Uncategorized

spectacled bear

5

Favorite Andean Bear Food: Sapote

Some of these sapote flower buds may develop into food for Andean bears, Sechuran foxes, and other wildlife.

Some of these sapote flower buds may develop into food for Andean bears, Sechuran foxes, and other wildlife.

In conservation research, we’re often interested in measuring variation across space and time, looking for patterns in that variation and deriving explanations for those patterns. However, during my last trip to the field, I found myself pondering changes over time on a much longer scale, across over 1,000 years. As I walked under the hot sun dragging a tape measure through the brush day after day, and I started stepping over ancient stone walls, it was easy to start wondering about the original purpose of the walls, even though that had nothing to do with the task at hand!

What I should have been totally focused on was making sure that we were correctly measuring the distances between trees in the tropical dry forest of northwest Peru. As part of the Andean bear conservation program, I was there working with the Spectacled Bear Conservation Society and with local citizen scientists (see post Citizen Science: Engaging People in Conservation Research). With support from the Disney Worldwide Conservation Fund, Samantha Young and I have been developing several initiatives to engage local people in conservation science and action (see Scientific Concepts for Non-scientists). One focus of my trip was to train citizen scientists in collecting data from woody plants, because we’re interested in knowing more about how plants that are important for Andean bears vary in space and time. In particular, we’re interested in understanding the variation in when and where sapote produces flowers and then fruit, because sapote fruit appears to be the critical food source for Andean bears in the dry forest of northwest Peru (see Andean Bears: A Surprising Discovery).

To get information on the sapote population, we measured little trees...

To get information on the sapote population, we measured little trees…

Although sapote is considered critically endangered, there have not been many studies done on its reproductive ecology, so we can’t simply visit a field site and estimate how much fruit the sapote trees there might produce or how many bears might be supported by those trees. So, our goal is to collect information every month, such as which trees have flowers, which trees have fruit, and the condition and size of those fruit. Because we don’t have any background information on these sapote trees, we’re going to learn something new practically every month. For example, during our first data-collection period we discovered some individual sapote with a few ripe fruit left from this past season and several new flower buds. I had no idea that the same tree might have both flowers and fruit at the same time!

...and we measured big sapote trees.

…and we measured big sapote trees.

Another new observation with more serious implications for bears and other wildlife that feed on sapote fruit is that sapote grows only in a narrow band on the lower slopes of the hills at the edge of the valleys. We knew this generally, but we had never measured the width of this strip; it’s much narrower than we thought, meaning that there’s less area covered by sapote trees than we expected, and, presumably, fewer sapote trees. Over the next several months, we’ll begin to get an idea of how many flowers and fruits those trees produce and how that production varies depending on characteristics of the sapote trees and the places where they’re living.

Although we’ll be looking at variation in flower and fruit production across relatively small-scale changes in space and time, especially in comparison to the scale of the landscape and the scale of human history in this area, these are the data we’ll need to understand variation in sapote and in Andean bear ecology.

Russ Van Horn is a scientist in the Applied Animal Ecology Division of the San Diego Zoo Institute for Conservation Research.

18

Andean Bears: A Surprising Discovery

A member of our collaborative field team watches a cliff for bear activity.

This summer my colleague Megan Owen and I were fortunate enough to have an intern working with us. Michael Forney was the John E. and Dorothy D. Helm Summer Fellow, working in our Applied Animal Ecology Division (see Summer Intern Enjoys Opportunities). He extracted behavioral data from videos of wild Andean, or spectacled, bears, living in the tropical dry forest of northwest Peru, where we work with the Spectacled Bear Conservation Society. Some of the videos were collected opportunistically by the field team, when they unexpectedly encountered a bear, and other videos were collected on a more systematic basis. There are more videos yet to review, but the preliminary results are pretty interesting.

These were the first behavioral data ever collected on wild Andean bears, and they delivered some surprises. For example, for most of the year the bears appear to lose weight, suggesting that there’s not enough food available. However, during the period of time when sapote fruit is available, the bears feed primarily on those fruits and appear to gain weight. We’d already seen this pattern, from different sources of data; however, Michael’s results suggest that dry forest Andean bears do not respond behaviorally to a feast and famine cycle like Northern Hemisphere bears would.

