Using Sound to Help Imperiled Species and Ecosystems
It's a quiet May morning on the Hawaiian island of Kauai. We're high on a cliff inside the fences of the Nihoku Ecosystem Restoration Project, with only the sound of the wind rushing past our ears and the crash of waves breaking on the shoreline far beneath. Only the slightest hints of animal cries reach our ears — until ecologist Lindsay Young turns on a loudspeaker. Then the air fills with the breathy squawks and raucous chirps of seabirds.
It's hardly Barry White, but for Pacific seabirds, it's music to their ears.
"These guys are so cued into the sound, at our other sites we have birds mounting the speakers, doing bad things to them," Young says as she tromps back up the hill from the loudspeaker.
As the executive director of Pacific Rim Conservation, Young has made it her mission to protect endangered seabirds. On this site that means Newell's shearwaters and Hawaiian petrels, known as ʻaʻo and ʻuaʻu on the islands. Both nocturnal species have declined due to predation by invasive species and the lure of artificial lighting, which often causes fatal collisions with power lines and other urban obstacles.
Young's organization and a handful of others began working on the Nihoku nesting site in 2014, after all the resident birds had been wiped out. They started by constructing a predator-proof fence to prevent everything from mice to feral cats from getting inside. The team also planted native shrubs and installed 50 artificial burrows to enhance the habitat. Then, beginning in 2015, they used helicopters to translocate chicks from mountain colonies down to Nihoku, where they raised them on a slurry of squid and fish, hoping the chicks would imprint on the night sky from this new location and return to it in three to five years when they reached breeding age.
But in the meantime, the conservation team saw the need to lure additional adult birds to this newly predator-free habitat.
There was just one problem: silence.
Hawaiian seabirds are social animals — they need to know the party has started before they're willing to settle down in a new colony. With no adult birds at Nihoku, passing birds had no one to listen to and invite them in.
Enter the seabird stereo. It plays every night, sundown to sunup, from March to November, and is audible up to about a half-mile away.
And it works, to a degree. When I followed up with Young nine months after our trek to the site, she told me that some other bird species have been attracted to the site, but not the target birds — at least, not yet.
"Most seabird species nest in multi-species colonies," she explains, "so I think regardless of what species calls you're playing, it is going to be attractive on some level to closely related species." One of the species that did come to Nihoku, wedge-tailed shearwaters, is more abundant than Newell's shearwaters, so Young says it's not surprising that they might arrive sooner.
She's still hopeful the target species will arrive, lured in by the daily broadcasts. In the meantime it's a waiting game: When will any of the several dozen chicks that have fledged here return to look for mates? Young's listening for their calls.
Echoes and Questions
Nikoku and other degraded habitats are the flip side of the story of noise pollution. While human-generated sounds have harmed wildlife and ecosystems around the planet, the absence of natural sounds also causes cascading ecological problems.
Scientists around the world have started to investigate the soundscapes — or lack of them — for a range of species, and they're realizing just how crucial critter calls are for healthy ecosystems. Planting native vegetation and removing sources of pollution aren't necessarily enough to get an ecosystem functioning again. For that wildlife needs to fulfill key ecological roles such as pollination and seed dispersal — and eating, or being eaten by, other animals.
Darren Proppe has been investigating the role of sound in habitat restoration for years. He's currently the research director at the Wild Basin Creative Research Center of St. Edward's University in Texas, but he previously studied songbirds in Michigan and the effect that birdcall recordings might have on conservation efforts.
"One of the challenges that drove this whole thing initially is that there were areas where people had restored habitat and it looked great, but it was left vacant," Proppe says.
Previous research had already established that broadcasting sounds of bird calls could attract individual songbirds to a specific area. Proppe wanted to test whether that technique could be expanded for a larger number of species. In a key 2015 study, his research group used recordings of six different songbirds in northern Michigan to see whether playing those calls together would attract more birds to a given tract of forest. The speakers, camouflaged as rocks and powered by solar-charged batteries, broadcast the calls on daily playback loops between May and July.
The study was a resounding success. Multiple species nested in higher densities near the playback speakers than in other parts of the forest. The only problem was that birds of related species whose calls weren't broadcast seemed to be avoiding the areas with the speakers, perhaps because they feared the area was already overpopulated by competitors.
In addition to understanding the reasons for that avoidance, Proppe says there are plenty of other questions that need to be answered. Researchers don't know what happens when the recordings are no longer played, or whether there might be ecosystem-wide impacts they haven't yet noticed. They also want to make sure that birds moving into the sound-scaped environments are also doing well over the long term, that the habitat provides them with the right living conditions.
