NATURE & SCIENCE
A group of Indo-Pacific bottlenose dolphins in Shark Bay, Western Australia. Courtesy Madison Miketa/Shark Bay Dolphin Pro= ject/National Science Foundation)
Dolphins use coral reefs to treat skin ailments study reveals
SACRAMENTO (CN)—Indo-Pacific bottlenose dolphins repair skin and stay healthy by repeatedly rubbing up against corals that have natural medicinal properties, according to new research.
The study published May 19 in the journal iScience found dolphins along the coral reefs off the coast of Egypt in the Red Sea appear to be self-medicating their skin ailments.
When lead author Gertrud Morlock, an analytical chemist and food scientist at Justus Liebig University Giessen in Germany, and her team analyzed samples of coral from the waters where they had observed Indo-Pacific bottlenose dolphins repeatedly rubbing themselves from head to tail along the reefs, they found 17 active metabolites with antibacterial, antioxidative, hormonal and toxic activities.
Discovery of these bioactive compounds led the team to deduce that the mucus in the corals and sponges helps regulate dolphin skin and treat infections.
"Repeated rubbing allows the active metabolites to come into contact with the skin of the dolphins," Morlock said in a statement. "These metabolites could help them achieve skin homeostasis and be useful for prophylaxis or auxiliary treatment against microbial infections."
Co-lead author Angela Ziltener, a diver and wildlife biologist at the University of Zurich, has studied dolphins for more than a decade in the Egyptian Red Sea up close while diving. Dolphins are typically studied from the surface of the water, but Ziltener’s abilities as a diver allowed her to study the dolphins up close after she earned the pod’s trust, which she was able to do in part because the dolphins she was studying weren’t bothered by the large bubbles released by her diving tanks.
"Some dolphins, like spinner dolphins in the Southern Egyptian Red Sea, are shyer about bubbles," Ziltener explained.
When Ziltener and her team first observed dolphins rubbing along the corals off the coast of Egypt in 2009, they also noticed that the dolphins appeared to be selective about which coral they rubbed against. The researchers wanted to understand why.
"I hadn’t seen this coral rubbing behavior described before, and it was clear that the dolphins knew exactly which coral they wanted to use," Ziltener said in a statement. "I thought, 'There must be a reason.'"
Once the pod was comfortable enough with Ziltener’s visits, the team was able to identify and sample the corals the dolphins were rubbing on. They found by repeatedly rubbing against the corals, Indo-Pacific bottlenose dol- phins were agitating the little polyps that create the coral community and causing the invertebrates to secrete mucus. The team collected samples of the corals to turn over to Morlock for research.
What the scientists discovered amazed them: The coral and sponges contained properties that were healing and fortifying the dolphins’ skin. The reefs where the corals are found are important places for local dolphin populations. Dolphins go there to rest.
"Many people don’t realize that these coral reefs are bedrooms for the dolphins, and playgrounds," Ziltener said.
The dolphins alternate between taking naps on the corals and waking to rub against them.
"It’s almost like they are showering, cleaning themselves before sleep,” Ziltener noted.
Conservationists maintain that the peddling of even antique ivory pieces threatens elephants and rhinoceroses living today.
NY bar on ivory sales stirs passions at 2nd circuit
MANHATTAN (CN) — New York state governs antique ivory sales more strictly than the federal government does. The future of those protections is in the hands of a panel of appellate judges.
“Before the enactment of the state ivory law,” Grace X. Zhou, an assistant state solicitor general, said March 4, arguing before the Second Circuit. “New York was a hub for trade in ivory, contributing to the demand in ivory.”
New York adopted the law at issue in 2014, largely banning the sale of ivory antiques within state borders. Only pieces that are at least 100 years old and contain less than 20 percent ivory are legal to sell here though with proper permits dealers in the Empire State can still sell ivory antiques to out-of-state buyers, online or by catalog for instance.
Buyers who come into the state to make the purchase, however, run afoul of the law, and shops can’t display illicit ivory antiques in the windows or on their shelves.
“The truth is that the sale of these parts, even antique parts, increases the commodification of ivory sales in a way that contributes to the current commodification of these animals,” Ralph Henry, director of litigation at the Humane Society, said in an interview this afternoon.
