Friday, April 15, 2022

Black Rhino extinction risk sharply increased by killing of specific female rhinos

UNIVERSITY OF MANCHESTER

Rhinos in Kenya - Credit, Nick Harvey Sky — IMAGE: RHINOS IN KENYA - CREDIT, NICK HARVEY SKY view more
CREDIT: RHINOS IN KENYA - CREDIT, NICK HARVEY SKY

New research from The University of Manchester, in collaboration with Kenyan conservationists and scientists, has examined data from the Critically Endangered Kenyan black rhino populations which suggest that individuals really matter when assessing the impact of poaching on species’ survival chances.

The research published today in journal, Proceedings of the Royal Society B, demonstrates that poaching combined with individual rhino’s reproductive variance, or how successful mums are at raising young, leads to a greater than first thought risk to the survival of the black rhino.

In the case of these rhino, reproductive variance increased extinction risk by as much as 70% when combined with poaching.

Within black rhino populations (and most likely in most animals), some individuals have more babies than others. This variation increases existing estimates of extinction risk, especially when there is poaching. This is because indiscriminate killing can lead to some of these important animals which contribute a greater number of offspring being removed.

Susanne Shultz, Professor of Evolutionary Ecology and conservation at The University of Manchester said: “Preventing population declines is a crucial step for stopping biodiversity loss. In this study, we identified how losing key rhinos can make small populations very vulnerable, which can help us design more effective conservation actions.”

The new research is important because it shows that we may underestimate risk (or overestimate viability) if we do not recognise that some individuals contribute a lot more to the population (and their loss will have a much bigger impact).

Lead author on the work, Dr Nick Harvey Sky said: “This study shows that poaching has effects on rhinos beyond the death of targeted individuals. The deaths of healthy females that would have gone on to produce lots of calves can make whole populations more vulnerable to extinction.”

Estimating the extinction risk faced by different populations is vital for conservation. This can be affected by differences in breeding success between individual females (called reproductive skew), but reproductive skew is not often included in predictions of future population growth because it requires detailed individual breeding histories.

This information is available for the Critically Endangered eastern black rhino because of intensive monitoring to protect them from poaching. The University of Manchester has collaborated closely with Kenyan rhino managers, scientists and security teams who have meticulously recorded births and deaths for decades. Across three Kenyan populations of black rhinos on Lew Wildlife Conservancy, Ol Pejeta Conservancy and Ol Jogi Wildlife Conservancy, the researchers found that there is significant variation in breeding success between females, with many females not breeding or doing so very slowly.

Dr John Jackson, Post-doctoral researcher at the University of Oxford said: “For me, our study really highlights a deadly combination of small populations, individual differences, and poaching for vulnerable populations. When working in combination, these factors can completely reshape the fate of an endangered species.”

Crucially, variation in female breeding success can exacerbate the effects of poaching, especially on small populations. If key individuals, ones that breed very well, are killed then it can make the whole population more vulnerable to extinction. This highlights how important it is to protect rhinos from poaching. It may be possible to even out the variation in breeding success by creating new rhino reserves, moving rhinos between current reserves, or even creating more valuable habitat, but the causes of reproductive skew must first be identified. Differences between individuals in their contribution of young to at risk populations is likely an issue across many more species and should be evaluated when assessing their risk of extinction.

JOURNAL

Proceedings of the Royal Society B Biological Sciences

DOI

10.1098/rspb.2022.0075

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Female reproductive skew exacerbates the extinction risk from poaching in the eastern black rhino

ARTICLE PUBLICATION DATE

13-Apr-2022

EVERYDAY CHEMISTRY

Structure of the active ingredient bismuth subsalicylate in Pepto-Bismol revealed

Peer-Reviewed Publication

STOCKHOLM UNIVERSITY

Bottle of Pepto-Bismol stomach reliever — IMAGE: BOTTLE OF PEPTO-BISMOL STOMACH RELIEVER view more
CREDIT: MATHIAS NERO

Researchers at Stockholm University have applied advanced electron microscopy techniques to finally unveil the structure of the widely used and century-old active pharmaceutical ingredient bismuth subsalicylate. The discovery provides a major step towards understanding the properties of one of the most commercially significant bismuth compounds, and highlights modern methods of gaining insight into long-used pharmaceutical ingredients. The results are published today in the scientific journal Nature Communications.

