Applied Animal Ecology


Burrowing into Owl City

Nan holds a burrowing owl chick.

Nan holds a burrowing owl chick.

Being a native San Diegan, the world-famous San Diego Zoo and Safari Park had an immense impact on my interest in the natural world during my early adolescent years. One thinks of the word excellence when it comes to the Zoo and Safari Park being able to showcase rare and endangered plants and animals from all over the globe. Yearly visits to the Zoo and Park instilled many valuable lessons. The most valuable lesson of all: to be able to personally experience biodiversity at such an intimate level was, and still is, an extreme privilege.

Naturally, these types of experiences eventually led me to pursue bachelors of science degrees in biology/ecology and environmental sciences at San Diego State University. Realizing that the activities of humans had a direct impact on vulnerable species and ecosystems around the world, and having an innate desire to make a positive difference in the field of conservation, I made a commitment to myself to become a conservation scientist. I was then extremely excited to find out that I had been selected to conduct research as the Sefton Summer Research Fellow within the Applied Animal Ecology (AAE) Division of the San Diego Zoo Institute for Conservation Research.

A burrowing owl family peers at the researcher studying them.

A wild burrowing owl family peers at the researcher studying them.

This summer, my research project focused on a very charismatic species of concern in our very own backyard: the western burrowing owl. Once thought to be thriving in San Diego County, burrowing owls are now a rare sight, due to habitat loss, fragmentation, and degradation due to human activity. With the help from my super team of AAE mentors—Dr. Lisa Nordstrom, Colleen Wisinski, and Susanne Marczak—we are currently seeking how to answer such questions as: how do burrowing owls select their nesting habitat from different spatial scales? Do burrowing owls reproduce more successfully when nesting in artificial burrows or when nesting in natural burrows excavated and engineered by California ground squirrels?

To help gain valuable information about burrowing owls and their habitat, I had to learn how to conduct habitat assessment surveys, extract soil cores for soil texture analysis, identify many different types of exotic and native grassland and coastal sage scrub vegetation, and use state-of-the-art computer software such as geographic information systems to tease apart the environmental factors that may potentially affect owl site selection at different spatial scales. To obtain these types of data, many long, grueling, yet very fun and fulfilling hours were spent outside in the field and inside the Ellen Browning Scripps Spatial Ecology Lab.

Nan feds a rhino during a Caravan Safari at the Safari Park.

Not all work and no play! Nan feds a rhino during a Caravan Safari at the Safari Park.

I’ve also had a number of various experiences this summer that complemented my internship, which included releasing translocated California ground squirrels to new study sites, releasing critically endangered mountain yellow-legged frogs into their native creek habitat in the San Gabriel Mountains, and getting up close and personal with the giraffes and rhinos on a spectacular Caravan Safari at the Safari Park.

My goal for this summer was to have a better understanding of what it took to become a scientist in applied animal conservation, and I feel that I have definitely met those expectations from working closely with a wonderful and intelligent team who truly cares about effectively protecting the planet’s threatened wildlife with well-thought-out science. Though I am only in the infant stages of my scientific conservation career, the experiences this summer at the Institute for Conservation Research have definitely provided me with unique insights, valuable learning experiences, and a solid foundation on what it takes to become a conservation ecologist.

Nan Nourn is the 2013 Sefton Summer Research Fellow for the San Diego Zoo Institute for Conservation Research.


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.


The Roo-Rats of Temecula

A juvenile Stephen's kangaroo rat

A juvenile Stephen’s kangaroo rat

Between 2008 and 2011, we conducted several translocations of the endangered Stephens’ kangaroo rat, creating or supplementing populations in the Southwestern Riverside County Multi-Species Reserve. This fall, we continued to monitor their success by trapping at each of the sites to check on their progress in the wild. When we capture a “roo-rat,” we always record its sex, age, weight, location, and tag number if it has one or tag it if it’s new. This provides us with valuable information about each population.

This year, we successfully trapped hundreds of roo-rats, including many reproductive adults and independent young of the year. More than half of these animals were new roo-rats that we tagged during the trapping week. This suggests that despite this being a year with heavy predation pressure, Stephen’s kangaroo rats are persisting at each site in good numbers. Their natural predators include coyotes, owls, and rattlesnakes.

Our North Shore site was interesting because there were so many cottontail rabbits there. They often ate the trap bait, a combination of white millet and oats, and often bumped or turned over our traps. At all of our sites this season, captures of other species such as deer mice and San Diego pocket mice were low. This suggests that their numbers may be low due to competition with the roo-rats.

The North Shore site (lake Skinner in the background) with traps and flags

The North Shore site (lake Skinner in the background) with traps and flags

At Bachelor Mountain, near Lake Skinner, herbicide had been used to remove invasive plants and grasses, resulting in open ground with small native shrubs such as doveweed. This was an effort to increase possible habitat area and create corridors between the sites for the roo-rats. Their colonization appears to be restricted by dense grassland with complete ground cover. We found that a few had moved across a road into a corridor area. Furthermore, in 2011 a few San Diego kangaroo rats, a common species, had been trapped at site D. This season, we did not trap any San Diego roo-rats at site D. We only trapped one of them overall, suggesting this species is not moving into Stephen’s kangaroo rat habitat.