And they want to find out what these sounds mean for the next generation of birds.
"What we're working on now is, what does this do for reproduction? This is breeding season. If we bring them into certain areas, do they reproduce poorly? If that's the case, this isn't a conservation methodology we want to use."
The Sounds Heard 'Round the World'
Birds aren't the only species that could benefit from this emerging research. The possibility of using sound as a conservation tool is being explored across species and habitats. In Kenya researchers have used broadcasts of hyena and lion vocalizations to draw the carnivores to certain locations in order to more easily conduct population surveys. A similar technique was used in Zimbabwe to count African wild dogs.
And more recently, biologists in Australia have turned to a different medium to fill with sound: the ocean.
"We've recently discovered that as coral reefs degrade, their biological soundscape gets quieter," writes marine scientist Timothy Gordon, with the University of Exeter, by email.
Because some fish species spend parts of their life in the open ocean, they need a way to eventually navigate back to the reef. That's where sound comes in, and why it's such a problem when cyclones or mass bleaching cause reefs to empty out.
"The animals that usually make a symphony of crackles, snaps, pops, grunts and whoops are dead, and in their absence the reef turns ghostly quiet," Gordon says. "This is tragic to hear, and also concerning — without these sounds, there's a real danger that fishes can no longer hear their way home."
Gordon and his colleagues wanted to see if they could develop a solution for this problem. Working on the northern Great Barrier Reef, they used underwater loudspeakers to broadcast the sounds of healthy reefs onto coral-rubble patch reefs. Unlike the environment hosting birds, coral reefs are filled with a jumble of sounds. Gordon says it would be almost impossible to disentangle the sounds to target one individual species, since healthy reefs feature a cacophony of sounds (he compared the noise of moving sea urchins to "sizzling bacon").
And it worked: Compared to the parts of the reef without any fishy noises being projected onto them, the artificially loud reefs doubled in overall abundance and had a 50% greater species richness.
"That's good news for reef restoration," Gordon says, since previous research has shown that healthy fish populations can help facilitate recovery of damaged reefs. "At the stage in life that fish are being attracted back to reef habitat from the open ocean, many species are very site-attached and territorial. That means if we can persuade them to settle somewhere, and they're able to survive, they are likely to stay put."
The biggest challenge with all these cases is the lack of high-quality habitat in the first place. Neither Gordon nor Young were particularly optimistic about using animal soundscapes as a panacea for an enormous, multifaceted problem.
"No reef restoration can work without simultaneous dramatic action on carbon emissions to reduce global warming and prevent further damage," Gordon says. "But if we can limit our emissions to stop ocean warming, new understanding like this gives us a real chance of helping our heavily damaged reefs to recover."
For Hawaii's seabirds, Young says, the solution must go beyond the sounds of a restored habitat. Although they're making progress with expanding the number of safe spaces for the birds, and have even created a website to catalogue seabird restoration and social attraction recordings from around the world, they still have to deal with the predators and artificial lights that decimated bird populations in the first place.
"The restoration only creates another safe site, it doesn't address why they're going extinct on their colonies," Young says. "We're creating a new safe space for them, but it doesn't mean the threat doesn't exist at all the other colonies. And until we really get that addressed, it's not going to be optimistic."
Reposted with permission from The Revelator.
