Keeping Amazon fish connected is key to their conservation

Imagine a fish isolated in an Amazonian lake — part of the vast freshwater ecosystem of the Amazon basin, an ever-changing network of rivers, lakes and floodplains that extends to 1 million square kilometers (386,102 square miles).

Now imagine that isolated fish as water levels rise during the wet season, and floodplains vanish beneath up to 15 meters (49 feet) of water. The fish — once restricted by the lake’s edge — swims freely into the flooded forest and mingles with others of its kind from elsewhere.

For thousands of years, isolated fish populations across the Amazon have likewise played a game of musical chairs: intermixing between flooding water bodies, migrating short and vast distances between lakes and along river channels, and then as the waters receded, forming new lake and river populations.

This connectivity — with the genetic mixing it affords — is vital for healthy fish populations, but is extremely vulnerable to changes in the annual “flood pulse” that inundates forests.

Read the rest of the article on Mongabay.

A South American Leaf Fish (Monocirrhus polyacanthus). More than 2,000 fish species live in the Amazon, the highest fish biodiversity in the world. That diversity has been greatly enriched due to the periodic isolation and intermixing of freshwater species that occurs across the region. Photo © Rhett A. Butler/MongabayA South American Leaf Fish (Monocirrhus polyacanthus). More than 2,000 fish species live in the Amazon, the highest fish biodiversity in the world. That diversity has been greatly enriched due to the periodic isolation and intermixing of freshwater species that occurs across the region. Photo © Rhett A. Butler/Mongabay

Imperiled Amazon freshwater ecosystems urgently need basin-wide study, management

My latest piece for Mongabay looks at some of the threats facing the Amazon’s freshwater ecosystems, and at how a fragmented protected area network and policy framework – based on terrestrial ecosystems – is failing to protect the connectivity of the freshwater world. As multiple impacts interact with each other the functioning of the whole ecosystem is under threat. You can read the full article here.cropped-p1030605.jpg

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!


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.

Ocean acidifying 10 times faster than anytime in the last 55 million years, putting polar ecosystems at risk

This article was written for; the original can be found here.
An assessment of ocean acidification, presented at the UN Climate Change Conference in Warsaw in November 2013, starkly concluded that acidity is on track to rise 170 percent by the end of this century. As many key species are sensitive to changes in acidity, this would drastically impact ocean ecosystems, with effects especially pronounced in polar regions where the cold waters intensify acidification, and which are home to many organisms that are particularly vulnerable to acidification.The ocean acts as a giant sink for carbon, absorbing 24 million tons of CO2 from the atmosphere every day. Since industrialization, approximately 30 percent of anthropogenic (human generated) CO2 has been absorbed in this way. In the context of climate change this is incredibly important, as the amount of atmospheric CO2 is directly linked to global temperatures. But as CO2 is absorbed, the pH of the water decreases, and it becomes more acidic. Compared with pre-industrial levels, the ocean’s acidity has soared 26 percent, and will only increase as CO2 emissions rise. Not only will this likely injure marine ecosystems, but the more acidic the water becomes the less it is capable of absorbing carbon, thereby exacerbating CO2 emissions.

Dr Ceri Lewis from the University of Exeter with sample bottles. Credit: Al Humphries- Catlin Arctic Survey

In addition to ecosystem damage, ocean acidification could bring about significant economic losses.

“People who rely on the ocean’s ecosystem services – often in developing countries – are especially vulnerable,” stated a press release by the International Council for Science.

The report’s authors represented the largest-ever gathering of ocean acidification scientists, with 540 experts representing 37 countries contributing to the discussion of acidification research. They found that the current rate of acidification is unprecedented, and is ten times faster than at any other time in the last 55 million years.

With the changing chemistry of the oceans comes a myriad of cascading effects. Coral reefs may start to erode faster than they are being built. Species that rely on calcification to build their shells and skeletons – using forms of calcium carbonate – may find acidic waters too corrosive to survive. This means the shellfish industry will likely suffer as mollusks (including mussels and oysters) are among the organisms most sensitive to acidification. And with other factors also changing at the same time, such as temperature, overfishing, and pollution levels, the cumulative effects are likely to be even more pronounced.

“Multiple stressors compound the effects of ocean acidification,” the authors wrote.

As CO2 is more soluble in colder water, the polar oceans are especially vulnerable. Not only are these regions suffering the greatest impacts of acidification today, they also act as an indicator of how acidification may impact warmer oceans in the future.

