Many sea turtles at Costa Rican beach


This 25 November 2018 video says about itself:

A Mass Synchronized Nesting Event | Jaguar Beach Battle

The arribada finally begins on the Nancite Beach of Costa Rica, a mass synchronized nesting event for three days where tens of thousands of female Olive Ridley sea turtles return to the beach they were born to lay their own eggs.

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Lonesome George, other Galápagos tortoises, new research


This 27 February 2018 video says about itself:

Galápagos Tortoise Movement Ecology Programme

The film captures the hidden mystery of the lives of giant tortoises, among the longest lived vertebrates on earth. It illustrates the diverse ecological roles played by Galápagos tortoises and how the environment has shaped complex yet predictable patterns on movement, morphology and ecological relationships among tortoises across the Galápagos Archipelago.

It demonstrates how a team of conservation biologists developed and implemented a research programme that revealed the hitherto unknown secret lives of Galápagos tortoises – one of the earth’s most iconic wildlife species. It documents the movement ecology of tortoises, their feeding ecology, their role as ecosystem engineers, and their pivotal role in ecosystems.

Touching on their conservation history from the time humans discovered the islands, and how humans will determine the fate of tortoises and their habitats. It demonstrates how scientific research can inform conservation management, and highlight the importance of pure and applied research toward understanding and conserving the tortoises and the ecosystems they shape.

From Yale University in the USA:

In death, Lonesome George reveals why giant tortoises live so long

December 3, 2018

Lonesome George’s species may have died with him in 2012, but he and other giant tortoises of the Galápagos are still providing genetic clues to individual longevity through a new study by researchers at Yale University, the University of Oviedo in Spain, the Galápagos Conservancy, and the Galápagos National Park Service.

Genetic analysis of DNA from Lonesome George and samples from other giant tortoises of the Galápagos — which can live more than 100 years in captivity — found they possessed a number of gene variants linked to DNA repair, immune response, and cancer suppression not possessed by shorter-lived vertebrates.

The findings were reported Dec. 3 in the journal Nature Ecology & Evolution.

“Lonesome George is still teaching us lessons”, said Adalgisa “Gisella” Caccone, senior researcher in Yale’s Department of Ecology and Evolutionary Biology and co-senior author of the paper.

In 2010, Caccone began sequencing the whole genome of Lonesome George, the last of the species Chelonoidis abingdonii, to study evolution of the tortoise population on the Galápagos. Carlos Lopez-Otin at the University of Oviedo in Spain analyzed this data and other species of tortoises to look for gene variants associated with longevity.

“We had previously described nine hallmarks of aging, and after studying 500 genes on the basis of this classification, we found interesting variants potentially affecting six of those hallmarks in giant tortoises, opening new lines for aging research”, Lopez-Otin said.

Giant tortoises, why did they get so big?


This 2019 video says about itself:

The Galápagos Tortoise

This is a video of the Galápagos tortoise from the BBC’s Life in Cold Blood documentary series.

From Martin-Luther-Universität Halle-Wittenberg in Germany:

Tortoise evolution: How did they become so big?

October 23, 2018

Summary: The evolution of giant tortoises might not be linked to islands, as had been previously thought. In a first-of-its-kind study, researchers present the most comprehensive family tree of extinct and extant tortoises so far. Analyzing genetic and osteological data from living species and fossil tortoises they rewrite the evolution of tortoises. Giant size evolved on multiple occasions on the mainland.

Tortoises are a group of terrestrial turtles globally distributed in habitats ranging from deserts to forests and include species such as the Greek and the Galapagos tortoise. Some species evolved large body sizes with a shell length exceeding 1 metre whereas others are no larger than 6-8 centimetres. Despite a particular interest from naturalists ever since the times of Darwin, the evolution of gigantism in tortoises remains enigmatic.

The fact that all living giant tortoises are insular may suggest that their evolution followed the so-called island rule: a trend toward dwarfism of large animals and gigantism of small animals on islands. An example of insular dwarfism is the Florida key deer, a dwarf version of the mainland white-tailed deer; its small size may be an adaptation to the limited resources found on the islands. Insular gigantism is best exemplified by the famous dodo, an extinct flightless pigeon from Mauritius, probably evolving large body size due to release from predatory pressure. Previous studies on extant tortoises were partly inconclusive: giant size has been linked to the absence of predatory mammals in islands but it has been also proposed that tortoises were already giants when they reached the remote archipelagos. Since very few giant tortoise species survive to the present, these hypotheses are impossible to test without analysing extinct species through the help of the fossil record.