EcoWatch Daily Newsletter
By Alexander Richard Braczkowski, Christopher O'Bryan, Duan Biggs, and Raymond Jansen
A Cute But Threatened Species<p><a href="https://www.worldwildlife.org/stories/what-is-a-pangolin" target="_blank">Pangolins</a> are the only mammals wholly-covered in scales, which they use to protect themselves from predators. They can also curl up into a tight ball.</p><p>They eat mainly ants, termites and larvae which they pick up with their sticky tongue. They can grow up to 1m in length from nose to tail and are sometimes referred to as scaly anteaters.</p><p>But <a href="https://www.sciencedirect.com/science/article/pii/B9780128155073000332" title="Chapter 33 - Conservation strategies and priority actions for pangolins" target="_blank">all eight</a> pangolin species are classified as "<a href="https://www.pangolins.org/tag/endangered-species/" target="_blank">threatened</a>" under International Union for Conservation of Nature <a href="https://www.iucnredlist.org/search?query=pangolin&searchType=species" target="_blank">criteria</a>.</p><p>There is an unprecedented demand for their scales, primarily from countries in Asia and <a href="https://conbio.onlinelibrary.wiley.com/doi/10.1111/conl.12389" title="Assessing Africa‐Wide Pangolin Exploitation by Scaling Local Data" target="_blank">Africa</a> where they are used in food, cultural remedies and <a href="https://www.nature.com/articles/141072b0" title="Chinese Medicine and the Pangolin" target="_blank">medicine</a>.</p><p>Between 2017 and 2019, seizures of pangolin scales <a href="https://www.nationalgeographic.com/animals/2020/02/pangolin-scale-trade-shipments-growing/" target="_blank">tripled in volume</a>. In 2019 alone, 97 tons of pangolin scales, equivalent to about 150,000 animals, were <a href="https://oxpeckers.org/2020/03/nigeria-steps-up-for-pangolins/" target="_blank">reportedly</a> intercepted leaving Africa.</p>
Reintroduction of an Extinct Species<p>Each year in South Africa the African Pangolin Working Group (<a href="https://africanpangolin.org/" target="_blank">APWG</a>) retrieves between 20 and 40 pangolins through intelligence operations with security forces.</p><p>These pangolins are often-traumatised and injured and are admitted to the <a href="http://www.johannesburgwildlifevet.com/our-hospital" target="_blank">Johannesburg Wildlife Veterinary Hospital</a> for extensive medical treatment and rehabilitation before they can be considered for release.</p><p>In 2019, seven rescued Temminck's pangolins were reintroduced into South Africa's <a href="https://www.andbeyond.com/destinations/africa/south-africa/kwazulu-natal/phinda-private-game-reserve/" target="_blank">Phinda Private Game Reserve</a> in the KwaZulu Natal Province.</p><p>Nine months on, five have survived. This reintroduction is a world first for a region that last saw a viable population of this species in the 1980s.</p><p>During the release, every individual pangolin followed a strict regime. They needed to become familiar with their new surroundings and be able to forage efficiently.</p>
A ‘Soft Release’ in to the Wild<p>The process on Phinda game reserve involved a more gentle ease into re-wilding a population in a region that had not seen pangolins for many decades.</p><p>The soft release had two phases:</p><ol><li>a pre-release observational period</li><li>an intensive monitoring period post release employing GPS satellite as well as VHF tracking tags.</li></ol>
Why Pangolin Reintroduction is Important<p>We know so little about this group of mammals that are vastly understudied and hold many secrets yet to be discovered by science but are on the verge of collapse.</p><p>The South African and Phinda story is one of hope for the Temminck's pangolin where they once again roam the savanna hills and plains of Zululand.</p><p>The process of relocating these trade animals back into the wild has taken many turns, failures and tribulations but, the recipe of the "soft release" is working.</p>
- 10 Facts About Pangolins on World Pangolin Day - EcoWatch ›
- Meet the 'Pangolin Men' Saving the World's Most Trafficked Mammal ... ›
By Jake Johnson
In a move that environmentalists warned could further imperil hundreds of endangered species and a protected habitat for the sake of profit, President Donald Trump on Friday signed a proclamation rolling back an Obama-era order and opening nearly 5,000 square miles off the coast of New England to commercial fishing.
Why You Should Wash Fresh Produce<p>Global pandemic or not, properly washing fresh fruits and vegetables is a good habit to practice to minimize the ingestion of potentially harmful residues and germs.</p><p>Fresh produce is handled by numerous people before you purchase it from the grocery store or the farmers market. It's best to assume that not every hand that has touched fresh produce has been clean.</p><p>With all of the people constantly bustling through these environments, it's also safe to assume that much of the <a href="https://www.healthline.com/nutrition/fresh-vs-frozen-fruit-and-vegetables" target="_blank">fresh produce</a> you purchase has been coughed on, sneezed on, and breathed on as well.</p><p>Adequately washing fresh fruits and vegetables before you eat them can significantly reduce residues that may be left on them during their journey to your kitchen.</p><p><strong>Summary</strong></p><p><strong></strong>Washing fresh fruits and vegetables is a proven way to remove germs and unwanted residues from their surfaces before eating them.</p>