Dr Helen Findlay from Plymouth Marine Laboratory with the water sampler. Credit: Martin Hartley-Catlin Arctic Survey
Dr Helen Findlay from Plymouth Marine Laboratory with the water sampler. Credit: Martin Hartley-Catlin Arctic Survey

A key question in acidification research is the effect of acidity not only on individual species, but on the entire marine ecosystem. One way to assess this is by investigating how organisms at the bottom of the food chain are dealing with decreasing pH, since their health and abundance is vital for the health of the ecosystem as a whole.

An intrepid research expedition to the high Canadian Arctic in 2011 aimed to address this question by studying copepods, small crustaceans that form the dominant zooplankton in the Arctic Ocean. The investigations were led by scientists from the University of Exeter and the Plymouth Marine Laboratory in the UK, and their results were recently published in the Proceedings of the National Academy of Sciences (PNAS). They indicate that the range of pH levels copepods experience in their daily lives may predict the extent to which they will be able to cope with rises in acidity: those with the most specialized requirements may struggle to survive, while more generalist species may well be able to cope in the future.

“Our study found that some marine animals may not be able to survive the impact of ocean acidification, particularly the early-life stages,” said Ceri Lewis from the University of Exeter. “This unique insight into how marine life will respond to future changes in the oceans has implications that reach far beyond the Arctic regions.”

By teaming up with the Catlin Arctic Survey – a collaboration between explorers and scientists – a crucial gap in scientific knowledge could be addressed: what happens to these organisms under the ice during the Arctic winter? Conducting research during this time is extremely challenging, but understanding what happens then may be particularly important.

“If we don’t understand what goes on over the whole seasonal cycle (and there are very few winter studies) then we have no way of knowing how and what is changing, and why. In winter, there will still be sea ice even if it does eventually all melt in summer. It will always be dark and there will also be food limitations,” Helen Findlay, of the Plymouth Marine Laboratory, told

Drawings of different copepods. Photo in the US public domain.

“This is therefore an incredibly harsh time of year for any organism living in the Arctic, and as organisms are potentially most vulnerable at this time of year, we need to understand how they survive this time,” Findlay continued. “We were fortunate to get the opportunity to take part in the Catlin Arctic Survey, who wanted to team scientists up with explorers to undertake this difficult fieldwork. Without their support we wouldn’t have had the ice base facility and ability to go to the location in the high Arctic at that time of year.”

The team spent two months camping in sub-zero temperatures to undertake their research, which involved drilling through 1.6 meters (5.3 feet) of ice to collect samples of copepods to determine how their presence and abundance changes at various ocean depths. Although the conditions were almost unimaginably harsh, the experience was not without its rewards.

“Actually, it was amazing. It was quite strenuous both physically and mentally; keeping on top of everything for two months at constant temperatures below minus 25 ºC (-15 ºF) was quite a challenge. Especially as we were sleeping in unheated tents – just a sleeping bag and thermo-rest between us and the ice,” said Findlay. “On a trip like this the hours are long and you don’t really get a day off, but the rewards are that you are living and working in a beautiful environment with amazing wind and light conditions, gathering data that no-one else has collected before you.”

The researchers took samples from a range of depths down to 200 meters (650 feet) below the surface, and monitored the response of both adult and nauplii (early life stage) copepods to pH and CO2 levels that are predicted to occur in the next 100 years.

The sampling revealed distinct layers in the water chemistry, with highest CO2 and lowest pH at around 100 meters (325 feet) below the surface. Adult copepods from the endemic genus Calanus were found to migrate over the whole 200-meter range of sampling, and were thus exposed to a broad range of CO2 and pH conditions. Fortunately, these species did not suffer higher mortality in experiments that imitated future high acidity environments. But adults of the smaller, globally distributed copepod Oithona similis were found to be restricted to the upper 50 meters (150 feet) of the ocean, meaning that they live in a relatively constant environment in comparison with Calanus species. Survival was significantly reduced for Oithona similis in the experiments; its global distribution means that the implications of this could be far reaching.

A photo of a Copepod - Photo by Uwe Kils, provided under a Creative Commons Attribution-Share Alike 3.0 Unported license.
A photo of a Copepod – Photo by Uwe Kils, provided under a Creative Commons Attribution-Share Alike 3.0 Unported license.

Importantly, scientists only found the larval stages of all species in the upper layer of the water column. These responded in a similar way to adult Oithona similis, with reduced survival at high CO2 experimental treatments.

