Latest news with #ecologist
ABC News
19-07-2025
- Science
- ABC News
Australian native fungi spring to life during colder, wetter months
Deep in native Australian forests is a wonderland that springs to life each winter. It is a mysterious world of colourful toadstools right out of a fairy tale, of bizarre white "cages" that smell of death and decay and of ghostly mushrooms that glow eerily in the dark. Australia's native macrofungi — those visible fungus forms that can be seen with the naked eye and often appear during the coldest, darkest time of the year — play an essential role within any ecosystem. They are nature's recyclers, fertilisers and rehabilitators. While a few notorious introduced varieties have engendered a toxic reputation, Australia's native macrofungi remain largely an enigma. Fewer than 10 per cent of the potentially hundreds of thousands of fungus species in Australia (estimates range up to 250,000) have been formally identified and described. "It shows how little we know," ecologist and author Alison Pouliot said. "There are whole lot of reasons for that. I think the big thing, for a lot of them, is they are out of sight, out of mind. "They are most often underground for most of the year." Fungi occupy a strange space somewhere between the animal and vegetable kingdoms, having some traits of each but being truly neither. "They are a whole separate kingdom," Dr Pouliot explained. Dr Pouliot said fungi get their nutrition through digestion like animals rather than from sunlight like plants. "Fungi don't photosynthesise like plants," she said. "They digest like we do. "They are also made of a compound called chitin instead of cellulose like a plant. We find that in the animal kingdom. That's what a crayfish's shell is made of, for example." The most visible component of macrofungi, such as the parasol-shaped mushroom, makes up a mere fraction of the living thing itself. It is, in fact, the sex organ of a much larger organism that is most often hidden underground. "Collectively we call them [the visible component] the reproductive sporing bodies," Dr Pouliot said "A mushroom is just one type of structure. There are puffballs and morels, for example, and these are not mushrooms." The greater part of the organism below the surface is called a "mycelium", which includes the seldom seen root structure. A mycelium can range in size from mere specks to metres. Some are among the largest living things on the planet, stretching square kilometres. Many of the most familiar varieties become active in autumn, activated by changes in the soil. "Why we see [them] most in autumn is the mycelium responds to a drop in soil temperature and an increase in soil moisture," Dr Pouliot explained. A warmer, drier summer across south-eastern Australia has likely had an impact on how many native mushrooms and other macrofungi are able to be seen this year, according to Victorian Western District field naturalist Helen Langley. "A few are appearing now in the Western District," Ms Langley said. "There does appear to be less of them because it has been so dry. "It has also got cold quickly this year, which hasn't helped." Dr Pouliot said fungi were resilient, however, and should bounce back if and when the rain returned next year. News stories about toxic mushrooms have blurred the terms "mushroom" and "toadstool". Scientifically, at least, they are all now referred to as mushrooms. "Originally a mushroom was an umbrella-shaped fungus that was edible, and a toadstool was an umbrella-shaped fungus that was toxic," Dr Pouliot explained. "Over the years, those two terms have been used synonymously, and we saw books being published about things like poisonous mushrooms. The world was like, 'Hang on a minute. They're supposed to be edible'. "Today, the word 'toadstool' has pretty much fallen out of use. It's more a poetic or literary term. "And today the word mushroom doesn't refer to edibility, it just means umbrella-shaped." The term "toadstool" (a stool for toads in English) has an etymology rooted in its toxicity, however. "Tod" is the German word for "death", while "stuhl" is German for "chair". A "bolete", meanwhile, is mushroom-shaped macrofungus that has a spongy underside with pores rather than the gills synonymous with mushrooms. Ms Langley said people should avoid foraging for native fungi. "Like many native plants, native mushrooms are not supposed to be picked and collected," she said. "They are meant