How Studying Poop May Help Us Boost White Rhino Populations

White Rhinoceros with baby, being protected from poachers. Shot in the Kruger National Park, South Africa.
Photo Credit: Nadine Venter

Researchers at North Carolina State University have identified significant differences in the gut microbiome of female southern white rhinos who are reproducing successfully in captivity, as compared to females who have not reproduced successfully in captivity. The work raises questions about the role that a particular genus of gut microbes may be playing in limiting captive breeding of this rhinoceros species.

“Our work focuses on the southern white rhinoceros (Ceratotherium simum simum), because while it is not yet endangered, species numbers are declining in the wild due to poaching,” says Christina Burnham, first author of a paper on the work and a former graduate student at NC State.

“There is a significant population of southern white rhinos under human care in the United States, but there have been challenges in getting many of these animals to reproduce successfully. It is critical we understand why, as the managed rhinos serve as important assurance populations in case wild rhino numbers continue to fall. We wanted to know how the gut microbiome may influence the reproductive ability of these rhinos.”

Butterflies on the decline

According to the analysis of the scientists, the orange tip (Anthocharis cardamines) is the only butterfly species in Europe for which a significant increase can be recorded.
Photo Credit: Ulrike Schäfer

Research shows that the numbers of butterflies in meadows and pastures of Europe are in a continuous decline. A new EU regulation aims to stop this trend.

Grassland butterflies will soon play an even greater role in EU nature conservation legislation. Based on the occurrences and population trends of butterflies, the member states are supposed to document the progress they have made in implementing the planned "Nature Restoration Law". The Butterfly Grassland Indicator, recently calculated for the eighth time by European foundation "Butterfly Conservation Europe", is to be used for this. This analysis, which also includes data and expertise from many volunteers in Germany - coordinated by experts from the Helmholtz Centre for Environmental Research (UFZ) in Halle - shows an urgent need for action. This is because the situation of grassland butterflies in Europe has deteriorated considerably since the first calculations in 1990.

The diagnosis sounds worrying: More than 80% of habitats in the EU are currently considered vulnerable. This has negative consequences on their functional capability and thus the services they provide for humans. In order to counter this, the European Commission has proposed a new set of rules. This "Nature Restoration Law" is one of the key elements of the EU Biodiversity Strategy 2030 to be published this May. It defines binding targets for the entire EU for the renaturation of various ecosystems. Two years after the regulation enters into force, member states must submit plans on how they intend to meet these targets. They must also document the success of their measures.

Researchers Track Endangered Nassau Grouper Eggs with Underwater Microscope

Nassau grouper spawning aggregation off Little Cayman, Cayman Islands. Credit: Jason Belport
 Photo Credit: Grouper Moon Project

Scripps Oceanography researchers show fertilized eggs stayed local, but in some years drifted to nearby islands.

Each winter off the western tip of the Caribbean island of Little Cayman, thousands of endangered Nassau grouper gather to spawn under the light of the full moon. The fish pack the coral reef and when the ritual begins individual females dash out of the fray straight up towards the surface with multiple males in pursuit. During these vertical bursts, females release their eggs and the males jostle to fertilize them, leaving milky plumes drifting in the moonlit sea.  

These precious fertilized eggs are the engine that powers the still-limited recovery of this critically endangered species that is a key reef predator and was once the target of an important fishery in the Caribbean. But where do these eggs end up after they’re cast adrift? 

Scientists at the University of California San Diego’s Scripps Institution of Oceanography, Oregon State University (OSU), and the conservation organization Reef Environmental Education Foundation (REEF) teamed up with the Cayman Islands Department of the Environment to address this question by physically tracking clouds of tiny, transparent Nassau grouper eggs through the night with an underwater microscope developed by Scripps Oceanography Marine Physical Laboratory scientist Jules Jaffe. 

iDNA from flies to track native species across Western Australian wheatbelt

Carrion Fly
Photo Credit: Ian Lindsay

Researchers from Curtin University have collected iDNA from flies to track the movements of Australia’s native species across the Western Australian wheatbelt, with hopes to improve future conservation efforts in the region.

Published in the Journal Conservation Biology, the research team found that native animals, such as the echidna, numbat, woylie and chuditch, were predominantly located in conservation reserves and not across the wider wheatbelt landscape, compared to invasive species like foxes and feral cats which were found across all areas.

Senior researcher and co-author Associate Professor Bill Bateman, from Curtin’s School of Molecular and Life Sciences, said native mammal populations were declining at alarming rates and there was an urgent need to monitor and protect their wellbeing.

