Uncategorized

About Author: Russ Van Horn

Posts by Russ Van Horn

38

What to Eat When There’s Nothing to Eat?

Bear ambassador Mi Ton Teiow finds relatively shallow snow, but no food, as the northern winter begins.

Bear ambassador Mi Ton Teiow finds relatively shallow snow, but no food, as the northern winter begins.

The answer? Nothing.

Most of us are familiar with the idea that some bears spend long periods of time in dens, inactive and not consuming significant amounts of food or water. Some bears in some locations survive eating nothing by doing almost nothing. They become inactive, which is sometimes called winter sleep or hibernation. Although you may be familiar with this aspect of bear ecology, have you thought about how incredible it is? These big mammals can go without eating or drinking for months, sometimes while birthing and nursing cubs, yet wake up without bedsores or weakened muscles! This is why the physiology of bears, including that of giant pandas and polar bears, has been a hot field of research.

The only way for a wild American black bear to survive for months without food in the northern U.S. is to save energy by hibernating in a safe, insulated den. The hole to the right of the tree trunk is the only obvious indication that there is an American black bear below the snow.

The only way for a wild American black bear to survive for months without food in the northern US is to save energy by hibernating in a safe, insulated den. The hole to the right of the tree trunk is the only obvious indication that there is an American black bear below the snow.

Although all female bears seclude themselves in dens to give birth to cubs, not all bears enter dens for long periods of time. There’s even variation within species in whether or not individual bears remain in dens or for how long. Researchers have found that in general, bears spend long periods in dens not to avoid cold temperatures, but to reduce their metabolic requirements when there is not enough food to survive environmental conditions. So, in the southern part of their range where their energy balance can remain positive, individual brown bears, Asiatic black bears, and American black bears may not den except to give birth. At last year’s meeting of the International Association for Bear Research and Management (see post, A Whimsical Bear Ambassador Arrives), Lorraine Scotson and Dave Garshelis reported that some sun bears might den for periods of time in the most northern parts of their range, meaning that non-reproductive denning may occur among at least half of the world’s bear species.

The holes melted in the snow are made by the black bear’s respiration.

The holes melted in the snow are made by the black bear’s respiration.

The giant panda is one bear species that has not been known to den in response to a relative lack of food, and perhaps it cannot do so. During the rare times when all the bamboo plants in an area have flowered and then died, the giant pandas have left the area in search of food; they have not entered dens. Perhaps this is because a bamboo die-off is unpredictable from the giant panda’s point of view, or perhaps this is because a giant panda eating bamboo cannot build up sufficient energy reserves to be able to wait out the lean time in a den, or maybe both factors play a role.

Adult polar bears also do not enter dens solely to avoid food shortages. Pregnant polar bears do spend prolonged periods of time in dens, but biologists think other adult polar bears don’t do so. However, polar bears in some populations regularly fast for extended periods when sea ice conditions don’t allow them to hunt. As for other bears, anything that causes a polar bear to expend more energy, whether inside or outside of a den, or to fast for a longer period of time, makes it less likely that the bear will survive. Climate change is doing just that by reducing the amount of sea ice available to polar bears: the bears expend more energy and go without eating for a longer period of time, creating a great challenge for the conservation of this species (see Polar Bears, Climate Change, and Mi Ton Teiow).

Hibernating bears often line their den with leaves, twigs, and grasses, insulating themselves from the cold ground and conserving additional energy.

Hibernating bears often line their den with leaves, twigs, and grasses, insulating themselves from the cold ground and conserving additional energy.

The Bear Specialist Group’s Ambassador Mi Ton Teiow recently made a visit to the northern US, where he found plenty of snow but little food for bears. After a short stay in this area, which receives an average of 45 inches of snow per year, the ambassador returned (fled?) back to sunny San Diego, where the last measurable snow fell on the city in 1967. The odds are good that Ambassador Mi will not be snow camping in San Diego any time soon.

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research. Read his previous post, Courtship in Front of the Camera.

11

Bear Courtship

This camera-trap photo shows a male Andean bear, left, being rebuffed by a female Andean bear.

This camera-trap photo shows a male Andean bear, left, being rebuffed by a female Andean bear.

To improve giant panda captive breeding programs, researchers have carried out numerous investigations of how male and female giant pandas communicate with each other, and how their hormone profiles change independently, and in response to each other. Applying this knowledge has contributed to the success of giant panda captive breeding efforts, which are now based on more information than is available for any of the other bear species.