“It seems that copepods that are smaller, or earlier in their life stages, tend not to experience as wide ranging variability as large adults, and this makes them vulnerable to [environmental] shifts,” said Findlay. “The small stuff (copepods and their nauplii) are still very important parts of the food chain, with larger zooplankton and other organisms eating them, so indirectly a decline in these types of organisms could impact the food chain. More directly, if the nauplii (the early life stages) are not able to survive, then there won’t be any adults!”

The effect of increasing acidity and CO2 concentrations on individual copepods is not completely understood, but scientists believe a lack of food in the winter may cause higher mortality, as well as direct effects from pH and CO2 changes on their biological processes.

“These types of small simple organisms do not have very complicated internal structures like a blood system to regulate internal CO2 and pH conditions, both of which are important for things like enzyme activity, ion balance, and many other physiological processes,” said Findlay. “So we think that if we change the external pH or CO2 this influences the internal pH and CO2 conditions, causing a disruption to these normal physiological processes.”

“It’s a problem for some copepods because they don’t have complicated systems for dealing with this, that’s the same for many other organisms, not just copepods,” Findlay continued. “Some organisms are able to adjust proteins or ion exchange to counter-balance the shift, but this generally requires more energy.”

The researchers in the Arctic. Credit: Martin Hartley-Catlin Arctic SurveyThe researchers in the Arctic. Credit: Martin Hartley-Catlin Arctic Survey

Findlay’s findings mirror studies that have looked at temperature response in an array of organisms, and found the normal temperate range of a species can be used to predict its reaction to potential changes.

“The fact [that] this also applies to the pH or CO2 conditions makes sense because a lot of internal processes are dependent on the external pH and CO2 conditions and so if an organism experiences a wide range of these conditions we would expect it to be able to cope with that shift,” Findlay notes.

Although troubling for smaller and more specialized species, the potential for resilience among those that are more generalized is good news. However, the nature of future Arctic ecosystems remains uncertain.

“Certainly there will be species that can survive these changes,” said Findlay. “This is just one more piece of the jigsaw, and there are still many parts that need to be filled in. The ecosystems are likely to shift with both warming and acidification, indeed for Arctic species there are many stressors that will play a part in determining what the ecosystem will look like in the future.”


  • IGBP, IOC, SCOR (2013). Ocean Acidification Summary for Policymakers – Third Symposium on the Ocean in a High-CO2 World. International Geosphere-Biosphere Programme, Stockholm, Sweden
  • Lewis, C. N., Brown, K. A., Edwards, L. A., Cooper, G., and Findlay, H. S. (2013) Sensitivity to ocean acidification parallels natural pCO2 gradients experienced by Arctic copepods under winter sea ice. PNAS. DOI:

Spider monkey fieldwork at Tiputini, Yasuni, Ecuador

More monkeying in the jungle, this time a primatologist with nearly a decade of research experience at Tiputini Biodiversity Station who has been researching the ecology and behaviour of the largest monkey in the region, the spider monkey. You may get a strong urge to swat a mosquito from his face during the video (and you can read about visiting Tiputini, in the most biodiverse place on earth, here, here, here, and here…it is an amazing place, there was a lot to write about!).

The Road to Cocha Cashu

Cocha Cashu is one of the most renowned rainforest research stations in the world. It is in Manu National Park, Peru, one of the most biodiverse places on earth, where the Andes give way to the Amazon lowlands. A lot of hugely influential work has been carried out at Cocha Cashu, and it is on my wish list of destinations to visit. This lovely video by primatologist and conservationist Mark Bowler gives an insight into the journey into the jungle from the mountain city of Cusco. Getting to the rainforest can be half the fun, and if this doesn’t make you want to run away to the jungle then nothing will.

Jaguars in Argentine Chaco on verge of local extinction

This article was written for the environmental news website, and the original can be found here.
The majestic jaguar (Panthera onca), the largest of the New World cats, is found as far north as the southern states of the US, and as far south as northern Argentina. In the past jaguars ranged 1,500 kilometers (930 miles) further south, but their range has shrunk as habitat loss and human disturbance have increased. Overall, jaguars are classified as Near Threatened by the IUCN, but the level of risk facing jaguars varies by region. Populations in Argentina, at the present-day southern range limit, have previously been identified as some of the most threatened of them all.

