B&Bs for birds and bees: transform your garden or balcony into a wildlife haven



Wes Mountain/The Conversation, CC BY-NC

Judith Friedlander, University of Technology Sydney

Just like humans, animals like living near coastal plains and waterways. In fact, cities such as Sydney and Melbourne are “biodiversity hotspots” – boasting fresh water, varied topographies and relatively rich soil to sustain and nourish life.

Recent research showed urban areas can support a greater range of animals and insects than some bushland and rural habitat, if we revegetate with biodiversity in mind.




Read more:
How you can help – not harm – wild animals recovering from bushfires


Urban regeneration is especially important now, amid unfathomable estimates that more than one billion animals were killed in the recent bushfires. Even before the fires, we were in the middle of a mass extinction event in Australia and around the world.

Losing animals, especially pollinators such as bees, has huge implications for biodiversity and food supplies.

My team and I are creating a B&B Highway – a series of nest boxes, artificial hollows and pollinating plants – in Sydney and coastal urban areas of New South Wales. These essentially act as “bed and breakfasts” where creatures such as birds, bees, butterflies and bats can rest and recharge. Everyday Australians can also build a B&B in their own backyards or on balconies.

City living for climate refugees

I spoke to Charles Sturt University ecologist Dr Watson about the importance of protecting animals such as pollinators during the climate crisis. He said:

The current drought has devastated inland areas – anything that can move has cleared out, with many birds and other mobile animals retreating to the wetter, more temperate forests to the south and east.

So, when considering the wider impacts of these fires […] we need to include these climate refugees in our thinking.

Native birds like the white-winged triller have been spotted in urban areas.
Shutterstock

Many woodland birds such as honeyeaters and parrots have moved in droves to cities, including Sydney, over the last few years because of droughts and climate change, attracted to the rich variety of berries, fruits and seeds.

I also spoke to BirdLife Australia’s Holly Parsons, who said last year’s Aussie Backyard Bird Count recorded other inland birds – such as the white-winged triller, the crimson chat, pied honeyeater, rainforest pigeons and doves – outside their usual range, attracted to the richer food variety in coastal cities.




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To save these threatened seahorses, we built them 5-star underwater hotels


What’s more, there have been increased sightings of powerful owls in Sydney and Melbourne, squirrel gliders in Albury, marbled geckos in Melbourne, and blue-tongue lizards in urban gardens across south-east Australia.

With so many birds and pollinators flocking to the cities, it’s important we support them with vegetated regions they can shelter in, such as through the B&B Highway we’re developing.

The B&B Highway: an urban restoration project

B&Bs on our “highway” are green sanctuaries, containing pollinating plants, water and shelters such as beehives and nesting boxes.




Read more:
Spiders are threatened by climate change – and even the biggest arachnophobes should be worried


We’re setting up B&Bs across New South Wales in schools and community centres, with plans to expand them in Melbourne, Brisbane and other major cities. In fact, by mid-2020, we’ll have 30 B&Bs located across five different Sydney municipalities, with more planned outside Sydney.

The NSW Department of Education is also developing an associated curriculum for primary and early high school students to engage them in ecosystem restoration.

One of the biodiversity havens the author developed to attract pollinators.
Author provided

If you have space in your garden, or even on a balcony, you can help too. Here’s how.

For birds

Find out what bird species live in your area and which are endangered using the Birdata directory. Then select plants native to your area – your local nursery can help you out here.

The type of plants will vary on whether your local birds feed on insects, nectar, seed, fruit or meat. Use the guide below.



Wes Mountain/The Conversation, CC BY-ND

More tips

Plant dense shrubs to allow smaller birds, such as the superb fairy-wren, to hide from predatory birds.

Order hollows and nesting boxes from La Trobe University to house birds, possums, gliders and bats.

Put out water for birds, insects and other animals. Bird baths should be elevated to enable escape from predators. Clean water stations and bowls regularly.

For native stingless bees

If you live on the eastern seaboard from Sydney northward, consider installing a native stingless beehive. They require very little maintenance, and no permits or special training.

These bees are perfect for garden pollination. Suppliers of bees and hives can be found online – sometimes you can even rescue an endangered hive.

A blue banded bee at a B&B rest stops in NSW.
Author provided

Also add bee-friendly plants – sting or no sting – to your garden, such as butterfly bush, bottlebrush, daisies, eucalyptus and angophora gum trees, grevillea, lavender, tea tree, honey myrtle and native rosemary.

For other insects

Wherever you are in Australia, you can buy or make your own insect hotel. There is no standard design, because our gardens host a wide range of native insects partial to different natural materials.