Best Produce Cleaning Methods<p>While rinsing fresh produce with water has long been the traditional method of preparing fruits and veggies before consumption, the current pandemic has many people wondering whether that's enough to really clean them.</p><p>Some people have advocated the use of soap, <a href="https://www.healthline.com/nutrition/white-vinegar" target="_blank">vinegar</a>, lemon juice, or even commercial cleaners like bleach as an added measure.</p><p>However, health and food safety experts, including the Food and Drug Administration (FDA) and Centers for Disease Control (CDC), strongly urge consumers not to take this advice and stick with plain water.</p><p>Using such substances may pose further health dangers, and they're unnecessary to remove the most harmful residues from produce. <a href="https://www.healthline.com/health/chlorine-poisoning" target="_blank">Ingesting commercial cleaning chemicals</a> like bleach can be lethal and should never be used to clean food.</p><p>Furthermore, substances like lemon juice, vinegar, and produce washes have not been shown to be any more effective at cleaning produce than plain water — and may even leave additional deposits on food.</p><p>While some research has suggested that using neutral electrolyzed water or a baking soda bath can be even more effective at removing certain substances, the consensus continues to be that cool tap water is sufficient in most cases.</p><p><strong>Summary</strong></p><p><strong></strong>The best way to wash fresh produce before eating it is with cool water. Using other substances is largely unnecessary. Plus they're often not as effective as water and gentle friction. Commercial cleaners should never be used on food.</p>
How to Wash Fruits and Vegetables With Water<p>Washing fresh fruits and vegetables in cool water before eating them is a good practice when it comes to health hygiene and food safety.</p><p>Note that fresh produce should not be washed until right before you're ready to eat it. Washing fruits and vegetables before storing them may create an environment in which bacterial growth is more likely.</p><p>Before you begin washing fresh produce, <a href="https://www.healthline.com/health/how-long-should-you-wash-your-hands" target="_blank">wash your hands well</a> with soap and water. Be sure that any utensils, sinks, and surfaces you're using to prepare your produce are also thoroughly cleaned first.</p><p>Begin by cutting away any bruised or visibly rotten areas of fresh produce. If you're handling a fruit or vegetable that'll be peeled, such as an orange, wash it before peeling it to prevent any surface bacteria from entering the flesh.</p><p>The general methods to wash produce are as follows:</p><ul><li><strong>Firm produce.</strong> Fruits with firmer skins like apples, lemons, and pears, as well as <a href="https://www.healthline.com/nutrition/root-vegetables" target="_blank">root vegetables</a> like potatoes, carrots, and turnips, can benefit from being brushed with a clean, soft bristle to better remove residues from their pores.</li><li><strong>Leafy greens.</strong> Spinach, lettuce, Swiss chard, leeks, and cruciferous vegetables like Brussels sprouts and bok choy should have their outermost layer removed, then be submerged in a bowl of cool water, swished, drained, and rinsed with fresh water.</li><li><strong>Delicate produce.</strong> Berries, mushrooms, and other types of produce that are more likely to fall apart can be cleaned with a steady stream of water and gentle friction using your fingers to remove grit.</li></ul><p>Once you have thoroughly rinsed your produce, dry it using a clean paper or cloth towel. More fragile produce can be laid out on the towel and gently patted or rolled around to dry them without damaging them.</p><p>Before consuming your fruits and veggies, follow the simple steps above to minimize the amount of germs and substances that may be on them.</p><p><strong>Summary</strong></p><p><strong></strong>Most fresh fruits and veggies can gently be scrubbed under cold running water (using a clean soft brush for those with firmer skins) and then dried. It can help to soak, drain, and rinse produce that has more dirt-trapping layers.</p>
The Bottom Line<p>Practicing good food hygiene is an important health habit. Washing fresh produce helps minimize surface germs and residues that could make you sick.</p><p>Recent fears during the <a href="https://www.healthline.com/coronavirus" target="_blank">COVID-19 pandemic</a> have caused many people to wonder whether more aggressive washing methods, such as using soap or commercial cleaners on fresh produce, are better.</p><p>Health professionals agree that this isn't recommended or necessary — and could even be dangerous. Most fruits and vegetables can be sufficiently cleaned with cool water and light friction right before eating them.</p><p>Produce that has more layers and surface area can be more thoroughly washed by swishing it in a bowl of cool water to remove dirt particles.</p><p>Fresh fruits and vegetables offer a number of healthy nutrients and should continue to be eaten, as long as safe cleaning methods are practiced.</p>
- 30 Awesome Ways to Use Apple Cider Vinegar Everyday - EcoWatch ›
- Here's How to Clean Your Groceries During the COVID-19 Outbreak ... ›
- 5 Facts You Should Know About Pesticides on Fruits and Vegetables ›
By Danielle Nierenberg
Following the murder of George Floyd by police in Minneapolis, people around the United States are protesting racism, police brutality, inequality, and violence in their own communities. No matter your political affiliation, the violence by multiple police departments in this country is unacceptable.
Mangroves play a vital role in capturing carbon from the atmosphere. Mangrove forests are tremendous assets in the fight to stem the climate crisis. They store more carbon than a rainforest of the same size.