The Chaco is considered home to the largest Argentine population, but the inaccessibility of the region has meant that until recently very little was known about the exact status of the population here. To address this lack of knowledge, biologists have undertaken a major study of jaguar range and abundance, recently published in Fauna and Flora International’s journal, Oryx. The results of the study point to a striking conclusion: the jaguar population in the Argentine Chaco is in crisis, and at risk of imminent local extinction.

Biologist Veronica Quiroga with a jaguar pelt hunted in the Argentinean Chaco.
Biologist Veronica Quiroga with a jaguar pelt hunted in the Argentinean Chaco. Photo courtesy of Verónica Quiroga.

A vast wilderness of dry forest, scrubland and plains, the Gran Chaco is the second largest forest region in the Americas. It encompasses parts of Argentina, Bolivia and Paraguay, and is a hot, inhospitable and sparsely populated region. It was partly this isolation that drew biologist Verónica Quiroga, of the National Research Council of Argentina, lead author of the study, to the Argentine Chaco, where she has been working for over a decade.

“From the first time I went to the Chaco and watched the first mammal footprints marked in the dry powder, I knew that I wanted to work some time in that environment and with large mammals,” she told Her studies of mammals in the Copo National Park sparked an interest in jaguars in particular. “The first alarming conclusions were that very little was known of the species in the Chaco region, that nobody was studying jaguars particularly there and that, apparently, populations were having an important numerical decrease throughout the region.”

Biologist Verónica Quiroga colecting scats of pumas in the Aborigen Reserve. Photo courtesy of Verónica Quiroga.

Quiroga and her team have since carried out an intensive long-term survey of jaguars in the Argentine Chaco. They focused on locations thought to have the highest likelihood of jaguars, including Copo National Park and Aborigen Reserve, as well as sites that differ in their levels of legal protection, livestock burden and hunting pressure. A large network of camera traps collected more than 5,320 nights of footage, and over 120 local people were interviewed about their knowledge and experiences with jaguars. The team walked more than 900 kilometers (560 miles), searching for signs of jaguar presence. But despite this exhaustive effort, the results were bleak. No photographs of jaguars were captured by the camera traps, and very few tracks were found. In total, 35 records of jaguars were obtained, and only 13 of these were direct observations.

Jaguars inhabit three regions in Argentina, and the Chaco population is important to maintain population connectivity not only within Argentina, but also between populations in Bolivia and Paraguay.

“Until this study began, it was believed that the Chaco population of jaguars was the largest in Argentina, by the large surface area occupied and its connection with other populations, like the Paraguayan Chaco,” said Quiroga. “It was a big surprise to discover that not only the densities were very low, but this population is the most threatened of the three remaining in the country.”

A puma (Puma-concolor) marking its territory on the banks of the Bermejo River in La Fidelidad.
A puma (Puma-concolor) marking its territory on the banks of the Bermejo River in La Fidelidad. Photo courtesy of Verónica Quiroga.

The conversion of jaguar habitat to cattle ranching and the persecution of jaguars themselves are the main drivers of this population decline. The number of hunted jaguars reported in interviews can be used as an indicator of jaguar abundance, and the study found that this has dropped ten-fold over the last decade. Rather than indicating a change in hunting practice, or in the perception of jaguars as a threat to livestock and people, this reflects the rate at which local people now come into contact with jaguars. Although the overall range size has not decreased, the dramatic drop in abundance will spur conservation action.

“At this time it is necessary, with utmost urgency, to develop a campaign to improve awareness of the problems facing the species, its conservation value, and its importance in the ecosystem as top predator,” Quiroga explained.

“We also need a campaign to suggest changes in livestock management to prevent possible conflicts with the species. It is necessary to work with rural schools, with park rangers, with local communities and with other key actors of the rural Chaco region, to try to change the local perception about the species.”

An Aguará guazú (Chrysocyon-brachiurus) in dry chaco forest from La Fidelidad Argentina.
An Aguará guazú (Chrysocyon-brachiurus) in dry chaco forest from La Fidelidad Argentina. Photo courtesy of Verónica Quiroga.

The jaguar’s decline in the Chaco is indicative of wider population declines affecting other species, such as the giant armadillo (Priodontes maximus), white-lipped peccary (Tayassu pecari), the endemic Chacoan peccary (Chacoan wagneri), and puma (Puma concolor). Therefore, action taken to benefit the jaguar will also benefit many other species.

“The creation of new protected areas, as well as the correct implementation of those that already exist, such as conservation corridors where poaching is controlled, are urgent actions to be carried out by the local government,” Quiroga said.

