High temperatures send bats swooping in – Irish Examiner, July 2 2018

Bats are harmless and benevolent. Amy Lewis presents a beginner’s guide to spotting these wonderful creatures in Ireland.

As darkness descends on another long summer’s day and we tug our curtains shut, a group of unique creatures are just beginning to emerge in every county across Ireland.

They can eat up to 3,000 insects in one night, have been found to defy some of the usual processes of ageing and have echolocation so finely tuned that they can navigate around a single strand of hair.

While they might sound like something from a sci-fi novel, they’re actually something we are all familiar with: Bats. Ireland is currently home to nine resident species of bat and summer is the ideal time to witness them in action.

“In summer, bats are not long out of hibernation, while it’s also reproduction season. This makes it peak foraging time for them,” says Megan Power, PhD research fellow at the Laboratory of Molecular Evolution and Mammalian Phylogenetics in UCD.

“The weather we’ve been having is ideal for them too. If the weather is good, insect populations will be high.”

Our most common bats are the common and soprano pipistrelles and the Leisler’s bat, also known as the Irish bat as Ireland is a stronghold for the species. Regardless of your location, Paul Scott of Dublin Bat Group and Bat Conservation Ireland says bats are easily found.

“The best place to spot them is somewhere with water and not too much street lighting, so perhaps by canals or in public parks. To see larger numbers, large lakes or canals are best,” says Paul, who adds that anywhere with trees or waterbodies attracts them due to the availability of insects. “The time to look for them is just after sunset.”

When it comes to choosing between rural and city living, bats aren’t fussy. In Dublin, places such as Phoenix Park, and the banks of the Dodder and Tolka rivers are popular bat-spotting sites, while Paul has even witnessed them flying above O’Connell St.

“You find them in strangest of places. They’re not at all bothered with people.”

Bat populations in Ireland can generally be described as stable, according to Dr Tina Aughney of Bat Conservation Ireland, adding that we must be cautious when saying this.

“Bats are very slow reproducing animals and only have one baby per year. You need to get about 25 years worth of data to see what is happening with them before you can really say something about their populations.”

To help in the conservation of Irish bats, Bat Conservation Ireland currently manages four main monitoring schemes: The car-based bat monitoring surveys, the brown long-eared bat roost monitoring scheme, lesser horseshoe bat roost monitoring and the all-Ireland Daubenton’s bat waterways survey. They place a great emphasis on citizen science and offer free training to members of the public who wish to get involved. The waterways survey, which takes place each August, is their most popular.

“We have up to 200 people participating each year. Along with learning to spot various species of bat, it’s great for seeing other wildlife such as badgers foxes and owls,” says Tina.

Volunteers can participate in one of the many two-hour training courses nationwide in July. The survey itself sees every team monitoring ten spots along a one kilometre stretch of waterway, each one for four minutes each. Bat Conservation Ireland will loan bat detectors — devices that pick up ultrasound and convert it to an audible sound — to anyone taking part.

People can also take smaller steps in their locality to help in bat conservation, by erecting a bat box, planting night-scented plants and reducing the amount of light in their garden and community. Additionally, they can take part in a bat walk held by one of the many local bat groups nationwide. Paul currently leads the Dublin Bat Group walks.

“Although it’s a night-time activity, you would be surprised at the number of kids there. Kids will be there until 11pm. because they’re fascinated by bats. When you start to tell anyone the facts, they become fascinated too.”

Paul tries to kick off the walks by dispelling some of the myths about bats. They are more closely related to humans and primates than rodents. Contrary to common belief, bats aren’t blind and they don’t get caught in people’s hair or spread rabies.

“Everyone is afraid of things that creep around in the dark,” he says. “For a long time, people didn’t know much about bats because they’re harder to study so people generated myths around them.”

The true facts about bats are as astounding as the myths. Earlier this year, a team of UCD researchers discovered one reason why certain species of bats have extraordinarily long lifespans relative to their small size. By focusing on telomeres — structures at the end of chromosomes that usually shorten with age and lead to cell breakdown — they found that some species of bat retain long telomeres throughout their lives. Through her research, which is funded through an Irish Research Council Scholarship, Megan is building on these previous findings.

“I’m trying to discover whether bats are regulating their telomeres during stressful life events,” she explains, adding that some bats have been found to live to 41 years of age.

While bats may help scientists to unlock some of the secrets about ageing, they also play other useful roles. “They are a bio-indicator meaning they are good indicators of how healthy our environment is,” says Paul. “Bats are an extremely vital part of our ecosystem,” adds Megan. “They help maintain and regulate insects. They provide key ecosystem services worldwide through the pollination of plants and crops.”