to be left alone in their natural environment. "For a lot of native fungi, we just don't know about their toxicity. It is not worth the risk. "My advice is not to touch them and just to look at them and enjoy them for what they are." Several of the most recognisable macrofungi, including the charismatic fly amanita (Amanita muscaria), the infamous death cap mushroom (Amanita phalloides) and familiar edible varieties such as the common mushroom (Agaricus bisporus), are not native to Australia. Dr Pouliot encouraged bush explorers to find and photograph Australia's fantastic and fabulous native fungi but suggested we don't disturb them and leave them be. She said, among the potentially hundreds of thousands of species that could be discovered in Australian forests, were these spectacular varieties: The striking rhubarb bolete (Boletellus obscurecoccineus) is distinctive for its red-to-rhubarb-coloured cap and underbelly of yellow pores. It's found among eucalypt leaf litter in Victoria, Tasmania, south-western WA and south-east NSW. The widespread pretty horn (Calocera sinensis – calo = beautiful and cera = horn in Greek) appears as little yellow clubs or spikes. It's a wood-recycling fungus that grows on logs, branches and twigs. Growing in south-eastern Australia, the green skinhead (Cortinarius austrovenetus) is unusual for its green colouration. Members of the genus Cortinarius are known as webcaps as they have a cortina, or web-like veil that protects the gills during early growth stages. Appearing like rubies among the leaf litter on the forest floor, the tiny but conspicuous ruby bonnet (Cruentomycena viscidocruenta) is always a joy to find. It grows in wetter forests in Australia and New Zealand. This fungus is not your average umbrella-shaped mushroom. The smooth cage fungus (Ileodictyon gracile), while striking to look at, has a fetid odour that is likely to repel you. Native to Australia, it often pops up in garden beds. The gem-studded puffball (Lycoperdon perlatum) is a cosmopolitan species with many common names including warted puffball, common puffball and devil's snuff-box. You'll find it in all kinds of habitats from forests and woodlands to grass clearings, gardens and track edges. The Australian parasol (Macrolepiota clelandii) often appears in grassy verges along roadsides. This handsome species is recognisable for its raised central brown knob, or umbo, and "chocolate-chip" scales. It's also known as the graceful parasol or slender parasol. The endearing pixie's parasol (Mycena interrupta) has a Gondwanan distribution but here in Australia you'll find it in Tasmania, Victoria, NSW, South Australia and if you're really lucky, in Queensland.
CNN
15-07-2025
- Science
- CNN
Protecting Mexico's bats
Encountering vampire bats and snakes in dark caves may sound like the stuff of nightmares, but for Mexican ecologist Rodrigo Medellín it's just another day at work. As part of the Rolex Perpetual Planet Initiative, he continues to fight multiple threats to bats and is determined to overcome what he believes to be their biggest – human ignorance.
Yahoo
04-07-2025
- Health
- Yahoo
Deadly invasive spider spreading across NZ sparks warning for Aussie cities
Not only are noble false widow spiders venomous, but some populations harbour antibiotic-resistant bacteria on their fangs. A deadly invasive spider species is spreading quickly across New Zealand, and experts think it may have already reached Australia. Not only are noble false widow spiders venomous, but some populations harbour antibiotic resistant bacteria on their fangs. Ecologist Professor Steven Truick, who's been tracking the city-dwelling spiders since they were first detected on the North Island in late 2024, said it's possible the species has also made its way to Australia. Speaking to Yahoo News, he said, you may already have it, but it's just not noticed. Of course, that's a really fundamental issue with species invasion. If alien monsters turned up and started eating people, we'd notice very quickly, but with something rather subtle like this, we don't. The spider's rapid spread across New Zealand suggests it may have been there long before it was officially identified last year, thriving in harsh urban environments where native spiders struggle to live. While Australia's Department of Agriculture didn't confirm whether the species poses a threat, it did state that there are a number of measures in place to manage biosecurity.