Sapote fruit: Does it dictate bear activity?

You may already know that American black bears and brown bears really focus on foraging during the period before they hibernate. Generally, these black and brown bears are driven to fatten up before the months when they won’t eat, so they spend as much time eating as possible. If Andean bears in the dry forest, which don’t hibernate but which do spend months with little food, behaved like these other bears, then you’d expect the bears in the videos to spend most of their time eating sapote fruit during the relatively brief period when it was available. However, Michael’s data show that adult females, with or without cubs, spend relatively little time eating, even when there appears to be a surplus of sapote fruit.

Why don’t these females spend more time feeding? We’ve generated a few hypotheses to address this question, but confirming this phenomenon and testing these hypotheses will require more data from more videos.

This is not just an abstract academic question, without relevance for the conservation of these bears. If weight gain among female Andean bears in the dry forest is constrained by sapote fruit availability, then perhaps an increase in the number of sapote trees would improve the body condition of the bears. However, if weight gain among these females is constrained by something else in addition to food availability, as might be suggested by Michael’s data, then increasing the number of sapote trees would not improve the bears’ body condition. Michael’s work reminds us that we have a lot to learn about Andean bears to further their conservation.

Unfortunately, we’ll have to pursue this question without Michael’s help, as he’s finished his internship with us and has gone south to put his talents to work in Ecuador. Thanks, Michael, and good luck!

Russ Van Horn is a scientist in the Applied Animal Ecology Division of the San Diego Zoo Institute for Conservation Research. Read his previous post, Peru: Conservation Science at Local Level.

2

Andean Bear Sightings

Dimples in the sand show where Russ' sweat droplets landed.

As I stepped up onto the ledge and looked down the rocky trail, I realized that I needed to take a break. It was just too hot and dry for me to keep up with Javier and Isai, two parabiologists from the Spectacled Bear Conservation Society. We still had enough time to reach camp before it became too dark, so I stopped to catch my breath. As I stood there huffing and puffing, I noticed some dimples in the sand below me. It hadn’t rained for a long time, so what liquid could have fallen and created those dimples? After puzzling for a moment while looking down, I saw the answer as sweat dropped off my chin and fell to the ground: those dimples were made by me as I stopped in the same place to rest before dawn that day! We had walked up the trail while it was still dark, in order to be in a hiding place before dawn. We had then waited all day to see if and when an Andean bear (aka spectacled bear) would come to the waterhole.

Rinds left after an Andean bear fed on a sapote fruit

Most of the year this type of effort would be a waste of time. However, when the sapote fruit is ripe down in the valleys, the local bears often walk down from the hills to feed on sapote during the morning before returning to the hills before dark. On their way uphill, they often stop for a drink of water at one of the rare waterholes. Our most predictable opportunity to see a bear, and place a GPS transmitter on it, comes when we move in a pattern opposite to the bears and intercept them at the water.

A wild female Andean bear and her cub

As we walked to and from the waterhole for several days in a row, we saw evidence that bears were in the area. Sometimes we’d see partial tracks of bears, or else the rinds that bears leave behind after eating sapote fruit. Even better, we saw at least one bear on each of the nine days we spent waiting at the waterhole! Usually these were the same few bears, so in total I think we saw four different bears; twice the bears were too far away to identify with any certainty.

We saw the same female bear and her nearly independent cub come to the waterhole on eight of the nine days. This female’s behavior was different from that of females with very young cubs, which appear to avoid the waterholes as best as we can tell from data from GPS collars, camera traps, and direct observations. Perhaps mothers with young cubs act differently because their cubs cannot walk very far, or perhaps mothers with young cubs wish to avoid encountering adult male bears; we’ll need more data to better assess these two hypotheses. Meanwhile, I’m glad we have the opportunity, and the skilled field team, to collect those data. It’s also rewarding to see the bears!

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research, leading our Andean bear conservation program. Read his previous post, Camera Trap: Bush Dogs.

6

Little Fruit, Thin Bears

This is a camera trap photo of the female Andean bear Magaly on December 7, 2009, when she was thin and in poor condition, before many ripe sapote fruit were available.