An insect hotel. Note the holes, at a variety of depths, drilled into the material.
Dietmar Rabich/Wikimedia Commons, CC BY-SA

Building your insect hotel

Use recycled materials (wooden pallets, small wooden box or frames) or natural materials (wood, bamboo, sticks, straw, stones and clay).

Fill gaps in the structure with smaller materials, such as clay and bamboo.

In the wood, drill holes ranging from three to ten millimetres wide for insects to live in. Vary hole depths for different insects – but don’t drill all the way through. They shouldn’t be deeper than 30 centimetres.

Give your hotel a roof so it stays dry, and don’t use toxic paints or varnishes.

Place your insect hotel in a sheltered spot, with the opening facing the sun in cool climates, and facing the morning sun in warmer climates.

Apartment-dwellers can place their insect hotels on a balcony near pot plants. North-facing is often best, but make sure it’s sheltered from harsh afternoon sunshine and heavy rain.The Conversation

Judith Friedlander, Post-graduate Researcher, Institute for Sustainable Futures, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

These plants and animals are now flourishing as life creeps back after bushfires


Flickr

Kathryn Teare Ada Lambert, University of New England

As the east coast bushfire crisis finally abates, it’s easy to see nothing but loss: more than 11 million hectares of charcoal and ash, and more than a billion dead animals.

But it is heartening to remember that bushfire can be a boon to some plants and animals. We’re already seeing fresh green shoots as plants and trees resprout. Beetles and other insects are making short work of animal carcasses; they will soon be followed by the birds which feed on them.

Australia’s worsening fire regimes are challenging even these tolerant species. But let’s take a look at exactly how life is returning to our forests now, and what to expect in coming months.

Life is returning to fire-ravaged landscapes.
Flickr, CC BY

The science of resprouting

Of course, bushfires kill innumerous trees – but many do survive. Most of us are familiar with the image of bright green sprouts shooting from the trunks and branches of trees such as eucalypts. But how do they revive so quickly?

The secret is a protected “bud bank” which lies behind thick bark, protected from the flames. These “epicormic” buds produce leaves, which enables the tree to photosynthesise – create sugar from the sun so the tree can survive.

Under normal conditions, hormones from shoots higher in the tree suppress these buds. But when the tree loses canopy leaves due to fire, drought or insect attack, the hormone levels drop, allowing the buds to sprout.

Insect influx

This summer’s fires left in their wake a mass of decaying animal carcasses, logs and tree trunks. While such a loss can be devastating for many species – particularly those that were already vulnerable – many insects thrive in these conditions.

For example, flies lay eggs in the animal carcasses; when the maggots hatch, the rotting flesh provides an ample food source. This process helps break down the animal’s body – reducing bacteria, disease and bad smells. Flies are important decomposers and their increased numbers also provide food for birds, reptiles and other species.




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Looks like an ANZAC biscuit, tastes like a protein bar: Bogong Bikkies help mountain pygmy-possums after fire


Similarly, beetles such as the grey furrowed rosechafer, whose grubs feed on decaying logs and tree trunks, add nutrients to the soil when they defecate which helps plants grow again.

Insects also benefit from the mass of new leaves on trunks and branches. For example, native psyllids – an insect similar to aphids – feed on the sap from leaves and so thrive on the fresh growth.

Animal carcasses are a sad consequence of bushfire, but provide a boon to some insect species.
Sean Davey/AAP

Then come the birds

Once insects start to move back into an area from forested areas nearby, the birds that eat them will follow.

An increase in psyllids encourages honeyeaters – such as bell miners and noisy miners – to return. These birds are considered pests.

A CSIRO study after bushfires in Victoria’s East Gippsland in 1983 found several native bird species – flame and scarlet robins, the buff-rumped thornbill and superb fairy-wren – increased quickly to levels greater than before fire. As shrubs in the understorey regrow, other species will move in, slowly increasing biodiversity.




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Not all weeds are villains. After a fire, some plants – even weeds – can be better than none


Since the recent bushfire in woodland near Moonbi in New South Wales, numerous bird species have returned. On a visit over this past weekend, I observed currawongs landing in the canopy, saw fairy wrens darting in and out of foliage sprouting from the ground, and heard peep wrens in tufts of foliage on bark and high branches.

Honeyeaters moved between burnt and intact trees on the edge of the blackened forest and butterflies visited new plants flowering after recent rain.

The presence of the currawong, while a pest species, shows birdlife is returning to the bush.
Flickr, CC BY

Weeds can help

Weeds usually benefit when fire opens up the tree canopy and lets in light. While this has a downside – preventing native plants from regenerating – weeds can also provide cover for native animal species.

A study I co-authored in 2018 found highly invasive Lantana camara provided habitat for small mammals such as the brown rat in some forests. Mammal numbers in areas where lantana was present were greater than where it was absent.