The Guardian
17-06-2025
- Science
- The Guardian
Insects are dying: here are 25 easy and effective ways you can help protect them
Insects are in trouble. Around the world, scientists are reporting catastrophic declines in their numbers, even in nature reserves that are largely protected from human touch. We are also beginning to see huge drops in the populations of other animals – such as birds – that depend on insects as food. Many of the drivers of those declines are structural, and require strong action by governments to turn around. But there are clear, easy steps that anyone can take to support the insect world. For species under such pressure, any respite is important, and we can create refuges for insects in a world increasingly hostile to their survival. In creating better habitats for insects, you can also reap the benefits: thriving gardens, more songbirds, and a healthier web of life. Here are 25 small, achievable, science-backed actions you can take today – at home, in the garden, or out in the city. Everyone has seen moths circle a bulb at night. But if that light stays on, researchers estimate one-third of insects trapped in its orbit will die before morning. Light pollution is a huge driver of insect declines: it changes insect behaviour and can even make leaves too tough for them to eat. It is also a relatively easy one to solve, says Brett Seymoure, a behavioural ecologist at Washington University in St Louis. 'Once you turn off a light, it is gone. You don't have to go and clean up, like you do with most pollutants. I am not saying we need to get rid of light at night, I think we just need to use it wisely.' You can help by switching off your outdoor lights or putting them on a sensor, and shading windows so they're not shining out into the night. You can also ask your local council to consider switching off some street lights for at least part of the night, particularly in parks and nature reserves – a move that studies have shown benefits insects and saves councils money. One of the best things you can do for insects is cultivate native plants, says Prof Douglas Tallamy, an entomologist at the University of Delaware. Local insects have evolved alongside local plants, and adapted to specific bloom shapes or leaf textures – many bees, for example, will only visit a single type of flower, even if others are growing nearby. Imported ornamental species and foreign plants often don't work as food or shelter for local species – by installing native plants, you can help insects get the food they need. Clothing moths are a huge pest in many households, chewing through winter coats, jumpers and wool carpets. But insecticides such as moth bombs can kill off every other insect in the vicinity. Now, some experts – including museums, which can't expose their artworks to chemicals – are experimenting with a natural ally: tiny parasitic wasps. The wasps are minuscule, barely visible to the naked eye, and lay eggs in moth larvae. Once the moths are gone, the wasps go too. The tiny wardrobe allies have been trialled by the National Trust, and used for pest control on cassava crops. You can order sachets of the wasps online. Even on the coldest winter days, compost heaps provide warm, safe habitat for insects to thrive. Over time, compost also improves soil structure and fertility, providing food and habitat for other garden insects. If you don't have a compost heap of your own, many organisations run neighbourhood composting schemes. As the climate heats, droughts are ramping up – and insects are struggling to survive the dry conditions. Providing sources of water with a basin, puddle, pond or bowl can help. Keep in mind that bees can't swim, so deeper water sources will need either a clear rim to drink from, or 'islands': according to University of California, floating corks or piles of rocks can work. Research has also shown that bees get important nutrients from 'dirty' water, where leaves or algae are breaking down, so don't keep your bee pools pristine. When trees shed their greenery, resist the urge to rake them up: leaf litter is a crucial habitat. Researchers have found that raking up leaves reduces moth and butterfly numbers by 45%, beetles 24%, and spiders up to 67%. Save yourself the trouble, and let the leaves lie. Creating food for insects can happen on any scale: a sprawling meadow, tiny balcony, or even single window box. If you have a balcony, you can create a pollinator garden entirely in pots. If you don't have any outdoor space at all, even window pots or boxes with flowering native plants can provide a valuable pitstop for pollinators flying through. Most people aren't aware of the link between medical prescriptions and insect life. But overuse of antibiotics and other medications was ranked in the top five emerging threats to pollinators. The clearest links to damage are from agricultural antibiotics, sprayed on fields. But human medications – huge amounts of which enter ecosystems through waterways – are also affecting many species, and are of growing concern for ecologists. No one should stop taking necessary medications, but you should use them only as directed, and dispose of them properly when out of date – don't just flush them down the toilet. Some butterflies rely on just a few plant species for food and reproduction. They also need variations in habitat, particularly scrubby areas with sparse, longer vegetation, shade from intense heat, and shelter. That's where butterfly banks come in. By creating a raised area of habitat that