It was about 16 months ago when I first saw an Andean bear in the dry forest of Peru during the Southern Hemisphere winter. When I did, I was shocked. As this bear walked down the hillside toward a waterhole I could count her ribs, I could see her backbone, and I could watch her hipbones moving. Her fur was dull, and I could hardly believe how bad she looked. My colleagues had told me that the bears living in the dry forest were thin during the winter because there wasn’t much for them to eat, but I didn’t know the bears became THIN! The only other wild bear I have ever seen so scrawny was an American black bear I encountered many years ago in southwest Montana; that bear had become dependent on food it obtained from people, and it began starving when it no longer had access to the supplemental food.

This is a camera trap photo of the same female Andean bear, Magaly on April 29, 2011, after she’d become plump by feeding on sapote fruit.

When I expressed my concern over the skinniness of the dry forest bear to the field team of the Spectacled Bear Conservation Society (SBC), they told me that they had seen bears in the dry forest that looked even worse than the bear I was watching but that had nevertheless survived. In reality, I was shocked only because I didn’t have much experience in the dry forest; that bear was not unusual. She not only survived, but she mated a few months later and is now raising a young cub. Skinny dry forest bears look shocking to people who don’t have experience in the dry forest, but in fact their weight loss is part of a natural cycle that becomes obvious to anyone who studies dry forest bears for more than a year.

This is a portrait of nearly ripe sapote fruit still on the tree when there were ripe sapote fruits lying on the ground beneath the tree, and when bears were foraging on sapote fruits. We hypothesize that fruits like this one are critical for the survival of individual bears, and the bear population, in the dry forest.

Working with SBC in the dry forest, we’ve accumulated evidence over the last several years that Andean bear movements and body condition are linked to a species of tree, the sapote. Evidence from direct observations, camera traps, and satellite telemetry collars all suggests that bears focus their movements and foraging on sapote fruit when it is available, which is usually only for two to three months just before the annual rainy season.

After ripe sapote fruit become available, usually beginning in late November, the bears’ body condition improves noticeably, so that within a few weeks the bears no longer look like walking skeletons. After a few more weeks of feeding on sapote fruit, the bears start to look a little plump, although they never get as fat as American black bears and brown bears do in autumn. During the rest of the year when sapote fruit is not available, Andean bears in the dry forest gradually lose weight so that they are skinniest just before the sapote fruit is ripe. These observations strongly suggest that healthy populations of sapote trees are critical for the health of individual Andean bears in the dry forest and for the health of the dry forest bear population. The sapote tree is considered critically endangered by the Peruvian government, so we’re promoting conservation of sapote trees as part of the Andean bear conservation program.

A camera trap photo shows male Andean bear Russ on December 5, 2009, when he was thin and in poor condition before many ripe sapote fruits were available.

This is a camera trap photo of the same male Andean bear, Russ, on March 21, 2011, after he’d gained weight by feeding on sapote fruit.

The field team is seeing something unusual right now that may answer a question that’s been puzzling me for over a year. Young cubs and subadult bears often disappear when their mothers are skinniest, shortly before the sapote fruit ripens. We suspect that, unfortunately, when adult bears have a hard time finding food, many young bears do not survive. If that happens year after year, how can the population of bears in the dry forest remain stable? This year some sapote fruits are ripe earlier than normal, and some bears are starting to gain weight earlier than usual. This makes us hopeful that this year more cubs and subadult bears will survive. Of course, the survival of youngsters may depend on what the sapote trees do over the next few months, which reminds me of other questions we have. Why do sapote trees produce fruit when they do? What influences how many sapote fruits are produced? There has been a little research done on these questions, but we’ve still got some work to do to fill in the blanks!

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research, leading our Andean bear conservation program. Read his previous post, Mountain Lions and Palm Trees.

For more information about the seasonal fluctuations in resources such as sapote and the need to conserve them, see posts Dry Forest Bears of Peru and To See a Bear.

0

Vegetarian Bears?

Here is what is left of an an epiphetic bromeliad eaten by an Andean bear.

May 16 to 22, 2011, is Bear Awareness Week, and we hope you’ll join us in celebrating these amazing animals. Today we focus on Andean bears.