Worldwide, the ivory trade is worth roughly $23 billion per year, and the Natural Resources Defense Council estimates More than a thousand rhinos and tens of thousands of elephants are killed each year so that poachers can sell the ivory from their horns to designers making jewelry, furniture and other decorations. Henry says there’s good reason for New York to take action.
“It's a pretty booming market, even compared to other states,” he noted. In 2017, an antique shop raid in New York City resulted in authorities confiscating 130 illegal ivory items worth at least $25,000.
“My clients feel that states, including the state of New York, have an important role to play in supplementing federal laws,” Henry said. “I think we'll have a part we can play in reducing the commodification in endangered species.”
The statute faces a challenge, however, from the Art and Antique Dealers League of America and the National Antique and Art Dealers Association of America. They say federal law preempts the state from adopting more rigorous standards, and that the display-restricting rules violate the First Amendment. After a federal judge dismissed their preemption claim, the groups are eyeing a reversal from the Second Circuit.
A hearing on this appeal Friday went well over the allotted 12 minutes of argument for each party, with an attorney for the antique dealers insisting that New York has no basis for claiming that it is helping curb the ivory trade by regulating antique ivory so tightly. After the hearing, Caleb Trotter, who is a lawyer with the Pacific Legal Foundation in Sacramento, summed up his point.
“Simply," Trotter said, “it is unconstitutional to ban legal sales in order to prevent illegal sales. ... The dealers are hopeful for a decision freeing them to continue selling important antiques and works of art in accordance with federal law.”
The assistant solicitor general argued meanwhile that New York’s definitions are in agreement with the Endan- gered Species Act, which doesn’t explicitly delineate intrastate and interstate deals. State laws may be more, but not less, restrictive than the act, according to its text, Zhou said.
For the antique dealers, attorney Trotter pointed out that the act preempts state laws that “may effectively” forbid activity allowed by federal exemptions or permits.
“This is precisely what the State Ivory Law and the New York State Department of Environmental Conservation’s] licensing regulations do,” Trotter wrote in his brief. “Federal law exempts the sale of antique ivory pieces from federal trade prohibitions. Disagreeing with federal law, New York seeks to withdraw the state from this interstate market and restrict how sellers advertise interstate and foreign sales.”
Trotter zeroed in at the court hearing on the regulations for showing off ivory antiques in commercial settings, saying they prevent his clients from selling valuable inventory, blocking what he said was the only way a sale can happen.
“It comes down to the way that the department is enforcing this with its display restriction,” Trotter said. “The department is saying to address illegal sales, it must prohibit all legal sales in the state.”
The Humane Society's Henry told the court, on the other hand, that window shopping is “something of a precursor” to interstate sales. “There is certainly a conservation rationale for banning the sale of items that were procured from animals that are long since dead,” he said.
US Circuit Judge Pierre N. Leval focused on the state’s reasons for enacting its law in the first place.
“What is the state’s substantial interest in forbidding the display of antique items that are lawful to be sold to an interstate customer?” the Jimmy Carter appointee asked. “This is protecting elephants who were alive 50 and 100 years ago.”
Zhou noted that in-state sales turn on whether the buyer and seller are both in New York. Empire State dealers can still peddle their wares at trade shows outside New York, but the state is intent on preventing ivory sales within its borders.
“When the sale takes place in New York, the ivory good would also be changing hands between the buyer and the seller in New York,” Zhou reasoned.
U.S. Circuit Judge Richard J. Sullivan, a Trump appointee, probed that definition and compared ivory to selling guns across state lines, which is handled at the federal level.
“This is a foreign item. This is a rhinoceros horn from Africa,” Sullivan said. “It is the equivalent of a gun manufac- tured outside of New York state.”
Trotter noted that New York already requires dealers to submit annual reports that include buyers’ names. Rather than focus on in-person sales, the state could require proof that an antique was shipped out-of-state, preventing secret in-state deals.
Judges Sullivan and Leval were joined on the panel by U.S. Circuit Judge Myrna Pérez, a Biden appointee. They did not offer a timeline for when they will rule.
The California mountain lion, aka cougar or puma, is endemic to the Santa Monica and Santa Ana mountains.
Inbreeding among mountain lions raise extinction fears
LOS ANGELES (CNS)—Scientists tracking two local mountain lion populations, one in the Santa Monica Mountains and another in the Santa Anas, have identified the first reproductive signs of inbreeding among these groups, which are cut off from breeding options by busy freeways.
