LED lights can save seabirds’ lives

This 2016 video sdays about itself:

This mini-documentary explores the astounding seabird colonies of the British Indian Ocean Territory. The tiny islands of the Chagos Archipelago are havens for nesting birds, and a precious resource in the vastness of the Indian Ocean. Stewart McPherson was given rare access to visit several islands of the Territory to document the astounding diversity of birds that call this remote corner of the Indian Ocean home. In this film, we follow conservation efforts that aim to clear the islands of invasive rodents and coconut palms to allow the natural bird numbers to recover.

From the University of Exeter in England:

LED lights reduce seabird death toll from fishing by 85 percent

July 11, 2018

Illuminating fishing nets with low-cost lights could reduce the terrible impact they have on seabirds and marine-dwellers by more than 85 per cent, new research has shown.

A team of international researchers, led by Dr Jeffrey Mangel from the University of Exeter, has shown the number of birds caught in gillnets can be drastically reduced by attaching green battery-powered light-emitting diodes (LEDs).

For the study, the researchers compared 114 pairs of gillnets — which are anchored in fixed positions at sea and designed to snare fish by the gills — in fishing waters off the coast of Peru.

They discovered that the nets fitted with the LEDs caught 85 per cent fewer guanay cormorants — a native diving bird that commonly becomes entangled in nets — compared with those without lights.

Coupled with previous research conducted by the same team, that showed LED lighting also reduced the number of sea turtles caught in fishing nets by 64 per cent, the researchers believe the lights offer a cheap, reliable and durable way to dramatically reduce the capture and death of birds and turtles, without reducing the intended catch of fish.

The research is published in the Royal Society journal Open Science on Wednesday, July 11 2018.

Lead author Dr Mangel, from the Centre for Ecology and Conservation at the University’s Penryn Campus, said: “We are very encouraged by the results from this study.

“It shows us that we may be able to find cost-effective ways to reduce bycatch of multiple taxa of protected species, and do so while still making it possible for fishers to earn a livelihood.”

Peru’s gillnet fleet comprises the largest component of the nation’s small-scale fleet and is conservatively estimated to set 100,000km of net per year in which thousands of turtles and seabirds will die as “bycatch” or unintentionally.

The innovative study, carried out in Sechura Bay in northern Peru, saw the LED lights attached at regular intervals to commercial fishing gillnets which are anchored to the bottom of the water. The nets are left in situ from late afternoon until sunlight, when the fishermen collect their haul.

The researchers used 114 pairs of nets, each typically around 500-metres in length. In each pair, one was illuminated with light-emitting diodes (LEDs) placed every ten metres along the gillnet floatline. The other net in the pair was the control and not illuminated.

The control nets caught 39 cormorants, while the illuminated nets caught just six.

A previous study, using the same LED technology, showed they also reduced the number of sea turtles also caught in gillnets. Multiple populations of sea turtle species use Peruvian coastal waters as foraging grounds including green, olive ridley, hawksbill, loggerhead and leatherback.

For that study, the researchers found that the control nets caught 125 green turtles while illuminated nets caught 62. The target catch of guitarfish was unaffected by the net illumination. They are now working with larger fisheries in Peru and with different coloured lights to see if the results can be repeated and applied with more critically endangered species.

Professor Brendan Godley, who is an author of the study and Marine Strategy Lead for the University of Exeter, said: “It is satisfying to see the work coming from our Exeter Marine PhDs leading to such positive impact in the world. We need to find ways for coastal peoples to fish with the least impact on the rest of the biodiversity in their seas.”


Green turtles of the Persian Gulf

This video says about itself:

Mysterious Green Sea Turtles in the Persian Gulf Tracked By Scientists | National Geographic

19 June 2018

Green turtles in the Middle East are one of the world’s least understood turtle populations. An international team of researchers is wrangling dozens of turtles, rodeo-style, to learn more about their migration routes and locations of nesting beaches.

Dinosaurs, birds, turtles, new research

This video from Canada says about itself:

15 August 2013

Where are the baby dinosaurs? In a spellbinding talk paleontologist Jack Horner describes how slicing open fossil skulls revealed a shocking secret about some of our most beloved dinosaurs. (Filmed at TEDxVancouver.)

From the University of Kent in England:

Genome structure of dinosaurs discovered by bird-turtle comparisons

May 21, 2018

A discovery by scientists at the University of Kent has provided significant insight into the overall genome structure of dinosaurs.