Quiroga and her team are continuing their work to document and protect the mammals of the Argentine Chaco. A major focus for their future work is a region known as La Fidelidad, which has been proposed as a future national park.

Verónica Quiroga and Veterinarian Juan Arrabal checking trails in Copo National Park.
Verónica Quiroga and Veterinarian Juan Arrabal checking trails in Copo National Park. Photo courtesy of Verónica Quiroga.

“This area is located in the heart of the Argentine Chaco, it is 2,500 square kilometers of Chaco forest in excellent condition, without rural inhabitants and with a great potential for the recovery of the jaguar. This site is one of the last with these characteristics in the region, is in a strategic location with respect to other protected areas, and has a high availability of prey for the jaguar,” Quiroga explained.

“Our research efforts will be focused in the coming years at La Fidelidad and in other sites of the Chaco region where we believe that the jaguar still has a chance.”

Tapir (Tapirus-terrestris) in dry chaco forest from La Fidelidad Argentina.
Tapir (Tapirus-terrestris) in dry chaco forest from La Fidelidad Argentina. Photo courtesy of Verónica Quiroga.


  • Quiroga, V. A., Boaglio, G. I., Noss, A. J. and Di Bitetti, M. S. 2013. Critical population status of the jaguar Panthera onca in the Argentine Chaco: camera-trap surveys suggest recent collapse and imminent regional extinction. Oryx. DOI:

Agouti directed seed dispersal

Agoutis are one of the key players in the rainforest ecosystem (I wrote about them here for a guest blog post on species interactions). This fascinating project is looking at agoutis and their role in seed dispersal on Barro Colorado Island, Panama. Check out their ‘Background’ page for more info about how they track where seeds end up.

The Agouti Enterprise

One of the big discoveries of our project is that agoutis disperse Astrocaryum palm nuts in a complex step-wise manner: agoutis bury a seed, then dig it up and move it to another site over and over again. While collecting data in the field, and following seeds from one place to another over many weeks, we noticed that the movements didn’t seem to be completely random with respect to the surrounding trees. Astrocaryum palm trees are very conspicuous because they are covered in big spines, you have to keep an eye out for them when your walking off trail to avoid getting pricked.  When tracking down radio-tagged seeds, it almost seemed as though the seeds ended up in areas far away from other Astrocaryum trees. If this was true, this could be a really important phenomenon, because of something known as “Janzen-Connell effects”.

Janzen-Connell effects, first identified by Drs Janzen and Connell…

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Canopy crusade: world’s highest network of camera traps keeps an eye on animals impacted by gas project

This was a super cool interview to do for, the original can be found here.

Oil, gas, timber, gold: the Amazon rainforest is rich in resources, and their exploitation is booming. As resource extraction increases, so does the development of access roads and pipelines. These carve their way through previously intact forest, thereby interrupting the myriad pathways of the species that live there. For species that depend on the rainforest canopy, this can be particularly problematic. Home ranges become fragmented and species movements across habitats are disrupted, affecting the behavior, health, and genetic diversity of these species and consequently impacting broader ecosystem processes within the forest as a whole.

Tremaine Gregory climbing in a canopy bridge. Photo credit: Farah Carrasco/Smithsonian Conservation Biology Institute.

Now, a pioneering conservation project in the Peruvian Amazon is collaborating with a gas company to develop an effective way of mitigating some of these impacts. Natural canopy bridges have been left standing across a gas pipeline, and are being monitored by the highest network of camera traps ever deployed.

“In this project we are using more cameras, for more time, higher in the canopy than ever before. I can guess why other projects have not been so ambitious: placing a camera 100 feet above the forest floor is not easy!” Gregory says.

Gregory and her team have already recorded a huge range of species using the bridges (such as primates, kinkajous and anteaters), including one mammal species never before seen in the region. caught up with Tremaine Gregory, a Research Scientist at the Smithsonian Conservation Biology Institute, who is leading the project.


Mongabay: What is your background and how did you become a tropical biologist?

Gregory: I hold a Bachelor’s degree in Biology and Spanish, a Master’s in Anthropology, and a Ph.D. in Biological Anthropology. I recently told someone that I am a neotropical primate behavioral ecologist and conservation biologist, although in Peru I tend to refer to myself as a “mono-loga.” I came to this career through many twists and turns (Peace Corps volunteer, Spanish medical interpreter, wild trout biologist, veterinary assistant (of course), theatre technician), in search of a life that would be meaningful and fulfill both my dedication to understanding and conserving wildlife and as well as my love for adventure.