Despite its century-long history as an established antimicrobial and anti-inflammatory agent, particularly effective in the treatment of nausea, diarrhea and upset stomach, the structure of bismuth subsalicylate has hitherto remained unknown.

“I remember while growing up, my mom always gave me Pepto-Bismol whenever I had an upset stomach. Apparently over 10 billion doses have been consumed, making bismuth subsalicylate the most commercially significant bismuth compound, sold around the world as a common over-the-counter drug and widely referred to in pop culture. We were surprised to realize that there was a lack of understanding of its structure at a molecular level,” says Ken Inge, researcher at the Department of Materials and Environmental Chemistry (MMK) at Stockholm University. “Understanding the structures of pharmaceutical compounds is vital for predicting their properties.”

Possible antibiotic-resistance breakers

The use of bismuth in pharmaceutical formulations comes with several potential advantages.
“An interesting aspect of bismuth compounds is that recent studies have shown that they can reverse antibiotic resistance in bacteria, which is a very pressing topic in society today. The chemistry of bismuth and its compounds is still not that well understood, and so we are interested in investigating the molecular make-up of these materials,” says Ken Inge.

Advanced microscopy revealed a structure in disorder

The bismuth compound is used as a textbook example of an inorganic pharmaceutical compound, despite its structure previously not being known and hence has often been described with a speculative structure as a simple metal complex. By using advanced transmission electron microscopy, the researchers were able to investigate the structure at a molecular level, and even to take pictures of the molecules.

“By using the advanced microscopes at Stockholm University, it is possible to obtain images with atomic resolution, which was a key part of understanding the molecular packing within the bismuth subsalicylate crystals,” says Tom Willhammar, fellow researcher at the Department of Materials and Environmental Chemistry. “Characterization of bismuth subsalicylate by traditional methods, such as X-ray diffraction, was not enough to reveal the molecular packing due to its tendency to only form as very small crystals. We also found out that the packing contains intrinsic defects.”

Analysis of three-dimensional electron diffraction data from crystals of bismuth subsalicylate revealed a layered structure that was partially in disorder.
“A detailed investigation using high-resolution scanning transmission electron microscopy showed variations in the stacking of the layers. It is likely that this has hindered structure determination by other means,” says Tom Willhammar.

CAPTION

CREDIT

Mathias Nero

CAPTION

The research team at Stockholm University. Dr Ken Inge to the right.

CREDIT

Mathias

New materials to capture pollution

The results highlight the possibility of using modern methods to acquire insight into well-known and long-used pharmaceutical compounds.

“These modern electron crystallography techniques provide a toolbox for structure determination of active pharmaceutical ingredients and drug discovery,” says Erik Svensson Grape, doctoral student at Stockholm University.

The investigations have inspired the researchers even in other areas of research.

“It has made all of us very excited. Through these investigations we have been inspired to study and develop novel materials for a large range of applications even beyond pharmaceuticals, such as the sequestration of pollutants,” says Erik Svensson Grape at Stockholm university.

Find the publication: Structure of the active pharmaceutical ingredient bismuth subsalicylate. Nature Communications.
DOI number: 10.1038/s41467-022-29566-0

Contact:
Dr Ken Inge, Assistant professor, Department of Materials and Environmental Chemistry, Stockholm University, E-mail: andrew.inge@mmk.su.se

Dr. Tom Willhammar, researcher, Department of Materials and Environmental Chemistry, Stockholm University, E-mail: tom.willhammar@mmk.su.se