Dragonflies, info request

Objavljeno u Vaša pisma

Can anyone help with information about dragonflies on Hvar?

Dragonfly Dragonfly Steve Jones

Steve from Dol has sent us the following query by email on 23rd September 2016:

'Do you know much about dragonflies on the Island?

Over the Summer I have seen several and I know Norman nearby has also seen similar.

While I know a few of the more obvious ones I am puzzled, one thing I do know is that they like water in which to lay. The dragonfly life cycle is for the most part spent underwater and they only emerge as what we see towards the end of their life and to mate.

I am puzzled as to where they can possibly lay eggs, I only know one source of water down near the airfield and I don’t believe from there they would travel up to Dol. I often think they could be laying in the numerous wells/water storage places in the field but most are covered and I don’t know how they would emerge. One species described to me was the Golden Ringed Dragonfly and this as I read likes fast flowing water so I even more at a loss.

I was down near the airfield yesterday and several of just two species that I could tell were flying the one species tended to be flying joined to his mate, there were several of these

Didn’t know whether or not you can shed any light on this for me? I know of someone in the UK who specialises in Dragonflies, I may email him and see what comes of it.'

Eco Hvar's reply, 23rd September 2016:

Yes, actually there are many more sources of water than you'd think, off the beaten tracks, but also in the fields.

One of Hvar's 'secret' pools. Photo Vivian Grisogono

A lot of the enclosed wells have open basin on top,which can be home to all sorts of insects, including water snakes. Unless the fields around the wells have been doused in herbicide of course. There was a superb little water snake in the open part of the well by my field one year. It would curl itself round and round very lazily, right up to the time the basin went dry. I was afraid 'my' snake had died, lying there quietly, but it then discreetly disappeared, re-appearing a cuple of times in the grass above the well, presumably looking forward to the winter rains which would replenish its basking place. 

Talking about herbicide, did you see that the sale of Cidokor/Roundup is to be banned from October 1st, together with 12 other glyphosate-based herbicides? Good as far as it goes, but it still leaves 12 other glyphosate herbicides on the market!

We''ll look forward to hearing the results of your dragonfly investigations. A good place to see them is in the environs of Humac, where there are some lovely natural pools where the horses and some hunting dogs drink and butterflies abound, as there are no poisoned fields in the vicinity.

Nalazite se ovdje: Home vaša pisma Dragonflies, info request

Eco Environment News feeds

  • Deal expected to pave way for further scientific study, boost conservation and open up access to Dorset chalk figure

    The mystery of when, how and – perhaps most importantly – why a giant naked figure was carved into a dizzyingly steep hillside in the English West Country has been a source of wonder and intrigue for centuries.

    Future generations may come closer to solving the puzzle of the Cerne Giant after the National Trust stepped in to buy 340 acres of land around the 55-metre (180ft) figure.

    Continue reading...

  • Exclusive: Brazil’s environment minister talks about climate inaction and the course we have to plot to save ourselves and the planet

    Soon after I returned home to Altamira from Cop30, I found myself talking about dinosaurs, meteors and “ambassadors of harm” with Brazil’s environment minister, Marina Silva.

    No one in government knows the rainforest better than Marina, as she is best known in Brazil, who was born and raised in the Amazon. No one is more aware of the sacrifices that environmental and land defenders have made than this associate of the murdered activist Chico Mendes. And no one worked harder to raise ambition at Cop30, the first climate summit in the Amazon, than her. So what, I asked, had it achieved?

    Continue reading...

  • Fertilising arable land with human waste leaves array of toxins that could re-enter food chain, study finds

    More than 520 chemicals have been found in English soils, including pharmaceutical products and toxins that were banned decades ago, because of the practice of spreading human waste to fertilise arable land.

    Research by scientists at the University of Leeds, published as a preprint in the Journal of Hazardous Materials, found a worrying array of chemicals in English soils. Close to half (46.4%) of the pharmaceutical substances detected had not been reported in previous global monitoring campaigns.

    Continue reading...

  • Pew Charitable Trusts finds plastic pollution will more than double globally by 2040 unless action taken

    The 66m tonnes of pollution from plastic packaging that enters the global environment each year could be almost eliminated by 2040 primarily by reuse and return schemes, significant new research reveals.

    In the most wide-ranging analysis of the global plastic system, the Pew Charitable Trusts, in collaboration with academics including at Imperial College London and the University of Oxford, said plastic, a material once called revolutionary and modern, was now putting public health, world economies and the future of the planet at risk.