Lantana often grows quickly after fire due to the increase in light and its ability to suppress other plant growth.

Lantana provides cover for animal species.
Flickr, CC BY

Is there hope for threatened species?

Generalist species – those that thrive in a variety of environments – can adapt to burnt forest. But specialist species need particular features of an ecosystem to survive, and are far less resilient.

The critically endangered Leadbeater’s possum lives only in small pockets of forest in Victoria.

It requires large fires to create a specific habitat: big dead trees provide hollows for shelter and nesting, and insects feeding on burnt wood and carcasses provide a food source.

But for the Leadbeater’s possum to benefit from the fire regime, bushfires should be infrequent – perhaps every 75 years – allowing time for the forest to grow back. If fires are too frequent, larger trees will not have time to establish and hollows will not be created, causing the species’ numbers to decline.

Similarly in NSW, at least 50% and up to 80% of the habitat of threatened species such as the vulnerable rufous scrub-bird was burnt in the recent fires, an environmental department analysis found.

Looking ahead

Only time will tell whether biodiversity in these areas is forever damaged, or will return to its former state.

Large fires may benefit some native species but they also provide food and shelter for predatory species, such as feral cats and foxes. The newly open forest leaves many native mammals exposed, changing the foodweb, or feeding relationships, in an ecosystem.

This means we may see a change in the types of birds, reptiles and mammals found in forests after the fires. And if these areas don’t eventually return to their pre-fire state, these environments may be changed forever – and extinctions will be imminent.




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Fire almost wiped out rare species in the Australian Alps. Feral horses are finishing the job


The Conversation


Kathryn Teare Ada Lambert, Adjunct Lecturer/ Ecologist, University of New England

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Buildings kill millions of birds. Here’s how to reduce the toll



These birds were killed by flying into a set of surveyed buildings in Washington DC in 2013.
USGS Bee Inventory and Monitoring Lab/Flickr

Norman Day, Swinburne University of Technology

As high-rise cities grow upwards and outwards, increasing numbers of birds die by crashing into glass buildings each year. And of course many others break beaks, wings and legs or suffer other physical harm. But we can help eradicate the danger by good design.

Most research into building-related bird deaths has been done in the United States and Canada, where cities such as Toronto and New York City are located on bird migration paths. In New York City alone, the death toll from flying into buildings is about 200,000 birds a year.

Across the US and Canada, bird populations have shrunk by about 3 billion since 1970. The causes include loss of habitat and urbanisation, pesticides and the effects of global warming, which reduces food sources.

An estimated 365 million to 1 billion birds die each year from “unnatural” causes like building collisions in the US. The greatest bird killer in the US remains the estimated 60-100 million free-range cats that kill up to 4 billion birds a year. Australia is thought to have up to 6 million feral cats.




Read more:
For whom the bell tolls: cats kill more than a million Australian birds every day


But rampant global urbanisation is putting the reliance on glass buildings front-of-stage as an “unnatural” cause of bird deaths, and the problem is growing exponentially.

In the line of flight

Most birds fly at around 30-50km/h, with falcons capable of up to 200km/h. When migrating, birds generally spend five to six hours flying at a height of 150 metres, sometimes much higher.

And that’s where the problems start with high-rise buildings. Most of them are much taller than the height at which birds fly. In Melbourne, for example, Australia 108 is 316 metres, Eureka 300 metres, Aurora 270 metres and Rialto 251 metres. The list is growing as the city expands vertically.

The paradigm of high-rise gothams, New York City, has hundreds of skyscrapers, most with fully glass, reflective walls. One World Trade is 541 metres high, the 1931 Empire State is 381 metres (although not all glass) and even the city’s 100th-highest building, 712 Fifth Avenue, is 198 metres.

To add to the problems of this forest of glass the city requires buildings to provide rooftop green places. These attract roosting birds, which then launch off inside the canyons of reflective glass walls – often mistaking these for open sky or trees reflected from behind.

Reflections of trees and sky lure birds into flying straight into buildings.
Frank L Junior/Shutterstock

A problem of lighting and reflections

Most cities today contain predominantly glass buildings – about 60% of the external wall surface. These buildings do not rely on visible frames, as in the past, and have very limited or no openable windows (for human safety reasons). They are fully air-conditioned, of course.




Read more:
Glass skyscrapers: a great environmental folly that could have been avoided


Birds cannot recognise daylight reflections and glass does not appear to them to be solid. If it is clear they see it as the image beyond the glass. They can also be caught in building cul-de-sac courtyards – open spaces with closed ends are traps.

At night, the problem is light from buildings, which may disorientate birds. Birds are drawn to lights at night. Glass walls then simply act as targets.