“I always encourage people to have a look at the many species of bat and the different things they do. I may be biased but I think they’re beautiful.”

More information can be found on the Bat Conservation Ireland Facebook page or website.

(First published in the Irish Examiner on July 2 2018. Available online at: https://www.irishexaminer.com/breakingnews/lifestyle/features/high-temperatures-send-bats-swooping-in-852307.html)

Advertisements

Is it okay to remove Cowbird eggs from host nests? – Audubon.org, June 6 2018

It can be tempting to interfere with these brood parasites. But there are many reasons—legal and behavioral—to leave them alone.

No parent appreciates another meddling in their child-rearing efforts. Unfortunately for many songbirds in North America, meddling is the Brown-headed Cowbird’s modus operandi.

The species is our best-known brood parasite—organisms (like some birds, insects, and fish) that rely on others to raise their young. In birds, this typically describes a species that lays its eggs in a host’s nest and lets that other parent do the chick-raising, often to the detriment of the host’s own offspring. Cowbird chicks don’t directly harm their nestmates (by pushing them out of the nest, for instance, like some cuckoo species), but tend to grow faster and outcompete them for resources.

Due to a perceived sense of injustice, cowbirds are often vilified by humans, who occasionally take matters into their own hands by removing cowbird eggs from nests. These are usually well-intentioned attempts to “save” the chicks of other species—but is it a good idea to allow people’s drive to nurture interfere with nature?

The short answer: no. “The best solution is to leave cowbirds eggs alone,” says Steve Rothstein, Emeritus Professor of Zoology at the University of California, Santa Barbara, who has researched the effects of cowbird parasitism on endangered species. “It’s a natural process and we shouldn’t attach human values about killing or being sneaky to the natural world.”

The reasons are multifold, and encompass both the law and unintended consequences.

U.S. law already says that people should not interfere with cowbird eggs. As a native species, the Brown-headed Cowbird is protected under the Migratory Bird Treaty Act, and taking eggs is illegal without a permit. While permits for cowbird control have been granted, it’s only done when they’re considered a threat to endangered birds. For example, in Michigan, the U.S. Fish and Wildlife Service traps an average of 4,000 cowbirds every year to protect endangered Kirtland’s Warblers.

The law is only one reason to leave eggs untouched, Rothstein says; interference can have unintended effects. That’s because “most birds in North America don’t have egg-recognition abilities”—often not even for their own eggs. However, parents do keep track of the total mass of eggs in their nest. “Many seem to assume the cowbird egg is part of their clutch and will have a nest-desertion response if we remove a certain proportion of eggs,” Rothstein, who has examined this behavior in his research, says. They may even desert the entire area and find a new nesting spot.

“This response is universal among birds, as they have the option to re-nest,” he continues. “However, if it’s late in the breeding season, the bird might not have time to.”

Worse, egg removal can result in retribution by cowbird parents. A 2007 study, led by avian ecologist Jeffrey Hoover with the Illinois Natural History Survey, was the first to document what’s known as “mafia behavior.” In the experiment, scientists observed the effects of removing Brown-headed Cowbird eggs from parasitized warbler nests. In 56 percent of cases, cowbird mothers returned and ransacked the nest, destroying most or all eggs. Comparatively, six percent of nests were destroyed when humans didn’t interfere.

While no additional research has confirmed this behavior in Brown-headed Cowbirds, it highlights “a potential further complication to removing cowbird eggs,” says Matthew Louder, who studies cowbird brood parasitism at the University of Illinois at Urbana-Champaign. For Louder, the only instances where cowbird egg removal is justifiable is when it’s legally conducted to help one of three endangered species: Golden-cheeked Warblers, Black-capped Vireos, and Kirtland’s Warblers.

“Cowbirds aren’t the main reason for their decline, and probably not even a great contributing factor. The only factor in the decline of these species is humans,” he says. “Now numbers are so low that any other problems [such as brood parasitism] would push them over the edge.” If cowbird control is permitted, Louder says it must be done alongside habitat restoration measures.

Rothstein agrees that cowbird control and habitat improvement must go together. “Cowbirds have been in North America for a million years,” he says. “If a species needs help, it’s because we have damaged their habitat. Any species that would go extinct just because of cowbirds and not human interference would have gone extinct long ago.”