In a recent study in the journal “Cladistics”, Dr Evangelos Vlachos from the Paleontological Museum of Trelew, Argentina, and Dr Márton Rabi from the Martin Luther University Halle-Wittenberg (MLU), funded by the German VolkswagenStiftung, assembled the most comprehensive family tree of extinct and extant tortoises so far. The researchers analysed genetic data from living species together with osteological data from fossil and living tortoises.

This is the first study of such global scale to allow for investigating body size evolution in tortoises. The fossils reveal a very different picture of the past compared to the present. Giant size evolved on multiple occasions independently in mainland Asia, Africa, Europe, North and South America at different times of Earth history. However, all of these species went extinct at latest during the Pleistocene ice age.

“The fossils highlight a great number of extinct mainland giant species and suggest that the evolution of giant size was not linked to islands”, says Dr Evangelos Vlachos.

Instead, living insular giant tortoises, such as the ones from Galapagos and Seychelles, more likely represent survivors of unrelated giant species that once inhabited South America, East Africa, and/or Madagascar.

“Giant tortoises may have been better island colonizers because they can tolerate water and food shortage during an oceanic dispersal for a longer period than smaller species. Giant tortoises have been reported to survive 740 km of floating in the ocean”, says Dr Márton Rabi.

What led to the extinction of these mainland giants remains enigmatic. For the ice age species, it may have been a combination of predatory (including human) pressure and climate change. It is likewise unclear, if not the island rule, then what is driving tortoises to repeatedly evolve into giant forms?

“We expect that warmer climate and predator pressure plays a role in the evolution of giant size but the picture is complex and our sampling of the fossil record is still limited.” — Vlachos adds.

An unexpected outcome of the study was that the Mediterranean tortoises (familiar due to their popularity as pets) actually represent a dwarf lineage as their ancestors turned out to be considerably larger.

“Tortoises have been around for more than 55 million years and we are now able to better understand the evolution of this successful group. Today, however, out of the approximately 43 living species 17 are considered endangered and many more are vulnerable largely due to human-induced habitat loss; this is a disappointing fact.” — Rabi points out.

Gopher tortoise conservation in the USA


This October 2014 video from the USA says about itself:

We all know the story of the tortoise and the hare but it might be time to rethink the concept of tortoises being slow!

On this week’s adventure Coyote’s chasing after some seriously speedy Gopher Tortoises on the Tortuga Trail Wildlife Preserve at Florida Atlantic University.

Working alongside tortoise conservationist Jessica Huffman, Coyote will have to be quick on his feet to get an up close look at this remarkable keystone species…and unfortunately for Coyote he’s also in for one “BIG” surprise! You aren’t going to want to miss this episode of Breaking Trail!

Special Thanks to Jessica Huffman and all the members of SEEDS who helped in the making of this episode. Keep up all the incredible conservation work, you guys are the best!

Breaking Trail leaves the map behind and follows adventurer and animal enthusiast Coyote Peterson and his crew as they explore a variety of wildlife in the most amazing environments throughout North America!

From the University of Georgia in the USA:

Giving tortoises a ‘head start’

Raising gopher tortoises in captivity may boost wild populations

September 4, 2018

Research from the University of Georgia indicates that head-starting — raising a species in captivity and releasing it into a protected habitat after it has grown large enough to be less vulnerable to predators — is a useful intervention for boosting the state’s gopher tortoise population, which has been declining in numbers for decades due to predation, poaching and loss of suitable habitat.

Seventy percent of head-started tortoises raised from donor eggs were still alive a year after release at Yuchi Wildlife Management Area in Burke County, according to research by Tracey Tuberville and Dan Quinn. They published their findings in the Journal of Wildlife Management.

The gopher tortoise, Georgia’s state reptile, is a keystone species whose burrows provide shelter for more than 250 other species, said Tuberville, associate research scientist at the Savannah River Ecology Laboratory and adjunct faculty at the Warnell School of Forestry and Natural Resources.