In the dry forest of northwest Peru, where we’ve been working with the Spectacled Bear Conservation Society, there appear to be some relatively predictable cycles. Food for the Andean (spectacled) bears appears to be scarce for most of the year, so some of them turn to eating pasallo trees, and all of them gradually lose weight. Then, when the fruit of the sapote is available, the bears focus on that fruit and gain weight. We’ve suspected that the bears mate during that same season.

Although there isn’t much information on what courtship looks like among wild Andean bears, we suspect that males crisscross the landscape, looking for females that are in estrus and so may be willing to mate, or which will be ready to mate in the near future. Once a male locates a female, probably through some sort of olfactory communication that is similar to but different from the means used by giant pandas and polar bears, we think a male will then follow that female, trying to determine when it’s safest to approach her, while chasing off any other males that might also try to mate with her.

Like all bears, Andean bears are not social as adults, but obviously a male and female have to respond positively toward each other in order to mate. We believe that in Andean bears, like giant pandas, the coordination of reproductive readiness (and willingness!) is influenced by hormones, chemical cues, and behavioral interactions. A male has to get the timing right. If he approaches the female at the wrong time, she’s likely to vocalize loudly at him, box his ears, run away, or any combination of those alternatives. We’ve recently retrieved photos from a camera trap in the dry forest that suggests that one male, at least, didn’t quite time his approach correctly!

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research. Read his previous post, Bear Ambassador Learns Importance of Plants.

26

Bear Ambassador Learns Importance of Plants

Ambassador Mi Ton Teiow explores some bamboo growing at the San Diego Zoo. This bamboo represents the incredible horticultural collection of San Diego Zoo Global and a key component of giant panda habitat.

Ambassador Mi Ton Teiow explores some bamboo growing at the San Diego Zoo. This bamboo represents the incredible horticultural collection of San Diego Zoo Global and a key component of giant panda habitat.

We’ve mentioned in previous Bear Blog posts that some of the major threats to different bear species are habitat loss, or habitat degradation, or habitat fragmentation. As you can tell, for bear conservation it’s important to consider the amount and quality of bear habitat. For food, bears (except for polar bears) rely on plants. Thus, people concerned about bear conservation often become concerned about the conservation of the plant communities on which the bears depend. Although San Diego Zoo Global is involved in conservation of animals, it also does a lot of work with plants.

Recently I talked to botanists and horticulturists at the San Diego Zoo, and our whimsical Bear Ambassador, Mi Ton Teiow, was able to visit plants from bear habitats around the world. You might know that our horticultural staff grow most of the bamboo eaten by the giant pandas or the eucalyptus eaten by the koalas, but that’s just the beginning of what they do! I knew that certain parts of the Zoo contained plants related to some I’d seen in Andean bear habitat in the cloud forest of southeast Peru, but our horticulturists pointed out close relatives of plants that are important to Andean bears in the dry forest of northwest Peru, as well as plants from Australia, Hawaii, and Africa.

This flowering powder puff tree (Calliandra haematocephala) may catch your eye, but there’s more to the plant collection than what meets the eye.

This flowering powder puff tree (Calliandra haematocephala) may catch your eye, but there’s more to the plant collection than what meets the eye.

One reason they are able to grow such a diversity of plants at the Zoo is its variation in topography, which helps create a wide range of microclimates. I was surprised to learn that during winter, certain parts of the Zoo may receive frost at night! Of course, another reason the horticulture staff is able to grow such diverse plants is their research to understand just what the different plants need to grow and reproduce. Sometimes this research requires them to conduct experiments such as those in the lab to determine the best conditions for propagating orchid seeds, or field trips like those to investigate wild fig trees.

San Diego Zoo Global grows plants for many different reasons, and sometimes because the plants themselves are of conservation concern, plant species can be endangered, and captive reproduction can be an effective tool for plants as well as animals. In addition to plant conservation efforts, horticulture staff grow plants for several reasons related to animal husbandry. As I mentioned earlier, some plants are fed to the animals, providing them with more natural sources of nutrition than they would get otherwise. Parts of other plants are given to animals as a form of enrichment, especially because of their scents. When an animal shreds a few branches it’s been given, the animal is performing a natural behavior in a renewable manner: the horticulture department will grow more!

This diversity of plant species and structure may resemble tropical bear habitat, but it’s actually part of the horticultural collection at the San Diego Zoo.

This diversity of plant species and structure may resemble tropical bear habitat, but it’s actually part of the horticultural collection at the San Diego Zoo.