All this evidence points to a single conclusion: Cowbird eggs should be left alone. It can be disturbing to observe what looks like “cheating” at the expense of less common species—but it’s just nature’s way, even if it’s ugly. Sarah Winnicki, an avian ecologist at Kansas State University, has found a way to adjust her own perspective on the species to avoid moralizing their behavior.

“I try to convince people about how amazing [cowbirds’] evolutionary story is,” she says. “How did they learn to find nests, to lay eggs, and to re-find them later? How do they learn to time their reproduction to their hosts? As an ornithologist, this is incredible to me.”

(First published on Audubon.org on June 6 2018. Available online at: https://www.audubon.org/news/is-it-okay-remove-cowbird-eggs-host-nests)

The Eskimo Curlew hasn’t been seen for 55 years. Is it time to declare it extinct? -Audubon, April 22 2018

Scientists hope the plight of this shorebird, once among the most common in North America, will spur conservation for other troubled curlew species.

Victor Emanuel will never forget the day he saw his first Eskimo Curlew. It was around 60 years ago, in Galveston, Texas, when the foot-long, brown-speckled bird poked its down-curved bill through the grass—a rare gem nearly invisible among a field of other mottled shorebirds. At first, Emanuel and several others believed it was a runt Whimbrel. But after checking all possible field marks and consulting guides, they confirmed that what they saw was the rare Eskimo Curlew. They were among the last people to see the species alive.

“There’s a chapter in my memoir in which I call it the bird of my life,” Emanuel says. “For a birder who had seen this bird in field guides, which said it was possibly extinct, it was like seeing a dinosaur. It had a huge effect on me.”

At one point, the Eskimo Curlew may have been one of the most common shorebirds in North America, with a population numbering in the many millions. Flocks once migrated from wintering grounds in South America, through the Great Plains, to breeding territories in Alaska and Canada—and back south off the Atlantic Coast.

For most people today, though, the species is merely a legend, fueled by old stories and the highly regarded 1954 book Last of the Curlews by Fred Bodsworth. Photographer Don Bleitz took the last known photo of the shorebird in Galveston in 1962, and the last confirmed sighting was in 1963, when a lone bird was shot in Barbados. In 1983, a reported sighting of 23 Eskimo Curlews in Texas stirred up much excitement, but it was not accepted by the state bird records committee.

“It seems quite unbelievable to me that so many birds would show up on a single occasion, and not be seen ever again,” says Jon McCracken, director of national programs at Bird Studies Canada. “It’s like verifying that there are UFOs out there without good solid physical evidence.”

Though most cite the Barbados record as the last true sighting of the Eskimo Curlew, reports are still occurring—but they’re mostly wishful thinking. “Every season starting in June or July, I get a call with someone reporting an Eskimo Curlew,” says Bob Gill, a shorebird biologist at the U.S. Geological Survey’s Alaska Science Center in Anchorage who co-authored a detailed account of the species in The Birds of North America. “Invariably they are juvenile Whimbrels.”

What happened to this once-widespread species, you ask? They were hunted in large numbers through the 1800s; hunting migratory birds, except for those species approved by the government, largely ceased in 1918 with the passage of the Migratory Bird Treaty Act. Yet hunting is not the sole cause of decline, Gill says.

“Was it a contributing factor? Absolutely. Was it the only factor? No way,” he says. “As this bird was being hunted, the prairies were being plowed under and a principal food source, the Rocky Mountain grasshopper, was going extinct.” These grasshoppers once had population booms in the billions; in 1875, they formed the largest recorded locust swarm: 1,800 miles long and 110 miles wide, blanketing Plattsmouth, Nebraska for five days. As grasslands were converted to cornfields, the locusts vanished—and grassland birds, like the curlew, did, too.

“Hunting is an easy thing to blame,” Gill continues. “I just hope people can be more objective and look at the big picture.”

That’s particularly important given the threats to the seven other curlew species. This genus of wading migratory shorebirds, distinguishable from others by their down-curved bill and mottled plumage, faces threats in regions across the globe. The Eurasian Curlew, for example, has seen its European breeding population decline by at least one-third in 30 years due to loss of its grassland habitat, and significant declines have also been recorded in central Asian populations. The Bristle-thighed Curlew, with 7,000 individuals, is currently classed as vulnerable by the IUCN Red List, with drops in numbers largely attributed to predation by introduced predators on its wintering grounds in tropical Oceania; considering that more than 50 percent of adults are flightless during autumn molt, they are particularly easy targets.

