Slow slimy slugs slaughter songbirds

What harm could a slimy little critter slowly crawling on the forest floor possibly do to a bird? A lot, it turns out. Slugs are shell-less mollusks that have a specialized mouth with a sandpaper-like structure. That rough surface can easily rip the skin and eyes off of a baby bird, leaving the chick to fight for its life.

Many don’t survive.

To be sure, this chick-icide by slugs is rare, European scientists now report. Still, they note, it could become a problem for ground- and shrub-nesting birds if slug numbers climb.

Justyna Chachulska is a graduate student at the University of Zielona Góra in Poland. Katarzyna Turzańska studies at the University of Wrocław, also in Poland. In 2014, both PhD students were monitoring nests of the common whitethroat (Sylvia communis), a mid-size European warbler. They were on the outskirts of the city of Wrocław.

The season was wet and cold. As a result, the ground teemed with slugs. One day, the young scientists noticed a slug in a nest with three newly-hatched chicks. They couldn’t imagine this slug posed a threat to the baby birds. So, they carried on with their work on other nests. But when they returned to the same nest the next day, two nestlings were dead. The third was missing.

To know how this avian murder mystery was solved, read the full story over at Science News for Students.

Photo Credit: Andrzej Wuczyñski

Butterfly back-stabs its guardian ants

The metalmark butterfly cooperates with ants when it’s a caterpillar, only to stab them in the back when it has metamorphosed into a beautiful – thieving – butterfly.

While still a caterpillar, the metalmark butterfly wins over local ants, including those of the species Ectatomma tuberculatum, with gifts of sugary secretions. In return, the ants, which could easily eat the caterpillar or its adult butterfly form, defend the vulnerable caterpillars from other predators.

But this friendly give-and-take doesn’t last forever, work by Phillip Torres of Rice University in Houston, Texas and Aaron Pomerantz of the University of Florida, Gainesville, has now revealed. When the caterpillars have become butterflies, they turn on their protectors, plundering the source of their nectar.

This nectar is produced by organs called nectaries at the tips of new bamboo shoots, which are tended by ants. Using their mouthparts, they improve the flow from these nectaries, and stop them from running dry. The nectar is an important source of food for them, so they defend these nectaries fiercely.

Read the full story here at New Scientist. 

Photo credit: Phillip Torres

The tadpoles that swim in sand

In 2014, 14 new species of “dancing frogs” were discovered in the Western Ghats, a wildlife-rich mountainous region along the west coast of Peninsular India.

5. Tadpoles of Micrixalus herrei

These Indian dancing frogs are named for the antics males get up to when they want to grab the attention of a female.

Perched on a wet rock in a noisy, fast-flowing stream, a male sings and waves to the females. He lifts and stretches a leg to flag his white, webbed toe.

Any rival males on the territory are literally kicked out by the singing-and-dancing male.

It now turns out that this foot-waving, which was observed in nine species of the genus Micrixalus, is not the only bizarre trait that runs in the family. For the first time, researchers have found the tadpoles of a dancing frog, specifically the Kallar dancing frog (Micrixalus herrei).

Unlike most tadpoles, which live in water, they live underground until they develop into froglets.

Read more about the tadpoles here at BBC Earth.

Photo credit: SD Biju

Beautiful bright beasts

One new genus and five new species of fan-throated lizards have been found in the drier parts of India.

Fan-throated lizards are small ground dwellers. The males flaunt a multihued, fan-shaped fold of skin on their throats during the breeding season.

Because they live in dry and barren soils, when the midday heat starts to get to them they skitter about on their rear legs. Fan-throated lizards are restricted to parts of South Asia. Little has been known about them since the first species was reported in 1829 from India. After this, only six more species have been found: three from Nepal, two from Sri Lanka and one from India.

Know more about the lizards at BBC Earth.

Photo credits: V. Deepak

Found: Snake that remained hidden for 145 years

Indian researchers, in collaboration with the Natural History Museum in London, have found a new species of burrowing, non-venomous snake that has smooth, shiny scales.

The species remained misidentified and stashed among museum specimens for a long time before scientists thought it might be distinct. To confirm their doubts, they looked in the wild – and unlike many museum finds that are extinct by the time they are discovered, this one still existed. And it continues to do so in the semi-evergreen forests of the Western Ghats of India.

Read the full story at Nature India.

Photo credit: Varad Giri

Songbirds tap dance to seduce their mate

The blue-capped cordon-bleu (Uraeginthus cyanocephalus) has a special talent. Not only can it sing, it can shake a leg or two. For its courtship display, it holds a piece of nesting material in its beak, points its head upward, moves up and down, and sings. Both males and females bob and sing like this, and choose their partner…

Read the full story here at Science.

DJ frogs remix tunes on the hop

Deep in the evergreen forests of Vietnam, curious little green-blooded frogs spend monsoon nights performing vocals, improvising new melodies each time they sing.

Known popularly as “frogs that sing like birds”, male Gracixalus treefrogs perform to attract females and to ward off other males.

But these are not your average frogs, croaking out the same old tunes. Gracixalus frogs shuffle notes to compose a new melody every single time they sing.

To human ears, songs of the three related species – G. quangi, G. supercornutus and G. gracilipes – sound like birds chirping.

They randomly mix high-pitched, long notes called “whistles” with short, sharp “clicks” to compose new tunes.

Each song is unique in its complexity, duration, amplitude, frequency and structure, as opposed to being specific to an individual or a species as it is in most frogs.

Listen to their songs in my story for New Scientist.

Photo credit: Jodi Rowley

Eye shape reveals whether animal is predator or prey

A link between pupil shape and the feeding behaviour of animals has been made by studying the eyes of 214 species. By modelling how differently shaped pupils collect light, researchers in the UK and US have argued that the shape of an animal’s pupil – the aperture through which light enters the eye – is related to whether that animal is predator or prey.