Woody plants are also used as structures in the animal enclosures. Large limbs, logs, and sometimes stumps are placed so that animals have items to rub on, climb on, and sometimes sleep upon. You can probably see our bears interacting with their log “furniture” any time you visit the Zoo. And, any time you visit, you can pick up a free map and take yourself on a self-guided walking tour of the botanical collection surrounding you. If you’re able to visit the Zoo on the third Friday of a month, you can explore the plant collections further. On those Fridays, called Plant Day & Orchid Odyssey, you can take a free narrated botanical bus tour to learn more about the plant collections, and you can visit the orchid greenhouse, which is home to more than 3,000 orchid plants!

The next time you’re visiting the San Diego Zoo or Safari Park, or a zoo elsewhere, take a closer look at the plants; they’re a whole lot more than “just” landscaping; they’re food, furniture, and enrichment for the animals and plant ambassadors of the habitats on which their wild relatives depend.

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research. Read his previous post, Bad News Bears.

0

Bad News Bears

Ambassador Mi and flag

Mi Ton Teiow, an international ambassador for bear conservation, rests near the commonplace image of a California grizzly.

The last update on the travels of whimsical bear ambassador Mi Ton Teiow focused on a meeting of zoo professionals working for the conservation of polar bears, and an earlier blog described how the American black bear illustrates that our efforts for the conservation of bears can succeed. We can also fail.

The International Union for the Conservation of Nature lists the brown bear as a species of Least Concern, meaning that it’s not likely that this species will go extinct in the near future. That’s the good news. And now, the bad news: Even though this is the bear species found across the widest area and the most diverse habitats, and its global population is stable, some brown bear populations are in critical condition. It’s not yet clear whether the Gobi brown bear is a separate subspecies of brown bear or if it’s a population of Himalayan brown bear, but it is clear that the Gobi brown bear is in trouble, with a population of less than 30 individuals due to various impacts of human activities. Conservation and research efforts are underway, but in the face of long-term changes in climate, there’s no guarantee of success.

The Cantabrian brown bear in the Pyrenees Mountains of Europe has been the focus of long-term intensive conservation efforts, but it is still not certain if those efforts will be successful. Other regional populations of brown bears are also the focus of conservation efforts, such as the grizzly bears in the northern Rocky Mountains of the US, but ironically, all around me in San Diego are symbols and images of a bear that once was but never will be again: the California grizzly.

This street sign reminds us that this developed landscape was once good habitat for the California grizzly.

This street sign reminds us that this developed landscape was once good habitat for the California grizzly.

Ambassador Mi recently traveled to the San Diego Zoo Institute for Conservation Research, which is headquartered at the Beckman Center for Conservation Research near Bear Valley Parkway. Bear Valley was named for a famous male California grizzly, a species that has been extinct since around 1924. Yet images of the California grizzly are common and widespread throughout California on the state flag and the state seal. In addition, many people wear clothes bearing (yes, pun intended!) the image of a California grizzly. Many sports teams use the California grizzly as a mascot, and many places are named for it.

The California grizzly faced challenges common to other bear species: habitat loss, habitat fragmentation, and high mortality due to unsustainable hunting and deaths due to real or perceived conflict and competition with the modern human economies. Unfortunately for the California grizzly, its populations crashed before modern conservation thinking, science, and planning developed to the point where people in the western US were willing and able to prevent its extinction. When the last California grizzly died, we lost this bear’s value as a part of the functioning ecosystem, and we lost a wonderful product of evolution. If it still survived, the California grizzly would be a symbol of our willingness to share existence with a large carnivore, but when it went extinct, most of us did not recognize the value of large carnivores. We recognize those values now, don’t we?
There is absolutely no doubt that there would have been disadvantages to living near California grizzlies. The negative aspects of living among bears are often forgotten by urban dwellers, as those stories fade with the passage of time and changes in lifestyles. What we’ve remembered are the positive traits and values we project on the bear, so that now the California grizzly lives on only as a cultural cartoon. Can we prevent another bear from becoming a cartoon of a ghost?

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research.

1

Black Bears: A Conservation Success

There are American black bears in Zion National Park. Ambassador Mi Ton Teiow, the special traveling “ambassador” of the Bear Specialist Group, paused for a photo here.

There are American black bears in Zion National Park. Ambassador Mi Ton Teiow, the special traveling “ambassador” of the Bear Specialist Group, paused for a photo here.