Some species send out flight calls that may lure other birds to their death.

White-throated Sparrows collected in a University of Michigan-led study of birds killed by flying into buildings lit up at night in Chicago and Cleveland.
Roger Hart, University of Michigan/Futurity, CC BY



Read more:
Want to save millions of migratory birds? Turn off your outdoor lights in spring and fall


We can make buildings safer for birds

Architectural elements like awnings, screens, grilles, shutters and verandas deter birds from hitting buildings. Opaque glass also provides a warning.

Birds see ultraviolet light, which humans cannot. Some manufacturers are now developing glass with patterns using a mixed UV wavelength range that alerts birds but has no effect on human sight.

New York City recently passed a bird-friendly law requiring all new buildings and building alterations (at least under 23 metres tall, where most fly) be designed so birds can recognise glass. Windows must be “fritted” using applied labels, dots, stripes and so on.

The search is on for various other ways of warning birds of the dangers of glass walls and windows.

Combinations of methods are being used to scare or warn away birds from flying into glass walls. These range from dummy hawks (a natural enemy) and actual falcons and hawks, which scare birds, to balloons (like those used during the London Blitz in the second world war), scary noises and gas cannons … even other dead birds.

Researchers are using lasers to produce light ray disturbance in cities especially at night and on dark days.

Noise can be effective, although birds do acclimatise if the noises are produced full-time. However, noise used as a “sonic net” can effectively drown out bird chatter and that interference forces them to move on looking for quietness. The technology has been used at airports, for example.

A zen curtain developed in Brisbane has worked at the University of Queensland. This approach uses an open curtain of ropes strung on the side of buildings. These flutter in the breeze, making patterns and shadows on glass, which birds don’t like.

These zen curtains can also be used to make windows on a house safer for birds. However, such a device would take some doing for the huge structures of a metropolis.

More common, and best adopted at the design phase of a building, is to mark window glass so birds can see it. Just as we etch images on glass doors to alert people, we can apply a label or decal to a window as a warning to birds. Even using interior blinds semi-open will deter birds.

Birds make cities friendlier as part of the shared environment. We have a responsibility to provide safe flying and security from the effects of human habitation and construction, and we know how to achieve that.


This article has been updated to correct the figure for the estimated number of birds killed by the cats in the US to “up to 4 billion”, not 4 million.The Conversation

Norman Day, Lecturer in Architecture, Practice and Design, Swinburne University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Six million hectares of threatened species habitat up in smoke



At least 250 threatened species have had their habitat hit by fires.
Gena Dray

Michelle Ward, The University of Queensland; Aaron Greenville, University of Sydney; April Reside, The University of Queensland; Ayesha Tulloch, University of Sydney; Brooke Williams, The University of Queensland; Emily Massingham, The University of Queensland; Helen Mayfield, The University of Queensland; Hugh Possingham, The University of Queensland; James Watson, The University of Queensland; Jim Radford, La Trobe University, and Laura Sonter, The University of Queensland

More than one billion mammals, birds, and reptiles across eastern Australia are estimated to have been affected by the current fire catastrophe.

Many animals and plants have been incinerated or suffocated by smoke and ash. Others may have escaped the blaze only to die of exhaustion or starvation, or be picked off by predators.



But even these huge losses of individual animals and plants do not reveal the full scale of impact that the recent fires have had on biodiversity.

Plants, invertebrates, freshwater fish, and frogs have also been affected, and the impact of the fires is likely to be disproportionately greater for threatened species.




Read more:
A season in hell: bushfires push at least 20 threatened species closer to extinction


To delve deeper into the conservation impact, we used publicly available satellite imagery to look at the burnt areas (up to January 7, 2020) and see how they overlapped with the approximate distributions of all the threatened animals and plants listed under the Environment Protection and Biodiversity Conservation Act.

We restricted our analysis to the mediterranean and temperate zone of south-east and south-west Australia.

The bad news

We found that 99% of the area burned in the current fires contains potential habitat for at least one nationally listed threatened species. We conservatively estimate that six million hectares of threatened species habitat has been burned.



Given that many fires are still burning and it is not yet clear how severe the burning has been in many areas, the number of species affected and the extent of the impact may yet change.

What we do know is that these species are already on the brink of extinction due to other threats, such as land clearing, invasive species, climate change, disease, or previous fires.

Approximately 70 nationally threatened species have had at least 50% of their range burnt, while nearly 160 threatened species have had more than 20% of their range burnt.

More threatened plants have been affected than other groups: 209 threatened plant species have had more than 5% of their range burnt compared to 16 mammals, ten frogs, six birds, four reptiles, and four freshwater fish.