provides shade and natural variations in temperature throughout the day, butterflies have areas of refuge from unpredictable weather extremes. Many nature reserves and some farms are using them to help butterflies survive global heating. Recent trials have built the banks in an 'E' shape – if you have access to a larger garden or piece of land, you can do the same. While many harmful insecticides have been banned in food production, some remain legal for treating fleas in dogs and cats. A growing number of studies show that they are a disaster for wildlife, often leaching into waterways from fur. One monthly flea treatment for a large dog contains enough imidacloprid to kill 25 million bees, according to recent research. Avoid them altogether, or if you absolutely must de-flea, don't let your dog swim for at least a month after treatment. If you're planting for pollinators, knowing where to start can feel overwhelming. Many nature-loving gardeners advocate for the 3 x 3 x 3 method: pick three native plant species that flower in each growing season – spring, summer and autumn – and plant them each roughly in their own area. This way, you provide insects with food and habitat throughout the year. Here is a beginners' guide to getting started. While native plants in general will help, a smaller subset are absolutely critical for insects – particularly caterpillars – and the birds that feed on them. 'Just 14% of our native plants are supporting 90% of the caterpillar species in North America – we call them keystone plants,' Tallamy says – and the same applies to many other countries. After he rehabilitated his own plot of land with keystone species, Tallamy says, he watched the numbers of insects and birds shoot up. For the US, those keystone plant species are listed by region by the National Wildlife Federation. The UK also has lists of local keystone plants: native varieties of cherry, birch, and oak, for example, support 400 species of caterpillar each. In other regions, try searching for insect keystone species for your area. Of the world's more than 20,000 bee species, between 64% and 83% nest in the ground. Researchers from Australia conducted an experiment to find how native bees responded to different nest materials, and found that sprinkling rocks and gravel over the soil resulted in the greatest increase of nests. Different bee species need different environments to survive – you can speak to local bee conservation groups about specific ways to make gardens around you more nest-friendly for local and endangered species. There is very clear evidence that collapsing insect populations are driven by the rollout of intensive agriculture and pesticide use. If you can afford it, buying organic foods, which are produced without the use of synthetic pesticides, can help give space for insects to recover. 'Tiny plastic particles are everywhere and can reduce pollinator health and lifespan,' a new report on threats to global pollinators has found – ranking microplastics as the second most significant emerging threat to insects. All polyester, nylon, spandex and acrylic fabrics are plastic, and they shed millions of fragments as they're washed and worn – a single load of polyester-containing laundry can shed 700,000 microplastic fibres. Natural fibres, such as wool, silk and linen don't shed any (cotton also does not shed microplastics, but is responsible for about 4% to 10% of the world's pesticide and insecticide use – you could opt for organic cotton, which does not use synthetic pesticides). Likewise, reducing all of your plastic use – bags, packaging, bottles, toys – will help cut the microplastics you release into the world. Death and disintegration are part of the life cycle of ecosystems, providing vital food and homes for insects, and adding nutrients to the soil. Dead trees, fallen branches and logs – even small dead mammals – all provide important food for invertebrates. By clearing them away, we eliminate habitats and nutrients. If you can safely do so, let things rot. Herbicides and pesticides are one of the most significant threats to insect life. Glyphosate, one of the world's most common herbicides, has significant effects on insects, damaging their immune systems. Avoid blasting unwanted plants with chemicals and weed by hand instead – there is also research to indicate that spending time gardening is linked to better physical and psychological health. Insects are particularly sensitive to changes in temperature, which act as a trigger for stages of their lifecycle. But as global heating disrupts previously predictable weather patterns, these processes are increasingly out of sync. Creating cooler areas of shade – particularly when temperatures are abnormally high – provides shelter and respite for insects. No mow May is one of the most successful recent environmental campaigns in the UK, intended to provide more habitat to bees, butterflies and other invertebrates during a key part of their lifecycle when they are emerging from a cold, hard winter. But it doesn't have to be only May. Letting grasses grow uninterrupted, particularly where native wildflowers thrive, can be a big boost for insects. Sometimes, all a vacant plot, neglected berm or empty lot needs to boost its biodiversity value is seeds. Researchers from Poland recently found that patches of wildflowers in cities can be just as good for insects as natural meadows. By protecting and growing those patches, 'we can alleviate the hostile environment of urban space for wildlife', the researchers