A first cub photo in over a decade of Europe’s largest and rarest cat, a wild Balkan lynx, raises hopes for the survival of this critically endangered animal.

With less than 50 cats remaining in the wild in the mountains of the Western Balkans, this subspecies of the eurasian lynx is close to extinction.

The lynx  faces habitat loss, illegal hunting, and revenge killing by farmers whose domestic animals they sometimes attack.

Just two years ago a cub was stoned by a local shepherd on Munella mountain in Albania — the only recent evidence of this subspecies rearing young.

Fight for survival

The biggest challenge is the population’s small size and low survival of cubs, says Mareike Brix from who have been working on the protection of Balkan lynx for a decade with their partners. “Only 25 per cent of all kittens born reach adulthood,“ says Brix.

But now, a picture of a new live cub has been captured in a second location, the Mavrovo National Park in neighbouring Macedonia, suggesting there is a healthy reproducing population there.

The photo was made possible only after the team managed to put a GPS collar around a female called Maya, in February this year — the first Balkan lynx female to wear GPS collar.

This led them to Maya’s cub, and they hope to put a GPS collar on it, too, when it is old enough to go its own way, at around 10 months of age, says at .

Melovski thinks the cub is a good sign for the subspecies – and he’s not alone.

Good news

This is good news because it confirms that there are still reproducing animals in this population, says John Durrus Linnell at the Norwegian Institute for Nature Research, which cooperates with the Macedonian Ecological Society on the Balkan Lynx Recovery Programme that started in 2006.

“When this project started almost 10 years ago there was no real proof that the population even existed,” he says. “Since then, the team have collected hundreds of camera trap pictures of lynx in both Macedonia and Albania, including evidence of reproduction.”

This means that there is still a nucleus of a population to form the basis for recovery, says Linnell.

Reproduction in a critically endangered population is always good news, agrees at the University of Freiburg.  “The extinction of a top predator is – ecologically speaking – always a loss, because in a complete, functioning ecosystems, top carnivores have a significant function,” she says.

Just one cub

But a single cub may not make much of a difference to the survival chances of the population, he adds.

Brix and Melovski both worry that the cub might not survive to adulthood. Disease, malnourishment and road accidents are all real threats the young lynx may have to face.

And more widely, the outlook is not great for the lynx. Others have failed to capture pictures of cubs in its natural habitat, which would provide evidence that the population is reproducing.

Aleksandar Petrovic from the Center for the Protection and Research of Birds from Podgorica in nearby Montenegro says that in the last four years they have used camera traps without success in the region where the lynx was present until at least 2002 when the last specimen was recorded after being shot.

Illegal hunting

He thinks overhunting of the lynx prey – rabbits, roe deer, chamois  – only add to the threat from illegal hunting the animal directly.

Protection efforts, experts think, should focus on Mavrovo National Park, the only area now known to have reproducing lynx.

“This area on the border between Macedonia and Albania is incredibly beautiful and hosts some amazing biodiversity, including charismatic wildlife like lynx, bears, wolves, chamois etc,” says Linnell. “But it is facing massive threats from poor regulations governing development of transport infrastructure, hydropower plants, construction, tourism, forestry and so on.”

What’s needed to protect lynx, says from Carnivore Ecology and Wildlife Management () in Switzerland, another organisation collaborating on the recovery project, is law enforcement and sustainable wildlife management, as well as habitat protection when infrastructure projects run though it.

Also, she says, raising awareness and working with rural populations – and ensuring they benefit from having lynx around, perhaps through income from ecotourism, for example.

“There is a long way to go before the future of these landscapes and their biodiversity are secure,” says Linnell. “But images like these remind us that as long as there is life, there is hope – and that is what keeps conservationists’ motivation up.”

Read more: Iberian lynx beats extinction as cats are released to the wild

Scented trail

It’s not just humans who get pregnancy cravings. The females of one bird species also seem to get an itch for certain foods when they are incubating eggs – and their partners are able to pander to their dietary whims.

“For the first time, we tested whether and how males cater to the specific desires of their mates in the wild,” says at the Victoria University of Wellington, New Zealand, who led the study conducted at Zealandia, a nature sanctuary in the city.

The researchers tested 16 pairs of New Zealand robins (Petroica longipes) while the female was incubating. Females were fed mealworms and two types of insect larvae under two conditions: when a male could see what his partner ate and when he couldn’t.

The female birds generally preferred a food type if they hadn’t eaten it recently. The males somehow knew what food the females wanted, even when they couldn’t see what they were being fed by the researchers. When a male robin held a preferred food item, his partner begged more intensely for it prior to or during food sharing.

Subtle signs

The study demonstrates the subtlety with which a mated pair of birds conveys important information crucial to successful breeding, says at the University of Washington in Seattle.

“This study is the first to confirm in the wild that not only the hunger of the female, but [also] the specific preference for food type is conveyed to the male, and that this information is most likely encoded in the vigour of her begging behaviour,” he says.

This suggests that females can somehow signal their current desires to their mates, enabling males to cater to female desire in the wild.

This is important because in monogamous species such as New Zealand robins, food sharing by the male is vital to help the female offset the energetic costs of reproduction, such as egg laying and incubation. The male’s ability to give his mate what she wants could be an important factor in determining the success of a pair, as well as influencing whether they stay together, says Shaw.

This discovery raises the possibility that many other species might be capable of doing the same, she adds.

Read more: Birds sing to their newborn chicks to warn them of hot weather; Birds do impressions – it’s time to take them seriously

An elusive deep-sea giant has been filmed with its prey for the first time. It turns out it eats jellyfish and other gelatinous animals.