After the recent meeting of the IUCN’s Bear Specialist Group and the International Association for Bear Research and Management in Provo, Utah, I explored some bear habitat between Provo and San Diego and was reminded that one bear species in North America is an example of great conservation success: the American black bear. The IUCN (International Union for Conservation of Nature) maintains the Red List of Threatened Species, which is a global list of species and their conservation status. The American black bear Ursus americanus is listed as a species of Least Concern, primarily for two reasons. First, overall there are a lot of black bears. There may be twice as many American black bears as all the other bears in the world combined! Second, most populations of American black bears are stable or increasing, making this a great story of how a species can recover through conservation action and human tolerance. Some local black bear populations are not doing very well, but overall the prognosis for the species looks fantastically better than it did 100 years ago.

When European settlers reached North America, black bears were found throughout much of Canada, the US, and northern Mexico. There are once again black bears in most of those areas. However, there was a great decline in the number and range of black bears until the early to mid-20th century. In fact, I think that if the IUCN Red List had existed 100 years ago, the reduction in numbers and range of the American black bear would have led it to be listed as Endangered, which is the same category of conservation concern as the giant panda is now!

What led to such a dramatic decline in American black bears? The main causes were habitat loss, habitat fragmentation, overhunting, and conflict between humans and bears. These are the same issues that still threaten most of the other bear species. It’s taken decades and a lot of effort by many national, state, and provincial governments, conservation organizations, scientists, educators, and citizens, but the recovery of the American black bear illustrates that conservation of bears can succeed.

How did the recovery happen? A wide variety of actions were taken in support of American black bear conservation, including habitat protection, changes in bounties and hunting laws, changes in programs mitigating human-wildlife conflict, and more intensive efforts such as translocations and reintroductions. It’s also helped that this bear is an omnivorous habitat generalist, so although it is restricted to forested habitats, it can and will learn to eat a wide variety of foods, and it can live in fairly dense populations. That means that a population of American black bears can survive in an area that would be too small to support a population of brown bears.

Researchers with San Diego Zoo Global have collaborated with others to investigate various aspects of the physiology and behavior of American black bears, both to understand this species better and as a means to better understand other bear species. Doctors Barbara Durrant and Tom Spady have described the seasonally polyestrus, promiscuous mating system of the American black bear, showing that ovulation and conception occurs in each of a black bear female’s estruses during a breeding season. DNA analysis of preimplantation embryos proved that if a female mates with more than one male during the same mating season, the cubs born in her litter may be maternal half-siblings and not full siblings. Barbara and Tom also investigated the potential use of the hormone leptin as a wildlife management tool to monitor the adiposity (fatness) of American black bears and found that serum leptin measurements markedly improved the resolution and accuracy of common field estimates of body condition in this species.

A sign in the Olympic Peninsula of Washington reminds people hiking and camping in the forest that their behavior can have negative consequences for bears.

A sign in the Olympic Peninsula of Washington reminds people hiking and camping in the forest that their behavior can have negative consequences for bears.

Did you know that bears hum? Megan Owen has worked with others to study humming by bears, which occurs in all bear species but the giant panda. Most humming is done by cubs and is generally associated with suckling; however, the exact function of this behavior is still unknown. The relative loudness and very persistent nature of humming are puzzling! Further, we still don’t know whether the hum is an acoustic signal or whether its associated vibration physically stimulates the mother, perhaps enhancing milk production. Megan has also researched the interactions between mothers and their young cubs, in hopes of developing a better understanding of maternal care behavior and the range of variation associated with maternal care and cub behavior. Understanding this process in black bears may help us better understand the process in other bear species as well, including brown and polar bears.

Although the overall picture looks good for American black bears, as populations of both bears and humans have grown, new conservation challenges have developed. Because American black bears are fairly quick to learn to feed on new food sources, whether or not those food sources are “natural,” black bears learn to feed on foods they get from humans, whether the humans want them to or not. This leads to new conflicts as the bears use their intelligence and strength to seek the most profitable food source available. If you are fortunate enough to live or recreate in bear country, you can help bears and bear conservation, and avoid damage and risk from food-habituated bears, by ensuring that bears don’t get access to any human sources of food. That includes foods like pet foods, seed in bird feeders, greasy barbecue grills, garbage, etc. With your help, the support of citizens like you, and effective conservation actions, the American black bear can continue to be a great conservation success story.

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research. Read his previous post, Whimsical Bear Ambassador Arrives.

493

Whimsical Bear Ambassador Arrives

Ambassador Mi travels the world in an effort to aid in the conservation of bears.

Ambassador Mi travels the world in an effort to aid in the conservation of bears.

