Hope for monkey on brink of extinction: new population found in Vietnam

Scientists have discovered at least 500 Critically Endangered grey-shanked doucs in Vietnam — their only home — boosting species estimates to up to 1,500 animals

Grey-shanked douc (4) - CREDIT Nguyen Van Truong, FFI

Photo copyright: Nguyen Van Truong/Fauna & Flora International

Grey-shanked doucs live in the forest canopy of the Central Highlands of Vietnam. Their numbers have been severely reduced by habitat loss and fragmentation, along with hunting for food and the pet trade.

Fauna & Flora International (FFI) researchers located the 500+ animals in several subpopulations within the Kon Tum forest, which provides important connectivity to protected areas to the south and north, and across the border into Cambodia.

FFI Vietnam is now developing a conservation strategy which may include ecotourism and forest patrols for the newly discovered population. Vietnam is home to 11 Critically Endangered primate species, and a priority for primate conservation in Southeast Asia and the world.

Read the full article on Mongabay.

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Damming the Amazon: new hydropower projects put river dolphins at risk

A little while ago I wrote about the plight of Amazon river dolphins in the face of dam-building across the region. Here’s the opening few lines, but to read the whole piece please follow the link to the original on Mongabay. A National Geographic photographer kindly let us use some of his pictures, so it is worth a look!

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A dam-building boom is underway in the Amazon. More than 400 hydroelectric dams are in operation, being built, or planned for the river’s headwaters and basin. Scientists know that tropical dams disrupt water flow and nutrient deposition, with negative consequences for aquatic animals, especially migratory species. But little detailed knowledge exists as to the impacts of dams on specific species, or as to the best mitigations to prevent harm.

A recent study that tries to fill in that knowledge gap zeroes in on Brazil’s river dolphins. It found that as many as 26 dams could negatively impact dolphin populations and their prey.

The research, led by Dr Claryana Araújo of the Federal University of Goiás, Brazil, focused on two freshwater species: the Amazon River Dolphin, or boto (Inia geoffrensis), which is sometimes famously pink; and the Tucuxi (Sotalia fluviatilis).

The river dolphins of South America are charismatic emblems of rainforest biodiversity, and have captured the public imagination. Swimming in rivers, lagoons, and among submerged tree trunks in flooded forests to chase down prey, they can be found as far inland as the upper reaches of Amazonian tributaries, more than 2,600 kilometers (1,615 miles) from the Atlantic Ocean.

To continue reading, click here.

Tropical reforestation: how, when, where, and for how long…?

These are some of the questions that a new multidisciplinary project aims to address. People and Reforestation in the Tropics: a Network for Education, Research, and Synthesis (PARTNERS) aims to ‘to help scientists, governments, and peoples around the world understand and plan for sustainable and socially responsible tropical forest regrowth.’ Led by Robin Chazdon, an expert in tropical forest regeneration, PARTNERS brings together biologists, geographers, social and political scientists, economists, and NGOs, in recognition of the fact that is the interaction between people and forests that not only determines how forests are cut down or degraded, but also how they regrow.

It was a privilege to participate in the network’s inaugural workshop held at the University of Connecticut in May. The main themes we focused on were how to achieve resilient reforestation, how reforestation can both mitigate and adapt to climate change, what drives different land transitions, and what might the consequences of these be for forest recovery, and what are the synergies and trade-offs between different outcomes when reforestation is undertaken. For more information you can read about the recent workshop here, and about the network in more depth here.

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Marvellous spatuletails and Gocta waterfall

Hummingbird diversity is highest in the Andean foothills. Species ranges are limited by elevation, or by the complex topography of the region, and many species are endemic to a small area. Hummingbirds had captivated us since our journey began in Ecuador, and we had been lucky to see many dazzling species by the time we reached Peru, but there was one species, found only in the Northern highlands near Chachapoyas and one of the rarest in the world, that we were especially keen to see. The marvellous spatuletail has the most extravagant plumage of all hummingbirds, with males having long curved tail feathers, each with a disc on the end. These are extremely cumbersome for such a small bird, and make performing an acrobatic courtship display exhausting. The display therefore serves to demonstrate male quality.