Mongabay: Your previous research investigated the little-known Guianan bearded saki monkey (Chiropotes sagulatus) in Suriname, can you tell us about what you found in that study? 

Gregory: For about six years I worked in Suriname studying both the bearded saki monkey and the white-faced saki monkey (Pithecia pithecia). My Master’s research contributed to our understanding of the evolution and niche divergence of these two species. During my dissertation research, I had the opportunity to spend 13 months in the field focusing on bearded saki ecology and social behavior. The bearded saki has been studied very little in continuous forest in the wild. This is largely due to the fact that these monkeys are exceedingly difficult to study—they travel through the huge, emergent trees at the top of the canopy, and they live in very large, fast moving groups. Trying to keep one eye on them while running across the forest floor can be a challenge. It’s amazing how easy it is to lose track of 40 monkeys. My research explored how the monkeys potentially use the forest’s complex topography strategically to reduce the costs of travel. I’ve also contributed to our understanding of bearded saki social behavior, particularly with regards to the relationships between males. Male bearded sakis seem to be highly affiliative with one another, showing signs of very tight bonds. There is also evidence of sexual mimicry and other unique characteristics. I look forward to returning to Suriname someday to delve back into many fascinating questions that remain about this group of monkeys.

Tamandua (Tamandua tetradactyla) with baby. Photo courtesy of the Smithsonian Conservation Biology Institute. Tamandua (Tamandua tetradactyla) with baby. Photo courtesy of the Smithsonian Conservation Biology Institute.

Mongabay: What is the main aim of your current work in Peru?

Gregory: The goal of my current work in the Peruvian Amazon is to provide scientifically sound recommendations to industrial development companies that operate in tropical forests to reduce their impact. I know that industrial development in the Amazon Basin will continue, and as a conservationist, I hope to do as much as possible to limit its impact.

In the Lower Urubamba Region of Peru, I am working in an area where a natural gas pipeline is being constructed. In order to install the pipeline, a swath is cut through the forest. This swath can be over 16 meters (53 feet) wide, and it eliminates connectivity of the forest canopy overhead. The good news is that the pipe is buried and the swath is reforested, but during the five to ten years it takes for the canopy to reconnect, arboreal animals can become isolated on either side. Some animals may venture down to the ground to cross, but doing so can be dangerous, and our results so far suggest that they do so very rarely. In order to reduce the fragmentary effect caused by the pipeline swath, the company with which we are working agreed to leave connections above the pipeline to preserve some connectivity. We call the connections “natural canopy bridges” because they are made up of the branches of the largest trees that connect over the top of the swath. Before pipeline construction began, I walked back and forth along the proposed pipeline path with my team mapping out locations where it looked like the branches would connect after clearing. We then worked with the construction company to preserve the trees that connected. Leaving the trees can be challenging for operations, so this required careful coordination. In the end, there were 13 canopy bridges, and we are now testing whether animals use them.

Black-capped capuchin monkey (Sapajus apella). Photo courtesy of the Smithsonian Conservation Biology Institute.
Black-capped capuchin monkey (Sapajus apella). Photo courtesy of the Smithsonian Conservation Biology Institute.

Dwarf porcupine (species yet to be determined). Photo courtesy of the Smithsonian Conservation Biology Institute.
Dwarf porcupine (species yet to be determined). Photo courtesy of the Smithsonian Conservation Biology Institute.

Mongabay: How widespread are infrastructure development projects in the Amazon, such as the one you are working on?

Gregory: Most of the Western Amazon is zoned for hydrocarbon exploration (Finer et al. 2008; Finer and Orta-Martínez 2010), and in 2012, over half of the Peruvian Amazon was under concession (there are detailed maps available on the Perupetro website: However, while these numbers may seem surprising, it is important to understand that within a concession block, a corporation will generally do some seismic research and drill a few exploratory wells, impacting a relatively small proportion of this area (see “Effective Area of Work” on Perupetro maps). In fact, pockets of natural gas or oil large enough to lead to the construction of a pipeline are very rare. Industry environmental standards have become strict, and many corporations use the off-shore model for their operations. This model simply means that corporations do not create access roads but instead treat operations camps as if they were “offshore,” and all access is by helicopter. All of this is to say that hydrocarbon exploration and extraction activity has the potential to impact a large part of the Amazon Basin, and my research explores ways to keep that impact to as much of a minimum as possible.