wrote. A number of NGOs distribute free native wildflower seed packs. You can even buy (or construct) your own sprinkling system: put a mix of seeds in a spice shaker, and carry it to sow flowering species in neglected spots of green. Research on insects has been troubled by a lack of good population data. To fill the gap, some researchers are turning to surveys by citizen scientists or local communities: one of the most influential, robust pieces of research on insect declines was a study that used data from amateur entomologists across Germany, and found insects in nature reserves had dropped 82%. You can volunteer for one of the butterfly counts now run across the UK, US, Europe, and many other parts of the world. Often, that involves just 15 minutes of counting butterflies in a nearby location. The UK also has the Buglife 'splatometer' survey, measuring how many bugs are squashed on vehicle number plates over time. Invasive species can be catastrophic for biodiversity. A single colony of Asian hornets, for example, can 'butcher' 90,000 UK pollinating insects in just one season. You can help control invasive species that haven't yet established breeding populations by learning what to look for, and reporting sightings to the relevant government department. The UK, for example, runs an Asian hornet-spotting app, and most US states have their own process for reporting an invasive species to their wildlife departments. While often hidden from sight, bats and some owl species feast on insects through the spring, summer and early autumn, and play a key role in regulating their populations. Where owls and bats disappear, farmers tend to increase their insecticides: a study last year found that when the local bat population died, farmers dramatically increased chemical pesticide use. By supporting your local bat and owl populations, you can have positive knock-on effects for insects. 'We're at a new point in human history,' entomologist David Wagner says, where the heating planet has become the biggest threat to insect life across the world. Up until the last decade, 'the major drivers of biodiversity losses around the planet were really land degradation and land loss, habitat loss. But I think now, that climate change is by far exceeding that,' Wagner says. Stopping the worst of global heating – and saving trillions of insects – requires us to dramatically cut our use of fossil fuels. Find more age of extinction coverage here, and follow the biodiversity reporters Phoebe Weston and Patrick Greenfield in the Guardian app for more nature coverage
The Guardian
03-06-2025
- Health
- The Guardian
‘Half the tree of life': ecologists' horror as nature reserves are emptied of insects
Daniel Janzen only began watching the insects – truly watching them – when his ribcage was shattered. Nearly half a century ago, the young ecologist had been out documenting fruit crops in a dense stretch of Costa Rican forest when he fell in a ravine, landing on his back. The long lens of his camera punched up through three ribs, snapping the bones into his thorax. Slowly, he dragged himself out, crawling nearly two miles back to the research hut. There were no immediate neighbours, no good roads, no simple solutions for getting to a hospital. Selecting a rocking chair on the porch, Janzen used a bedsheet to strap his torso tightly to the frame. For a month, he sat, barely moving, waiting for his bones to knit back together. And he watched. In front of him was a world seething with life. Every branch of every tree seemed to host its own small metropolis of creatures hunting, flying, crawling, eating. The research facility lay in a patchwork of protected rainforest, dry forest, cloud forest, mangroves and coastline covering an area the size of New York, and astonishingly rich in biodiverse life. Here, the bugs gorged, coating the leaf litter with a thick carpet of droppings. But the real show was at night: for two hours each evening, the site got power and a 25-watt bulb flickered on above the porch. Out of the forest darkness, a tornado of insects would flock to its glow, spinning and dancing before the light. Lit up, the side of the house would be 'absolutely plastered with moths – tens of thousands of them', Janzen says. Inspired, he decided to erect a sheet for a light trap with a camera – a common way to document flying insect numbers and diversity. In that first photograph, taken in 1978, the lit-up sheet is so thickly studded with moths that in places the fabric is barely visible, transformed into what looks like densely patterned, crawling wallpaper. Scientists identified an astonishing 3,000 species from that light trap, and the trajectory of Janzen's career was transformed, from the study of seeds to a lifetime specialising in the forest's barely documented populations of caterpillars and moths. Now 86, Janzen still works in the same research hut in the Guanacaste conservation area, alongside his longtime collaborator, spouse and fellow ecologist, Winnie Hallwachs. But in the forest that surrounds them, something has changed. Trees that once crawled with insects lie uncannily still. The hum of wild bees has faded, and leaves that should be chewed to the stem hang whole and un-nibbled. It is these glossy, untouched leaves that most spook Janzen and Hallwachs. They are more like a pristine greenhouse than a living ecosystem: a wilderness that has been fumigated and left sterile. Not a forest, but a museum. Over the decades, Janzen has repeated his light traps, hanging the sheet, watching for what comes. Today, some moths flutter to the glow, but their numbers are far fewer. 