Then there’s the Far Eastern Curlew, with a population of 32,000 birds in 2006, according to Wetlands International estimates. Habitat loss on the Yellow Sea staging grounds is considered the primary threat to the species and, with the rate of intertidal habitat loss averaging over 1 percent annually, this trend is expected to continue. While the Long-billed Curlew, Whimbrel, and Little Curlew are not currently a cause for concern, due to their relatively stable populations and wide range, ongoing climate change and habitat degradation could threaten them in the future.

Finally, there’s the Slender-billed Curlew, which hasn’t been spotted since 1995. Similarly to the Eskimo Curlew, historical hunting and habitat loss are believed to be key to their disappearance.

The Eskimo Curlew has not been declared extinct—yet. It is currently considered “critically endangered (possibly extinct)” by the IUCN. The latest report by the Committee on the Status of Endangered Wildlife in Canada again declared the bird endangered in 2009. In 2011, the U.S. Fish and Wildlife Service launched a five-year status review of the bird, which upon completion continued to list it as endangered.

Despite there being no confirmed sightings since 1963 and no evident breeding in more than 100 years, it’s difficult to definitively say whether the Eskimo Curlew is extinct.

“It’s a case of trying to prove a negative; absence of evidence isn’t proof of absence. If you can’t prove an absence, is it extinct or not?” says McCracken, who authored Canada’s 2009 report. “I personally believe that it probably, almost certainly, is extinct, and I think that’s the general consensus.”

Canada plans to reassess the Eskimo Curlew’s status in 2020, with no confirmed date yet for the U.S. review.

Regardless, circumstances remain dire for other curlews and birds that breed or migrate through landscapes that have been transformed. And based on the lack of optimism Gill hears at shorebird meetings, he’s not sure how much can be done to reverse the damage. For decades, scientists have sounded the alarm about the wildlife impacts of land fragmentation and the conversion of prairies and forests to farmland. At this point, he says, it might be too late. The changes people have made are vast; there’s no converting all of that farmland back to grassland.

Still, Gill maintains some hope that people might be convinced even quirky birds like curlews are worth the effort. And the story of the Eskimo Curlew could help.

“If we declare this bird extinct, let’s use it to our advantage and prevent others from becoming extinct,” he says. “I think anything we can do to raise public awareness will help [to protect other species]. We need to get people to get in touch with their concerns they may not have even known that they had.”

(First published on Audubon on April 20 2018. Available online at: http://www.audubon.org/news/the-eskimo-curlew-hasnt-been-seen-55-years-it-time-declare-it-extinct)

Tackling Ireland’s alien invaders – Irish Times, March 8 2018

The Japanese knotweed, rhododendron and giant hogweed are fast becoming household names as these pests continue to invade Irish landscapes. These ill-famed plants are just some of many invasive species causing destruction to Ireland’s ecosystems.

An inaugural global register of invasive species recently presented in Scientific Data shows that the Republic of Ireland is currently home to 1,266 non-native species – 63 of which have a negative impact. Ireland was one of 20 countries randomly selected for inclusion in this Global Registry of Introduced and Invasive Species (GRIIS), which will include every country by 2019.

“We focused solely on environmental and economic impacts,” says Shyama Pagad, lead author of the work and member of the IUCN SSC Invasive Species Specialist Group (ISSG). “We think it will help countries with trading partners. When you know your trading partner has listed this invasive species, you can set preventative measures to stop them from entering your country. It forms a basic alert system.”

While the ISSG researchers formed their database through analysing existing publications, they required the assistance of local editors to check and add to it. Invasive species officer at the National Biodiversity Data Centre Colette O’Flynn was recruited as editor for Ireland. The use of universal terminology, in addition to the fact that her team are currently undertaking a similar exercise, meant that editing wasn’t difficult.

“It’s always going to be a dynamic list,” O’Flynn says. “Assessments must be repeated as more animals come in and things we thought were invasive turn out not to be, or at least not as invasive as they appeared.”

Asked what our most harmful invasive species is, she says aquatics like the zebra mussel are particularly problematic. These creatures arrived in Ireland in the 1990s, attached to the hulls of imported leisure boats.

“Zebra mussels change the whole ecology of the lake system. They filter water when feeding; you would think that’s a great thing as they clean out the water but this causes more sunlight to reach the plants on the bottom. Those plants then grow more vigorously and this completely changes the food web in the lake.”

In addition to threatening lake systems and native mussels, Zebra mussels also block water intake pipes, filters and boat engines where they settle in large clusters.

Notorious plants such as Japanese knotweed are also acknowledged by O’Flynn as damaging species, which hold the potential to undermine road and building foundations. However, she feels that recent years have seen a big shift in efforts to deal with invasive species.