Author supplied

Twenty-nine of the 30 species that have had more than 80% of their range burnt are plants. Several species have had their entire range consumed by the fires, such as the Mountain Trachymene, a fire-sensitive plant found in only four locations in the South Eastern Highlands of NSW.

Other species that have been severely impacted include the Kangaroo Island dunnart and the Kangaroo Island glossy black cockatoo. These species’ entire populations numbered only in the hundreds prior to these bushfires that have burned more than 50% of their habitat.

The Kangaroo Island glossy black cockatoo has had more than 50% its habitat impacted by fire.
Mike Barth

Glossy black cockatoos have a highly specialised diet. They eat the seeds of the drooping sheoak (Allocasuarina verticillata). These trees may take anywhere from 10 to 50 years to recover enough to produce sufficient food for the black cockatoos.

The populations of many species will need careful management and protection to give their habitats enough time to recover and re-supply critical resources.

The figures above do not account for cumulative impacts of previous fires. For example, the critically endangered western ground parrot had around 6,000 hectares of potential habitat burnt in these fires, which exacerbates the impact of earlier extensive fires in 2015 and early 2019.

Threatened species vary in their ability to cope with fire. For fire-sensitive species, almost every individual dies or is displaced. The long-term consequences are likely to be dire, particularly if vegetation composition is irrevocably changed by severe fire or the area is subject to repeat fires.

More than 50% of the habitat of several species known to be susceptible to fire has been burnt – these include the long-footed potoroo and Littlejohn’s tree frog.

The endangered long-footed potoroo has had more than 50% of its potential habitat impacted by fire.
George Bayliss

Some species are likely to thrive after fire. Indeed, of the top 30 most impacted species on our list, almost 20% will likely flourish due to low competition in their burnt environments – these are all re-sprouting plants. Others will do well if they are not burnt again before they can set seed.

Rising from the ashes

For fire-sensitive threatened species, these fires could have substantially increased the probability of extinction by virtue of direct mortality in the fires or reducing the amount of suitable habitat. However, after the embers settle, with enough investment and conservation actions, guided by evidence-based science, it may be possible to help threatened species recover.

For species on the brink of extinction, insurance populations need to be established. Captive breeding and release can complement wild populations, as occurs for the regent honeyeater.
Dean Ingwersen / BirdLife Australia

Protection and conservation-focussed management of areas that have not burned will be the single most important action if threatened species are to have any chance of persistence and eventual recovery.

Management of threatening processes (such as weeds, feral predators, introduced herbivores, and habitat loss through logging or thinning) must occur not just at key sites, but across the landscapes they sit in. Maintaining only small pockets of habitat in a landscape of destruction will lock many species on the pathway to extinction.

In some cases, rigorous post-fire restoration will be necessary to allow species to re-colonise burnt areas. This may include intensive weed control and assisted regeneration of threatened flora and specific food sources for fauna, installing nest boxes and artificial cover, or even targeted supplementary feeding.

Unconventional recovery actions will be needed because this unique situation calls for outside-the-box thinking.




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Playing the long game

These fires were made larger and more severe by record hot, dry conditions. Global temperatures have so far risen by approximately 1°C from pre-industrial levels.

Current projections indicate that we are on track for a 3°C increase. What will that look like?

We are in a moment of collective grief for what has been lost. A species lost is not just a word on a page, but an entire world of unique traits, behaviours, connections to other living things, and beauty.

These losses do not need to be in vain. We have an opportunity to transform our collective grief into collective action.

Australians are now personally experiencing climate impacts in an unprecedented way. We must use this moment to galvanise our leaders to act on climate change, here in Australia and on the world stage.

The futures of our beloved plants and animals, and our own, depend on it.The Conversation

Michelle Ward, PhD Candidate, The University of Queensland; Aaron Greenville, Lecturer in Spatial Agricultural and Environmental Sciences, University of Sydney; April Reside, Researcher, Centre for Biodiversity and Conservation Science, The University of Queensland; Ayesha Tulloch, DECRA Research Fellow, University of Sydney; Brooke Williams, PhD Candidate, The University of Queensland; Emily Massingham, PhD Student, The University of Queensland; Helen Mayfield, Postdoctoral Research Fellow School of Earth and Environmental Sciences, The University of Queensland; Hugh Possingham, Professor, The University of Queensland; James Watson, Professor, The University of Queensland; Jim Radford, Principal Research Fellow, Research Centre for Future Landscapes, La Trobe University, and Laura Sonter, PhD Candidate in Global Environmental Change, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia’s bushfires could drive more than 700 animal species to extinction. Check the numbers for yourself



Invertebrates out greatly outnumber mammals everywhere, including in bushfire zones.
Michael Lee, CC BY-NC-ND

Mike Lee, Flinders University

The scale and speed of the current bushfire crisis has caught many people off-guard, including biodiversity scientists. People are scrambling to estimate the long-term effects. It is certain that many animal species will be pushed to the brink of extinction, but how many?