Mongabay: Why is it important to ensure the connectivity of populations?

Gregory: There are many reasons why it is important to maintain canopy connectivity and gene flow between populations of animals. First of all, when populations become isolated, the gene pool shrinks. With reduced genetic diversity, animals are more susceptible to disease and inbreeding depression. This, in turn, affects their survival and can even lead to localized extinctions. Another problem with fragmenting the area used by a community of animals is that they lose access to resources. Animals have complex mental maps that help them remember the location of feeding resources and shelter in their environment. They also are likely to have knowledge of neighboring individuals or groups of animals—information important for territorial and mating decisions. When an animal’s or group of animals’ home range is divided, they lose access to those resources. The area they use shifts, and they are forced into unknown territory. This can affect survival by influencing nutrition and increasing stress through augmented search time for resources and conflict with novel groups of animals. Effects on arboreal animals can then affect the forest as a whole. Many primates, for example, are seed dispersers. This means that they eat fruits, swallow the seeds, and after the seeds pass through their gut, they drop them in a different location. This is an extremely important process that contributes to the survival of the fruit tree species, and from a broad perspective to the function of the ecosystem as a whole.

Peruvian night monkeys (Aotus nigriceps) with baby. Photo courtesy of the Smithsonian Conservation Biology Institute.
Peruvian night monkeys (Aotus nigriceps) with baby. Photo courtesy of the Smithsonian Conservation Biology Institute.

Bald-faced saki (Pithecia irorrata). Photo courtesy of the Smithsonian Conservation Biology Institute.
Bald-faced saki (Pithecia irorrata). Photo courtesy of the Smithsonian Conservation Biology Institute.

Mongabay: Have camera traps been used in the forest canopy before? 

Gregory: In this project we are using more cameras, for more time, higher in the canopy than ever before. I can guess why other projects have not been so ambitious: placing a camera 100 feet above the forest floor is not easy! It took me and Farah Carrasco, my Peruvian collaborator, two weeks to place our 25 canopy cameras, and keeping them running for a year has been a major challenge. The conditions for the cameras are much harsher in the canopy than they are on the ground. More of our canopy cameras (we have another 55 cameras on the ground) have been invaded by ants, and they are exposed to more wind, constant sun and rain, and extremely tenacious animals like porcupines who enjoy gnawing on and opening them.

Mongabay: How do you install and monitor the camera traps?

Gregory: Installing camera traps in the high canopy is quite an adventure. When we decided we needed to monitor the canopy bridges with camera traps, we realized we needed to learn how to climb trees—tropical trees. Off we went to a tree climbing course in Panama. There we learned to use a seven-foot-tall sling shot to place a climbing line in a tree. But getting up into the tree was just the beginning. In some cases it took us upwards of five hours to figure out where the camera should go to capture the crossing point, transfer between branches to reach that point, then place and test the camera—all the while trying to remember not to drop anything. My dad and I designed a mounting system with two ball joints, allowing the camera to be angled in any direction. Cameras on the ground can just be bungeed to a tree trunk, but the canopy is a more complex, three dimensional world. I’m currently working on a manuscript that describes our methods in detail so that other researchers may benefit from what we’ve learned.

Mongabay: What is it like climbing such enormous trees?

Gregory: Climbing canopy trees is exhilarating, to say the least! As I bustle around juggling the cameras and ropes and things, I have to remind myself to stop, take in the view, and feel the breeze. I think the most fascinating part has been experiencing a world that I had only observed from below. After years of watching monkeys in the canopy through binoculars, it is an entirely different experience to be in the top of a tree. You realize that rather than a plane-like environment, like the forest floor, the canopy is a network of linear pathways, and a false move can be very costly.

Kinkajou, Potos flavus. Photo courtesy of the Smithsonian Conservation Biology Institute.
Kinkajou, Potos flavus. Photo courtesy of the Smithsonian Conservation Biology Institute.

Emperor tamarin (Saguinus imperator). Photo courtesy of the Smithsonian Conservation Biology Institute.
Emperor tamarin (Saguinus imperator). Photo courtesy of the Smithsonian Conservation Biology Institute.

Mongabay: Have you been surprised by any of the camera trap footage, and have there been any unexpected species using the bridges?