What is the role of the Andean bear, also called the spectacled bear, in its environment? That is a good question! The answer is not well known, and it definitely depends on which Andean bear population you’re talking about.

Andean bears use a wide range of habitats, ranging from alpine habitats above treeline through humid cloud forests and transitional montane forests to dry tropical forests. Because each of these habitats varies in its complexity, and because the bears’ range extends from the border of Columbia and Panama south to northern Argentina, the bears’ role in its environment also varies. Wherever they live, though, they’re thought to be primarily vegetarian.

Because the bears forage on a variety of forest fruits when they’re available, and because each bear might travel a long distance each day, Andean bears have often been thought to be important seed dispersers. That means that they ingest the fruits and seeds in one place, then transport them to another as they go about their bear business, before depositing them with a little bit of fertilizer. This would generally be thought of as beneficial to the plants, because the seeds would have a better chance of growing up without competing with their parents. The importance of Andean bears as seed dispersers has not often been well tested, but if they are important seed dispersers it is probably for plants whose fruits and seeds are too large and heavy for other animals to transport.

Andean bears are known to forage on a wide variety of bromeliads that live on the branches of trees, and on the ground above treeline. When they eat bromeliads, bears tear them apart to get at the fleshy core, similar to how humans eat artichokes. Now, being torn apart is not likely to be any more beneficial to a bromeliad than it is to an artichoke, but no one has yet investigated the impact of bear foraging on bromeliad populations. In places in the cloud forest, most tree limbs are liberally covered with bromeliads, so perhaps the bears are not in danger of running out of food.

A fruiting sapote tree offers tasty treats for Andean bears.

In the dry tropical forest of northwest Peru, the role of Andean bears as seed dispersers, and the role of bears as consumers of plants, may be enhanced because in the dry forest there are not many alternative foods for the bears to eat. Bears congregate every year when the fruit of the sapote tree is ripe and focus their energies on consuming these large fatty fruits filled with seeds. These fruits and their seeds are also consumed by a wide range of birds and other mammals, including the Sechuran desert fox, but each bear can consume more fruit and travel farther than each fox, making it possible that the bears play a vital role in distributing the seed of the sapote tree.

Here are the remains of a pasallo tree after an Andean bear has shredded its trunk.

It’s a little harder to evaluate the impact of the dry forest bears on the pasallo tree, which they turn into woodchips. The bears don’t just peel back the outer bark to feed on the inner bark, or to feed on insects—the bears actually eat the wood itself! Amazingly, it appears that a pasallo tree that has been exploded by an Andean bear is often not killed. The pasallo resprouts and regrows. This must be an energetically expensive process for the pasallo trees, and it seems as though there must be a negative effect on the pasallo population, but apparently healthy populations of pasallo survive.

We’re in the process of planning research to investigate more closely the interactions between the bears and their primary food sources, so hopefully in a few years we’ll better understand how the bears benefit from their various food sources and how the plants are impacted by the bears. We’ll keep you posted on our progress.

Read more about San Diego Zoo Global’s conservation work with bears…

Russ Van Horn is a senior researcher for the San Diego Zoo Institute for Conservation Research. Read his previous post, Andean Bears: 30 Years Later.

0

Andean Bears: Camera Trappers

Photo of a hind footprint of an Andean bear in the cloud forest of southern Peru.

Photo of a hind footprint of an Andean bear in the cloud forest of southern Peru.

It’s been a while since I’ve written a blog post (see Bear Culture). To be honest, I was waiting until I could include a remote-camera photo of a wild Andean bear! However, people keep asking me about the cameras (see post Andean Bears and Cameras), so I thought I’d provide an update now.

Due to logistical challenges, it took longer than I expected to place the cameras in Peru’s cloud forest last fall. I now understand well why no one’s done this before! However, one issue that I thought might be a challenge turned out to be no challenge at all.

The local people who worked with me to install the cameras in the forest have very little experience with electronic technology, so I wasn’t sure how fast they’d learn to use the cameras. Another challenge for them was that all the buttons on the cameras, and the programming menus, are written in English, which none of them speak or write.

Peruvian field workers with a camera trap in the cloud forest.

Peruvian field workers with a camera trap in the cloud forest.