According to the UCLA-led study—which is available online and will be published in the January 2022 edition of the journal Theriogenology—the animals averaged a 93 percent abnormal sperm rate, while some also displayed physical signs of inbreeding, like deformed tails or testicular defects.
Researchers have long had genetic evidence of inbreeding, but the malformed sperm is the first evidence that inbreeding is manifesting in the reproductive system.
"This is a serious problem for an animal that's already endangered locally," said the study's lead author, Audra Huffmeyer, a UCLA postdoctoral researcher who studies fertility in large cat species and is a National Geographic Explorer. ``It's quite severe.''
Researchers said the results lend urgency to the need for wildlife crossings, structures that allow the mountain lions and other animals to roam further and find a broader pool of potential mates. Mountain lions—also known as cougars—are a bellwether species, making them a leading indicator that inbreeding could soon cause woes for other species in the Santa Monica and Santa Ana mountains, the authors said.
The California Department of Transportation has scheduled groundbreaking for early 2022 on one such wildlife crossing, a bridge over the Ventura (101) Freeway in Agoura Hills, thanks to a mix of public and private funding.
Biologists and land managers hope this project will lead to more crossings. Early plans are being formu- lated for a possible structure over Interstate 15 in Riverside County.
The latest study draws on work by scientists from UCLA, the National Park Service's Santa Monica Mountains National Recreation Area and the UC Davis Wildlife Health Center. Both the NPS and UC Davis are carrying out long-term studies of Southern California mountain lion populations, currently following 17 cats.
Over the past year, the research team identified nine adult males from the Santa Monica and Santa Ana ranges with signs of inbreeding, including the first evidence of reduced fertility.
Their findings are similar to the signs of severe inbreeding seen early on among most Florida panthers in the 1990s, including the kinked tails, undescended testes and teratospermia (60 percent or more abnor- mal sperm), Huffmeyer noted. The Florida panther population only recovered with the introduction of
mountain lions from Texas.
"The Florida panthers were also severely isolated and severely inbred, so the fact that we're seeing the same traits in our mountain lion population is alarming,'' she said. "If we don't do anything to introduce more genetic diversity to the Southern California mountain lions, we will have more males with reproduc- tive problems, fewer kittens and a lower rate of kitten survival."
The scientists cited a real risk of extinction for the mountain lions in the Santa Monica and Santa Ana ranges. Once significant inbreeding depression is found—meaning decreased fertility and reduced kitten survival—extinction is predicted to occur within 50 years, according to 2016 and 2019 papers evaluating population viability that included scientists from UCLA, NPS, UC Davis, the University of Wyoming, and the University of Nebraska.
While a few mountain lions—in particular the cougar known as P-22, who frequents Griffith Park—have successfully crossed freeways, far more have been killed trying to do so.
WHEN T-REX WAS KING
How many roamed the Earth?
By MADELINE REYES, Contributing Writer
A cast of a T. Rex skeleton on display outside the UC Museum of Paleontology at the University of California, Berkeley. The original, a nearly complete skeleton excavated in 1990 from the badlands of eastern Montana, is at the Museum of the Rockies in Bozeman, Montana. (Keegan Houser, UC Berkeley)
A breakthrough new study has satisfied the long unanswered question of how many T. Rexes lived on Earth in their time, finding that approximately 2.5 billion roamed the Earth over the span of 2½ million years.
In the study published Thursday in the journal Science, paleontologist Charles Marshall and a team of his students used statistics, computer simulations and an ecological formula to estimate the number of T. Rexes that lived at a given time.
The Tyrannosaurus rex, — with a name that means “king of the tyrant lizards” — was one of the most feared predators of the Cretaceous period. Its body was as long as a school bus, it weighed up to 8 tons, it walked on two giant, muscular legs and had a terrifying set of razor-sharp teeth with a bite force of up to 6 tons of pressure. It preyed on living animals, but if prompted would also eat scavenged prey and even each other.
Paleontologists have wondered how many of these apex predators lived, but until now it’s always been an impossible question to answer. Computing the population of any extinct animal had yet to be done, and leading experts had doubts about the concept. Even Marshall, who had been curious for years, was shocked when he and his team finally found an avenue.
“The project just started off as a lark, in a way,” said Marshall, director of the University of California Museum of Paleontology, the Philip Sandford Boone Chair in Paleontology, and UC Berkeley professor of integrative biology and of earth and planetary science, in a statement accompanying the study.