Gregory: So many of the camera trap photos are breath-taking. I have to discipline myself to avoid spending all day marveling at photos of monkeys, kinkajous, anteaters, opossums, and many other animals. In addition to mammal species, we’ve had many photos of birds and even reptiles. I usually take a quick look at the photos while up in the tree to make sure the camera is working properly, and my guides are accustomed to hearing me exclaim over the photos. In camp in the evening, everyone gathers round to see what goodies we’ve brought back on the memory cards. One of our many exciting finds has been an arboreal dwarf porcupine species that was not known to occur within 800km of the study area. Others include some spectacular photos of saki monkeys and anteaters with their babies. These really blew me away. If you haven’t been up in the tree to see the camera, it’s hard to imagine that the animals are actually up so high.

The canopy bridge research team this past October.  Photo credit: Smithsonian Conservation Biology Institute.
The canopy bridge research team this past October. Photo credit: Smithsonian Conservation Biology Institute.

Mongabay: Do you know yet how successful the canopy bridges have been? Are they likely to be effective enough to mitigate all impacts of the pipeline on these arboreal species?

Gregory: Interestingly, arboreal animals were already using the bridges immediately after they were exposed by the construction activities. I thought it would take them some time to locate the crossing branches, but they had no trouble finding them. The bridges have been used by over 20 species of arboreal mammals, and we recorded over 1,000 crossing events in the first six months. Because the canopy was continuous before construction, we could not monitor all possible crossing branches in order to make before and after comparisons. The 13 bridges are spread over a five-kilometer (three-mile) area, so potential crossing options have been dramatically reduced, likely leading to fewer crossings, overall. I would therefore not say that the bridges have mitigated ALL impacts, per se. Our monitoring has also suggested that groups of primates may migrate away from the area during construction. However, we’ve also had very few recordings of crossings by arboreal animals on the ground, suggesting that the bridges have been a huge success, allowing animals to continue to access feeding resources, shelter, and social partners on either side of the swath. We plan to recommend that all pipeline projects in tropical rainforest habitats include canopy bridges.

Mongabay: What about in situations where the largest trees have already been felled – could there be a role for artificial bridges to help mitigate the impact of development projects that have already been completed?

Gregory: That’s a good question and one that many people have asked me. In future research, I hope to address that question. I imagine that animals would be inclined to use artificial bridges, particularly over roads, where there can be continuous activity. There are projects all over the world that are using different types of artificial bridges or crossing structures. One major difference, however, between natural bridges and artificial bridges is that animals must habituate to the artificial bridges. While we observed animals using the natural bridges within days after they were exposed, I understand that it can take many months for animals to feel safe enough to use artificial bridges. In this time, they lose access to resources on the other side. With proper planning, natural bridges should also be cheaper and require less maintenance. But certainly, where there are no bridges, artificial bridges are a good solution.

Mongabay: Being able to monitor species before, during and after the pipeline construction must be crucial to understanding the effectiveness of the bridges – was it difficult to initiate collaboration with the company building the pipeline? 

Gregory: While this is my first collaboration with a large corporation, the Center in which I work (the Smithsonian Conservation Biology Institute’s Center for Conservation Education and Sustainability) has over a decade of experience around the world, with multiple corporations. We therefore have a good reputation both in the world of conservation and with industry. And while the goals of conservation and industry can be very different, I think there is a surprising amount of common ground to be found. Particularly in recent years, corporations have begun to pay more and more attention to conservation issues. While this project has been very challenging, I think it is a great example of the positive conservation outcomes that can be achieved through partnerships.

Mongabay: What are your future research plans? 

Gregory: With over one million camera trap photos from a year of data collection on this project, at the moment, I am focused on data analysis and publication. I also look forward to providing recommendations to corporations and the Peruvian government on the mitigation benefits of canopy bridges. After that, I look forward to exploring new ways to help corporations reduce their impacts. While I miss working in a national park, as I did as a graduate student, and find working in concession blocks with corporations to be much more challenging, I know that as a conservation biologist this line of research is where I can be most effective. But, if I can sneak in a trip to Suriname to catch sight of a bearded saki, I’m unlikely to pass it up!

Dwarf porcupine (species yet to be determined). Photo courtesy of the Smithsonian Conservation Biology Institute.
Dwarf porcupine (species yet to be determined). Photo courtesy of the Smithsonian Conservation Biology Institute.

Tremaine Gregory and Farah Carrasco.  Photo credit: Joe Maher/Smithsonian Conservation Biology Institute.
Tremaine Gregory and Farah Carrasco. Photo credit: Joe Maher/Smithsonian Conservation Biology Institute.


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