur gradually, and the effects appear only with time,”  said Chris Harvey, a d coauthor of the report. “The advantage of doing this monitoring and watching these indicators is that we can get a sense of what is likely to happen in the ecosystem and how that is likely to affect communities and economies that are closely tied to these waters.”

By Kay Vandette, Earth.com Staff Writer

Image Credit: Adam Obaza/West Coast Region/NOAA Fisheries

Study: therapy dogs help college students relieve stress

Midterms are right around the corner, and then the grind toward finals, summer classes, internships and more begins. Needless to say, it’s stress season for college students. Time to bust out the secret weapon against stress: therapy dogs.

A new study, led by Emma Ward-Griffin, a research assistant at the University of British Columbia, looked at how spending some facetime with a therapy dog affected students’ stress levels.

“Therapy dog sessions are becoming more popular on university campuses, but there has been surprisingly little research on how much attending a single drop-in therapy dog session actually helps students,” she said in a press release.

The team of psychology researchers surveyed more than 240 students who took advantage of drop-in sessions with therapy dogs. The students filled out questionnaires before, immediate after, and 10 hours after their sessions.

The study participants reported feeling happier and much less stressed after spending time with the therapy dogs, and reported higher levels of energy and happiness than a control group that didn’t visit with the dogs.

“Our findings suggest that therapy dog sessions have a measurable, positive effect on the wellbeing of university students, particularly on stress reduction and feelings of negativity,” Ward-Griffin said.

The benefits didn’t appear to favor one gender or other group of students. Instead, the positive effects of pup therapy were pretty evenly spread among the participants, the researchers said.

Some effects of the sessions lasted, such as feeling less stress and more supported, but the happiness and life satisfaction faded after several hours.

“These sessions clearly provide benefits for students in the short-term, so we think universities should try to schedule them during particularly stressful times, such as around exam periods,” senior author Dr. Frances Chen said. “Even having therapy dogs around while students are working on their out-of-class assignments could be helpful.”

The study has been published in the journal Stress and Health. Funding was provided by the Social Science and Humanities Research Council of Canada.

By Kyla Cathey, Earth.com staff writer

Dog owners perceived as more caring and attractive, study finds

Researchers have found that owning a dog can make you appear happier, more attractive, and more approachable to others. Dog owners are also perceived as being more caring and empathetic, according to experts.

In particular, men are viewed by women as being more compassionate when they have a pet. Women take it as a positive sign of how a man would be as a partner when he has made the long-term commitment of caring for a dog.

Dr. Helen Fisher is a senior researcher at the Kinsey Institute and a chief adviser to Match.com. She said that men who own dogs come across as more capable of nurturing others.

Dr. Fisher told the New York Times:

“Having a dog really says something about you. It says you can care for a creature, that you can follow a schedule and get home to feed it, that you can walk it and love it and spend time with it.”

“That’s the bottom line message that women get when they see a man with a dog: He’s capable of nurturing, of giving without receiving a lot, of caring for another. He’s made a commitment to this animal.”

Previous studies have revealed that the presence of a dog helps to promote social interactions. In one study, men were shown to be much more successful in getting the attention of women on the street when they had a dog.

Dr. Fisher also told the Times: “One thing women have needed for years and years is a partner who could share the load, be responsible, care for them if they’re sick and show up on time.”

By Chrissy Sexton, Earth.com Staff Writer

Pangolins: The most illegally trafficked mammal in the world

These animals have a day dedicated to them. They’re also really adorable and look like something from the last ice age or perhaps a mutant armadillo. But sadly, Pangolins are also the most illegally trafficked mammal on Earth.

Pangolins are just now being recognized by the public, despite their fascinating appearance and the threat they face.  For most people, the most bizarre aspect of a pangolin is its status as the only mammal to have scales instead of normal hair.  The scaly pangolin has something primordially about its appearance, a look that seems more appropriate to a strange extinct beast than a living mammal and that may be part of its problems.      

There are eight species of Pangolin across the world.  Four species occur only in Africa and the other four Pangolin species are found in Asia.  Pangolins are little studied but they have only one offspring per year, born live and it seems that some species take a long time to mature; not reaching breeding age until as late as 7 years.  Recent research suggests that Pangolins may live as long as 20 years. Though pangolins are not closely related to the new world anteaters and sloths (Superorder Xenarthra) they share some striking similarities.  Pangolins eat only ants and termites and have no teeth, depending on a strong stomach and swallowed grit for digestion. Also like anteaters, pangolins have long tongues, tongues nearly as long as their bodies which with sticky saliva are used to extract ants and termites from burrows.  Pangolins closest relatives are dissimilar carnivores, as odd as it seems but genetics is a telling science, evolution can create the same body plan separately.

Trapped and hunted in Africa and Asia, Pangolin body parts are used for traditional Chinese medicine, much like how snake oil was once used for cure-alls.  Tragically, the Pangolins natural defense of curling into a ball of impregnable scales makes it all too easy to be collected by humans. Pangolin fetuses are especially prized, considered a delicacy that enhances virility.  The Chinese government even permits designated hospitals to use pangolins for medicine while simultaneously outlawing Pangolin retail. Since the 1960s, the population of Pangolins in China and nearby areas has dropped by 96%.  This is bad news for Asian pangolins obvious but it also paints a bleak future for Pangolins in Africa. African pangolins are increasingly filling the demand for Pangolins in Asia.