One recent article suggested 20 to 100, but this estimate mostly considers large, well-known species (especially mammals and birds).

A far greater number of smaller creatures such as insects, snails and worms will also be imperilled. They make up the bulk of biodiversity and are the little rivets holding ecosystems together.




Read more:
A season in hell: bushfires push at least 20 threatened species closer to extinction


But we have scant data on how many species of small creatures have been wiped out in the fires, and detailed surveys comparing populations before and after the fires will not be forthcoming. So how can we come to grips with this silent catastrophe?

This native bee (Amphylaeus morosus) has been devastated by the bushfires across much of its range. It plays important roles in pollinating plants and as part of the food web, but has no common name, and its plight is so far unheralded.
Reiner Richter https://www.ala.org.au/

Using the information that is available, I calculate that at least 700 animal species have had their populations decimated – and that’s only counting the insects.

This may sound like an implausibly large figure, but the calculation is a simple one. I’ll explain it below, and show you how to make your own extinction estimate with only a few clicks of a calculator.

Using insects to estimate true extinction numbers

More than three-quarters of the known animal species on Earth are insects. To get a handle on the true extent of animal extinctions, insects are a good place to start.

My estimate that 700 insect species are at critical risk involves extrapolating from the information we have about the catastrophic effect of the fires on mammals.

We can work this out using only two numbers: A, how many mammal species are being pushed towards extinction, and B, how many insect species there are for each mammal species.

To get a “best case” estimate, I use the most conservative estimates for A and B below, but jot down your own numbers.

How many mammals are critically affected?

A recent Time article lists four mammal species that will be severely impacted: the long-footed potoroo, the greater glider, the Kangaroo Island dunnart, and the black-tailed dusky antechinus. The eventual number could be much greater (e.g the Hastings River mouse, the silver-headed antechinus), but let’s use this most optimistic (lowest) figure (A = 4).

Make your own estimate of this number A. How many mammal species do you think would be pushed close to extinction by these bushfires?

We can expect that for every mammal species that is severely affected there will be a huge number of insect species that suffer a similar fate. To estimate exactly how many, we need an idea of insect biodiversity, relative to mammals.

How many insect species are out there, for each mammal species?

The world has around 1 million named insect species, and around 5,400 species of land mammals.

So there are at least 185 insect species for every single land mammal species (B = 185). If the current bushfires have burnt enough habitat to devastate 4 mammal species, they have probably taken out around 185 × 4 = 740 insect species in total. Along with many species of other invertebrates such as spiders, snails, and worms.

There are hundreds of insect species for every mammal species.
https://imgbin.com/

For your own value for B, use your preferred estimate for the number of insect species on earth and divide it by 5,400 (the number of land mammal species).

One recent study suggests there are at least 5.5 million species of insects, giving a value of B of around 1,000. But there is reason to suspect the real number could be much greater.




Read more:
The Earth’s biodiversity could be much greater than we thought


How do our estimates compare?

My “best case” values of A = 4 and B = 185 indicate at least 740 insect species alone are being imperilled by the bushfires. The total number of animal species impacted is obviously much bigger than insects alone.

Feel free to perform your own calculations. Derive your values for A and B as above. Your estimate for the number of insect species at grave risk of extinction is simply A × B.

Post your estimate and your values for A and B please (and how you got those numbers if you wish) in the Comments section and compare with others. We can then see what the wisdom of the crowd tells us about the likely number of affected species.




Read more:
How to unleash the wisdom of crowds


Why simplistic models can still be very useful

The above calculations are a hasty estimate of the magnitude of the current biodiversity crisis, done on the fly (figuratively and literally). Technically speaking, we are using mammals as surrogates or proxies for insects.

To improve these estimates in the near future, we can try to get more exact and realistic estimates of A and B.

Additionally, the model itself is very simplistic and can be refined. For example, if the average insect is more susceptible to fire than the average mammal, our extinction estimates need to be revised upwards.

Also, there might be an unusually high (or low) ratio of insect species compared to mammal species in fire-affected regions. Our model assumes these areas have the global average – whatever that value is!

And most obviously, we need to consider terrestrial life apart from insects – land snails, spiders, worms, and plants too – and add their numbers in our extinction tally.

Nevertheless, even though we know this model gives a huge underestimate, we can still use it to get an absolute lower limit on the magnitude of the unfolding biodiversity crisis.