I’ll admit that at first they didn’t understand what the different programming options were or what the buttons did. Neither did they have any idea of how to prepare a site in the forest for the best chance at obtaining good photos. However, after working with me to install only a few cameras, they were debating with each other, and with me, the fine points of site preparation and camera positioning. “No, it should be turned a little more to the left!” “No, I think it’s very good where it is.” “Use a little stick to raise the bottom – no, not that stick, use one that’s a little thicker.” This was an excellent reminder of something I realized as a child surrounded by older generations who did not have access to higher education: a lack of education does not mean a lack of intelligence.

There were three other promising signs:
- First, these gentlemen kept teasing me about how many bears would be photographed, and what the chances were that all the photos would be of bears’, um, derrieres, and not of their faces.
- Second, as they programmed each new camera installation, team members would look over each other’s shoulder, ready to applaud, and critique. However, each man was careful and thorough, and mastered the process at hand.
- Third, two men encountered a bear on the trail, in broad daylight, about 400 meters (1,300 feet) away from where the rest of us were debating whether we had achieved optimal camera placement. At first I didn’t believe that they had seen a bear, because they had been teasing me so much. However, when we went down the trail, there was no denying the evidence in the mud: fresh tracks of an Andean bear.

The field workers are changing the batteries and memory cards in the cameras every month until I return there in March to begin the next stage of the project. The photos from the first month of operation have been collected, downloaded, and sent to Lima, Peru. However, there are so many photos that they cannot be e-mailed to me! So, I’ll have to wait for a DVD to arrive in the mail. I wonder, I wonder, what is in those photos?

Russ Van Horn is a senior researcher with the San Diego Zoo’s Institute for Conservation Research.

0

The Bear Goes over the Mountain

Javier going to great lengths, as usual, to get his job done.

Javier going to great lengths, as usual, to get his job done.

San Diego Zoo researchers are in Peru to study Andean (or spectacled) bears. Read a previous post, To See A Bear.

We awake in the predawn twilight, rouse ourselves out of our sleeping bags, down some coffee, and head for the viewpoint, hoping to spot last night’s bear making the ascent back up from the waterhole. José begins to gesticulate wildly, pointing to a dark form moving slowly up the face of the cliff.

Through the binoculars I can make out the white spectacles surrounding the eyes and see his powerful forelimbs reaching out to gain purchase in some crevice or ledge. He stops at a large boulder and uses his huge claws to pry out a few snails, precious morsels of protein in this resource-limited landscape. Then, he is on the move again and, before I know it, he is at the top of the cliff, some 1,500 feet above the waterhole, and he disappears over the ridge.

The rough trails take their toll…on my boots. José does makeshift repairs on my boot after the sole was ripped off by the treacherous terrain. Boots last less than 6 months here—just one of the difficulties endured by this dedicated field team.

The rough trails take their toll…on my boots. José does makeshift repairs on my boot after the sole was ripped off by the treacherous terrain. Boots last less than 6 months here—just one of the difficulties endured by this dedicated field team.

Most bears are good climbers, but spectacled bears move more nimbly and quickly over steep terrain than any other animal I have ever seen. This ascent, taking just a few minutes, would take a person the better part of a day…with ropes. This opportunity to witness this bear’s remarkable athleticism is another reminder of just how well adapted these bears are to this rugged and challenging landscape. Fortunately, this ruggedness keeps this wilderness relatively remote from the impacts of nearby humans. But for how long?

Robyn points out the paths traversed by bears, and the way we will return.

Robyn points out the paths traversed by bears, and the way we will return.

The juxtaposition of this majestic wilderness so close to an expanding human population motivates Robyn’s team to do something, and fast. See post, Andean Bear Collaboration. This is why they are working with the local communities and government officials to try to raise awareness of this situation and, hopefully, bring some protection. This is also why we at the San Diego Zoo’s Institute for Conservation Research are joining this noble effort.

We spend a couple more days exploring the habitats of these remarkable bears before descending back down the mountain and back to civilization, and the welcome comfort of a shower and a bed. The end of an adventure, but the beginning of a collaboration we hope to continue for years to come. Understanding these bears, and finding ways to protect them, will require a long-term commitment.

Ron Swaisgood is director of Applied Animal Ecology for the San Diego Zoo’s Institute for Conservation Research.