Despite predation risks at the release site, survival rates were higher than survival reported for their wild counterparts, according to Quinn, a graduate student at SREL and Warnell during the research.

Quinn conducted two soft-releases of yearlings at YWMA during consecutive years. The team said the second release was the largest tortoise release in the state to date.

“We initially released the tortoises into pens to acclimate them into the natural environment,” he said. “This gives them time to construct a burrow and in theory it reduces predation risk.”

Forty-two of 145 yearlings were radio tracked and monitored for a year following the soft releases, providing information to inform future head-starting efforts.

Tracking data revealed that the juveniles demonstrated a strong rate of site fidelity, remaining together in a protected area, which allows them to reproduce. This means the soft-release technique is not necessary, according to Tuberville.

Instead, the researchers will implement multiple releases in various locations to help reduce predation risk. Predators included fire ants, raccoons and dogs, with fire ants accounting for the majority of fatalities.

Head-starting efforts at YWMA will continue with tortoises that are 2 to 3 years old, an age when they are less susceptible to predators, Tuberville said. Additional research will evaluate whether the positive effect on post-release survival warrants the additional time in captivity.

Pacific ocean animals’ migrations, new study


This 2012 video says about itself:

An educational video by SEE Turtles about sea turtle migrations including leatherbacks and loggerheads. Learn how these amazing animals swim thousands of miles to find food and nesting beaches.

From the University of California – Santa Cruz in the USA:

Tracking marine migrations across geopolitical boundaries aids conservation

September 3, 2018

The leatherback sea turtle is the largest living turtle and a critically endangered species. Saving leatherback turtles from extinction in the Pacific Ocean will require a lot of international cooperation, however, because the massive turtles may visit more than 30 different countries during their migrations.

A new study uses tracking data for 14 species of migratory marine predators, from leatherback turtles to blue whales and white sharks, to show how their movements relate to the geopolitical boundaries of the Pacific Ocean. The results provide critical information for designing international cooperative agreements needed to manage these species.

“If a species spends most of its time in the jurisdiction of one or two countries, conservation and management is a much easier issue than it is for species that migrate through many different countries,” said Daniel Costa, professor of ecology and evolutionary biology at UC Santa Cruz and a coauthor of the study, published September 3 in Nature Ecology & Evolution.

“For these highly migratory species, we wanted to know how many jurisdictional regions they go through and how much time they spend in the open ocean beyond the jurisdiction of any one country,” Costa said.

Under international law, every coastal nation can establish an exclusive economic zone (EEZ) extending up to 200 nautical miles from shore, giving it exclusive rights to exploit resources and regulate fisheries within that zone. The high seas beyond the EEZs are a global commons and are among the least protected areas on Earth. Discussions have been under way at the United Nations since 2016 to negotiate a global treaty for conservation and management of the high seas.

First author Autumn-Lynn Harrison, now at the Smithsonian Conservation Biology Institute in Washington, D.C., began the study as a graduate student in Costa’s lab at UC Santa Cruz. Costa is a cofounder, with coauthor Barbara Block of Stanford University, of the Tagging of Pacific Predators (TOPP) program, which began tracking the movements of top ocean predators throughout the Pacific Ocean in 2000. Harrison wanted to use the TOPP data to address conservation issues, and as she looked at the data she began wondering how many countries the animals migrate through.

“I wanted to see if we could predict when during the year a species would be in the waters of a particular country,” Harrison said. “Some of these animals are mostly hidden beneath the sea, so being able to show with tracking data which countries they are in can help us understand who should be cooperating to manage these species.”

Harrison also began attending meetings on issues related to the high seas, which focused her attention on the time migratory species spend in these relatively unregulated waters. “Figuring out how much time these animals spend in the high seas was directly motivated by questions I was being asked by policy makers who are interested in high seas conservation,” she said.

The TOPP data set, part of the global Census of Marine Life, is one of the most extensive data sets available on the movements of large marine animals. Many of the top predators in the oceans are declining or threatened, partly because their mobility exposes them to a wide array of threats in different parts of the ocean.