“It is essential to monitor the distribution and movements of animals so we can identify which populations are most at risk, which ones are declining, and which ones are on the brink of extinction. Tracking wildlife through alternative techniques, such as camera trapping and audio recording, can be difficult, costly and take several weeks to gather data,” Associate Professor Bateman said.

Predators decrease prey disease levels but also population size

Microscope image showing a phantom midge larva (genus Chaoborus), top left, preying on a Daphnia dentifera water flea, bottom right. Chaoborus is a fierce predator with a complex “catching basket” on its head for quickly trapping small crustaceans like water fleas.
Photo Credit: Meghan Duffy, University of Michigan.

Nature documentaries will tell you that lions, cheetahs, wolves and other top predators target the weakest or slowest animals and that this culling benefits prey herds, whether it’s antelope in Africa or elk in Wyoming.

This idea has been widely accepted by biologists for many years and was formalized in 2003 as the healthy herds hypothesis. It proposes that predators can help prey populations by picking off the sick and injured and leaving healthy, strong animals to reproduce.

The healthy herds hypothesis has even been used to suggest that manipulating predator numbers to protect prey might be a useful conservation strategy. Even so, hard evidence supporting the hypothesis is scarce, and in recent years many of its assumptions and predictions have been questioned.

In a study published online April 26 in the journal Ecology, a University of Michigan-led research team used a pint-sized predator-prey-parasite system inside 20-gallon water tanks to test the healthy herds hypothesis.

Female butterflies breed despite male shortage

Monarch Butterfly
Photo Credit: Erin Minuskin

Female monarch butterflies have no trouble finding a mate – even when a parasite kills most of the males, new research shows.

Some females carry a parasite called Spiroplasma that kills all their male offspring, meaning highly infected populations have very few males.

But the new study – by the universities of Exeter, Rwanda and Edinburgh, and the Dian Fossey Gorilla Fund – found females mated about 1.5 times on average, regardless of how many males were around.

The male proportion dropped below 10% in some cases, but it appears the remaining hard-working males managed to breed with most of the available females.

10-20% of females remained unmated, only slightly higher than the expected average in a population with plenty of males (5-10%).

Turtle and crocodile species with unique characteristics are more likely to go extinct

A Mugger Crocodile (Crocodylus palustris). In Pakistan, this species is still illegally hunted for its skin.
Image Credit: Bishnu Sarangi

New research led by the University of Oxford has revealed that the most endangered turtle and crocodile species are those that are most unique. Their loss could have widespread impacts on the ecosystems they live in since they carry out critical processes important for many other species. The results have been published in Nature Communications.

"When it comes to the conservation of turtles and crocodiles, we are dealing with a critical scenario. Furthermore, our actions are affecting unevenly more so those species that are characterized by unique life strategies. Once they are gone, these life strategies will be gone too, with no other species being able to provide a back-up." 

Professor Rob Salguero-Gómez, Department of Biology, University of Oxford

Turtles and crocodiles are two of the world's most endangered animal groups, with approximately half of the species globally threatened (International Union for Conservation of Nature, IUCN). Greater understanding of which species are most threatened and why is urgently needed to inform conservation efforts to save them.

In a new study led by researchers at the Department of Biology, University of Oxford, an international team examined the greatest risks to wild populations of turtles and crocodiles worldwide. The results demonstrate that the most endangered turtles and crocodile species are those that have evolved unique life strategies. These species typically carry out highly specific roles within their ecosystems that are unlikely to be taken up by other species if they disappear.

Climate change threatens lemurs on Madagascar

A female grey mouse lemur (Microcebus murinus) carrying an infant.
Photo Credit: Manfred Eberle

They are small, have a high reproductive output and live in the forests of Madagascar. During the 5-month rainy season, offspring are born and a fat pad is created to survive the cool dry season when food is scarce. But what happens when the rainy season becomes drier and the dry season warmer? Can mouse lemurs adapt to climate change thanks to their high reproductive output? Researchers from the German Primate Center – Leibniz Institute for Primate Research, together with colleagues from the University of Zurich, have analyzed long-term data from Madagascar and found that climate change is destabilizing mouse lemur populations and increasing their risk of extinction. The fact that climate change is leading to greater fluctuations in population density and thus increases extinction risk in a fast-paced, ecological generalist is an alarming warning signal for potential biodiversity losses in the tropics.

Effects of climate change have mostly been studied in large, long-lived species with low reproductive output. Small mammals with high reproductive rates can usually adapt well to changing environmental conditions, so they have been studied little in the context of climate change. Claudia Fichtel and Peter Kappeler from the German Primate Center – Leibniz Institute for Primate Research (DPZ) have been researching lemurs on Madagascar for many years and have thus built up a unique data set to fill this knowledge gap.