This “best case” is still very sad. There is a strong argument that these unprecedented bushfires could cause one of biggest extinction events in the modern era. And these infernos will burn for a while longer yet.The Conversation

Mike Lee, Professor in Evolutionary Biology (jointly appointed with South Australian Museum), Flinders University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

You can leave water out for wildlife without attracting mosquitoes, if you take a few precautions



Leaving water out for wildlife is important during droughts and bushfires but if it’s not changed regularly it can be a breeding ground for mosquitoes.
Roger Smith/Flickr, CC BY-NC

Cameron Webb, University of Sydney

Australia is in for a long, hot summer. The recent bushfires have been devastating for communities and wildlife. Drought is also impacting many regions.

Understandably, people want to leave water out for thirsty birds and animals.

Health authorities generally warn against collecting and storing water in backyards as one measure to protect against mosquito bites and mosquito-borne diseases caused by, for example, dengue and Ross River viruses.




Read more:
How Australian wildlife spread and suppress Ross River virus


But it’s possible to leave water out for wildlife – and save water for your garden – without supplying a breeding ground for mosquitoes, if you take a few precautions.

For some mozzies, any water will do

Mosquitoes often look for wetlands and ponds to lay their eggs. But sometimes, anything that holds water – a bucket, bird bath, drain or rainwater tank – will do.

When the immature stages of mosquitoes hatch out of those eggs, they wriggle about in the water for a week or so before emerging to fly off in search of blood.

While there are many mosquitoes found in wetlands and bushland areas, Aedes notoscriptus and Culex quinquefasciatus are the mosquitoes most commonly found in our backyards and have been shown to transmit pathogens that cause mosquito-borne disease.

The Australian backyard mosquito (Aedes notoscriptus) is quick to take advantage of water-filled containers around the home.
Cameron Webb (NSW Health Pathology)

In central and north Queensland, mosquitoes such as Aedes aegypti can bring more serious health threats, such as dengue, to some towns.




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Mosquitoes can also impact our quality of life through bites as well as the nuisance of simply buzzing about our bedrooms and backyards.

So how can you stop mozzies making a home in your backyard?

Empty water containers once a week

Mosquitoes need access to standing water for about a week or so. Reduce the number of water-filled containers available or how long that water is available to mosquitoes.

Emptying a water-filled container once a week will stop the immature mosquitoes from completing their development and emerging as adults.

If you’re leaving water out for pets or wildlife, use smaller volume containers that will allow for easy emptying once a week. You can tip any remaining water into the garden, as mosquito larvae won’t survive if they’re “stranded” on soil.

For larger or heavier items, such as bird baths, flushing them out once a week with the hose will knock out most of the wrigglers and stop the mosquitoes completing their life cycle.

Make sure garden water doesn’t slosh about

Be careful with self-watering planter boxes. These often have a reservoir of water in their base and, while it may seem like a water-wise idea, these can turn into tiny mozzie hotels!

A simple trick to keep water available to plants, but not mosquitoes, is to fill your potted plant saucers with sand. The sand traps and stores some moisture but there is no water sloshing about for mosquitoes.

If you’re collecting water from showers, baths, or washing machines (commonly known as grey water), use it immediately on the garden, don’t store it outside in buckets or other containers.




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Gutters, ponds, tanks and pools

Make sure your roof gutters and drains are free of leaves and other debris that will trap water and provide opportunities for mosquitoes.

Ensure rainwater tanks (and other large water-storage containers) are appropriately screened to prevent access by mosquitoes.

Rainwater tanks can be a useful way to conserve water in our cities but they can also be a source of mosquitoes.
Cameron Webb (NSW Health Pathology)

A well maintained swimming pool won’t be a source of mosquitoes. But if it’s turning “green”, through neglect and not intent, it may become a problem. Mosquitoes don’t like the chlorine or salt treatments typically used for swimming pools but when there is a build up of leaves and other detritus, as well as algae, the mosquitoes will move in.




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For backyard ponds, introducing native fish can help keep mosquito numbers down.

But if you want your pond to be a home for frogs, avoid fish as they may eat the tadpoles. Instead, try to encourage other wildlife that may help keep mosquito numbers down by creating habitats for spiders and other predatory insects, reptiles, frogs, birds, and bats.

Avoiding excessive use of insecticides around the backyard will help encourage and protect that wildlife too.

Mozzies can still come

There isn’t much that can be done about those mosquitoes flying in from over the back fences from local bushland or wetland areas.

Mosquitoes are generally most active at dusk and dawn so keep that in mind when planning time outdoors. But when mosquito populations are peaking, they’ll be active almost all day long.

Applying an insect repellent can be a safe and effective way to stop those bites.




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Covering up with long pants, long-sleeved shirt and shoes will provide a physical barrier to mosquitoes. If you’re spending a lot of time outdoors, perhaps even consider treating your clothing with insecticide to add that extra little bit of protection.