- Protecting Mangroves Can Prevent Billions of Dollars in Global ... ›
- Could the 'Mangrove Effect' Save Coasts From Sea Level Rise ... ›
Monday is World Oceans Day, but how can you celebrate our blue planet while social distancing?
- 5 Things to Know About Earth's Warming Oceans - EcoWatch ›
- Bioluminescent Waves Mesmerize California Beachgoers, Surfers ... ›
- NOAA: 2020 Could Be Warmest Year on Record - EcoWatch ›
- On June 8, We Celebrate Our Oceans, Our Future - EcoWatch ›
- 5 Things to Know About the State of Our Oceans for World Oceans Day ›
By Jacob L. Steenwyk and Antonis Rokas
From the mythical minotaur to the mule, creatures created from merging two or more distinct organisms – hybrids – have played defining roles in human history and culture. However, not all hybrids are as fantastic as the minotaur or as dependable as the mule; in fact, some of them cause human diseases.
When Looking Through a Microscope Isn’t Close Enough.<p>For the last few years, <a href="http://www.rokaslab.org/" target="_blank">our team at Vanderbilt University</a>, <a href="https://www.researchgate.net/lab/Gustavo-Goldman-Lab" target="_blank">Gustavo Goldman's team at São Paulo University in Brazil</a> and many other collaborators around the world have been collecting samples of fungi from patients infected with different species of <em>Aspergillus</em> molds. One of the species we are particularly interested in is <a href="https://doi.org/10.1006/rwgn.2001.0082" target="_blank"><em>Aspergillus nidulans</em>, a relatively common and generally harmless fungus</a>. Clinical laboratories typically identify the species of <em>Aspergillus</em> causing the infection by examining cultures of the fungi under the microscope. The problem with this approach is that very closely related species of <em>Aspergillus</em> tend to look very similar in their broad morphology or physical appearance when viewing them through a microscope.</p><p>Interested in examining the varying abilities of different <em>A. nidulans</em> strains to cause disease, we decided to analyze their total genetic content, or genomes. What we saw came as a total surprise. We had not collected <em>A. nidulans</em> but <em>Aspergillus latus</em>, a close relative of <em>A. nidulans</em> and, as we were to soon find out, <a href="https://doi.org/10.1016/j.cub.2020.04.071" target="_blank">a hybrid species that evolved through the fusion of the genomes</a> of two other <em>Aspergillus</em> species: <em>Aspergillus spinulosporus</em> and an unknown close relative of <em>Aspergillus quadrilineatus</em>. Thus, we realized not only that these patients harbored infections from an entirely different species than we thought they were, but also that this species was the first ever <em>Aspergillus</em> hybrid known to cause human infections.</p>
Several Different Fungal Hybrids Cause Human Disease.<p>Hybrid fungi that can cause infections in humans are well known to occur in several different lineages of single-celled fungi known as yeasts. Notable examples include multiple different species of <a href="https://doi.org/10.1002/yea.3242" target="_blank">yeast hybrids</a> that cause the human diseases <a href="https://rarediseases.info.nih.gov/diseases/6218/cryptococcosis" target="_blank">cryptococcosis</a> and <a href="https://www.cdc.gov/fungal/diseases/candidiasis/index.html" target="_blank">candidiasis</a>. Although pathogenic yeast hybrids are well known, our discovery that the <em>A. latus</em> pathogen is a hybrid is a first for molds that cause disease in humans.</p>
(Left) Candida yeasts live on parts of the human body. Imbalance of microbes on the body can allow these yeasts, some of which are hybrids, to grow and cause infection. (Right) Cryptococcus yeasts, including ones that are hybrids, can cause life-threatening infections in primarily immunocompromised people. Centers for Disease Control and Prevention<p><a href="https://doi.org/10.1371/journal.ppat.1008315" target="_blank">Why certain <em>Aspergillus</em> species are so deadly</a> while others are harmless remains unknown. This may in part be because <a href="https://doi.org/10.1016/j.fbr.2007.02.007" target="_blank">combinations of traits, rather than individual traits</a>, underlie organisms' ability to cause disease. So why then are hybrids frequently associated with human disease? Hybrids inherit genetic material from both parents, which may result in new combinations of traits. This may make them more similar to one parent in some of their characteristics, reflect both parents in others or may differ from both in the rest. It is precisely this mix and match of traits that hybrids have inherited from their parental species that <a href="https://www.nytimes.com/2010/09/14/science/14creatures.html" target="_blank">facilitates their evolutionary success</a>, including their ability to cause disease.</p>