The octopus, Haliphron atlanticus, was filmed swimming docked on top of a medusa jellyfish, with its beak devouring its innards, while the medusa’s sticky tentacles were still hanging out of its mouth. The researchers think it might even be using the jellyfish tentacles as a handy feeding implement.

Little is known about H. atlanticus, and the researchers who filmed it using remotely operated vehicles have only seen it three times in as many decades. Most other octopuses eat more substantial prey such as fish and crustaceans, so it is a surprise to see this large species eating jellyfish.

What’s on the menu?

Most of what we know about the seven-armed octopus comes from specimens caught in trawl nets. It lives in deep open waters, growing up to 4 metres long and a weight of 75 kilograms. It is known to be eaten by sperm whales, swordfish and blue sharks. Males of the species have one of their eight arms permanently folded away, giving them the common name of seven-armed octopus.

Steven Haddock from the Monterey Bay Aquarium Research Institute in California and his colleagues have now filmed three of these octopuses in the wild. The team saw them feeding on jellyfish and also analysed the stomachs of five previously caught specimens, all of which contained gelatinous zooplankton and three of them contained jellyfish. This makes sense, because the open ocean is rich in such creatures, so the octopus makes use of what’s on the menu.

Haddock says that the discovery shows us just how complex the ocean food web is. It is a rare example of a marine animal that can grow large feeding primarily on gelatinous fauna, such as jellyfish, others being sea turtles and ocean sunfish, for example.

The way the octopus had the jellyfish arms freely hanging out, while keeping the bell in its mouth provides evidence for the idea that the octopus uses jellyfish as living tools, says the team.

The theory is that they use the jellyfish tentacles to ensnare more prey and then feed off whatever makes its way to the body of the medusa, with octopus beak docked inside it.

Plastic not fantastic

Haddock thinks the importance of jellyfish in marine food webs has been unappreciated and underestimated. Given that top predators feed on giant octopuses, this may be an important way of channelling energy from the bottom to the top of the oceanic food chain, his team argues.

A diet that relies on jellyfish might put the octopuses at risk from our plastic rubbish, says of the University of Southampton, UK. Plastic pollution is a massive problem on the sea surface where sea birds and turtles mistake plastic bags for jellyfish.

“We have leatherback turtles migrating from the Caribbean to the Irish Sea to feed on massive barrel jellyfish off the Welsh coast,” he says. “One of the sad consequences of turtles’ love of jellyfish is that they mistakenly eat plastic litter – plastic bags, balloons from mass publicity releases, which quite simply block their gut and they eventually die.”

When the bags eventually sink, it is supposedly the end of the story – but Collins wonders if the same could be happening to this octopus away from our sight.

from the University of St Andrews, UK, says that this study provides information about the basic biology and ecology of an underexplored ecosystem and will hopefully allow us to monitor and perhaps slow the impacts we have on this ecosystem.

“These trips have a real feeling of exploring the frontier in a way that research expeditions on land perhaps no longer provide, in part because the terrain and the animals that are encountered are so often unfamiliar and surprising,” says Webster.

Read more: Jellymageddon: Can we stop the rise of the jellyfish?; The Soul of an Octopus: Getting to know an intelligent mollusc

A large artificial lake in the Balkan state of Bosnia and Herzegovina totally vanished this month and with it an estimated 2 million fish.

Following rains and snowmelt, Jablanica lake has now started to reappear, but the ecological damage might take years to repair, say environmental groups and local fishers.

Water levels in the lake are usually regulated to keep enough water to generate hydroelectricity and to avoid floods in the city of Mostar, which lies downstream. So it came as a surprise to local people, especially fishers, to see the lake completely drained last week, and with it all its life gone, too.

Normally, the lake is 30 kilometres long, around a kilometre wide with a depth of about 70 metres. Water levels had dramatically dropped twice before, during droughts in 2005 and 2012, but never by this much.

The discharge was carried out largely last month by power firm Elektroprivreda BiH, which says it was needed to maintain electricity production during a dry and especially cold period when energy demand was above average.

Endangered fish

The lake was home to some ten fish species, including the endangered Adriatic trout (Salmo obtusirostris) and vulnerable Adriatic dace (Squalius svallize). It is also part of the Neretva river system, a with many endemic species.

It is clear that the lake’s disappearance has diminished the local wildlife habitat, says at the University of Split in Croatia. Aquatic species that can’t relocate would have died, while the rest would have had to migrate.

But a huge influx of fish into waterways already occupied by other fish would also cause long-term damage to animal numbers and biodiversity in those surrounding areas, he adds.

Fully draining the lake has completely degraded its ecosystem, agrees , a biologist at the University of Sarajevo in Bosnia.

Impact unclear

But , from the University of Sarajevo, who visited the site to evaluate the damage, says it’s not yet clear what damage has been caused to wildlife.

And there might be a silver lining, he adds. Đug says the fishers should take advantage of this situation to clean the lake by removing now-exposed waste before all the water comes back.

The whole episode points to a bigger problem in the region: a lack of integrated management of water resources, says , the freshwater programme manager of environmental campaigners WWF Adria.

Anes Podić from environmental NGO agrees. There has been no monitoring of how  changes in lake water levels affect wildlife, he says. Elektroprivreda BiH is ignoring the consequences for plants and animals, he adds.

Elektroprivreda BiH that the discharge didn’t cause an ecological disaster, and added that water is already returning, as it did in 2012, when low levels also didn’t hurt fish stocks.

Read more: Many of world’s lakes are vanishing and some may be gone forever