Make sure insect screens are installed, and in good condition, on windows and doors. Mosquitoes outdoors can be bad; you don’t want them inside as well.The Conversation

Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia’s threatened birds declined by 59% over the past 30 years


Elisa Bayraktarov, The University of Queensland and Jaana Dielenberg, The University of Queensland

Australia’s threatened birds declined by nearly 60% on average over 30 years, according to new research that reveals the true impact on native wildlife of habitat loss, introduced pests, and other human-caused pressures.

Alarmingly, migratory shorebirds have declined by 72%. Many of these species inhabit our mudflats and coasts on their migration from Siberia, Alaska or China each year.




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These concerning figures are revealed in our world-first Threatened Bird Index. The index, now updated with its second year of data, combines over 400,000 surveys at more than 17,000 locations.

It’s hoped the results will shed light on where conservation efforts are having success, and where more work must be done.

Bringing conservation efforts together

The index found a 59% fall in Australia’s threatened and near threatened bird populations between 1985 and 2016.

Migratory shorebirds in South Australia and New South Wales have been worst hit, losing 82% and 88% of their populations, respectively. In contrast, shorebirds in the Northern Territory have increased by 147% since 1985, potentially due to the safe roosting habitat at Darwin Harbour where human access to the site is restricted.

Habitat loss and pest species (particularly feral cats) are the most common reasons for these dramatic population declines.

Many of Australia’s threatened species are monitored by various organisations across the country. In the past there has never been a way to combine and analyse all of this evidence in one place.




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The Threatened Species Recovery Hub created the index to bring this information together. It combines 17,328 monitoring “time series” for threatened and near threatened bird species and subspecies. This means going back to the same sites in different years and using the same monitoring method, so results over time can be compared.

Over the past year the amount of data underpinning the index has grown considerably and now includes more than 400,000 surveys, across 43 monitoring programs on 65 bird species and subspecies, increasing our confidence in these alarming trends.

Threatened species like the Gilbert’s Whistler, Chestnut quail-thrush and Swift parrot are all on the decline.
Glenn Ehmke, BirdLife Australia, Author provided

About one-third of Australia’s threatened and near threatened birds are in the index but that proportion is expected to grow. As more quality data becomes available, the index will get more powerful, meaningful and representative. For the first time Australia will be able to tell how our threatened species are going overall, and which groups are doing better or worse, which is vital to identifying which groups and regions most need help.

Finding the trends

Trends can be calculated for any grouping with at least three species. A grouping might include all threatened species in a state or territory, all woodland birds or all migratory shorebirds.

The 59% average decrease in threatened bird relative abundance over the last 30 years is very similar to the global wildlife trends reported by the 2018 Living Planet Report. Between 1970 and 2014, global average mammal, fish, bird, amphibian and reptile populations fell by 60%.

One valuable feature of the Threatened Species Index is a visualisation tool which allows anyone to explore the wealth of data, and to look at trends for states and territories.

For instance, in Victoria by 2002 threatened birds had dropped to a bit more than half of their numbers in 1985 on average (60%), but they have remained fairly constant since then.

We can also look at different bird groups. Threatened migratory shorebirds have had the largest declines, with their numbers down by more than 72% since 1985. Threatened terrestrial birds, on the other hand, have decreased in relative abundance by about 51% between 2000 and the year 2016, and show a relatively stable trend since 2006.

Eastern Great Egret, and Bar-tailed Godwit. Pictures kindly provided by Glenn Ehmke, BirdLife Australia.

Making the index better

The index is being expanded to reveal trends in species other than birds. Monitoring data on threatened mammals and threatened plants is being assembled. Trends for these groups will be released in 2020, providing new insights into how a broader range of Australia’s threatened species are faring.

This research is led by the University of Queensland in close partnership with BirdLife Australia, and more than 40 partners from research, government, and non-government organisations. Collaboration on such a scale is unprecedented, and provides extremely detailed information.




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The index team are continuing to work with monitoring organisations across Australia to expand the amount of sites, and the number of species included in the index. We applaud the dedicated researchers, managers and citizen scientists from every corner of the country who have been assembling this data for the nation.

We’d also like to hear from community groups, consultants and other groups that have been monitoring threatened or near-threatened species, collecting data at the same site with the same method in multiple years.

The Threatened Species Index represents more than just data. Over time it will give us a window into the results of our collective conservation efforts.


This article also received input from James O’Connor (BirdLife Australia) and Hugh Possingham (The Nature Conservancy).The Conversation

Elisa Bayraktarov, Postdoctoral Research Fellow in Conservation Biology, The University of Queensland and Jaana Dielenberg, Science Communication Manager, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.