With fewer salmon to eat, Southern Resident killer whales spend less time in the San Juan Islands

killer whales
Photo Credit: Michelle Klampe

As a key food supply declines, the endangered population of Southern Resident killer whales, known to frequent the Salish Sea off the coasts of Washington and British Columbia, is spending far less time in that region, a new study shows.

The Salish Sea around the San Juan Islands has traditionally been a hotspot for the whales. The Southern Residents would spend the summer months feeding on Chinook salmon, much of which belonged to the Fraser River stock that passes through the islands on its way to spawning grounds upriver.

But 17 years of whale sighting data shows that as the Fraser River Chinook salmon population dropped, the time spent by the Southern Residents around the San Juan Islands also declined ­– by more than 75%, said Joshua Stewart, an assistant professor with Oregon State University’s Marine Mammal Institute and the study’s lead author.

The findings were just published in the journal Marine Mammal Science. Co-authors of the paper are Jane Cogan, an independent researcher in Friday Harbor, Washington; John Durban, a professor with MMI who is also affiliated with the nonprofit SeaLife Response, Rehabilitation and Research (SR3); Holly Fearnback of SR3; David Ellifrit, Mark Malleson and Ken Balcomb of the nonprofit Center for Whale Research; and Melisa Pinnow of San Juan Orcas, a website dedicated to identification of individual orcas.

At least 80% of the world’s most important sites for biodiversity on land currently contain human developments

Photo Credit: Siggy Nowak

A study has found that infrastructure worldwide is widespread in sites that have been identified as internationally important for biodiversity, and its prevalence is likely to increase.

This is the first ever assessment of the presence of infrastructure in Key Biodiversity Areas (KBAs): a global network of thousands of sites recognized internationally as being the world’s most critical areas for wildlife.

Infrastructure is one of the greatest drivers of threats to biodiversity according to the International Union for Conservation of Nature. It can cause natural habitat destruction and fragmentation, pollution, increased disturbance or hunting by humans, the spread of invasive species, direct mortality, and can have wider impacts beyond the development site.

Now, researchers from BirdLife International, WWF and the RSPB, in association with the University of Cambridge, have conducted an assessment of infrastructure in KBAs, finding that it is widespread and likely to increase. The results are published today in Biological Conservation.

“It’s concerning that human developments exist in the vast majority of sites that have been identified as being critical for nature,” said Ash Simkins, a Zoology PhD student at the University of Cambridge who led the study.

Recovery of endangered sunflower sea stars may play key role in restoring devastated submarine forests

Sunflower sea stars, such as the one that appears in the foreground, could help keep purple sea urchins in check, according to new research from Florida State University Assistant Professor Daniel Okamoto and colleagues published in Proceedings of the Royal Society B.
Photo Credit: Lynn Lee

Scientists working to understand the decimation of kelp forests on the Pacific Coast have found that the endangered sunflower sea star plays a vital role in maintaining the region’s ecological balance and that sea star recovery efforts could potentially help restore kelp forests as well.

The multi-institution team, which includes Florida State University Assistant Professor of Biological Science Daniel Okamoto, has published a new study showing that a healthy sea star population could keep purple sea urchins — which have contributed to the destruction of kelp forests — in check.

Their work is published in the Proceedings of the Royal Society B.

“Our work is focused on understanding what factors maintain healthy kelp forests as well as healthy urchin populations,” Okamoto said. “That is, what scenarios lead to collapse versus coexistence of these important species.”

Humans are Leading Source of Death for California Mountain Lions, Despite Hunting Protections

A female mountain lion (P-19) near Malibu Creek State Park in March 2014.
Photo Credit: National Park Service

Mountain lions are protected from hunting in California by a law passed by popular vote in 1990. However, a team of researchers working across the state found that human-caused mortality—primarily involving conflict with humans over livestock and collisions with vehicles—was more common than natural death for this protected large carnivore.

The study, published today in the Proceedings of the National Academy of Sciences, was led by the University of Nebraska-Lincoln, along with a broad team of coauthoring California researchers, including from the University of California, Davis.

Most research on mountain lions is conducted at relatively small scales, which limits understanding of mortality caused by humans across the large areas they roam. To address this, scientists from multiple universities, government agencies, and private organizations teamed up to better understand human-caused mortality for mountain lions across the entire state of California.

The team tracked almost 600 mountain lions in 23 different study areas, including the Sierra Nevada mountains, the northern redwoods, wine country north of San Francisco, the city of Los Angeles, and many other areas of the state.

