Related news I just saw thanks to PERCs TwitX feed: More jaguars coming back to Arizona.
1. Giving jaguars ‘food poisoning’ may stop them from killing livestock
Jaguar attacks on pets and farm animals are a common problem, but after developing a drug-induced stomach ache, the big cats seem to learn not to kill certain animals.
Here’s a link to the study.
By treating meat with high doses of deworming medication and wrapping it in the skin of domestic animals, scientists may have successfully thwarted attacks on livestock and pets – and hence lethal repercussions on the wild cats, says Ivonne Cassaigne at Primero Conservation in Mexico City.
In 1974, researchers reported trying to prevent coyote attacks on sheep by taking advantage of the “food poisoning” effect that occurs in people when we experience nausea and abdominal pains after a bad meal and then find the same food disgusting later. This reaction, called conditioned taste aversion, evolved in most animals as a way to avoid toxic food, says Cassaigne. Unfortunately, early taste-aversion studies in wild predators generally failed because the animals could smell the poison in the meat, she says.
In 2009, Ron Thompson at Primero Conservation in Pinetop, Arizona, found that thiabendazole – an odourless, tasteless deworming medication – gave two captive pumas a safe but serious stomach ache when injected into the skin-wrapped meat of desert bighorn sheep. The cats later refused to eat any desert bighorn sheep meat, he says.
Hoping to put jaguars off hunting domestic animals, Cassaigne, Thompson and their colleagues recently added high but non-lethal doses of powdered thiabendazole into 2 kilograms of mutton or pork wrapped in the animals’ own skin. They fed this meat to six captive jaguars in three Mexican wildlife refuges.
Within 3 hours, the cats became lethargic and sometimes howled, says Cassaigne. Some later vomited and had diarrhoea for a few hours.
The next day, the jaguars had good appetites and eagerly ate beef. But none of them ate the pork or mutton offered to them. “[One female] grabbed it and had it in her mouth, but then she spit it away,” says Cassaigne. “She was like, ‘Oh wow, yeah, I remember now!’” Their aversion to those specific meats lasted at least a month, when the experiment ended.
Later, Cassaigne and her colleagues injected thiabendazole into the carcasses of a calf and a feral dog that had been killed and then left by two wild jaguars in Mexico. Villagers were contemplating targeting the cats due to their killing sprees. “We spoke with the locals and said, ‘Please just let us try this instead of killing them,’” she says.
In both cases, the wild males came back to continue eating the spoils. One never attacked another calf over the next seven months. The other killed one dog – but didn’t eat it – and never attacked again over the following year of monitoring, says Cassaigne. This jaguar might have been attacking dogs for years already and was used to hunting them, making it harder to stop the habit, she adds.
Jorge Tobajas at the University of Córdoba in Spain says he is relieved that researchers are finally exploring the use of conditioned taste aversion in endangered felines due to their conflicts with humans over livestock. While the tests in the wild were inconclusive, those in captive jaguars showed great promise, he says.
“It is crucial to conduct further field experiments in a more controlled manner, focusing on areas with recurring attacks that allow for before-and-after treatment comparisons,” says Tobajas. An important next step would be to follow tagged jaguars with GPS transmitters to better understand their reaction to treatment, he adds.
Training predators to learn a taste aversion before releasing them into the wild – such as in rewilding programmes – is the ideal scenario, says Cassaigne. “You don’t want to start with a problem.”
I wonder whether similar apps are being developed in the US?
“It’s a very serious problem,” says Andreas Kamilaris at the CYENS Center of Excellence in Cyprus. “The statistics show that casualties, as well as the area of land burned, around the world are increasing year by year.”
That prompted Kamilaris and his colleagues to build a mobile app that provides personalised evacuation routes to anyone caught in the path of a wildfire. The app connects over mobile networks to a web server running a fire simulation program, which uses publicly available data on geography, weather and vegetation type to predict the spread of fires at 15-minute intervals.
A fire management tool similar to those already in use lets local fire departments quickly tag when and where a fire starts, which is then used to generate real-time simulations. The app then uses the GPS location of each user to work out potential routes, selecting the best by weighing up how quickly each route gets them to safety against how close it takes them to the fire’s path. The best option is then displayed either as turn-by-turn directions or as a route overlaid on a map of the area.
In a small pilot at the Athalassa National Forest Park in Cyprus, all 17 people who took part successfully escaped a simulated fire. In questionnaires afterwards, they said the app was easy to use and that they would use it in a real wildfire.
But Ed Galea, a fire safety expert at the University of Greenwich in the UK, worries the route-planning algorithm the researchers use is too simple to deal with the complexities of a real-world evacuation, such as varying travel speeds or congestion on escape routes.
And while fire and evacuation models can help experts plan or respond to emergencies, he thinks even state-of-the-art systems have limitations that currently make them unsafe in the hands of untrained people. “That is not to say that the goal of having a personalised wildfire evacuation guidance system is not achievable,” he says. “Just not today.”
Kamilaris admits the app still needs work and says the researchers plan to add features, like the ability to tailor travel speed and monitor users to prevent congestion, before testing again in more challenging scenarios.
This story is interesting because there are two ideas here that seem a little different. First is the “intact forests” idea:
With Funga, Averill is using soil from intact forests to inoculate newly planted trees to make them grow bigger and faster, generating carbon credits the company can sell. The concept is similar to faecal transplants for gut microbiome disorders, says Averill. “But we apply it to the forest.”
In mid-February, planters started inoculating soil on 40 hectares of a commercial loblolly pine plantation near Lexington, Georgia. The planting itself is straightforward: a scoop of soil from an area of intact forest is added to a hole where a sapling is planted. Identifying precisely which soil to scoop is more complicated.
But this sounds like they figured out the best ones (like selecting trees, only microbes) and collected them from the test site (not “intact” forests).
Over the past year, Funga researchers analysed tree growth rates and sequenced the DNA of soil microbes in 500 loblolly pine forests around the south-eastern US to determine which composition of microbes is associated with the most growth. They then collected these candidate microbes from the test site in Lexington and inoculated new saplings.
Averill says they also planted trees without the added soil to establish a baseline against which to compare any additional carbon stored by the inoculated trees.
Results won’t be available until the end of 2023, but Averill says similar methods increased forest productivity between 30 and 70 per cent at a research plot where he works in Wales.
He and his colleagues also analysed 81 experiments that examined how inoculating soil with wild microbiomes affected various types of plants in different ecosystems. They found a range of effects, from a small reduction of biomass to a more than 700 per cent increase. On average, plant biomass increased 64 per cent.
“It’s going to do something,” says Jennifer Bhatnagar at Boston University, though she says how much depends on a lot of factors, such as how degraded the soil is to begin with. She also says the effects of soil restoration are better understood with saplings than with older trees. “When they get older, will that initial inoculant be enough?”
Sourcing the soil poses another challenge, says Prescott. Many species of fungi can’t be cultured, and at larger scales, soil extraction could degrade the collection sites.