“This is driven by a number of things. Finding out more about species through databases like this definitely helps, as does people sending sighting reports to our centre,” she adds. “When we have the data, we can analyse it and use it to inform decision-making.”

The European Regulation of Invasive Alien Species enacted in 2015 involves a dynamic list of 49 invasive species of concern in the EU. Once a species is added, each member state is required to carry out appropriate prevention, early detection and rapid eradication and management measures.

Acknowledging the regulation’s potential, head of the Department of Environmental Science at IT Sligo Dr Frances Lucy says it hasn’t truly been enacted yet in Ireland or other member states. “The reason why [it’s not being followed] is because it’s a very new regulation. The European Commission is still gathering information and there hasn’t been any punitive measures attached to it yet.”

Lucy is a firm believer that citizen science is key to tackling our invasive species and in turn, protecting biodiversity. “Even if we had 1,000 biodiversity officers and a whole legislative system in place, it’s not what is going to save biodiversity in Ireland,” she notes. “Right now, we are in danger of disengaging from nature because we don’t spend as much time outdoors as we used to due to the virtual reality we’re using. Why not use virtual reality to re-engage people?”

She refers to the use of various apps, Twitter and other tools currently being used by the public to report and record various species. For example, the National Biodiversity Data Centre receives 10,000 sighting reports a month through interactive tools.

“The recording of species is one key area where citizens can get involved. The other vital part regards invasive species management, particularly biosecurity. The man on the street needs to know how to manage and prevent their spread,” she says. “This can be done by taking simple precautions every time we engage in outdoor recreational activities; this should be automatic, like putting on your seatbelt.”

If the Government put more funds into educating people on recognising and managing these species, money would be saved in the long run, Lucy points out.

While recognising it’s a concern, campaigns officer at the Irish Wildlife Trust Pádraic Fogarty feels the invasive species issue has “been overblown”.

“A lot of ecologists have taken their eye off the ball. Habitat loss, pollution and biodiversity loss are still our biggest problems in Ireland. Invasive species thrive in habitats that are damaged and degraded,” says Fogarty, who feels these big issues are not being addressed.

“The idea of invasive species is easier to tackle than habitat loss. That’s often more controversial, particularly as agriculture and peat extraction industries can be difficult to deal with.”

There’s an app for that

Technology plays an integral role in identifying and mapping locations of particular species, including invasive ones. The National Biodiversity Data Centre’s Biodiversity Data Capture App allows people to capture details of any species they encounter and send them directly to the National Biodiversity Data Centre’s database.

Meanwhile, the Report Invasive Plants app was developed by Limerick County Council in 2016 specifically in response to invasive plants. It records four species – Japanese knotweed, winter heliotrope, giant hogweed and Himalayan balsam – in addition to having an “other” category.

To date they have received 900 sighting reports from 130 individual users, with Japanese knotweed being the most commonly recorded. Collected data is fed back to the National Biodiversity Data Centre.

“We used cameras and GPS prior to this but it was very time consuming. With just one person doing it, it was never going to work,” explains senior executive engineer with Limerick County Council Anne Goggin. “There are other apps out there to capture invasives but many are complicated. We wanted something quick and simple, aimed at someone who is not a specialist but does have a passing interest.”

Inland Fisheries Ireland also have developed an app to allow for the reporting of invasive species occurring within Irish fresh water.

(First published in The Irish Times on March 8 2018. Available online at: https://www.irishtimes.com/news/science/tackling-ireland-s-alien-invaders-1.3419509)

Leopards that live in cities are protecting people from rabies – New Scientist, March 8 2018

When leopards stray into a city, people often fear them because of the danger they pose. But it turns out these big cats could be valuable neighbours: by preying on feral dogs in Mumbai, they are reducing the risk of people catching rabies.

About 20,000 people die of rabies in India every year. Feral dogs are the main source, as they bite people and pass on the rabies virus.

Christopher O’Bryan and Alexander Braczkowski at the University of Queensland and their colleagues compiled existing data on the diet of leopards living in Sanjay Gandhi National Park, on the edges of Mumbai. They found that 40 per cent of the average leopard’s diet consists of feral dogs.

All told, the 35 leopards in the park probably eat 1,500 dogs per year. Given how often the dogs bite people and how many of them have rabies, the leopards’ kills are preventing about 1,000 bite incidents per year – and 90 potential rabies cases.

“This study is a striking example of a large carnivorous animal providing a direct benefit to humans,” says O’Bryan.