Leatherback turtle populations in the Pacific could face a 96 percent decline by 2040, according to the IUCN Red List of Threatened Species, and leatherbacks are a priority species for the National Oceanic and Atmospheric Administration (NOAA). Laysan and black-footed albatrosses, both listed as near threatened on the IUCN Red List, spend most of their time on the high seas, where they are vulnerable to being inadvertently caught on long lines during commercial fishing operations.

White sharks are protected in U.S. and Mexican waters, but the TOPP data show that they spend about 60 percent of their time in the high seas. Pacific bluefin tuna, leatherback turtles, Laysan albatross, and sooty shearwaters all travel across the Pacific Ocean during their migrations.

“Bluefin tuna breed in the western North Pacific, then cross the Pacific Ocean to feed in the California Current off the United States and Mexico,” Costa said. “Sooty shearwaters not only cross the open ocean, they use the entire Pacific Ocean from north to south and go through the jurisdictions of more than 30 different countries.”

International cooperation has led to agreements for managing some of these migratory species, in some cases through regional fisheries management organizations. The Inter-American Tropical Tuna Commission (IATTC), for example, oversees conservation and management of tunas and other marine resources in the eastern Pacific Ocean.

The first session of a U.N. Intergovernmental Conference to negotiate an international agreement on the conservation of marine biological diversity beyond areas of national jurisdiction will be held in September. Harrison said she has already been asked to provide preprints and figures from the paper for this session.

“These migratory species are a shared heritage, and this paper shows their international travels better than ever before,” Harrison said. “The first step to protect them is knowing where they are over their annual cycle and promoting international agreements to manage the threats they may face across several countries.”

Tortoise indeed faster than hare


This 2015 video is called The Hare and The Tortoise Story | Bedtime Story by Kids Hut | English Stories For Kids.

From Duke University in the USA:

In the race of life, the tortoise beats the hare every time

Research shows that, when speed is averaged throughout a lifetime, the fastest animals and machines are actually the slowest

August 27, 2018

Summary: Researchers have discovered that, over the long-run, the race will indeed go to the slower, steadier animal. An analysis of the reported speeds of animals based on land, air and water shows that some of the world’s fastest animals are actually some of the slowest when their movements are averaged throughout their lifetimes, giving credence to Aesop’s fable ‘The Tortoise and the Hare.’

Over the long-run, the race will indeed go to the slower, steadier animal.

“The fable of ‘The Tortoise and the Hare’ is a metaphor about life, not a story about a race”, said Adrian Bejan, the J.A. Jones Professor of Mechanical Engineering at Duke University. “We see in animal life two starkly different lifestyles — one with nearly steady feeding and daily sleep and another with short bursts of intermittent feeding interspersed with day-long siestas. Both of these patterns are the rhythms of living that Aesop taught.”

In the iconic parable, Aesop tells of a race between a fast but often-distracted hare and a slow but relentless tortoise. Readers are supposed to be surprised when the tortoise manages to defeat the hare, coining the phrase “slow and steady wins the race.” But according to Bejan’s new analysis, they shouldn’t be.

Published on August 27 in the journal Scientific Reports, Bejan analyzes the reported speeds of animals based on land, air and water. The results show that some of the world’s fastest animals are actually some of the slowest when their movements are averaged throughout their lifetimes.

Bejan then goes on to demonstrate that this counterintuitive result is also true of the modern aviation industry. With data from hundreds of historical airplane models in hand, Bejan shows that the general trend in their design is for size and speed to increase hand-in-hand.

Except, that is, for the modern jet fighter.

Just like in the animal world, the jet fighter may be faster than other airplanes in short bursts, but it spends much of its time grounded. When averaged over its service lifetime, jet fighters are surprisingly slow when compared to models designed for transport or reconnaissance.

The study emerged as a consequence of a previous paper that used Bejan’s constructal theory to show that all animals’ speeds tend to rise along with their body mass and adhere to a similar ratio. For example, the stride frequency of running vertebrates bears the same relationship to the animals’ mass as does the rate at which fish swim. Similarly, the velocity of runners conforms to the same principles as the speed of birds in flight. These models can be used to predict future evolutionary trends and design directions for aircraft and other vehicles.

“When I would give speeches on this topic, somebody would always bring up outliers to this principle such as the cheetah as counterexamples”, said Bejan. “But this study shows that these ‘outliers’ are to be expected and, when looked at over their lifetimes, are not so different from their lumbering cousins after all.”