By comparing the genomes of different species, chiefly birds and turtles, the Kent team were able to determine how the overall genome structure (i.e. the chromosomes) of many people’s favourite dinosaur species — like Velociraptor or Tyrannosaurus — might have looked through a microscope.

The research was carried out in the laboratory of Professor Darren Griffin, of the University’s School of Biosciences, and is now published in the journal Nature Communications. It involved extrapolating the likely genome structure of a shared common ancestor of birds and turtles that lived around 260 million years ago — 20 million years before the dinosaurs first emerged.

Dr Becky O’Connor, senior postdoctoral researcher and co-author of the Nature Communications paper, then traced how chromosomes changed over evolutionary time from a reptile ancestor to the present day.

The team found that, although the individual chromosomes rearranged their genes internally, this did not occur much at all between the chromosomes — what the scientists describe as ‘a significant discovery’.

Birds (which are themselves living dinosaurs) have a lot of chromosomes compared to most other species and that is possibly one of the reasons why they are so diverse. This research suggests that the pattern of chromosomes (karyotype) seen in early emerging dinosaurs and later theropods is similar to that of most birds and, again, may help explain their great diversity.

The new discovery suggests that, had scientists had the opportunity to make a chromosome preparation from a theropod dinosaur, it might have looked very similar to that of a modern-day ostrich, duck or chicken.

One of the key pieces of biotechnology that made it possible was the development of a set of fluorescent probes derived from birds that worked well on the chromosomes of turtles.

The genetics laboratory run by Professor Darren Griffin in Kent’s School of Biosciences carries out research into how genes organise into chromosomes and how that is different between species. The work is a collaboration with Dr Denis Larkin at the Royal Veterinary College in London, Iowa State University, the University of Cambridge, Oxford Genome Technologies and the Natural History Museum, London. The work is a collaboration with Dr Denis Larkin at the Royal Veterinary College in London, Iowa State University, the University of Cambridge, the Cambridge company Cytocell and the Natural History Museum, London.

Dinosaur age sea turtle discovery in Alabama, USA

This is a reconstruction of the new species (Peritresius martini). Credit: Drew Gentry CC-BY

From PLOS:

New ancestor of modern sea turtles found in Alabama

April 18, 2018

A sea turtle discovered in Alabama is a new species from the Late Cretaceous epoch, according to a study published April 18, 2018 in the open-access journal PLOS ONE by Drew Gentry from the University of Alabama at Birmingham, Alabama, USA, and colleagues.

Modern day sea turtles were previously thought to have had a single ancestor of the Peritresius clade during the Late Cretaceous epoch, from about 100 to 66 million years ago. This ancestral species, Peritresius ornatus, lived exclusively in North America, but few Peritresius fossils from this epoch had been found in what is now the southeastern U.S., an area known for producing large numbers of Late Cretaceous marine turtle fossils. In this study, the research team analyzed sea turtle fossils collected from marine sediments in Alabama and Mississippi, dating from about 83 to 66 million years ago.

The researchers identified some of the Alabama fossils as representing a new Peritresius species, which they named Peritresius martini after Mr. George Martin who discovered the fossils. Their identification was based on anatomical features including the shape of the turtle’s shell. Comparing P. martini and P. ornatus, the researchers noted that the shell of P. ornatus is unusual amongst Cretaceous sea turtles in having sculptured skin elements which are well-supplied with blood vessels. This unique feature may suggest that P. ornatus was capable of thermoregulation, which could have enabled Peritresius to keep warm and survive during the cooling period of the Cretaceous, unlike many other marine turtles that went extinct.

These findings extend the known evolutionary history for the Peritresius clade to include two anatomically distinct species from the Late Cretaceous epoch, and also reveal that Peritresius was distributed across a wider region than previously thought.

Drew Gentry says: “This discovery not only answers several important questions about the distribution and diversity of sea turtles during this period but also provides further evidence that Alabama is one of the best places in the world to study some of the earliest ancestors of modern sea turtles.”

Fossil and modern turtles, new study

This video from the USA says about itself:

3 July 2011

This is a 13 minute video about the Eastern Box Turtle. This is educational and teaches about the preservation of the turtles. Produced and Directed by Heather Noe, Richard Castle and Jordan Rolfes. Written by Heather Noe. Primary photography by Richard Castle. Sound Design by Jesse Waits.