The same could be true of other leopard populations that encroach on cities. The team found 19 studies describing leopards eating feral dogs in Asia and Africa. However, O’Bryan says that they would need to be studied more closely to be sure that they bring the same benefit.

The researchers also emphasise that leopards can  cause harm. In particular, they often kill livestock – leading people to persecute them.

“It’s difficult to weigh up the costs with the benefits with a large cat species that’s known to attack and even kill humans,” says O’Bryan. “We just want to provide an angle that hasn’t been explored before, despite the pieces of the puzzle being in front of us the whole time.”

Journal reference: Frontiers in Ecology and the Environment, DOI: 10.1002/fee.1776

(First published online by New Scientist. Available online at: https://www.newscientist.com/article/2163166-leopards-that-live-in-cities-are-protecting-people-from-rabies/)

Natural Pest Control Method Taking Flight – Earth Island Journal, February 26 2018

Farmers from Israel to California are embracing barn owls over toxic rodenticides

A recent study linking fatalities of California’s endangered northern spotted owl to rodenticide poisoning on marijuana farms reignited the flaming debate about the use of chemical agents in agriculture. Yet as discussion rages on, farmers elsewhere are using owls as a pest control solution, hopefully preventing them from becoming pest control victims. And the idea seems to be taking off.

photo of barn owl box

Photo by Bill Gracey: A mature barn owl delivers food to a young owl nesting in an owl box. Barn owls are cavity nesters, meaning they nest in places like hollow trees, open buildings, and nest boxes.

Most farmers use rodenticides to minimize the damage that rodents can cause to crops, but it is no secret that these chemicals can have unintended effects, such as the secondary poisoning of non-target species. As a result, some people have attempted to find other ways of keeping pests at bay, including by attracting barn owls to fields to prey on rodents.

Using barn owls as a form of biological pest control is certainly not a novel idea. First developed as a pest control technique through Malaysian studies in the 1970s, the idea truly took flight in Israel in 1981 when local researchers and farmers decided to test it out at Kibbutz Neot Mordechai, an agricultural community in the Hula Valley. Led by the Society for the Protection of Nature, the Nature and Parks Authority, three keen researchers, and some local farmers, this project saw the installation of eight barn owl boxes, three of which were occupied within a year. (Barn owls are drawn to boxes as nesting sites.) However, like most scientific experimentation, the trial did not come without complications. A pioneering young nature conservationist with the Society for the Protection for Nature, Yehuda Weiss, who played a pivotal role in the research, was killed in action in Lebanon when war later broke out in June 1982, bringing the vital work in this area to a halt.

This did not deter the researchers and farmers involved. Confident in the efficacy of the method following the trial and resulting nestbox occupation, they relaunched their project the following year in Israel’s Beit Shean Valley. Three decades later, and following plenty of ups and downs, between 3,500 and 4,000 owl boxes have been erected across Israel by open-minded farmers willing to give this method a try. The growing interest in natural pest control methods has spurred several related initiatives, including a national barn owl box program and a regional cross-border peace project with Jordan and the Palestinian Authority.

Another recent initiative is the Shamir Research Institute at Haifa University’s Project Bird Box Israel. This group aims to assist farmers who wish to set up their own owl boxes through education and the provision of boxes. Dr. Motti Charter, Head of Project Bird Box Israel, is quick to credit local farmers for the success of this pest control method.

“I’ve given many ideas in my life, but sometimes it’s very easy to simply just say an idea; the person who takes and does it deserves the credit. In Israel, this initiative is 100 percent down to the farmers. They did it slowly and took their time. Little by little, it grew,” explains Charter, whose scientific research sees him monitoring all of the boxes in the Hula Valley in order to improve the efficiency of the nest boxes. “I’ve been able to jump on board because I researched owls but I would have never been able to do this if it wasn’t for them.”

Such methods require more than just barn owls and some willing farmers; having the correct infrastructure in place is key. Barn owls are cavity nesters, so farmers can attract them to an area with a rodent problem — and encourage them to remain and breed there — by erecting simple pole-mounted nest boxes. Project Bird Box Israel offers some assistance to farmers to help purchase the boxes, which cost $250 each, but Charter says that farmers personally pay 95 percent of the price themselves.

Over in the US, Mark Browning, who owns the company Barn Owl Box, has supplied at least 5,000 boxes to farmers and landowners interested in testing out biological pest control. For him, it is not solely a business. It was Browning’s own satellite telemetry study on barn owls, which he conducted while working at the Pittsburgh Zoo, that encouraged him that this was a worthwhile cause. He spent a year and a half perfecting the perfect barn owl box design before putting it on the market.

