Fewer big predators may mean loss of plant diversity
UBC zoologist Adam Ford and colleagues have discovered that global declines in carnivore populations could embolden plant eaters to increasingly dine on succulent vegetation, driving losses in plant and tree biodiversity.
The team used GPS tracking on 20 adult female impala, four leopards and five wild dogs to measure how an impala’s fear of predators, as well as the growing patterns of thorny plants, combine to influence the landscape. The researchers combined the tracking data with a high‑resolution satellite image of tree cover and located carcasses to determine where impala are being killed. They also conducted feeding experiments to judge the effectiveness of thorns as a feeding deterrent.
“Our observations indicate that carnivores – like leopards and wild dogs – shape where herbivores eat,” says Ford, lead author of the paper. “Plant defenses – such as thorns – shape what herbivores eat.”
“As human activities continue to reduce populations of predators, herbivores like impala become willing to feed in areas that used to be risky – consuming more preferred vegetation and, ironically, allowing less‑preferred thorny plant species to take over,” says Ford.
The findings were published in Science. The same journal has also recently published data that indicate more than three quarters of the world’s 31 large carnivore species are in decline and that 17 species occupied less than half of their historical distributions.
“Plants have two pathways to success,” says Ford. “You either protect yourself from herbivores by growing large thorns, or thrive in areas that are risky to your predators – plant eaters.”
The study area, Mpala Research Center in Laikipia, Kenya, is used for traditional ranching. In the future, Ford will investigate whether the forage that impala don’t eat in dangerous areas could be used for livestock during drought years – a frequent occurrence that can threaten the livelihoods of many people in Laikipia. “We’re only beginning to understand the linkages between carnivores, their prey, plants and people,” he says.
Survive and Thrive
There’s a new research innovation facility at UBC’s Okanagan campus, where industry and university researchers can pool their knowledge to rapidly develop novel technologies for human protection, survivability and performance in extreme or remote conditions.
The Survive and Thrive Applied Research (STAR) facility was established with $3.8M of federal funding. It combines world‑class research expertise and global partner networks to help commercialize innovative products and develop ideas that can be applied in a wide range of sectors, including manufacturing, natural resources, health care, and defense.
One of the first STAR projects is a collaboration between UBC, Kelowna‑based Helios Global Technologies, and Imperial College London (UK) to develop a high‑tech helmet that can reduce the risk of concussion in contact sports such as hockey and football.
“Collaboration with STAR greatly enhances our capacity to develop innovative products,” says Helios CEO Martin Cronin. “It gives us access to world‑class research that helps us to quickly prove out concepts and explore multi‑sectoral applications, and also access to funding through our research partnerships.”
STAR partnerships create important opportunities for university researchers and their students, says Professor Paul van Donkelaar, director of UBC’s School of Health and Exercise Sciences and principal investigator with the UBC Sports Concussion Research Lab.
“We’re working on compelling projects directly related to our primary research, and which also create new ideas for future research and real‑world learning opportunities for students,” he says. The STAR partnership with Imperial College London has led to a new accord that will include student and faculty exchanges.
Other STAR initiatives include development of sensors for autonomous aerial vehicles (UAVs) for use in forestry and agriculture, and personal wireless stop‑button technology for workers using large industrial machinery.
From the words for colours to how to tie a shoelace, kids have lots to learn – and for the most part, they depend on others to teach it to them. But whether deliberately or inadvertently, other people sometimes misinform. So at what age can kids tell trustworthy teachers from confident tricksters?
A new study by psychology researchers from UBC and Concordia shows that by the age of five, children become wary of information provided by people who make overly‑confident claims.
For the study, Patricia Brosseau‑Liard, who is now a Concordia postdoctoral fellow, recruited 96 four‑ and five‑year‑olds. She and her UBC Department of Psychology co‑authors, Tracy Cassels and Susan Birch, had the youngsters weigh two important cues to a person’s credibility – prior accuracy and confidence – when deciding what to believe.
The researchers showed their subjects short videos of two adults talking about familiar animals. The speakers would either:
- Make true statements about the animal in a hesitant voice
“Hmm, I guess whales live in the water?”
- Make false statements about the animal in a confident voice
“Oh, I know! Whales live in the ground!”
The kids were then shown videos of the same two adults speaking about strange animals. The previously confident speaker would state facts with confidence, and the previously hesitant speaker remained hesitant while stating different facts. The participants were then asked whom they believed.
In children closer to the age of four, it was a 50/50 split: they were as likely to believe the confident liar as the hesitant truth‑teller. But as they neared the age of five, participants were more likely to believe the previously accurate but hesitant individual, suggesting a year can make a big difference in terms of a child’s evolution in the critical consumption of information.
