Red admiral, golden oriole, lizards, orchids


The path to Skafi beach on Tilos island

After 20 April 2019, we were still on Tilos island in Greece. The photo shows the path to Skafi beach on the north coast. We walked there; not all the way to the coast, as there was much too see underway.

Again, Sardinian warblers singing. And a nightingale.

Again, many painted lady butterflies; on their spring migration?

Then, a different butterfly: a red admiral.

The scientific name of this species is Vanessa atalanta. Linnaeus probably named the species after the Greek mythological young woman Atalante, famous for her beauty and speed.

A bit further, a collared flycatcher on a tree.

This is a collared flycatcher video from Sweden.

On a wall, the most common of the five lizard species of Tilos: a snake-eyed lizard.

A male red-footed falcon flies past.

Then. on a rock, the biggest Tilos lizard species: a sling-tailed agama.

This 28 April 2018 video is called Sling Tailed Agama – (Stellagama stellio) – Κουρκουτάς – Cyprus.

As we walk back, a male golden oriole flying.

Barn swallows flying.

So does a kestrel.

Cypress, 21 April 2019

We approach a cypress tree near the ruin of an old farmhouse.

Walls, 21 April 2019

Only some of its walls are still standing.

Holy orchids, 21 April 2019

Between the ruined walls, these holy orchids grow.

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Good Pacific green turtle news


This 30 December 2018 video from Australia says about itself:

Tracking Green Turtles in the Great Barrier Reef | Fearless Adventures with Jack Randall

Jack dives into the Great Barrier Reef to wrangle Green Sea Turtles for wildlife conservation and study.

From PLOS:

Immense Pacific coral reef survey shows green sea turtle populations increasing

First comprehensive in-water survey shows key role of ocean temperature and human protection

April 24, 2019

Densities of endangered green turtles are increasing in Pacific coral reefs, according to the first comprehensive in-water survey of turtle populations in the Pacific. The study, by Sarah Becker of the Monterey Bay Aquarium in California and colleagues, publishes April 24 in the open-access journal PLOS ONE.

Coral-dwelling sea turtles have long been endangered due largely to human exploitation — hawksbills for tortoiseshell and green turtles for food — and destruction of coral reef habitat, but the institution of global protection efforts beginning in the 1970s aimed to reverse this decline. Land-based surveys of breeding and nesting sites have provided important evidence of population sizes, but are limited in scope and without confirmation from the ocean where the turtles spend the vast majority of their time.

To more fully understand the density of the populations of these two turtle species, as well as the environmental and anthropogenic factors that have driven them, the authors combined data from 13 years of in-water visual surveys of turtle abundance near 53 islands, atolls, and reefs throughout the U.S. Pacific. During a survey, a slow-moving boat tows a pair of divers at about 15 meters below the surface, where they record details of habitat and sea life as it comes into view. In all, the surveys covered more than 7,300 linear kilometers and observed more than 3,400 turtles of the two species.

Survey data showed that American Samoa had the highest density of hawksbills, while the Pacific Remote Islands Area, a mostly uninhabited region about a thousand miles southwest of Hawaii, had the most green turtles. Hawksbill numbers were far lower (< 10%) than green turtle counts, indicating that many conservation threats still exist for this species. Density of green turtles were driven primarily by ocean temperatures and productivity, but suggested effects from historical and present-day human impacts. Over the survey period, green turtle populations were either stable or increased. The lowest density but the highest annual population growth was found in the Hawaiian Islands, suggesting that protective regulations may be paying off in allowing green turtle populations to rebound.

Becker adds: “This study represents one of the largest sea turtle population surveys ever conducted, filling critical gaps on in-water abundance and drivers of population density. Across the tropical Pacific several locations held impressive densities of sea turtles, and in all regions densities were driven by bottom-up forces like ocean temperatures and productivity and top-down forces such as human impacts.”

Aquatic ankylosaur dinosaur discovery?


This 21 April 2019 video says about itself:

An Aquatic Ankylosaur?

There were once some very strange dinosaurs, but one of the strangest may have been a species of small, possibly fish-eating aquatic ankylosaurLiaoningosaurus paradoxus.

Galapogos giant tortoises and climate change


This 23 March 2019 video says about itself:

Tracking Giant Galapagos Tortoises | BBC Earth

From the Ecological Society of America:

Giant tortoises migrate unpredictably in the face of climate change

Unlike many migratory species, Galapagos giant tortoises do not use current environmental conditions to time their seasonal migration

April 18, 2019

Summary: Researchers use GPS to track the timing and patterns of giant tortoise migration over multiple years. The tortoises often take the same migration routes over many years in order to find optimal food quality and temperatures. The timing of this migration is essential for keeping their energy levels high, and climate change could disrupt a tortoise’s ability to migrate at the right time.