Echoing Charter, Browning says he doesn’t try to convince farmers to use his solution, he just presents the information. “The way you encourage people to adopt a method is by ensuring that you get the information out there,” he explains. “It is easy for farmers to believe that using a bird is esoteric and mystical but they may not necessarily feel they’re effective at controlling rodents.”

But sometimes the research speaks for itself. Indeed, a three-year study conducted by Browning and colleagues to measure the impact of barn owls on rodent populations on a 40-ha vineyard in California appears promising. The installation of 25 nest boxes on the vineyard led to the rapid growth of the barn owl population on the treatment site. As bird numbers grew, there was a significant decline in the number of gopher mounds. The researchers estimated that the birds consumed 30,020 rodents over three years. They also deemed biological pest control as more cost-effective than trapping or poisoning as it only requires one initial investment in the boxes, rather than repeated investment in traps or rodenticides.

Barn owls are a species that lend themselves well to the task of pest control for several reasons, explains Browning. Unlike other birds, they are not territorial and are happy to nest near one another, as well as within close proximity to humans. They are also attracted to nest boxes, while the fact that they are not powerful fliers ensures that they won’t stray far from their prey source. All of these factors, along with the fact that barn owls pose no threat to livestock, has inspired landowners to test barn owl-based pest control through small initiatives in Argentina, the UK, and Indonesia. Other birds have also been shown to have a similar pest control benefit. For example, researchers in New Zealand found that vineyards with resident falcons had significantly fewer pest birds and less grape damage.

According to Browning, the relationship between barn owls and farmers is symbiotic: “Every time we are distributing a nest box, we are expanding habitat for a very important bird, as well as experiencing a practical application of using natural methods of control. That’s a win-win situation.”

While confident in the method, Browning hopes that more studies will be carried out to determine the effectiveness of barn owls across various cropping systems and scenarios. Roger Baldwin, a wildlife specialist at University of California, Davis, echoes the desire for more studies in this area. Together with colleagues, he is currently conducting research to see whether the birds of prey can help control rapidly expanding populations of rodents such as voles.

Baldwin believes that using barn owls to control rodent numbers will be more effective if all landowners in a given area use the same method, therefore encouraging a greater regional density of owls. However, based on current knowledge, he feels that there’s no one size fits all solution to pest control, and is a firm believer in a combined approach.

“I suspect that in most cases regarding the management of pests, the integrated pest management approach is the most effective; this incorporates multiple strategies of pest control and can target the susceptibility of an animal,” he says. “For example, some creatures are not as prone to walking into traps, others are not as prone to feed on bait or be predated on.”

Baldwin believes that there will always be a place for rodenticides and is quick to address their dirty reputation. “Everyone thinks of rodenticide as one product. There are a variety of different kinds with different active ingredients. Not all of them have the same risk to non-target species and some have no secondary risks. It is a bit challenging to use the term rodenticide without understanding the differences,” he says.

While second generation anticoagulants have been shown to cause harm to non-target species, Baldwin says that other chemicals such as zinc phosphide have relatively no harmful secondary effects. Overall, he feels that responsible usage is key.

However, Maggie Ruffo, a wildlife volunteer with Earth Island Institute’s Raptors Are The Solution (RATS) initiative, would “strongly disagree” that any rodenticides can be used safely.

“From all the research we have read, there are no safe poisons,” says Ruffo, who is also a certified naturalist and volunteer with the Hungry Owl Project. “Anything you put out into the environment is going to cause a problem for wildlife.”

The primary aim of the RATS initiative is to take rat poison off the market and educate the public in alternative pest control methods. According to Ruffo, barn owls are one tool in the toolbox of Integrated Pest Management,” and can in fact be more effective than rodenticides, which can wipe out beneficial predator species through secondary poisoning.

“Rodents are always going to be part of the environment,” Ruffo adds. “They are the chosen prey item for many species. It’s a question of us learning to live with that fact, and doing our best to keep them out of our dwellings and businesses … and then creating attractive habitat for our beneficial predators.”

(First published on Earth Island Journal on February 26 2018. Available online at: http://www.earthisland.org/journal/index.php/elist/eListRead/natural_pest_control_method_taking_flight/)

How microbes may influence our behaviour – The Scientist, September 2017

Stress, anxiety, and depression are emotions we all feel at some point in our lives, some people to a greater degree than others. Part of the human experience, right?