    Continue reading...

  • These delicate cloud systems appear to be seeded by massive atmospheric waves thousands of miles away

    Cirrus clouds are our highest clouds; their delicate wispy strands are like an artist’s brushstrokes through the sky. During the day they are bright white and at dawn and dusk they can take on the hues of sunrise and sunset. But how are they made? New research reveals that some cirrus clouds are seeded by storms on the other side of the world, many thousands of miles away. This has implications for global heating as storm patterns shift.

    Meteorologists have long recognised two types of cirrus cloud: “anvil” cirrus, which spread out from large storm systems, and “in-situ” cirrus, which seem to form on their own. Telling them apart is tricky, but by applying a new computer analysis to cloud satellite data, researchers spotted that in-situ cirrus emerged in response to major storm systems on the other side of the Earth.

    Continue reading...

  • Inkpen, Berkshire: Drifting in and out of sleep on the woodland floor, I’m in searing pain, but far from alone

    It was nobody’s fault, but here I am, lying on the damp floor of a wood, half a mile from the road. Drifting down with the falling leaves are the voices of two women, too easily accepting of blame. I reassure them and try to sit up, but the high singing in my ears turns to static, the edges of the wood begin to pixelate, and I lie down again before I faint.

    Moments earlier, deep into Long Copse, Mum’s one-year-old labrador and my two-year-old collie crossbreed had met a young whippet. A case of the zoomies ensued, and as I turned to warn Mum, there was a sledgehammer blow to my lower leg as one, two or maybe all three dogs cannoned into me. Though I didn’t realise for two more days, my leg was broken before I hit the ground.

    Continue reading...

  • From the threat of superintelligent AI to the secrets of a longer life; plus the evolution of language and the restless genius of Francis Crick

    This felt like the year that AI really arrived. It is on our phones and laptops; it is creeping into digital and corporate infrastructure; it is changing the way we learn, work and create; and the global economy rests on the stratospheric valuations of the corporate giants vying to control it.

    But the unchecked rush to go faster and further could extinguish humanity, according to the surprisingly readable and chillingly plausible If Anyone Builds It, Everyone Dies (Bodley Head), by computer scientists Eliezer Yudkowsky and Nate Soares, which argues against creating superintelligent AI able to cognitively outpace Homo sapiens in all departments. “Even an AI that cares about understanding the universe is likely to annihilate humans as a side-effect,” they write, “because humans are not the most efficient method for producing truths … out of all possible ways to arrange matter.” Not exactly cheery Christmas reading but, as the machines literally calculate our demise, you’ll finally grasp all that tech bro lingo about tokens, weights and maximising preferences.

    Continue reading...

  • Project on ‘very poorly understood’ terrain and likely to pass through Rocky Mountain trench, which researchers say poses immense geological hazard

    When an earthquake in 2002 struck in a remote pocket of Alaska, the shock was the strongest ever recorded in the interior of the state. But, miraculously, an oil pipeline that crossed directly over the fault line was unscathed.

    Engineers behind the design of the 800 mile system were prepared. Knowing the high likelihood of seismic activity along the route, which bisected the Denali fault, they constructed sections where the pipeline rested on rail girders, allowing it to sway and shear without snapping.

    Continue reading...

  • The country is the world’s second-largest producer of the popular fish, and the biggest supplier to the US, but its farms are beset by accusations of dangerous labour conditions, antibiotic overuse and ecological harm

    Julia Cárcamo López’s house faces the sea, near enough to hear the gulls calling through the salt-encrusted windows. She lives in the small town of Maullín, on the edge of Chile’s Patagonia, an area where almost everyone works in the fishing industry.

    Outside, it is drizzling and the sky is darkening as she recalls 1 May 2019, one of the worst days of her life. “Two men knocked on my door and told me they had bad news: my husband had had an accident while working at sea,” she says. Since then, she has discovered that the accident seems to have been caused by negligence.

    Continue reading...

  • Banks of servers operating 24/7 generate massive amounts of heat, requiring power to run and cool them

    Datacentre power demand in Australia could triple in five years and is forecast to exceed by 2030 the energy used by electric vehicles.

    Datacentres now draw about 2% of electricity from the National Grid, about 4 terawatt hours of power. The Australian Energy Market Operator (Aemo) expects that share to rise rapidly – growing 25% year-on-year – to reach 12TWh, or 6% of grid demand, by 2030, and 12% by 2050.

    Continue reading...

Novosti: Cybermed.hr

Novosti: Biologija.com

Izvor nije pronađen