Our hostel (the excellent Chachapoyas Backpackers) put us in touch with a man named Santos Montenegro, who has been instrumental in establishing the Huembo reserve and interpretation centre near Pomacochas where a number of hummingbird species can be seen. We gave him a call, and arranged to visit. Not knowing quite what to expect, and crossing our fingers that we would be lucky enough to see this beautiful bird, we were astounded when within two minutes of sitting down near his homemade feeders a male appeared. We were the only visitors, and we spent the next few hours quietly watching the comings and goings of not only both male and female spatuletails but many other species too, including the little woodstar, and the chestnut-breasted coronet. We were thrilled with our encounter with this amazing species. Peru (36)

The female spatuletail has discs too, but on shorter tail feathers. These female discs are a bit of an evolutionary mystery, because if their evolution in males is solely a result of female mate choice (females preferring males that are of a higher quality, as demonstrated by more elaborate and cumbersome plumage, with these males having a higher number of offspring, which inherit the same elaborate plumage, and so on) then they would not be expected in females too… a conundrum waiting to be solved.

Unfortunately we were too late in the day to have a chance of seeing the display itself, but keen birders can arrange to visit Santos’ private reserve on the land behind his home in Pomacochas, just up the road from Huembo, where he has found a lek (display) site. It was here that the BBC filmed the courtship display in slow-motion and high definition for the Life series, which revealed exactly what is happening during the display for the first time. The video can be seen here (unfortunately I can’t embed it, but I urge you to click the link and take a look!).

From this biological wonder, we then headed for a geological one: Gocta waterfall, one of the highest in the world at 771m (3rd, 5th or 16th highest depending on who you ask; who knew that waterfall measuring was such a controversial field). Regardless of ranking, the waterfall is spectacular, and incredibly it was largely unknown to the outside world until 2006 when it was measured for the first time. The falls have two drops, the top often disappearing amongst the clouds, and at the bottom the water disappears into tropical forest that is home to toucans, monkeys and cock of the rock birds.

We splurged with a stay at Gocta Lodge, a small hotel that was by far the most luxurious place on the trip, and an amazing treat, especially after some of the (bud beg ridden) mattresses we had slept on in the previous few weeks. The hotel is in the tiny village of Cocachimba, at the end of a long twisting unpaved road. Driving round each bend took us deeper and deeper into the stunning valley. Peru (42)Peru (39)

Each room at the hotel has a stonking view of the falls, and from the hotel it was a hot, sweaty, but beautiful 6km walk to the base of waterfall. We skirted the hillside, passing from agricultural land into the tropical forest, hearing the strange grating growling noise made by the elusive cock of the rock, and seeing the falls appear and disappear between the trees. Peru (49)Peru (53)Peru (60)

Finally we reached the bottom, the top section no longer in view. Rather than the roar of crashing water on rocks that we were expecting, it was quiet, as the water turned to vapour long before it reached the ground, and a fine mist drenched the rocks, cliffs, and us, as we gazed up in awe. Peru (65)Peru (58)

The pool made our bare feet ache with cold within seconds, so a swim was out, but we sat eating our picnic of enormous avocado, hyponotised by the spray, until all other visitors had left and we had the falls to ourselves. At last we headed back, finding the rough path tiring, the heat oppressive, and spurred on by the thought of jumping in the pool at the hotel as soon as we got back. Peru (63)Peru (71)Peru (85)

Climate change pushing tropical trees upslope ‘exactly as predicted’

This article was first published on mongabay.com. You can read the original here.

Tropical tree communities are moving up mountainsides to cooler habitats as temperatures rise, a new study in Global Change Biology has found. By examining the tree species present in ten one-hectare plots at various intervals over a decade, researchers found that the proportion of lowland species increased in the plots at higher elevations. The study, which was undertaken in Volcan Barva, Costa Rica, adds to a growing body of evidence that climate change is having an impact on species range distributions.

As climate change leads to warmer temperatures, species must respond if they are to survive. One way to do this is to migrate to new habitats that become suitable (and away from old ones that become unsuitable); another way is to adapt to hotter temperatures, but the speed of climate change may be too fast for some species to evolve to keep up. In some cases, if their physiology permits it, species may be capable of tolerating increases in temperature, but the likelihood of this is unknown.