From the Florida Museum of Natural History in the USA:

Turtle shells help decode complex links between modern, fossil species

March 28, 2018

Summary: A new study shows how scientists can use animals’ physical features — also known as morphology — to make connections between a modern species and its fossilized relatives, even if they look strikingly different.

Imagine that Labradors and golden retrievers died out a million years ago, leaving only fossilized skeletons behind. Without the help of DNA, how could we determine that a fossil Labrador, a fossil retriever and a modern Chihuahua all belong to the same species, Canis lupus familiaris? And could we look at the wide variety of dogs today to gain clues about lost diversity in the past?

A new study by Florida Museum of Natural History researcher Natasha Vitek shows how scientists can use animals’ physical features — also known as morphology — to make connections between a modern species and its fossilized relatives, even if they look strikingly different.

“We can’t magically create more fossils”, said Vitek, a doctoral candidate in vertebrate paleontology. “A lot of it is trying to figure out what we can do with what we have at hand to find diversity within a species — diversity we no longer have.”

Scientists often use color, sexual differences, soft tissues, signs of age and DNA to analyze variation within modern species. But these can be missing in fossil specimens.

Vitek relied on a technique known as geometric morphometrics, a way of quantifying an object’s shape, to test whether shape is a reliable way to tease out the subtle relationships between species, subspecies and individuals of the same species that just look different from each other.

She used eastern box turtles, Terrapene carolina — a species that comes in all kinds of shapes, sizes and colors — to make links between the rich variation in modern specimens and their fossil relatives from as far back as the Pleistocene, from about 2.6 million to about 11,700 years ago.

Unfortunately, turtles don’t make anything easy.

Modern eastern box turtles display a dizzying amount of variation. A box turtle in Oklahoma can be straw-colored while the same species in Florida is dark with yellow sunburst patterns. Adult box turtles also come in a wide array of sizes with no direct link between size and age. A small turtle in one location could be the same size or older than a large turtle of the same species in another location, even within a short distance.

Similar levels of variation also crop up in fossil eastern box turtles. How different must two turtles be to indicate that they belong to different species or subspecies?

To make sure she was “comparing apples to apples”, Vitek only analyzed the shape of eastern box turtle shells, which preserve well and are common in the fossil record.

In doing so, she was wading into a debate about eastern box turtle variation that has lasted more than 80 years, with some scientists suggesting that fossil and modern box turtles are all the same species, while others — pointing to a distinction in size or shape — hypothesizing that some fossils represented a separate, extinct species. Some researchers have also argued that certain subtle differences between fossils are evidence of various subspecies.

Vitek, who began the study as a master’s student at the University of Texas at Austin, compared 435 shells of modern eastern box turtles and 57 shells of fossil specimens, analyzing changes in location, shape, size and sex.

“It’s almost ‘more money, more problems'”, Vitek said. “You’d think that with so many fossils, it would be great, but it just means that you can’t hide from all the natural complexity.”

To find a signal in the noise, she used geometric morphometrics to plot shell shape into a series of coordinates, “like a connect-the-dots puzzle,” she said, which created a more complete model of a shape in space.

“This allows you to see how that overall constellation of points is changing from shape to shape”, Vitek said. “You might see whole new patterns you would never have thought to measure before and capture things like curvature — things that are really hard to measure in just a single linear feature.”

Her results showed that scientists on both sides of the debate are partially right.

The argument that modern variation in eastern box turtles mirrors variation in fossil specimens of the same species does have some merit.

“It’s not like we hit the fossil record and there’s a hard boundary between what’s extinct and what still exists today,” she said. “Just like we’d expect from evolution, there is a gradient of variation that carries through to modern box turtles. Having some shells that aren’t that different is reassuring in the sense that, yes, some species do go back in time.”

But, she added, some shells likely do belong to lost subspecies, existing subspecies or closely related extinct species.

“Some sites have shells that are not only bigger than modern eastern box turtles but also very different,” she said. “There is lost variation in the eastern box turtle record. It turns out that if you go back to fossils, there is even more diversity than you would be able to pick up just by studying today’s box turtles.”

Vitek said she is hopeful her study will spur more researchers to look deeper at bony structures within species as a means of detecting variation in fossils.