Humans are altering the diet of Tasmanian devils, which may accelerate their decline

The researchers investigated the diets of devils from habitats of differing levels of disturbance.
Photo Credit: Ariana Ananda.

New research shows how human-modified landscapes affect the diets of these marsupial scavengers.

The Tasmanian devil roams the island state of Australia as the apex predator of the land, feeding on whatever it pleases as the top dog – or the top devil. But some of these marsupial scavengers could be starting to miss out on a few items from the menu.

According to a study led by UNSW Sydney, living in human-modified landscapes could be narrowing the diet of the Tasmanian devil. The research, published recently in Scientific Reports, suggests devils have access to vastly different cuisines depending on the type of environment they live in.

“We found Tasmanian devil populations had different levels of variation in their diet depending on their habitat,” says Anna Lewis, a PhD candidate at UNSW Science and lead author of the study. “The more that habitat was impacted by humans, the more restrictive the diet became.”

A previous study by the team found most devils are individual specialists, feeding on the same food items consistently over time. But human impacts could be influencing whether they have access to their favorite foods.

“How humans change the environment impacts the animals within them,” says Professor Tracey Rogers, an ecologist at UNSW Science and senior author of the study. “Even small changes can have significant consequences for devils, so we need to be mindful of the consequences of our actions.”

Berkeley researchers present plan for freshwater conservation

Study authors say freshwater conservation priorities should include connectivity, watershed disturbance, flow alteration, water quality, and biodiversity.
(A) Briones Dam reduces connectivity in Bear Creek, California.
(B) Wildfire in Hopland, California, creates widespread watershed disturbance.
(C) poor water quality in Porter Creek, California, kills fish and reduces recreational opportunities.
(D) freshwater ecosystems support biodiversity in Klamath Lake, Oregon.
Photo Credits: (A) L Andrews, (B) P Parker Shames, (C) G Rossi, (D) J Shames

The 30x30 initiative is a global effort to set aside 30% of land and sea area for conservation by 2030, a move scientists hope will reverse biodiversity loss and mitigate the effects of climate change. Now adopted by state and national governments around the world, 30x30 creates an unprecedented opportunity to advance global conservation.

When it comes to the water side of 30x30, most programs focus primarily on conservation of oceans, but a new study by researchers at the University of California, Berkeley argues that freshwater ecosystems must not be neglected. Published today in the journal Frontiers in Ecology and the Environment, the paper urges policy makers to explicitly include freshwater ecosystems like rivers, lakes, and wetlands in 30x30 plans, and outlines how their conservation will be critical to achieving the initiative’s broader goals. 

Grassroots data is vital for reducing deadly bird-window strikes

FLAP holds an annual event at which all collision casualties from the past year are placed together.
Photo Credit: Nancy Barrett

Citizen science has enabled much of the progress in understanding the scope of bird deaths from building and window collisions, according to a new study, but these grassroots efforts need better funding and more buy-in from government and industry.

These conclusions stem from research by authors at 22 universities, non-governmental organizations, government agencies and conservation organizations. Their study, “Citizen Science to Address the Global Issue of Bird-Window Collisions,” published March 7 in the journal Frontiers in Ecology and the Environment. As examples, the study highlights the Lights Out Texas program in the United States, the China Anti-Bird Window Collision Action Alliance and the Fatal Light Awareness Program (FLAP) in Canada. FLAP Canada has been at the forefront of this issue for 25 years and is the template for many of the newer collision prevention efforts.

“During the last five to 10 years there’s been a groundswell of public, conservation and scientific attention to bird-window collisions,” said lead author Scott Loss at Oklahoma State University. “Citizen scientists are leading the way, growing awareness of this major threat to birds, and advocating for bird-friendly buildings and policies. There’s tremendous potential for these projects to do more but they need support, and more conservation organizations need to make collision reduction a key part of their objectives. Conservation funding is always a challenge and perhaps especially so with this often-overlooked global issue.”

Does current shellfish culture gear curb ‘crunching’ rays?

Whitespotted eagle rays “crunching” on clams in a large outdoor tank with clams housed within a variety of anti-predator materials.

Video Credit: Florida Atlantic University / Harbor Branch Oceanographic Institute 

According to NOAA Fisheries, more than 80 percent of marine aquaculture production in the United States consists of bivalve mollusks such as oysters, clams and mussels. However, it’s not just humans who enjoy eating these shellfish, so do marine rays. They like to “crunch” on clams, which can sometimes take a big bite out of clammers’ profits.