'It's the same sheet, with the same lights, in the same place, looking over the same vegetation. Same time of year, same time of the moon cycle, everything about it is identical,' he says. 'There's just no moths on that sheet.' The declines witnessed by Janzen – and described by others around the world – are part of what some ecologists call a 'new era' of ecological collapse, where rapid extinctions occur in regions that have little direct contact with people. Reports of falling insect numbers around the world are not new. International reviews have estimated annual losses globally of between 1% and 2.5% of total biomass every year. Widespread use of pesticides and fertilisers, light and chemical pollution, loss of habitat and the growth of industrial agriculture have all carved into their numbers. Often, these were deaths of proximity: insects are sensitive creatures, and any nearby source of pollution can send their populations crumbling. But what Janzen and Hallwachs are witnessing is a part of a newer phenomenon: the catastrophic collapse of insect populations in supposedly protected regions of forest. 'In the parts of Costa Rica that are heavily hit by pesticides, the insects are completely wiped out,' Hallwachs says. 'But what we see here in the preserved areas – that as far as we can tell, are free of even these destructive insecticides and pesticides – even here, the insect numbers are going down horrifyingly dramatically,' she says. Long-term data for insect populations – particularly less charismatic species – is still patchy, but Janzen and Hallwachs join a number of scientists that have recorded huge die-offs of insects in nature reserves around the world. They include in Germany, where flying insects across 63 insect reserves dropped 75% in less than 30 years; the US, where beetle numbers dropped 83% in 45 years; and Puerto Rico, where insect biomass dropped up to 60-fold since the 1970s. These declines are occurring in ecosystems that are otherwise protected from direct human influence. When David Wagner stepped out into the US's southern wilderness this spring, he found landscapes emptied of life. The entomologist has devoted much of his career to documenting the vast diversity of US insect life, particularly rare caterpillars. He traverses the country to find specimens, often on long road trips searching for caterpillars by day and moths by night. Now, he finds himself coming home empty-handed. 'I just got back from Texas, and it was the most unsuccessful trip I've ever taken,' he says. 'There just wasn't any insect life to speak of.' It was not only the insects missing, he says, it was everything. 'Everything was crispy, fried; the lizard numbers were down to the lowest numbers I can ever remember. And then the things that eat lizards were not present – I didn't see a single snake the entire time.' Wagner recalls when a series of international reviews began hitting headlines in 2019, saying global insect biomass was declining at a rate of 1% a year (although some estimates put it as high as 2.5%). 'We [entomologists] were thinking conservatively,' he says, looking at the data that has emerged in the five years since then. 'I now think that that's too low. Now I would say that 2% is happening in some areas, and we're seeing some places threatened by climate change or urbanisation or agriculture get as high as 5% decline per year.' A few percentage points a year may not have the ring of disaster. 'But if you run that forward just four decades,' Wagner says, 'we're talking about nearly half the tree of life disappearing in one human lifetime. That is absolutely catastrophic.' Developing a clear picture of how many insects we have lost is complicated by a lack of baseline data for many species: while some eye-catching insects, such as butterflies, have been collected and monitored for decades, others have been mostly ignored. And within the overall declines, the picture is not homogeneous: populations and losses vary by species, by location, by habitat. The same heat that destroys the living conditions of one butterfly, for example, could expand the range of a mosquito or help a cricket species thrive. 'No matter what we do in nature, there will be winners and losers,' Wagner says. 'But we are seeing a lot of losers.' And those who doubt there is sufficient species data to prove the 'insectageddon' can now track it by proxy, Wagner says: via the sharp declines in birds, lizards and other creatures that depend on them for food. Scientists in the US, Brazil, Ecuador and Panama have now reported the catastrophic declines of birds in 'untouched' regions – including reserves inside millions of hectares of pristine forest. In each case, the worst losses were among insectivorous birds. At one research centre – falling within a 22,000-hectare (85 sq mile) stretch of intact forest in Panama – scientists comparing current bird numbers with the 1970s found 70% of species had declined and 88% had lost more than half of their population. In 2019, researchers found that almost a third of US birds – about 3 billion – had disappeared from the skies since the 1970s. The losses, however, were not evenly distributed: those birds that ate insects as their main food had declined by 2.9 billion. Those that didn't depend on insects had actually gained, increasing by 26 million. More recent research from the US found a decline in three-quarters of nearly 500 bird species studied – with the steepest downward trend in stronghold areas, where they once thrived. In Puerto Rico's Luquillo rainforest, scientists in 2018 mapped how the loss of insects set other dominoes falling: as bugs declined, so too did the populations of lizards, frogs and birds. Their disappearance, they wrote, had triggered 'a bottom-up trophic cascade and consequent collapse of the forest food web'. In Costa Rica, Janzen described the fall in numbers of insectivorous birds in the reserve as 'cratering'. A colony of about 20 nectar-eating bats have long nested in the dark nooks of Janzen and Hallwachs' house, but Janzen has noticed the flowers they used to feed from are now failing to bloom. Hallwachs began to find their small, emaciated bodies lying on the floor. 