“We’re doing a great job of seeing what drives patterns like mouse coat color, but let’s also see what drives patterns in things like mouse teeth and arm bones,” she said. “There’s a lot of opportunity to start better documenting what the morphology we pick up in the fossil record might actually mean in terms of evolution.”

Sea turtles use flippers in feeding

This video says about itself:

28 August 2016

After nesting, leatherbacks use their rear flippers to cover their nests. Check out this video from Surinam of a leatherback camouflaging her nest after STC researcher Dan Evans attached one of the new, slim satellite transmitters.

From PeerJ:

Sea turtles use flippers to manipulate food

March 28, 2018

Summary: Sea turtles use their flippers to handle prey despite the limbs being evolutionarily designed for locomotion. Research reveals a behavior thought to be less likely in marine tetrapods is actually widespread and that this type of exaptation of flippers may have been occurring 70 million years earlier than previously thought.

Sea turtles use their flippers to handle prey despite the limbs being evolutionarily designed for locomotion, a discovery by Monterey Bay Aquarium researchers published today in PeerJ.

The in-depth examination of the phenomenon — Limb-use By Foraging Sea Turtles, an Evolutionary Perspective — by authors Jessica Fujii and Dr. Kyle Van Houtan and others reveals a behavior thought to be less likely in marine tetrapods is actually widespread and that this type of exaptation of flippers may have been occurring 70 million years earlier than previously thought.

“Sea turtles don’t have a developed frontal cortex, independent articulating digits or any social learning”, says Van Houtan, Director of Science at Monterey Bay Aquarium. “And yet here we have them ‘licking their fingers’ just like a kid who does have all those tools. It shows an important aspect of evolution — that opportunities can shape adaptations.”

Lead author Jessica Fujii is part of the Aquarium’s sea otter research team where she specializes in ecomorphology — the intersection of evolution, behavior and body form. Fujii’s expertise in sea otter foraging and tool use behavior has influenced her recent examination of sea turtles and how they have evolved to use their limbs in novel ways.

Analysis by Fujii and Van Houtan using crowd-sourced photos and videos finds widespread examples of behaviors such as a green turtle holding a jelly, a loggerhead rolling a scallop on the seafloor and a hawksbill pushing against a reef for leverage to rip an anemone loose.

Similar behaviors have been documented in marine mammals from walruses to seals to manatees — but not in sea turtles. The paper shows that sea turtles are similar to the other groups in that flippers are used for a variety of foraging tasks (holding, bracing, corralling).

Sea turtles‘ limbs have evolved mostly for locomotion, not for manipulating prey”, Fujii says. “But that they’re doing it anyway suggests that, even if it’s not the most efficient or effective way, it’s better than not using them at all.”

The finding came as a surprise to the authors, given sea turtles’ ancient lineage and the fact that the reptiles are considered to have simple brains and simple flippers. The results also offer an insight into the evolution of four-limbed ocean creatures that raises questions about which traits are learned and which are hardwired.

“We expect these things to happen with a highly intelligent, adaptive social animal”, Van Houtan says. “With sea turtles, it’s different; they never meet their parents”, Kyle says. “They’re never trained to forage by their mom. It’s amazing that they’re figuring out how to do this without any apprenticing, and with flippers that aren’t well adapted for these tasks.”

The study may also help inform the aquarium’s ongoing sea otter research. How developmental biology predisposes animals to adopt dining strategies is of particular interest, given the aquarium’s efforts to raise stranded sea otter pups and prepare them for a return to the wild. Rearing and releasing stranded pups contributes to the aquarium’s work to recover California’s threatened sea otter population.

Before they’re released, ecologically naïve pups have to be taught foraging behaviors, be it for crabs or abalone, by adult female sea otters at the aquarium, which serve as surrogate mothers to the pups.

“What we’re trying to understand is how to have the best sea otter surrogacy program,” Kyle says. “This is kind of one end of the spectrum of that — the opposite end of the spectrum.”

Male loggerhead turtles also go back to nesting beaches

This 2014 video says about itself:

Loggerhead Sea Turtle Hatchling Rescue!!!

Words cannot describe…

I came across some baby sea turtle tracks one morning at the refuge and noticed many of the tracks went up into the dune instead of directly to the water. A quick search revealed several hatchlings floundering in the dune vegetation. As the acting refuge biologist, I am permitted to handle these protected turtles for purpose of rescue. This was an amazing opportunity for me to examine these amazing creatures up close and personal, a rare and priceless occurrence.