Galapagos giant tortoises, sometimes called Gardeners of the Galapagos, are creatures of habit. In the cool dry season, the highlands of the volcano slopes are engulfed in cloud which allows the vegetation to grow despite the lack of rain. On the lower slopes, however, there is no thick fog layer, and vegetation is not available year round. Adult tortoises thus spend the dry season in the higher regions, and trek back to the lower, relatively warmer zones where there is abundant, nutritious vegetation when the rainy season begins.

The tortoises often take the same migration routes over many years in order to find optimal food quality and temperatures. The timing of this migration is essential for keeping their energy levels high, and climate change could disrupt a tortoise’s ability to migrate at the right time.

In the Ecological Society of America’s journal Ecology, researchers use GPS to track the timing and patterns of tortoise migration over multiple years.

“We had three main goals in the study,” says Guillaume Bastille-Rousseau, lead author of the paper. “One was determining if tortoises adjust their timing of migration to current environmental conditions. Two, if so, what clues do they use to adjust the timing, and, three, what are the energetic consequences of migration mis-timing for tortoises?”

The researchers expected the migrations to be timed with current food and temperature conditions because many other migratory species operate that way. Bastille-Rousseau says “many animals, such as ungulates, can track current environmental conditions and migrate accordingly — what researchers sometime refer to as surfing the green-wave.”

Contrary to the researchers’ expectations, however, migration is weakly associated with current conditions such as fog, rain, and temperature. For instance, if it is unseasonably arid, it appears the tortoises do not take that variation into account when deciding it is time to migrate. It is unclear at this point whether they are basing their migration decisions on memories of past conditions or if they are simply incorrectly assessing current local conditions.

Bastille-Rousseau says the team is surprised by the mismatch, stating “tortoise timing of migration fluctuated a lot among years, often by over two months. This indicates that migration for tortoises may not just be about foraging opportunities. For example, female tortoises have to make decisions related to nesting, and we still have a lot to learn about migration in giant tortoises.”

Fortunately, this sub-optimal timing may not yet have critical impact on tortoise health. Potentially due to their long lives of up to 100 years and large body size, bad timing of migration has smaller consequences for giant tortoises compared to small, short lived animals. Giant tortoises can go up to a year without eating and survive, while other migrating species must eat more regularly to sustain their energy levels.

Giant tortoises are important ecosystem engineers in the Galapagos, responsible for long-distance seed dispersal, and their migration is key for many tree and plant species’ survival. How the tortoises’ variation in migration timing will affect the rest of the ecosystem is still unclear. Because tortoises do not seem to be tracking annual variation in environmental conditions, it is quite possible that the mistiming of migration will keep increasing in the future.

“One concern is that at some point in the future,” Bastille-Rousseau adds, “migration may not be an optimal strategy for tortoises. There may be a reduction in the number of individuals doing these long-distance movements. This would likely have cascading consequences for the whole ecosystem.”

THE CLIMATE KIDS ARE ALL RIGHT The last five years were the five hottest on record. The amount of carbon dioxide in the atmosphere has soared past 410 parts per million. As many as 150 species die off each day. As the call for action grows louder, the youth climate movement ― which scientists say has moved the needle on action to address the climate emergency ― is taking center stage. [HuffPost]

HAWAII BEACHES MAY SOON BE UNDERWATER Hawaii’s iconic Waikiki Beach could soon be underwater as rising sea levels caused by climate change overtake its white sand beaches and bustling city streets. State lawmakers are trying to pass legislation that would spend millions for a coastline protection program. [AP]

A new Stanford University study shows global warming has increased economic inequality since the 1960s. Temperature changes caused by growing concentrations of greenhouse gases in Earth’s atmosphere have enriched cool countries like Norway and Sweden, while dragging down economic growth in warm countries such as India and Nigeria: here.

How Cayman Islands lizards adapt


This December 2018 video says about itself:

The Lizard’s Tale 101: Meet the Anoles

Anoles are small lizards with an abundance of charm. There are over 400 species of anoles, scattered all over the American and Caribbean tropics: from remote rainforests in the Bahamas, to busy cities on the mainland. In recent years, anoles have come to be viewed as a great model organism for understanding key evolutionary principles. They’ve helped scientists tackle many of the big questions in biology: from the links between ecology and evolution, to the effects of physiology and behaviour. The results are nothing short of eye-opening.