The researchers first turned to herbarium records to calculate the preferred temperature of thousands of tree species, by looking at the geographic location of sampling locations and the temperature ranges they encompassed. With the temperature preferences for each species known, it was then possible to calculate a ‘community temperature score’ for each of the ten study plots, by averaging the preferred temperatures of all species present. A high community temperature score indicated an abundance of species found in the hot lowlands, whereas a low community temperature score reflected the presence of high altitude species from cooler habitats.

Looking up at a giant tree in the Costa Rican rainforest Photo credit: Rhett A. Butler / mongabay.com

Looking up at a giant tree in the Costa Rican rainforest Photo credit: Rhett A. Butler / mongabay.com

Plots were monitored over the course of a decade, and in nine of the ten plots the community temperature score increased. This indicates a shift in species composition, with the relative abundance of lowland species increasing over time “exactly as predicted under climate-driven upward species migrations,” Kenneth Feeley, lead author of the study with Florida International University and Fairchild Tropical Botanic Garden, told mongabay.com.

These changes corresponded to a mean thermal migration rate of 0.0065°C per year. However, over the past 60 years regional warming has been 0.0167°C per year, so the average migration rate observed across plots is not fast enough to keep up with the rate of warming. Still, encouragingly, when looked at individually, migration in 4 of the 10 plots did keep pace with regional warming.

Changes in species composition can be the result of different processes: species abundance can change without shifts in the overall range distribution, ranges can shift, and ranges can expand or contract. Identifying which of these underlies changes in species composition is important, because “depending on which of these processes is occurring, predictions for the future of ‘migrating species’ will vary from positive (under range expansions), to neutral (under range shifts) to dire (under range contractions),” Feeley explains.

To examine the specific causes of the compositional shifts in the study plots, the researchers measured stem growth, recruitment (the establishment of new trees), and mortality. They found that the main driver behind the increase in the relative abundance of lowland species upslope was in fact the disproportionate death of higher elevation species.

“Our results indicate that dieback is happening much faster than expansion. This means that species’ ranges will shrink. As ranges shrink, species will be more and more prone to extinction,” Feeley said.

Forested mountains in Costa Rica, where tropical trees communities are changing in response to climate change. Photo credit Kenneth Feeley

Forested mountains in Costa Rica, where tropical trees communities are changing in response to climate change. Photo credit Kenneth Feeley

An earlier study by Feeley and colleagues investigated related questions in the Peruvian Andes and came to similar conclusions, suggesting that their findings may be generally applicable across the tropics.

“The rates of migration that we have documented for the forests of Costa Rica are remarkably similar to what we found in the Peruvian Andes. The rates are also fairly close to the maximum rates of migration recorded for tropical trees during the warming period that followed the last glacial maximum. As such, it appears that what we are observing is trees moving at their fastest,” Feeley said. “In the past, this was fast enough; it is not fast enough now and it certainly won’t be fast enough in the future,”

While range contractions increase the likelihood of extinction for individual species, they also have a broader impact on patterns of biodiversity.

“As species experience dieback at the trailing edges of their distributions due to temperatures becoming intolerably hot, we will get decreases in local diversity through a process that has been termed ‘biotic attrition’,” Feeley said. If species are able to shift their ranges upslope, and not just suffer dieback in the lowlands, “then we may expect an increase in alpha (local) diversity in the mountains over long time periods as large numbers of species move up out of the lowlands and into the highlands. In this case, the real losses of biodiversity are expected in the lowlands where there is no known pool of ‘hot-adapted’ species waiting to fill in the lowlands after the existing species emigrate.”

Migrating to track climate change – either by moving up mountainsides or by moving towards the poles – is not easy: temperature is not the only factor that determines whether a habitat is suitable for a species, it is just the simplest to study in order to predict how species might respond to our warming world.

“Other climatic factors such as precipitation and seasonality can be hugely important for some species as can other non-climatic factors such as soil type and slope. Furthermore, biotic factors such as competition, predation, herbivory, disease, and mutualisms, may also be just as if not more important,” Feeley explains.