I’ve never seen a live Pangolin in the wild but I’ve encountered them in a bushmeat market in Equatorial Guinea in western Africa.  Stacked along tables as if they were nothing more than artichokes, pangolins shared space with monkeys, lizards and porcupines. Varanid lizards, such as monitor lizards were tied three to a net bag, panting, unable to move; monkeys were cooked on spits.  I’ve seen pictures of the same market with live monkeys in cages and so much more horror. This is a market spurred by a growing market built on capital of international workers, tourists and multinational businesses as well as Chinese ‘medicine’. Wildlife hurt by this industry includes not only pangolins and rhinos but tigers, apes, bats, and more, even narwhals are targeted.  

Conservation efforts have mainly focused on attacking the illegal Pangolin market, with some governments trying to legalize Pangolin trade to monitor and manage it.  The work involves busting smugglers and putting pressure on governments for additional laws or enforcement of anti-trafficking laws already on the books. Additionally, outreach and education efforts, trying to discourage consumers from eating pangolins are part of conservation efforts.  Researchers even tested Pangolin meat, concluding that it has no more nutritional benefit than chicken meat, which unsurprisingly it’s said to taste like.

Zoos have recently stepped into the Pangolin fight.  Despite the fact that pangolins typically survive less than five years in captivity, some zoos have decided to try breeding programs.  Some worry that despite being unsuited to captivity zoos are buying wild pangolins, and thus further encouraging the illegal pangolin trade.  

On the other side of the issue, some pangolins have been born in captivity.  The problem is more complex than breeding in captivity can solve alone, though.  If Pangolins are hunted out in the wild, the best case scenario is a self-sustained population living solely in zoos, a proposition I find exceptionally depressing.   In the meantime, you can see a Tree Pangolin (Manis tricuspis) in the San Diego Zoo, before it dies.                    

By Zach Fitzner, Earth.com Staff Writer

Climate changes will significantly reduce fishery yields

According to research from the University of California, Irvine, climate change could drive fishery yields down by 20 percent across the world ocean and by 60 percent in the North Atlantic before the year 2300.

The decline is primarily linked to a lack of ocean mixing. When the surface layer of ocean water is warm, it prevents the nutrients that have built up in the deep waters from rising to the surface.

The study authors explained that significant changes in ocean mixing would ultimately drive a decline in fish populations near the surface.

Many studies have confirmed that fisheries will be significantly less productive by the end of this century, but little research has investigated the fate of fisheries beyond 2100.

A team led by J. Keith Moore used modeling to predict the effects of climate change on fisheries under the condition that the rate of carbon emissions remains the same as it is today.

Currently, the Southern Ocean has such a successful amount of mixing that nutrients abundantly flow into other oceans.

But now, model simulations produced by the current study indicate that changing wind patterns and warmer ocean surface layers will cause an increased portion of nutrients to sink into the deeper layer of the ocean and become trapped there. The model showed that phosphate, for example, will become 41 percent less abundant.

The steep decline of mixing in the Southern Ocean will also be facilitated by a polar shift of nutrient upwelling into the Antarctic.

The study authors also established that ocean mixing will be particularly reduced in the North Atlantic. They explained that the long-term impact of these changes in ocean mixing will reduce fishery yields for at least a thousand years.

The study is published in the journal Science.

By Chrissy Sexton, Earth.com Staff Writer

New platform allows the public to contribute to science research

When a team of researchers set out to better understand liverworts, they discovered that they had hundreds of thousands of images to examine. The experts developed an online tool that would enable citizen scientists and volunteers from a variety of backgrounds to help out with the analysis.

Matt von Konrat is the collections manager of plants at the Field Museum and the study’s lead author.

“Citizen science is an opportunity for an individual, group, or community to participate in and contribute to an active research program,” explained von Konrat. “It’s public contribution to science.”

Liverworts first appeared on Earth about 400 million years ago, and they can survive in even the harshest climates from deserts to the Arctic. They are very small and will respond much faster to global warming than bigger plants, making them a valuable resource for studying the effects of climate change.

Liverworts have rounded leaves that are somewhat shaped like a liver. The tiny details of these plants must be studied under a microscope.

“It’s tedious for one individual to go through these photos for hours on end,” said von Konrat. “But if you get a hundred people to do it for five minutes each, it’s a lot easier.”

The team created the online platform Zooniverse for the citizen science volunteers to study photos of liverworts and measure their primitive leaflike structures. This helps scientists better determine the differences among liverwort species, which may respond differently to climate change.

“The Microplants project is two-pronged: to help find differences between these species, and see if measurements can actually be done by lay people,” said co-author Kalman Strauss, a high school student who has volunteered at the Field Museum since 2014.

Ultimately, over 11,000 online users helped with the study both remotely and at a digital kiosk located in the Field Museum. The Zooniverse platform was also used in classrooms ranging from kindergarten to college Biology classes.

According to von Konrat, the findings of the study are accurate enough for use in research that can inform environmental policy. He said that the project is also notable for its efforts in public engagement with science.

“This project goes beyond the data,” said von Konrat. “It’s about breaking down barriers and showing that everyone can contribute to science. One key audience is students and younger generations – exposing them to museum collections and science, help them get excited about science.”

The study is published in an issue of Applications in Plant Sciences dedicated to the digitization of botanical natural history collections.

By Chrissy Sexton, Earth.com Staff Writer

Image Credit: The Field Museum