“When I hold a fossil in my hand, I can’t help wondering at the improbability that this very beast was alive millions of years ago, and here I am holding part of its skeleton — it seems so improbable,” he continued. “The question just kept popping into my head, ‘Just how improbable is it? Is it one in a thousand, one in a million, one in a billion?’ And then I began to realize that maybe we can actually estimate how many were alive, and thus, that I could answer that question.”
While the new formula is a huge step forward, Marshall acknowledges the figure is an estimate and has room for error. They believe that there were probably 20,000 adult T. Rexes at a given time, with a 95% confidence range that the true number lies between 1,300 and 328,000. Therefore, there could have been approximately 140 million to 42 billion T. Rexes across the entire Cretaceous period.
The team then used the Monte Carlo computer simulation, a mathematical technique that estimates probable outcomes, to examine how their uncertainties about the dinosaurs themselves would affect the results. Specifically, the biggest unknown factor had to do with the dinosaurs’ ecology, like how warm-blooded they were, as their method relied heavily on this question.
Specifically, they used a method recently published by John Damuth of the University of California, Santa Barbara, called Damuth’s Law that looks at how body mass affects population density in animals. While a significant correlation exists, it is also affected by differences in a species’ physiology and role in an ecosystem. The authors offer hyenas and jaguars as a prime example, since they are similar in stature but more hyenas can occupy an environment than jaguars can.
“Our calculations depend on this relationship for living animals between their body mass and their population density, but the uncertainty in the relationship spans about two orders of magnitude,” Marshall said. “Surprisingly, then, the uncertainty in our estimates is dominated by this ecological variability and not from the uncertainty in the paleontological data we used.”
To fill this knowledge gap, Marshall proposed that the T. Rex’s energy levels fell somewhere in between a lion and a Komodo dragon.
The team also acknowledged their research, like most existing fossil records, ignored juvenile T. Rexes. The species could live up to 28 years and were considered juveniles at 13 or younger, subadults at 14, young adults at 18 and reached adulthood at 23. Judging by the differences in jaw size and strength, as well as recent evidence, the scientists believe that juvenile and adult T. Rexes were likely unique predators from one another.
They estimated that the T. Rex most likely reached sexual maturity at 15½ years old and lived into its late 20s, with an average body mass of 5.2 tons. They also estimated the dinosaurs hit a growth spurt around the time of their sexual maturity, with some able to reach 7 tons during this time. Additionally, they found only one T. Rex typically lived within a radius of 38.6 square miles.
They also found a generation lasted about 19 years, and since the species lived for about 2½ million years and had an average population size of 20,000, they calculated there were a total of 127,000 generations — with a total of 2.5 billion dinosaurs.
The next question was if their estimate is correct and millions of T. Rexes lived throughout the Cretaceous, why do we only have the fossils of about 100 of them?
“There are about 32 relatively well-preserved, post-juvenile T. rexes in public museums today,” Marshall said. “Of all the post-juvenile adults that ever lived, this means we have about one in 80 million of them.”
He added: “If we restrict our analysis of the fossil recovery rate to where T. rex fossils are most common, a portion of the famous Hell Creek Formation in Montana, we estimate we have recovered about one in 16,000 of the T. rexes that lived in that region over that time interval that the rocks were deposited. We were surprised by this number; this fossil record has a much higher representation of the living than I first guessed. It could be as good as one in a 1,000, if hardly any lived there, or it could be as low as one in a quarter million, given the uncertainties in the estimated population densities of the beast.”
Marshall said he expects much dispute over the findings, but he is confident that his method will persevere and become very useful in estimating extinct populations.
“In some ways, this has been a paleontological exercise in how much we can know, and how we go about knowing it,” he said. “It’s surprising how much we actually know about these dinosaurs and, from that, how much more we can compute. Our knowledge of T. rex has expanded so greatly in the past few decades thanks to more fossils, more ways of analyzing them and better ways of integrating information over the multiple fossils known.”
Furthermore, the team believes the computer code they have developed will allow scientists to start to estimate how many fossils of species they have yet to uncover.
“With these numbers, we can start to estimate how many short-lived, geographically specialized species we might be missing in the fossil record,” he said. “This may be a way of beginning to quantify what we don’t know.”