The plight of tropical migratory species

So much remains unknown about the tropics, including the extent to which species living in these environments migrate seasonally.  Dr Lisa Davenport has worked for many years in the tropics, especially the Peruvian Amazon.  Here she tells us about her intriguing work on a particular migrator, and its broader implications for nature conservation:

A foraging Black Skimmer

A foraging Black Skimmer

An unknown number of tropical species, such as certain birds, bats, and moths, migrate up and down elevational gradients over the year, tracking seasonal changes in the abundance of fruits, nectar, or insect prey. 

Others, notably birds such as warblers and some raptors, undertake much longer-distance migrations, wintering in the tropics while breeding in far-away temperate regions.

Manu National Park in Peru, where I have long worked, also has its share of migrators, along with being one of the most biologically stunning places on Earth.  Certain fish, birds, and mammals at Manu appear to move large distances during the course of the year. 

But as we begin to learn more about these migratory species, we increasingly suspect they could be vulnerable to escalating human pressures in this region.

Growing pressures

For instance, just downstream of Manu, on the Madre de Dios River, huge areas of river and riparian forest are being devastated by illegal gold mining.  Among these impacts is contamination of the rivers by toxic mercury, which is used by miners to separate gold from river sediments.

An illegal gold miner scours the forest soil  (photo by William Laurance)

An illegal gold miner scours the forest soil (photo by William Laurance)

Since 2010, biologists at Cocha Cashu Biological Station at Manu have used cutting-edge satellite telemetry to track some of the park’s rare and endangered birds -- many of which are very poorly known.  One key reason to do this is to learn where these species go when they move outside the park, where they may be highly vulnerable.

In a new study, I and my colleagues report our research on Black Skimmers (Rynchops niger), an elegant bird that skims over water surfaces while flying, in order to catch unwary fish.  To do this it uses its uniquely elongated lower beak, which it drags through the water and which instantly snaps shut when it contacts a fish. 

We found that Skimmers tagged in Manu move extremely long distances both during and outside their breeding season. 

A Black Skimmer feeds its chick

A Black Skimmer feeds its chick

'Albatrosses of the Amazon'

I would liken our Black Skimmers to “Albatrosses of the Amazon" -- they fly surprisingly long distances, even in the breeding season, and seem to soar effortlessly. 

We found that some Black Skimmers move not only to other watersheds in Peru but even to other nations, including Brazil and Bolivia, during their breeding season.  Unfortunately, some of these areas are being severely degraded by illegal gold mining. 

Remarkably, some of the birds tagged inside Manu even crossed the Peruvian Andes -- flying above 5,000 meters in altitude to cross the towering Andes mountains -- in order to spend their non-breeding season along the Pacific coasts of Peru and Chile. 

But the Skimmers face hazards on the Pacific coast as well.  Many of the natural wetlands they need for feeding are being severely depleted by the extraction of freshwater for agriculture

Some Skimmers may go even farther afield.  One bird radio-tagged in Manu moved not to the Pacific but southeast to Bolivia and then even further to Paraguay.  Its transmitter stopped at that point but it may have been heading to Argentina’s Atlantic coast, where large numbers of Skimmers are known to summer.

New threats on the horizon

With rising development pressures, threats to large-distance migrators like Black Skimmers will only increase.  Both Peru and Brazil plan to dramatically increasing the damming of wild rivers in the Amazon and Andean headwaters.   Agriculture and mining activities are also expanding apace.

Scores of new dams are being planned (yellow) in the Amazon-Andes region (blue symbols indicate existing dams).

Scores of new dams are being planned (yellow) in the Amazon-Andes region (blue symbols indicate existing dams).

Species that need freshwater for survival and migration, and the ecological processes that sustain such species, will be intensely vulnerable

The recent collapse of a poorly constructed mining dam on the Doce River in Brazil devastated aquatic wildlife across a vast area that stretched for more than 500 kilometers to the sea. 

The lax environmental standards that allowed this catastrophe to occur should give us all pause, as we consider the avalanche of new development projects slated for the greater Amazon region.

Especially alarming is how little we know about the ecology of the Amazon and its many natural denizens -- some of which evidently traverse and require vast areas of habitat for survival.

 

For wildlife, huge difference between different kinds of agriculture

We live in an increasingly human-dominated world, where once-intact native habitats are being rapidly fragmented into smaller 'islands' surrounded by a hostile 'sea' of human land-uses.  But for wildlife, not all human land-uses are equal.

Bobcats like having trees overhead

Bobcats like having trees overhead

A recent study in southern California shows that the bobcat, an important but shy wildlife species, is affected very differently by different types of farming.

