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.
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.
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.
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.
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.
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…
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…
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.
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 (Elephasmaximus) 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.
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):
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!
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.
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.
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 Morulagranulata 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.
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.