There are eight bear species living today, and, until recently, the San Diego Zoo hosted ambassadors for five of them. We’re happy to announce the arrival at San Diego Zoo Global of another bear ambassador: Ambassador Mi Ton Teiow, also known as Traveling Bear. Ambassador Mi represents all eight living bear species as the special traveling ambassador of the International Union for the Conservation of Nature’s (IUCN) Bear Specialist Group (BSG). As such, Mi travels “to gain worldly experience and aid in bear conservation endeavors” and to promote the conservation of bears.

Ambassador Mi was “born” in the Lao People’s Democratic Republic and has since traveled to Canada, South Korea, India, Venezuela, and the US (Minnesota). Mi was officially posted to the San Diego Zoo Institute for Conservation Research (ICR) at the recent conference of the International Association for Bear Research and Management in Utah, and plans are underway for Mi to travel with our staff both internationally (China, India, and Peru) and within the US before traveling to Greece in October 2014. This bear gets around!

Although you may never have heard of the IUCN or the BSG, these are among the most credible international groups for the conservation of wildlife, and bears. The IUCN is the world’s oldest and largest global environmental organization, composed of more than 1,200 member organizations, including more than 200 governmental and 900 nongovernmental organizations. The BSG is one part of the IUCN, and it is made up entirely of more than 200 volunteer scientists from around the world. Several of our scientists are part of the BSG in various Expert Teams, including Ron Swaisgood (co-chair, Giant Panda Expert Team), Megan Owen (member, Captive Bear Expert Team), and Russ Van Horn (member, Andean Bear Expert Team). Many Institute staff members belong to other Specialist Groups within the IUCN (e.g., the Iguana Specialist Group, the Tapir Specialist Group), providing technical advice and mobilizing action for the IUCN as it works to “find pragmatic solutions to our most pressing environment and development challenges.”

Ambassador Mi Ton Teiow of the BSG was officially posted to the delegation from the San Diego Zoo Institute for Conservation Research on 17 September, 2013. From left to right: Megan Owen (ICR, BSG), Lorraine Scotson (BSG), the author, Ron Swaisgood (ICR, BSG), Barbara Durrant (ICR), Dave Garshelis (BSG), and Emre Can (BSG). Photo credit: Dr. Mei-hsiu Hwang, National Pingtung University of Science & Technology and the Taiwan Black Bear Conservation Association

Ambassador Mi Ton Teiow of the BSG was officially posted to the delegation from the San Diego Zoo Institute for Conservation Research on September 17, 2013. From left to right: Megan Owen (ICR, BSG), Lorraine Scotson (BSG), the author, Ron Swaisgood (ICR, BSG), Barbara Durrant (ICR), Dave Garshelis (BSG), and Emre Can (BSG).
Photo credit: Dr. Mei-hsiu Hwang, National Pingtung University of Science & Technology and the Taiwan Black Bear Conservation Association

Now, all of this probably sounds pretty bureaucratic, dry, and abstract, which might be part of why you can’t remember ever hearing of the BSG or the IUCN in spite of their conservation significance. However, given Mi’s colorful personality, willingness to put up with inconvenient travel without complaining, and hardiness in the face of harsh field conditions, we hope you’ll find Mi’s adventures to be enjoyable, memorable, and educational about bear conservation. Mi’s earlier travels have included a visit to the den of an American black bear, participation in technical scientific conferences, representing the BSG at the World Conservation Congress during a debate on curtailing bear farming, hiking to the highest point in South Korea, and waterskiing. Welcome to San Diego Zoo Global, Ambassador Mi Ton Teiow!

Russ Van Horn is a scientist with the San Diego Zoo Institute for Conservation Research. Read his previous post, Andean Bears and Their Favorite Food: Sapote.

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.

1

Peru: Conservation Science at Local Level

The SBC field team Isaí Sanchez, Javier Vallejo, and José Vallejo) practices the collection of behavioral observations on domestic sheep.

“Se ha producido el error ‘2176’ en tiempo de ejucución; el valor para esta propiedad es demasiado largo.”
Okay, that’s not good. Let’s try it again. Go ahead and click on the “save” icon.
“No se ha encontrado la ruto de acceso.”
Well, that’s just great.
Isn’t it about time for a coffee break?