Like most species, bobcats must move to survive.  Animals trapped in small habitat fragments live in populations too small to be viable.  Bobcats are therefore far more likely to survive if human-dominated lands surrounding habitat fragments are 'permeable' to their movements.

One way to make fragmented landscapes more permeable is to create movement corridors linking the fragments together -- what some have called "bandages for wounded landscapes". 

Another way is to use less-hostile types of agriculture that pose less of a barrier to sensitive species.  For bobcats, it turns out that orchards pose considerably less of a barrier to movements than do intensively cultivated row-crops such as maize, soy, and sugar beets.

Bobcats used row crops only rarely, and even then tried to dash through them quickly, evidently feeling highly vulnerable.  However, their movements in orchards were much more relaxed and similar to those in native habitats.

Studies in the tropics have similarly shown that agriculture that retains tree cover is often much more benign for nature. 

In the New World tropics, for instance, birds, bats, and many other species tend to be much more abundant in shade-cacao plantations (used for producing cocoa), where larger trees are retained or grown to shade the cacao trees, than in more intensively used lands. 

Bare-eyed antbird, an understory specialist in New World rainforests

Bare-eyed antbird, an understory specialist in New World rainforests

Wildlife diversity is especially high when native tree species are retained in the shade-cacao plantations, rather than using exotic fruit or timber species.  Another big bonus for wildlife is having native forest nearby the shade-cacao plantation.

However, shade-cacao is not a panacea for tropical species.  The most sensitive wildlife, such as understory birds, rarely use cacao and are mostly restricted to native rainforest.

The bottom line: native habitats are always the best, but when agriculture is unavoidable, not all types of farming are created equal.  Understanding how different farming methods affect wildlife -- and which wildlife species are most vulnerable -- will give us a leg up for managing and conserving nature.


GM crops: Good or bad for nature?

One of the more heated controversies in conservation science concerns genetically modified crops.  Are GM crops a boon for conservation or a serious danger?

On the one hard are those who believe GM crops are vital to increase agricultural production (and in some cases to reduce pesticide use), thereby allowing us produce more food on less land and spare more land for nature conservation.  The followers of this view often see the anti-GM crowd as hopelessly misguided or naive.

On the other hand are those who see potential dangers in GM crops -- ones that might outweigh their benefits in some if not many cases.  The term "Frankenfoods" has sometimes been applied to GM crops, reflecting the fear that these genetically modified foods might have a darker side.

ALERT member Jean-Philippe Puyravaud from India counts himself among those who worry about GM crops.  Here he tells us about his fears about one crop in particular.

A genetically modified crop is produced by introducing genes from another species, and the Bt. brinjal (a type of modified eggplant) was developing by introducing genes from a bacterium (Bacillus thuringensis) that is resistant to borers and caterpillars. 

However, GM organisms pose potential risks such as creating more vigorous pests, and could harm non-target species and disrupt biotic communities.

A recent study concludes that hybridization is possible between wild and cultivated brinjal in southern India, and another study showed there is a clear potential for transgenes to spread to wild brinjal populations.

Hence, the risk of transgene escape to wild or domesticated plants cannot be ignored.  Before introducing a GM crop, it is vital to check whether its genes can be transferred to wild relatives via pollinators.

Yes, we need to feed a hungry world.  But GM crops are not a panacea.  We have to study each one, on a case-by-case basis, before deciding whether or not its benefits will outweigh its risks. 

 

Will new supercrops feed the world and help save nature?

We live in a hungry world -- and one that will soon grow much hungrier.  Global food demand is expected to double by mid-century because of rapid population growth and changing food habits.  Producing that much food could require a billion hectares of additional farmland -- an area the size of Canada.

But if we develop new high-yielding 'supercrops' and farm them intensively, could we feed the world with less land and thereby spare some land for nature?  Many have argued in favor of this idea.

A tsunami of oil palm  (photo by William Laurance)

A tsunami of oil palm (photo by William Laurance)

But a new study published in the leading journal Science suggests the opposite: supercrops will actually encourage more habitat destruction for agriculture, especially in the species-rich tropics.

The authors argue that new varieties of palm oil, which are highly productive and profitable but grow only in the tropics, are simply going to keep spreading apace.  That's because there's so many different uses for palm oil, including for many food items, cosmetics, and biofuels, that demand for it will remain high.  

And, as palm-oil production rises, its price will likely fall, meaning that it will increasingly out-compete other oil-producing crops, such as canola (rapeseed), sesame seeds, and peanuts.

This, the authors say, will simply shift the footprint of agriculture from areas such as North America and Europe to mega-diversity regions such as the tropical rainforests of Southeast Asia, Latin America, and Africa.