As Brosseau‑Liard explains, these findings are important for teachers and caregivers.
“Our study gives us a window into children’s developing social cognition, skepticism and critical thinking. It shows us that, even though kindergarteners have a reputation for being gullible, they are actually pretty good at evaluating sources of information. Parents can use this ability to help guide them in their learning.”
A new step in the fight against Type 1 diabetes
UBC, in collaboration with BetaLogics Venture, a division of Janssen Research & Development, LLC, has published a study highlighting a protocol to convert stem cells into insulin‑producing cells. The new procedure could be an important step in the fight against Type 1 diabetes, which is the result of the body’s own immune system destroying insulin‑secreting pancreatic beta cells.
The protocol can turn stem cells into reliable, insulin‑producing cells in about six weeks, far quicker than the four months it took using previous methods.
“We are a step closer to having an unlimited supply of insulin‑producing cells to treat patients with Type 1 diabetes,” says Timothy Kieffer, a professor in UBC’s Department of Cellular and Physiological Sciences and the Department of Surgery who led the research.
The protocol transforms stem cells into insulin‑secreting pancreatic cells via a cell‑culture method. The conversion is completed after the cells are transplanted into a host. “We have not yet made fully functional cells in a dish, but we are very close,” says Kieffer. “The cells we make in the lab produce insulin, but are still immature and need the transplant host to complete the transformation into fully functioning cells.”
An important next step for UBC researchers and their industry collaborators is to determine how to prevent the insulin‑producing cells’ from being rejected by the body.
More than two million Canadians and close to 400 million people worldwide suffer from diabetes. Current treatment requires daily insulin injections. Experimental human donor transplants of healthy pancreatic islets, which contain the beta cells, have had success. But treatment is limited by donor availability.
How dopamine affects risky decisions
A gambler’s decision to stay or fold in a game of cards could be influenced by a chemical in the brain, suggests new research from UBC.
The rise and fall of dopamine plays a key role in decisions involving risk and reward – from a baseball player trying to steal a base to an investor buying or selling a stock. Previous studies have shown that dopamine signals increase when risky choices pay off.
“Our brains are constantly updating how we calculate risk and reward based on previous experiences, keeping an internal score of wins and losses,” says study co‑author Stan Floresco, a professor in UBC’s Department of Psychology. “Dopamine appears to play an important role in these processes, influencing our everyday choices.”
The study saw rats choose between safe and risky rewards – similar to what investors face on Wall Street. Pressing one lever gave the rodents a small but guaranteed reward, not unlike a bond. The other lever yielded a large reward or nothing, similar to a high‑risk stock.
Researchers altered the rats’ decision‑making process by shutting down or turning on the dopamine signals in their brains. When the rats played riskily and lost, researchers turned on dopamine signals when normally they would have decreased. Subsequently, the rats made riskier decisions. Conversely, when the rats played riskily and won, researchers turned dopamine signals off. Here, the rats began to play more conservatively.
“By temporarily knocking these chemical signals out, it demonstrates how significant they are in altering our decisions, even if it’s against our better judgment,” says Floresco.
Floresco’s co‑authors are Colin Stopper, Maric Tse, David Montes and Candice Wiedman of UBC’s Department of Psychology and the Brain Research Centre.
Fish moving poleward
Large numbers of fish will disappear from the tropics by 2050, finds a new UBC study that examined the impact of climate change on fish stocks. The study identified ocean hotspots for local fish extinction but also found that changing temperatures will drive more fish into the Arctic and Antarctic waters.
Using the same climate change scenarios as the Intergovernmental Panel on Climate Change, researchers projected a large‑scale shift of marine fish and invertebrates. In the worst‑case scenario, where the Earth’s oceans warm by three degrees Celsius by 2100, fish could move away from their current habitats at a rate of 26 kilometres per decade. Under the best‑case scenario, where the Earth’s oceans warm by one degree Celsius, fish would move 15 kilometres every decade. This is consistent with changes in the last few decades.
“The tropics will be the overall losers,” says William Cheung, associate professor at the UBC Fisheries Centre and co‑author of this study. “This area has a high dependence on fish for food, diet and nutrition. We’ll see a loss of fish populations that are important to the fisheries and communities in these regions.”
Cheung and his colleague used modelling to predict how 802 commercially important species of fish and invertebrates react to warming water temperatures, other changing ocean properties, and new habitats opening up at the poles.
“As fish move to cooler waters, this generates new opportunities for fisheries in the Arctic,” says Miranda Jones, a UBC Nereus Fellow and lead author of the study. “On the other hand it means it could disrupt the species that live there now and increase competition for resources.”