“It may seem odd that my research focuses on the gut if I’m interested in the brain,” says  John Cryan, a researcher at the APC Microbiome Institute at University College Cork in Ireland. “But when we think of how we express emotion in language, through sayings like ‘butterflies in your tummy’ and ‘gut feeling,’ it isn’t surprising that they’re connected.”

In a recent study, Cryan and his colleagues reported a link between the microbiome and fear. By examining mice with and without gut bacteria, they discovered that the germ-free mice had blunted fear responses (Mol Psychiatr, doi:10.1038/mp.2017.100, 2017). Their findings may pave the way for the development of novel treatments for anxiety-related illnesses, including posttraumatic stress disorder.

Researchers at Kyushu University in Japan were the first to show, in 2004, that bacteria in the gut can influence stress responses, prompting many subsequent investigations. Yet despite mounting research, scientists remain uncertain about exactly how the gut microbiome affects the brain. While some bacteria influence the brain through the vagus nerve, other strains seem to use different pathways. It is known, however, that the population of the gut microbiome begins in early life, and recent research suggests that disruptions to its normal development may influence future physical and mental health (Nat Commun, 6:7735, 2015).

Researchers are finding that this gut-brain connection could have clinical implications, as influencing the gut microbiome through diet may serve to ameliorate some psychiatric disorders. Together with University College Cork colleague Ted Dinan, Cryan coined the term “psychobiotics” in 2013 to describe live organisms that, when ingested, produce health benefits in patients with psychiatric illness. These include foods containing probiotics, live strains of gut-friendly bacteria.

While there are many rodent studies linking probiotics and mental health, UCLA biologist Emeran Mayer and his colleagues were the first to test them in humans, using functional magnetic resonance imaging (fMRI) scans to assess the results. After administering probiotic yogurt to a group of healthy women twice a day for four weeks, the researchers found that the women had a reduced brain response to negative images (Gastroenterology, 144:1394-401, 2013).

“We reanalysed the data several times and convinced ourselves that it’s real,” Mayer says. “You can almost say it was a career-changer for me.”

Having conducted this study on healthy participants, Mayer is reluctant to conclude that probiotics can cure mental illnesses such as anxiety. “It’s a complex emotion, not just a reflex behavior like in the mouse,” he says. However, Mayer says he’s very supportive of the potential of prebiotics—fiber-rich foods  that promote the growth of beneficial bacteria in the gut.

Researchers at Deakin University in Australia recently trialed a Mediterranean-style diet, which is predominately plant-based and fiber-rich, in a group of adults with major depression. They found that one-third of the participants reported a significant improvement in symptoms after 12 weeks on the diet (BMC Medicine, 15:23, 2017). One of them was Sarah Keeble from Melbourne. “I’ve suffered from depression for 17 years. At the start of this study, I was right at the bottom of the barrel,” she recalls. “After a few weeks, that sinking feeling slowly lifted, and my motivation and enthusiasm improved.”

Just as activity in the gut seems to affect the brain, mental stress can lead to intestinal problems. Scientists have demonstrated this in research on irritable bowel syndrome. For example, a study by Mayer and colleagues linked early-life emotional trauma to an increased risk of developing the bowel disorder (Clin Gastroenterol Hepatol, 10:385-90, 2012).

As data on the brain-gut axis accumulates, many scientists are taking notice. Trinity College Dublin researcher Shane O’Mara says that there is “great potential” in this area, but cautions that it’s too early to say whether targeting the microbiome will play a role in psychiatric treatment. University of Manitoba gastroenterologist Charles Bernstein also feels the research is promising but believes we are “far from manipulating the microbiome to treat mental health disorders.”

Those spearheading this research are equally aware of the need for more studies, particularly in human subjects, but they are hopeful that change lies ahead. “I’m almost certain that in several years, diet will be considered one branch of therapy for many mental illnesses, alongside medication and psychiatric treatments,” says Mayer.

“People with severe mental illness will still need something very strong, but this is a useful adjunctive,” agrees Cryan. “I think when we go to our GP in future, we will not only have blood tests, we will have the microbiome tested.”

“Within five years, I hope to see more clinical trials that demonstrate the efficacy of prebiotics and probiotics on mental health disorders,” says University of Chicago microbial ecologist Jack Gilbert. “There needs to be a revolution in how we deal with mental illness in our society.”

(First published in The Scientist magazine September 2017. Also available online at: http://www.the-scientist.com/?articles.view/articleNo/50146/title/How-Microbes-May-Influence-Our-Behavior/)