What's the answer to the tsunami of oil palm and other profitable tropical crops?  There really is only one alternative: we need proactive land-use zoning to determine where agriculture should and should not go -- to ensure it doesn't just overrun nature.  And we need better law enforcement to reduce illegal deforestation.

And we direly need to limit the explosive expansion of roads into wilderness and high-biodiversity areas.  By 2050, it's expected that we'll have an additional 25 million kilometers of new paved roads -- with nine-tenths of these in developing nations that sustain many of the world's biologically richest ecosystems.

There really is no other option.  Supercrops may help feed a hungry world, but if they're not constrained they will destroy much of nature in the process.

 

Climate change could threaten our beer

OK, now it's getting serious.

Enough is enough!

Enough is enough!

We all know that climate change is threatening our environment.  And our economies.  And our livelihoods. 

But now it appears that climate change could imperil the very foundations of our society.

Our beer.

That's right -- in a recent meeting with Australian Green Party Leader, Senator Christine Milne, researcher Peter Gous emphasized the likely impacts of global warming on beer production.

"It only takes one hot day" to destroy a crop of grain, said Gous.

This is a frightening prospect given that state-of-the-art climate models project up to a 1.5-degree Centigrade (2.7 degrees Fahrenheit) increase in average temperature by 2030. 

Add that on top of your average heat-wave, and you could get a serious crop-killer.

This is just one example of the complex -- and often highly disturbing -- ways that climate change could affect our future.

A forthcoming book, Climate Peril, by author John J. Berger, attempts to tease out many of these potentially alarming effects -- on nature, the economy, human health, society, and national security.

According to Berger, we're missing the boat by failing to consider critical interrelationships among effects such as drought, fire, disease, water shortages, habitat destruction, endangered species, resource collapse, energy production, and the economy.

Although a top-flight scientist and energy expert, Berger's book is remarkably easy to read. 

He argues at the outset that there's almost no way we're going to limit global warming to a 2-degree Centigrade (3.6-degree Fahrenheit) increase in average temperature, as many have hoped.

He then shows, again and again, how climate change is likely to provoke cascades of destabilizing changes.

To select just one from a wealth of examples: a strong drought can destroy crops and livestock, which in turn impacts on food processors, farm-equipment suppliers, and labor markets. 

This in turn can grind down local and regional economies, depressing real-estate values.

And this can then force economically stressed people to migrate elsewhere, weakening the social fabric of a community, harming mental and physical health, and promoting domestic violence.

Berger's book is one of the very best I've seen on climate change -- on understanding how it could impact on virtually every facet of our life, society, economy, and environment.

There's a lot more at stake here than just our beer.

 

Dramatic erosion of world's last intact forests

Since 2000, more than 100 million hectares of the world's surviving intact forests have been seriously degraded -- by logging, road building, fragmentation, and other disturbances. 

That's an area three times the size of Germany.

Forests under assault...  (photo by William Laurance)

Forests under assault... (photo by William Laurance)

These are the conclusions of a new analysis and report by the Greenpeace GIS Laboratory, University of Maryland, and Transparent World, with help from the World Resources Institute and WWF-Russia.

The report focuses on "Intact Forest Landscapes" -- large expanses of remaining forest land that survive in pristine or near-pristine condition.  Key findings include:

• Since 2000, over 8% of the world's intact forests have been degraded

• Almost 95% of remaining intact forests are in tropical and boreal regions

• The largest areas of degradation were in the northern boreal forests of Canada, Russia, and Alaska, and in tropical regions such as the Amazon and Congo

• Canada, Russia, and Brazil contain nearly two-thirds of the world’s remaining Intact Forest Landscapes, and accounted for over half of all forest degradation

Road building, often linked to logging and extractive industries, was a key driver of forest degradation, with fires and forest clearing for agriculture having big impacts in some regions

The new maps on which these analyses are based can be analyzed using tools on the cutting-edge Global Forest Watch platform.  This is a dynamic, online forest monitoring and alert system that can detect changes in near real time.

You can read more about the main findings in this press release

Kudos to the groups that produced this report for a vital and timely analysis.

 

Crisis underground: We're overharvesting water

Question: Since the year 1900, how many liters of water have been sucked from the world's underground aquifers

No water, no food... (photo by William Laurance)

No water, no food... (photo by William Laurance)

Answer: 4500 trillion.  That's 4500 cubic kilometers.  And we're currently draining away another 1000 cubic kilometers every year.

Why is this important?  Because in many parts of the world, agriculture and other human uses rely crucially on underground water supplies.

And in much of the world, we're exhausting those supplies.  This is becoming a crisis in many arid and semi-arid regions, where centuries of accumulated water are being quickly used up.

China, India, and the U.S. are the biggest over-consumers.  The worst-affected areas include the western U.S., Mexico, the northwestern Sahara, the Indus Basin, and the North China Plain.