'Over a period of five days, I found three of these bats dead,' she says. Researchers at another site 20 miles away told her they were witnessing the same thing. Behind the steepening declines, a clear culprit is beginning to emerge: global heating. A tropical forest ecosystem is 'a finely tuned Swiss watch', Hallwachs says – perfectly engineered to sustain a vastly biodiverse system of creatures. Each element is delicately tuned and interlocks with the rest: the heat, the humidity, the rainfall, the unfolding of leaves, the length of the seasons, the start and stop of the life cycles of insects and animals. With each incremental turn of one cog, the rest of the system responds. Insects and animals have evolved to time their hibernations and breeding times precisely to small signals from the system: a change in humidity, a lengthening of the light hours of the day, a small rise or fall in temperature. But now, the system has one gear spinning wildly out of time: the climate. 'When I arrived here in 1963 the dry season was four months. Today, it is six months,' Janzen says. Insects that typically spend four months underground, waiting for the rains, are now forced to try to survive another two months of hot, dry weather. Many are not succeeding. Alongside the changing seasons are other shifts, such as in rainfall or humidity. 'It's just a general disruption of all the little cues and synchronies that would be out there,' Janzen says. Across the entire clock of the forest, plants and creatures are falling out of sync. In the background, the temperature is rising. 'The killer – the cause that's pulling the trigger – is actually water,' says Wagner. For insects, staying hydrated is a unique physiological challenge: rather than lungs, their bodies are riddled with holes, called spiracles, that carry oxygen directly into the tissue. 'They're all surface area,' says Wagner. 'Insects can't hold water.' Even a brief drought lasting just a few days can wipe out millions of humidity-dependent insects. Some ecologists now believe these declines could mark a new era in which the changing climate overtakes other forms of human damage as the biggest driver of extinction. 'We're at a new point in human history,' Wagner says. Up until the last decade, 'the major drivers of biodiversity losses around the planet were really land degradation and land loss, habitat loss. But I think now that climate change is by far exceeding that.' Last month, the journal BioScience published new research examining how the five biggest drivers of biodiversity loss were affecting the US's endangered creatures. For the first time – albeit by a very slim margin – the climate crisis emerged in front, driving the decline of 91% of imperilled species. Heat-driven declines could have repercussions far beyond their immediate surroundings. In the past, even if pesticides wiped out insects over an agricultural region, as long as healthy populations remained elsewhere, species could return if the spraying stopped. 'Climate change is impacting all those different little spots at the same time. It doesn't just affect one particular spot that gets a pesticide dose or gets a tree cut down,' Janzen says. 'If the insect population collapses and it happens everywhere, you don't have a residual population.' Today, as well as being an ecologist Wagner feels he has taken on a second role – as an elegist for disappearing forms of life. 'I'm an optimist, in the sense that I think we will build a sustainable future,' Wagner says. 'But it's going to take 30 or 40 years, and by then, it's going to be too late for a lot of the creatures that I love. I want to do what I can with my last decade to chronicle the last days for many of these creatures.' Decades on from his months spent bound to the rocking chair, Janzen still watches. He records the yearly data, the shifts in dominant species. But today, there is so much less to see. Once, when he and Hallwachs would type up their notes in the night, they would pitch a tent in the living room to protect their computers from thousands of moths that flocked to the blue glow. Now, they work with the house open to the forest air. 'I find myself saying, 'Winnie! A moth has arrived at the light on my laptop,'' Janzen says. 'One moth.' Elsewhere in their profession, some scientists are starting to look away. 'We know quite a number of entomologists who have experience dating back to the 70s, 80s or 90s,' Hallwachs says. 'One of our very good friends – he now does not have the emotional courage to hang up a sheet to collect moths at night. It is too devastating to see how few there are.' Find more age of extinction coverage here, and follow the biodiversity reporters Phoebe Weston and Patrick Greenfield in the Guardian app for more nature coverage