“The more realistic you make the models, and the more variables you consider, the number of future options available to species almost invariably decreases.” Even if species are capable of keeping pace with climate change and move upslope, they will still suffer a reduction in available habitat as land area decreases the further up the mountain they go.

“For example, in Costa Rica there is over 6.5 times as much land area between 1800 m and the highest plot at 2800 m as between 2800 m and the highest point in Costa Rica at 3820 m elevation,” the scientists write. Species already adapted to cooler high elevation temperatures will have nowhere to migrate into. And other problems also face tropical species that are a long way from a mountain to begin with.

“Within the tropics there is no latitudinal gradient in temperature. This is very important because it means that species cannot migrate towards higher latitudes to escape the heat but instead must migrate to higher elevations where it does get invariably cooler,” Feeley explains. “For lowland species in the middle of the Amazon basin where it is remarkably flat, this means that they will have to migrate huge, perhaps impossibly huge, distances before they experience any sort of relief.” Add to that the destruction of habitat, and movement becomes more challenging still.

“If species cannot migrate upslope, then their potential responses to climate change are greatly limited. Indeed, the only options left are to adapt or to acclimate. And given the speed at which the world is now changing, I think it is safe to say that adaptation is not a viable option, at least for large long-lived trees with long generation times. So the question becomes, can lowland trees acclimate to climate change?” Feeley posits. “The future of global diversity depends on the answer to this question but right now we are nowhere close to having that answer.”

Species in the lowland tropics inhabit one of the hottest regions on earth, so it is impossible to gauge their heat preferences above present-day temperatures by looking at their range distributions. However, understanding the upper limit of species’ heat tolerance would vastly improve predictions about species survival in a warming world.

Map showing the team's study plots (green squares) stretching from the lowlands up the mountain to a height of 2800 metres. Image credit Kenneth Feeley.

Map showing the team’s study plots (green squares) stretching from the lowlands up the mountain to a height of 2800 metres. Image credit Kenneth Feeley.

“By far the single most important factor is how much warming the species can tolerate. If they can tolerate a significant amount of warming, then our predictions are relatively sanguine. If species are intolerant of warming, then their future will be dependent on migrations and predictions for the tropics become very bleak,” explains Feeley.

To date, the majority of studies examining the potential impact of climate change have focused on North America and Europe.

“In general, there is a dearth of studies looking at the impacts of climate change on the distributions of tropical species. This is despite the fact that the vast majority of species are tropical,” Feeley told mongabay.com. “We desperately need to fill the void and have more studies from the tropics. To do these studies we need a better and more systematic system of ecosystem monitoring plots and more importantly, but also harder, a better understanding of the complex abiotic (non-biological) and biotic (biological) factors that regulate species distributions and dynamics.”

Feeley and colleagues continue to monitor their study plots in Costa Rica and Peru, and are expanding their research to better understand the processes that determine species range distributions and movements.

“We are in the initial phase of a large-scale transplant study in which we are moving thousands of seedlings of dozens of tree species up and down the slopes of the Andes under various experimental treatments in order to identify the specific biotic and abiotic factors that limit their distributions,” he says. “Once we have this information we can build it into improved predictions for the fate of these species on a warmer planet.”

The best hope for conserving forests in the face of climate change, and climate-driven migrations, is to anticipate species movements, says Feeley.

“We need to expand the time scale of our thinking and determine not just where species are today but where they will be a hundred years from now. And then we need to protect both of those places and everything in between.”

Paper: Feeley K.J., Hurtado J., Saatchi S., Silman M.R., and Clark D.B. 2013. Compositional shifts in Costa Rican forests due to climate-driven species migrations. Global Change Biology, Available Online. DOI: 10.1111/gcb.12300

Montreal Botanical Garden: visiting an urban jungle

I have recently moved to the wonderful city of Montreal, and today we ventured to the Botanical Garden in the middle of the city. This is one of the most important plant collections in the world, with over 22,000 plant species, numerous themed gardens, and ten exhibition greenhouses. I gravitated towards the tropical greenhouses, and they were full of incredible palms, bromeliads, orchids, enormous leaves, bright colours, abstract patterns. Here are a few pictures. P1040735

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