0

Dry-forest Bears of Peru

Setting out. Destination: the top of that mountain. Weight of pack: a lot! Think food and water for five days.

Setting out. Destination: the top of that mountain. Weight of pack: a lot! Think food and water for five days.

The San Diego Zoo has two researchers studying bear habitat in Peru. Read a previous post, Andean Bears and Cameras.

Slowly, slowly, we trudge up the makeshift trail, recently machetted along the ridge. The sun beats down, the thorns scratch our arms, our calf muscles strain to carry us up another 100 feet, then another. But our spirits lift as we rise higher and higher, leaving behind civilization in the valley below, and enter the domain of the spectacled bear.

Nonprofit headquarters. The Spectacled Bear Conservation Society built two buildings in which to base their research and to provide outreach and education for the local community.

Nonprofit headquarters: The Spectacled Bear Conservation Society built two buildings in which to base their research and to provide outreach and education for the local community.

I have joined one of our newest collaborators at the San Diego Zoo’s Institute for Conservation Research, Robyn Appleton, director of a small nonprofit organization devoted to studying and saving the spectacled bear and its habitat. Also known as the Andean bear, because much of its range lies in the mountains of Columbia, Venezuela, Ecuador, and Peru, here they call it oso de anteojos, or spectacled bear, because of the distinct markings around the eyes that give the bear a bespectacled appearance.

Javier checks a camera trap by the waterhole.

Javier checks a camera trap by the waterhole.

Robyn and her small field team—a father-son duo named Javier and José—have worked miracles here. Through sheer grit and determination, they have entered the harsh dry-forest wilderness and discovered something truly amazing. Bears. Lots of them. Local people and experts alike dismissed this area as too dry and barren to support much of a population, but to everyone’s surprise, this team has found and identified no fewer than 31 bears living in a relatively small area.

Hot, steep and scratchy—the thick vegetation of the dry forest several months after the El Niño rains.

Hot, steep and scratchy—the thick vegetation of the dry forest several months after the El Niño rains.

The story of how these bears (and the people tracking them) manage to eek out an existence in this formidable environment is fascinating. In a dry forest, water is everything. Each year a few sprinkles fall here and there, but real rain comes only every few years with the El Niño. And then, it is super-abundant. As Robyn and her team soon learned, once this rain falls, the dry forest springs to life. They literally watched as the dirt patches turned to tangles of thick brush, and vines grew to cover all the trees. It was impenetrable. Apparently, the porous rocks of the soaring mountains capture much of this rain and slowly feed a few small springs scattered among the ravines. Hot, steep, and scratchy—the thick vegetation of the dry forest several months after the El Niño rains.

I’m smiling because I have a rope secure in my hands. Behind me is a 50-foot drop to the waterhole.

I’m smiling because I have a rope secure in my hands. Behind me is a 50-foot drop to the waterhole.

Halfway up the mountain, we descend a precarious slope, clinging to a system of ropes established by Robyn’s husband, Ian, to a waterhole the size of your kitchen sink. This pitifully small puddle sustains life for much of the surrounding fauna, including the bears. The water percolates through the rocks and feeds this hole for years without additional rain. Remove this waterhole and it all collapses. Protection of waterholes such as these has become Robyn’s team’s first order of business.

View of civilization. Wild, but this wilderness is at the mercy of nearby human inhabitants.

View of civilization. Wild, but this wilderness is at the mercy of nearby human inhabitants.

After a welcome respite in the cool shade and green plant life at the waterhole, we continue to ascend, a total of 2,500 feet (760 meters), to the crest of the mountains. Up here, the eagles soar and the views are sweeping and spectacular. As wild as it is up here, we are reminded that we are surrounded by humanity. Look off in one direction, and you can see the lights of the village below. Down the other side we see farms and hear roosters…and disco music. It’s wild here, but fragile. A few careless, or uncaring, people could take away the life of these bears. As goes the water, so goes the wildlife.

Brainstorming at base camp. José, Robyn, and Javier discuss the research plan.

Brainstorming at base camp. José, Robyn, and Javier discuss the research plan.