These animals are protected, please do not approach them in the wild.

From the Universidad de Barcelona in Spain:

Male loggerhead turtles also go back to their nesting beaches to breed

March 14, 2018

Most male loggerhead turtles go back to the nesting beaches to breed -a common behaviour among female turtles-, according to a study in which the researchers Marta Pascual, Àlex Aguilar, Carles Carreras, Lluís Cardona and Marcel Clusa, from the Faculty of Biology and the Biodiversity Research Institute of the University of Barcelona (IRBio) took part.

Also, experts from the Cyprus Wildlife Society (Cyprus), University of Tripoli (Libya) and the University Adnan Menderes (Turkey), among other institutions, collaborated in the study.

The study, published in the journal Marine Ecology Progress Series, outbreaks the classical view on the breeding behaviour of these marine turtles, and explains how the species could also breed in feeding areas or during their journey towards nesting beaches.

New paradigm: male turtles return to the nesting beach to breed

The loggerhead turtle (Caretta caretta) is a marine species that travels long journeys to tropical and temperate areas around the world. In the eastern Mediterranean, in particular, it nests in the coasts of Greece, Turkey, Cyprus, Libya, Lebanon and Israel, although there have been some sporadic nesting episodes in the western Mediterranean.

It was believed that only female turtles went back to the nesting areas to lay the eggs –philopatric behaviour- after reproducing with male turtles from different areas. Philopatry is a studied phenomenon among female C. caretta turtles. The process of detection, marking, and the chelonian genetic study (for instance, with the mitochondrial DNA, transmitted by maternal inheritance), are easily conducted if females are the ones that go back to the beach of birth to lay the eggs.

However, markers in males are not abundant and results have never been conclusive. Previous studies with few genetic nuclear markers ─microsatellite loci, the biparental inheritance─ suggested male turtles did not show philopatric behaviour and mated with females from different areas.

“Our study reveals the breeding behaviour of the C. caretta marine turtle can be more complex. In most populations, female turtles are not the only ones with philatropic behaviour: males also mate near nesting beaches”, says the lecturer Marta Pascual, member of the Department of Genetics, Microbiology and Statistics of the UB and IRBio.

Breeding far from nesting beaches

In the study, the UB-IRBio team increased the number of microsatellite markers to analyse the gene flow among loggerhead turtle populations in the Mediterranean. The results show a higher gene differentiation in the nesting beaches in the Mediterranean and suggest the possibility that turtles breed in feeding areas or during their journey towards nesting beaches.

“Therefore, the accepted belief that males do not display philopatry could be due -in some cases- the low number of molecular markers that were used so far”, states Marta Pascual. “Also, if we compare mitochondrial and nuclear markers, we can compare the spreading behaviour of male and female turtles in different areas, which shows complex and particular breeding behaviours in each area.”

Higher temperatures, more female turtles in the marine habitat

In most cases, philopatry happens in male and female turtles. However, there are cases of opportunistic breeding patterns between males and females in different areas other than their place of birth. According to the experts, the obtained results could be explained with some hypotheses that have to be tested in future studies.

“The breeding behaviour can change depending on the population; it can even be affected by the amount of male turtles that are born in a specific area,” says Pascual. The sex of marine turtles is determined by the temperature of incubation. If the temperature is high, there will only be female turtles: “with global warming, high temperatures would cause a feminization of the populations, a phenomenon that could be balanced through opportunist breeding with males from other areas”, concludes the expert.

Protecting an emblematic species in the Mediterranean

Although the Mediterranean can be understood as a regional unit to manage globally, when it comes to the loggerhead turtle there are genetically differentiated units that should be protected. In some cases, these are big populations -according to the annual number of nests in their beaches- but there are examples that show a lower balance. In a planet affected by global change, a more comprehensive study of different areas is necessary to identify bottlenecks -which reduce the number of population individuals- and to study the impact of the increase of consanguinity over the viability of the different units.

There are still many unknown issues on the breeding biology of the species C. caretta. Migratory routes that have been observed with telemetry on females in Cyprus show that they feed in Libya and travel near this area’s nesting beaches. New studies with genomic scale markers are necessary to get deeper in the biology and ecology of the most abundant marine turtle in the Mediterranean (sporadic nesting, non-philopatric breeding, etc.).