From the University of Plymouth in England:

Biological changes among invasive species

April 8, 2019

A remote island in the Caribbean could offer clues as to how invasive species are able to colonise new territories and then thrive in them, a new study suggests.

Scientists from the University of Plymouth have recently completed extensive research into a lizard population on the Cayman Islands.

Up until the mid-1980s, there had never been a recorded sighting of the Maynard’s Anole (Anolis maynardi) on Cayman Brac island despite it being less than 10km from its native territory, Little Cayman.

However, since the species was first discovered on Cayman Brac in 1987 — in what is thought to have been a human-assisted colonisation — its population has spread right across the 39km² island.

For this study, recent graduate Vaughn Bodden and Lecturer in Conservation Biology Dr Robert Puschendorf conducted a detailed analysis of the invasive species.

They wanted to assess whether individuals at the forefront of the invasion have developed distinct biological traits that are advantageous for dispersal, and compared their findings to animals in the area of first introduction and the native population on Little Cayman.

They discovered the Cayman Brac population has diverged morphologically from the native population, and within the invasive range there was trend of increasing forelimb length from the core to range edge areas. This ran contrary to the expected findings that longer hindlimbs would be the trait selected as a dispersal-related phenotype.

They also showed that the introduced population had lower levels of parasite prevalence, and that both males and females were of significantly higher body condition than the native population.

Writing in the Journal of Zoology, they say the results are a perfect example of how a species can colonise a new territory, and the biological adaptations it can make in order to do so.

Vaughn, who graduated with a First from the BSc (Hons) Conservation Biology programme in 2018, said: “There has been a history of lizard studies indicating that longer hindlimbs are an important factor affecting movement ability, so to not find longer hind limbed animals on the range edge was a surprise. For parasites, we found a clear decreasing trend in prevalence within the invasive population from the area of first introduction to the range edge, indicating that the parasites lag behind the host during periods of range expansion. We think our findings add to the growing body of literature that demonstrates the complex dynamics of species’ invasions. The results highlight that the animals on the range edge of an invasion are likely to be experiencing different ecological selection pressures that can result in changes in behaviour, morphology, and health for the animals.”

Dr Puschendorf has spent several years researching the consequences of emerging infectious diseases and climate change on biodiversity, with a particular focus on Central America. He added: “Biological invasions are an important conservation threat across the world. However, every invasion needs to be carefully investigated to identify impacts to native eco-systems and identify potential mitigation strategies. In this instance there is likely to be limited overlap with, and therefore a limited threat to, the endemic anole population — the Cayman Brac Anole (Anolis luteosignifer) — because one inhabit the crowns of trees while the other is found closer to the ground. This in some ways highlights the challenges biodiversity managers face when managing species invasions with limited resources, and emphasises the need for greater collaboration among scientific and policy communities.”

Buffalo saved by colleagues from lions, crocodiles


This 9 April 2019 video from South Africa says about itself:

Herd Rescues Buffalo from Lions and Crocodiles

Over a decade ago, there was an epic battle between lions, buffaloes and a crocodile at a waterhole called Transport dam. That video was aptly named Battle at Kruger.

Well, 10 years later, the next generations of lions at Transport Dam recently faced their own failed hunt due to a huge herd of buffalo and crocodiles interfering!

Thuli Khumalo, head of Atamela Tours, captured this heart-pumping sighting while on a tour to the Kruger National Park. After lunch at Skukuza Rest Camp, Atamela’s game drive full of tourists arrived at the world-famous Transport Dam, in the hopes of seeing some action. Little did they know what they were actually in for.

They spotted a pride of lions lying in the shade, overlooking the water. If you spot lions hiding in the shade at a waterhole, it is often a good idea to stick around. Lions are opportunistic, so they will often try and hunt any animal that comes close enough.

Surely enough, a large herd of impala went down to the water and the lions gave chase! The impalas were too fast for the lions, but at the edge of the water, they spotted an old buffalo bull. The lions chased that buffalo and it ran into the water where out of nowhere, a crocodile starts taking a go at the already targeted buffalo. The buffalo decides that the water is probably more dangerous than on land, where it can potentially outrun the pride of lions that are now waiting for him to re-emerge from the water.

As soon as the buffalo hit the surface, he makes a run for it, with the lions following close on its tail. When buffaloes are under threat, they will call for help. Luckily, for this buffalo, his calls were answered! A massive herd of buffalo that was on its way to the dam saw the commotion and chased the lions away, saving the life of a fellow buffalo, unbeknown to us if it is from the same herd.