What are the implications?  Among other things, higher food prices

As the human populace continues to climb, that will have an impact on us all. 

Water is a big concern today.  It'll be an even bigger worry tomorrow.

Is intensifying agriculture good or bad for nature?

It's a conundrum... should we intensify farming to get more food per acre, and thereby hope to spare wild lands for nature?  Or should we focus on extensive 'wildlife-friendly' farming that's less productive per acre but not so hard on biodiversity?

Do we want to turbocharge farming or make it wildlife-friendly?

Do we want to turbocharge farming or make it wildlife-friendly?

However, we might feel about this debate, many agronomists believe that intensifying agriculture is the only realistic way we're going to feed up to 11 billion people this century. 

In a new essay in Yale Environment 360, ALERT director Bill Laurance summarizes some of the pithy realities and tough choices ahead, especially for the tropics. 

The tropics are likely to be the epicenter of future agricultural expansion, because that's where crops grow the fastest, where land is the cheapest, and where human populations and food demand are increasing the fastest.

Of course, the tropics are also the epicenter of biodiversity--of life on Earth. 

Save a little land for me...

Save a little land for me...

The 21st century is going to bring truly remarkable changes.  The pressing question is: can we feed billions more people while also protecting the natural world?

 

Will we run out of food?

It's the year 2050.  Earth's population has just passed 9.5 billion and it's still climbing.  Africa's population has quadrupled, and global food demand is now twice what it was in 2014. 

Will there be enough food for everyone?

Food for today, but what about tomorrow? (photo by William Laurance)

Food for today, but what about tomorrow? (photo by William Laurance)

As daunting as it sounds, that is the reality we'll soon be facing, according to demographers and food-security experts.  And it gets worse.

To feed our burgeoning populace, we'll need to turbocharge agriculture--transforming vast areas of relatively unproductive smallholder farms to bigger, more efficient, industrial-style farms.

But modern farms demand a great deal of energy, and energy prices will surely rise in future.  As energy prices go up, food prices will go up.

Worldwide, billions of people already devote much of their income to food.  What will happen if food prices rise sharply--perhaps doubling?

That's the focus of an essay by ALERT director Bill Laurance, which just appeared in Ensia Magazine

Entitled "Food + Energy = Crisis?", it asks tough questions about the future--and has two urgent implications for how we manage our world today.

Agriculture will massively impact the tropics

In a review article that has just appeared in the leading journal Trends in Ecology & Evolution, I teamed up with Jeff Sayer and Ken Cassman to assess the impacts of agriculture this century on tropical ecosystems and biodiversity.  It's quite a sweeping review with many important conclusions.

Oil palm: highly profitable and often deadly for tropical forests (photo by Niels Anten).

Oil palm: highly profitable and often deadly for tropical forests (photo by Niels Anten).

Among the biggest concerns are:

- Prospects for dramatic expansion of agriculture in Sub-Saharan Africa and South America

- Great uncertainty in the amount of land that will be converted to agriculture, in order to meet growing global food demands

-The prospects that biofuel production could also impact greatly on native ecosystems and also compete with agriculture

- The likelihood of massive environmental impacts on freshwater ecosystems and water supplies

- Profound challenges ahead in producing enough food to feed the world

Those who wish to have a PDF of the paper can email me directly (bill.laurance@jcu.edu.au).

-Bill Laurance

Where should roads go and not go?

Mongabay.com is highlighting our current efforts to devise a 'global road-map' that identifies where on Earth new roads should and should not go.

Roads in intact forests or other frontier areas often open a Pandora's Box of environmental problems, such as increasing deforestation, logging, fires, hunting and illegal mining.

Roads can bring big environmental problems--a logging truck in Borneo (photo by Rhett Butler).

Roads can bring big environmental problems--a logging truck in Borneo (photo by Rhett Butler).

In our analysis, areas that should remain road free have high values for wilderness, biodiversity, carbon storage, and climate regulation.  Protected areas are also priority road-free zones.

Areas that would benefit from new or improved roads include regions that have already been settled but have low agricultural productivity.  In such areas, road improvements can increase access to markets, fertilizers, and farming technologies, raising agricultural production.  As farm production rises, these areas can act as 'magnets' for settlers, drawing them away from vulnerable frontier areas and thereby reducing pressures on native ecosystems.

The global road-map is seen as an urgent priority, as highlighted in a recent Nature paper by myself and Andrew Balmford.  The International Energy Agency estimates that 25 million kilometers of new roads will be added to the Earth by 2050.  Around 90% of these will be in developing nations, which harbor much of Earth's imperiled biodiversity.

-Bill Laurance