I am here to learn about this incredible environment and these surprisingly resourceful bears. As a representative of the San Diego Zoo, I am also here to see how we can help. We are helping financially, but we’re also here to brainstorm, to work together to find out how we can make this fantastic opportunity even better. A little weary from the climb, I contemplate the possibilities as I lie on my mat (already deflated by the thorns), gaze up at the stars, and hope a scorpion doesn’t join me in my bed. And I wonder, will tomorrow be the day I see my first wild spectacled bear?

Ron Swaisgood is the director of Applied Animal Ecology for the San Diego Zoo’s Institute for Conservation Research.

0

Andean Bears: Still Elusive

The cloud forest is, as you might expect, often cloudy.

The cloud forest is, as you might expect, often cloudy.

Russ Van Horn is studying Andean bears in Peru. Read his previous blog, Andean Bear Symposium.

I’m in Lima now, on my way to San Diego from the eastern slope of the Andes. I’ve spent most of my time since my last blog entry looking for evidence of Andean bears in the forests of eastern Peru. I began this search by returning to a mountainside where we’d earlier seen the leftovers of a bear’s meal and where we’ve had a camera “trap” in place for several weeks. Unfortunately, the camera did not take any photos of Andean bears, but it had snapped additional species of birds and mammals. There’s clearly quite a diversity of wildlife at that site, but it doesn’t appear to be used much by bears, at least at this time of year.

The bamboo was incredibly dense at this site.

The bamboo was incredibly dense at this site.

We spent a few days camping in the forest nearby, on a ridge that eventually climbs up to alpine grasslands. In other areas of their range, Andean bears are reported to use similar grasslands during some seasons of the year. Evidence of bear presence, such as feeding sites and feces, has been reported to last longer in such grasslands than in the cloud forest, so it would be interesting to look for evidence that bears use these particular grasslands. However, we weren’t able to get that far afield because of the fantastic density of bamboo. In one thicket there was more than nine bamboo stems per square meter, for a few hundred meters. Cutting a passage through the bamboo was a slow process, and although we rationed our drinking water, we eventually ran dry and had to turn back.

The diversity of canopy structure in the cloud forest

The diversity of canopy structure in the cloud forest

This ridge rises above the valley through which the Interoceanic Highway is being built. Periodically, loud explosions echoed off the surrounding mountains, as construction crews blasted through the cliffs, and these crashes would make us jump, even over the ringing of the machetes in the bamboo. There are parallels between the road construction and our trail construction, but we attempt to minimize our impact on the forest as much as possible. This is one of the challenges to ecological researchers: can you study a system without your activities changing the way it functions?

We’re trying.

Russ Van Horn is a senior researcher for the San Diego Zoo.

0

Andean Bear Symposium

Russ Van Horn is studying Andean bears in Peru. Read his previous blog,
Andean Bears: Ready for Their Closeup?

I’ve just left Lima after attending the Second International Symposium on Andean Bears. Nearly all of the scientists currently working on Andean bears attended this symposium, which was the first such meeting in 20 years. Dr. Ron Swaisgood, Division Head of the San Diego Zoo’s Applied Animal Ecology Division, presented an overview of reintroduction programs based on his experience working with several species, and he was one of three panelists in a lively workshop on rescue, rehabilitation, and reintroduction of Andean bears.

I presented the preliminary results of a survey conducted on captive Andean bears in North America. This survey is a joint effort between various groups at the San Diego Zoo: veterinarians, husbandry staff, and researchers. We’re working to identify the risk factors associated with chronic and progressive hair loss among captive Andean bears so that we can then form and test hypotheses about the underlying cause and develop effective responses. Through our work, we’ve realized that this condition is relatively common among female Andean bears in captivity, and we’ve formed some hypotheses as to what might cause this hair loss. We need to collect additional data, though, before we can reach conclusions and suggest treatments or preventative measures.
The symposium was an exciting opportunity to learn about the other work being conducted on Andean bears, both in situ and ex situ. There is some great conservation science being conducted by several South American researchers, and we discussed research and conservation goals. I believe we’ve laid the groundwork for some productive collaborations, but only time will tell how these develop. Because over 100 people attended the conference, exhibiting a mix of passion and scientific rigor, I suspect it will not take another 20 years before the Third International Symposium on Andean Bears is held.