Part of the process of culturing hard clams (Mercenaria mercenaria) involves deploying them in submerged bottom leases in the marine environment where clams can grow to market size. When deployed onto the clam lease, clammers incorporate a variety of anti-predator materials to protect their product, such as woven mesh netting and/or additional mesh, plastic or wire covers.

However, the effectiveness of these materials against highly mobile predators like rays has not been experimentally tested. Some rays, like the whitespotted eagle ray (Aetobatus narinari), are equipped with strong jaws, plate-like teeth and nimble pectoral fins, which make them formidable and highly maneuverable predators of clams.

Glacier National Park could provide climate haven for Canada lynx

An image of a Canada lynx taken by a motion sensitive camera as part of a study conducted in Glacier National Park
Photo Credit: Alissa Anderson

Glacier National Park is home to around 50 Canada lynx, more than expected, surprising scientists who recently conducted the first parkwide occupancy survey for the North American cat. 

The Washington State University-led survey reveals the iconic predator resides across most of Glacier’s 1,600 square-mile landscape, although at lower densities than in the core of its range further north. 

“The population in the park is still substantial and exceeded our expectations,” said Dan Thornton, WSU wildlife ecologist and senior author of the study published in the Journal of Wildlife Management. “Our results suggest the park could provide a much-needed climate refuge for the cats in the future.” 

Canada lynx are known for their long, black ear tufts and ability to hunt almost ghost-like across the surface of deep snow. Historically, the predator’s habitat extended from Alaska and Canada south down into much of the Northern United States. In the lower 48 today, the Canada lynx exists only in several disjunct populations in Maine, Minnesota, Montana, Colorado, Idaho and Washington.  

Voluntary UK initiatives to phase out toxic lead shot for pheasant hunting have had little impact

Pheasant
Photo Credit: Julie Mayo

The pledge, made in 2020 by nine major UK game shooting and rural organizations, aims to protect the natural environment and ensure a safer supply of game meat for consumers. Lead is toxic even in very small concentrations, and discarded shot from hunting poisons and kills tens of thousands of the UK’s wild birds each year.

A Cambridge-led team of 17 volunteers bought whole pheasants from butchers, game dealers and supermarkets across the UK in 2022-23. They dissected the birds at home and recovered embedded shotgun pellets from 235 of the 356 pheasant carcasses.

The main metal present in each shotgun pellet was revealed through laboratory analysis - conducted at the Environmental Research Institute, University of the Highlands and Islands, UK. Lead was the main element in 94% of the recovered shot pellets; the remaining 6% were predominantly composed of steel or a metal called bismuth.

Australia’s rarest bird of prey disappearing at alarming rate

Researchers analyzed 40 years of sightings by citizen scientists to uncover concerning population trends.
Photo Credit: Chris McColl

Australia’s rarest bird of prey - the red goshawk - is facing extinction, with Cape York Peninsula now the only place in Queensland known to support breeding populations.

PhD candidate Chris MacColl from The University of Queensland’s School of Earth and Environmental Sciences led the research project that made the discovery and was shocked by the hawk’s dwindling numbers.

“Over four decades the red goshawk has lost a third of its historical range, which is the area that’s it’s previously been known to occupy,” Mr. MacColl said.

“It’s barely hanging on in another 30 per cent of regions it has previously been known to inhabit.”

Mr. MacColl said the species is now considered extinct in New South Wales and the southern half of Queensland.

Trawlers intermix with whale ‘supergroup’ in Southern Ocean

Fin whales surround the research vessel National Geographic Endurance in January 2022.
Video Credit: Eric Wehrmeister

Trawlers working amidst a whale ‘supergroup’ raise red flag about human-whale conflicts in a changing ocean, Stanford study says

Scientists observed close to 1,000 fin whales foraging near Antarctica, while fishing vessels trawled for krill in their midst. Without action, such encounters are likely to become more common as this endangered species recovers and krill harvesting intensifies in the Southern Ocean.

Once driven nearly to extinction, the second-largest animals of all time have recently been spotted in big numbers in the Southern Ocean, competing directly with industrial trawlers for prey, according to research led by scientists from Stanford University and Lindblad Expeditions.

Published in Ecology, the study focuses on scientists’ sighting of an enormous “supergroup” of fin whales foraging for shrimplike animals called krill northwest of the South Orkney Islands in January 2022, with four commercial fishing vessels trawling among them for the same tiny creatures.

The researchers, led by Matthew Savoca of Stanford and Conor Ryan of Lindblad Expeditions, estimate at least 830 and possibly more than 1,100 fin whales were present. This ranks among the largest groups of baleen whales ever recorded since commercial whaling decimated their populations last century.