The study reveals that herbivorous prey animals such as deer and zebras are likely to have horizontal pupils, while predators actively hunting during the day – like cheetahs and coyotes – usually have circular pupils. Furthermore, animals that hunt at night, or both day and night, tend to have vertical pupils. This vertical group includes some foxes, cats and snakes…

Read the full story at Physics World.

Photo credit: David Corby

How Ant-Man ants got this Cheerio home

Study explains how wandering ants guide a group of food gatherers back to the nest.

When out of their nest, workers of the longhorn crazy ant (Paratrechina longicornis) band together toward a common goal: to bring food back to the nest. But even when a few of these long-legged, silver-haired ants (of Ant-Man fame) team up to carry a large item—such as a wasp—they often lose their way home.

Read the rest over at Science.

A map that tells where elephants are

Ecologists have mapped Asian elephants in the Indian state of Karnataka down to the smallest forest administrative unit. The detailed map, which shows where elephants exist inside and outside protected areas, could help conservation planning and minimize human–elephant conflicts.

Karnataka has the largest population of Asian elephants (Elephas maximus) in India. But recent decades have witnessed increased pressure on their habitat and clashes between people and the jumbos. A detailed map of elephant distribution is crucial to understand where humans should get priority, where elephants should and where they can coexist. Yet, there is no microscopic map of Asian elephants anywhere.

Read the rest over at Nature India.

Photo credit: Subhra Priyadarshini

The 13 most shielded eggs laid by birds

Birds prepare their eggs for the worst, whether the risk comes from predators or just the location of their nests. This Easter I wrote about some of these amazing eggs for BBC Earth. Here’s one of the birds eggs I highlighted in my piece for their sheer camouflage (besides their beauty): 

Japanese Quail (Coturnix japonica)

A female Japanese quail is selective about where she lays her eggs. She chooses a background that matches either the colour of her eggs or their pattern, whichever is more striking.

If her eggs have only a faint pattern, the female chooses a site that matches their colour. But if they have a strong pattern, she goes for a site that blends with it, and which hides the contour of the egg. This means the female must know the pattern of her own eggs.

To read about other wonderful bird eggs, click here!

Exceptionally preserved 300-Myr-old fossil

Researchers have unearthed a fossil fish so well preserved, it still has traces of eye tissues.

What’s more, these fossil tissues reveal that the 300-million-year-old fish called Acanthodes bridgei (pictured), like its living relatives, possessed two types of photoreceptors called rods and cones—cells that make vision possible. This is the first time that mineralized rods and cones have been found conserved in a vertebrate fossil, the team reports online today in Nature Communications, as soft tissues of the eye normally begin to disintegrate within days of death.

Read the full story at Science magazine.

Photo credit: Tanaka et al., Nature Communications

Treasure trove of new frogs found in India

Nine new species of bush frog have been discovered in the Western Ghats, a mountainous region in southern India that is a hotspot of biodiversity.

Bush frogs are tiny animals, found mainly in South and South-East Asia, some of which can fit onto a 20 pence coin. Beginning in 2008, S. P. Vijayakumar, then at the Indian Institute of Science in Bangalore, has been scouring the Western Ghats to find them. The new species he has found all belong to the genus Raorchestes, and he has identified them based on their appearance and genetics. Vijayakumar and his colleagues have published their findings in Zootaxa.

The Western Ghats is home to many species of frog, including the 14 dancing frogs discovered earlier this year. That’s because it is a fragmented landscape, with hills, valleys and plateaus. This means populations of frogs can easily wind up evolving in isolation.

Read the rest at BBC Earth.

Photo credit: S. P. Vijayakumar

Snails suffer genetic damage from pollution

Pollutants from oil spills, shipping activities and industrial effluents could be the reason for genetic damage in snails of Goa, research has found. The extent of genetic damage in snails could serve as a measure of the health of a marine ecosystem, it says.

A team of researchers collected snails of the species Morula granulata from nine locations along the coast of Goa – a major tourism and seafood industry hotspot of India. The team learnt that the extent of damage in the genetic material (DNA) of these snails increased with rising levels of toxic pollutants along the coast.

“When toxic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), are taken up by marine organisms, the snails will try to metabolize the contaminants for subsequent elimination. The toxins are degraded, ultimately converted into by-products and removed from the body,” explains A. Sarkar, lead author of the study at Global Enviro-Care, Goa. “But during their metabolism, reactive intermediate stages are formed, resulting in DNA strand breaks.”

Sarkar and co-workers used molecular biomarker techniques to assess breaks in the DNA isolated from snails and determined its integrity. They observed that DNA integrity reduced by as much as 56% at one of the most polluted of the chosen sites (Hollant) compared to the non-polluted, reference site (Arambol) located farther away from the industrial belt. They found the concentration of PAHs in sediments to be highest around Hollant (5.17 μg/g) and lowest at Arambol (1.65 μg/g) among all sites.

Read the rest at IndiaBioScience.

Photo credit: A. Sarkar

Why octopus arms don’t entangle

An octopus’s arm is covered with hundreds of suckers that give it a strong tendency to attach to everything it encounters but the octopus’s arms. A team of researchers has shown that chemical signals from the skin of octopus protect its arms from attaching to each other or onto themselves, without which the octopus might end up entangled.

The team studied the behaviour of severed octopus arms — which remain active and move for at least an hour following separation — because arms have their own network of neurons that to some extent can work independent of the central control of brain.

Suckers on severed arms — like the ones on intact arms — attached to any surface but avoided the skin. They did attach to another arm but only at points where the skin was damaged or missing, suggesting that the skin, wherever present, might play a role in inhibiting the attachment.

Read the rest in The Hindu.