In other words, we had some unexpected troubleshooting to do. The plan was that I would work with the team from the Spectacled Bear Conservation – Peru (SBC) and a Peruvian university student (Álvaro Garcia) to create a database for the management and analysis of the photos from the camera traps in the dry forest. The programming to create databases like this was written by Mathias Tobler, a large-mammal ecologist now with the San Diego Zoo Institute for Conservation Research. I’d successfully tested this programming, called Camera Base, with photos from camera traps in southern Peru. Unfortunately, we couldn’t get it to work right with the dry forest photos. Eventually, Mathias was able to help me identify the problems, which is a big relief since the database will make it much easier and faster to conduct analyses on the data from the camera trap photos.

One of the goals of the Andean (spectacled) bear program, and much of the work of the Institute for Conservation Research, is to train people from wherever we work to conduct conservation science. So, I’m excited that more Peruvians are now getting involved in the program and learning new techniques. The SBC field team members also continue to expand and hone their skill set. For example, we’ve developed protocols by which they’ll be able to collect data by observing the behavior of wild Andean bears in the dry forest. These methods are derived from standard practices in the fields of behavioral ecology, and they’ve been used to study the behavior of captive bears of several species, including those at the San Diego Zoo.

However, the practice of behavioral ecology is not common in Peru, so we’re breaking new ground, and it’s a challenge for me to convey to the field team the underlying concepts and technical issues involved in collecting behavioral data. So, to ensure we’ve got it right, we practice our technique. Sometimes this appears a bit strange to the neighbors. How do you explain to the guy next door why four people are intently watching his flock of sheep, not saying a word, and making notes on clipboards every minute? Ah, this is conservation science!

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, Dry Forest Rain.

1

Biodiversity at Cocha Cashu

Early morning on the lake at the Cocha Cashu Biological Field Station

As someone interested in nature, and as a scientist with San Diego Zoo Global, over the years I’ve been fortunate enough to see four of the world’s eight bear species in the wild. Often these sightings occurred in circumstances that left my heart pounding with wonder, although I admit that once or twice I’d have preferred to know beforehand that all would end well. How many bear species can you list, without referring to a reference? Similarly, how many primate species can you list? They may be big charismatic mammals, but both bears and primates are a tiny fraction of the biodiversity in our world. On a recent trip to the Cocha Cashu Biological Station in southeast Perú, I gained a much better appreciation for the biodiversity of the lowland Amazonian rainforest. You’ve probably heard that tropical rainforests have incredibly biodiversity, but it’s one thing to ‘know’ in your head that the rainforest features amazing biodiversity, and it’s something else to ‘know’ it from experience.

A white-fronted capuchin monkey at the Cocha Cashu Biological Station

Jessica Groendijk, education and outreach coordinator for the Cocha Cashu Biological Station, has written about how she and I began a morning at the field station. We saw giant river otters in the wild! Thus began a truly memorable day in the field. After returning to camp, I quizzed Jessica over breakfast on her interpretation of the otters’ behavior, and various aspects of their ecology. Patiently she explained what was known and not known about giant river otter behavior, ecology, and conservation. She politely refrained from reminding me that most of this information was included in the book on giant river otters she co-authored with her husband. I did read the book, honest! It’s just that I read it a few years ago, and I hadn’t yet had my first cup of coffee…

After fueling up, we grabbed our gear and left camp with Cesar Flores, director of the Cocha Cashu Biological Station, and Luis Ramirez and Samantha Young, both of San Diego Zoo Global’s Conservation Education division, to become more familiar with the habitat and animals surrounding the field station. I’ve spent much more time in the cloud forest, and the tropical dry forest, than in the lowland Amazon rainforest, so the Amazon is like a different world to me. In my humble opinion, it is truly wonderful, in the full sense of that word.

The forest canopy at Cocha Cashu Biological Station

By the end of this day at Cocha Cashu, Jessica and I had not only seen giant river otters (!) and numerous bird species, we’d also seen seven species of wild primates: white-fronted capuchin monkeys, brown capuchin monkeys, spider monkeys, common squirrel monkeys, red howler monkeys, saddleback tamarins, and emperor tamarins. My heart got a decent workout.

Cocha Cashu has long been known as a great place to conduct biological field research, to better understand how things work in the lowland Amazon rainforest. After seeing the improvements Cesar and his staff have made since I last visited the station, and talking to these folks about their vision and goals, I’m hopeful that Cocha Cashu will continue to be a source of knowledge, and that this knowledge will help guide efforts to conserve the lowland rainforest and its diverse components.

Thanks again, Jessica, for allowing me to share a wonderful morning on the lake at Cocha Cashu, and thanks to Cesar and all the other people in Perú and in the US who made our visit, and our involvement at Cocha Cashu, a possibility.

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, Are Wild Areas a Luxury?