An adult Stephens’ kangaroo rat with ear tags

An adult Stephens’ kangaroo rat with ear tags

Crown Valley proved to be a difficult site to trap this year. We had coyotes hunting and trying to steal traps. We had to use a hand-held spotlight and air horns to chase them away. This meant little sleep and long, vigilant watches over our little critters. A few rattlesnakes were also spotted at night during trapping. Crown Valley has six pie-shaped research sites with slices that have been mowed, grazed, and burned to create open grassland environments. In 2010 and 2011, we planted nearly 20,000 native grasses at these sites (see Kangaroo Rats Get Home Improvement). It was initially obvious that there were many more burrows on the slices with native plants, thus we put 52% more traps on those areas. Burrow counts on each site support this. For instance, Site 5 slices with plantings had 109, 95, and 108 burrows, and those without had 20, 17, and 10 burrows. Furthermore, we had 454 captures on the slices with plantings compared to 97 on slices without plant restoration, a four-fold differences in animal captures. This suggests that the native plants are really doing their job at making a nice habitat for roo-rats.

The Schoolhouse Plateau site at Lake Skinner

The Schoolhouse Plateau site at Lake Skinner

Our last site of the season was the Schoolhouse Plateau at Lake Skinner. This site is so large that every year we randomly trap half the site and estimate the population. The plateau is the size of several football fields. This site had many jackrabbits, but they did not bother the traps much. However, we did have issues with ants stealing the bait and infesting our traps. This site is also known for black widows, as they commonly coexist with roo-rats by sharing burrows. The roo-rats often use borrows with black widow spider webs across the entrance. We always had to look before we sat down, especially in the dark!

We will continue to track the progress of Stephen’s kangaroo rats with annual trapping and burrow counts for population estimates. In addition, we will continue to conduct behavioral research (see No Night-lights for Kangaroo Rats) and participate in an inter-departmental study on the species’ landscape genetics. Continuing to increase knowledge about these little animals is vital in protecting an endangered species and in making successful management plans.

Christine Slocomb is a senior research technician in the Applied Animal Ecology Division at the San Diego Zoo Institute for Conservation Research. Read her previous post, Endangered Rats and Mice: Unexpected Results.


Bling with a Purpose

Bands used on cactus wrens and burrowing owls, far left is aluminum wren band, middle are wren color bands, far right is alphanumeric band for owls.

Bands used on cactus wrens and burrowing owls, far left is aluminum wren band, middle are wren color bands, far right is alphanumeric band for owls.

Bird banding is an important tool for researching wild birds, allowing them to be individually identifiable in the hand or by sight. This can be especially important for birds that are too small to carry tracking devices such as radio collars or GPS tags. Both conservation research projects that I work on involve understanding some aspect of the population dynamics of birds that are too small to put transmitters on: coastal cactus wrens and western burrowing owls. An alternative method of distinguishing individual birds is to mark them with color or alphanumeric bands, in addition to standard aluminum bands from the US government, which are required for all banded birds and have a unique ID number.

This cactus wren sports a unique color band combination.

This cactus wren sports a unique color band combination.

To mark cactus wrens, we use plastic bands that come in several different colors and also have our US government aluminum bands dyed green so as to distinguish them from bands used by other organizations also conducting research on cactus wrens in southern California. Each wren gets two bands on each leg (two plastic on one leg, one plastic and one aluminum on the other), giving us lots of combinations to work with so that each wren has a unique color combination. In the field, we use binoculars, spotting scopes, and photographs to identify individual birds. Because we know where and when each bird was banded, we can get a sense of how long the birds live, how far they move, and how they interact with each other.

Federal and state governments both require researchers to have a permit to band birds, and obtaining one can be a lengthy process because it involves gaining a lot of experience with bird handling and capture techniques. Throughout my academic and professional career, I have been involved with capturing and banding many different species of birds, but only at a trainee/apprentice level. Recently, I took a class in bird banding through University of California, Riverside, Extension to gain additional experience with mist netting and banding of small passerines (songbirds).

A Gambel’s white-crowned sparrow is caught in a mist net.

A Gambel’s white-crowned sparrow is caught in a mist net.

Mist netting is a commonly used technique for capturing songbirds; mist nets are made of very fine material that is difficult to see when set up properly. They are usually set up in high flight traffic areas (e.g. between trees or shrubs), and when the birds fly into them, they are caught in a pocket and become slightly tangled. The nets must be checked often or watched from an inconspicuous location so birds can be removed in a timely manner. Although we already use mist nests to capture cactus wrens, taking the class allowed me to gain a lot of additional practice in extracting birds from the nets. We also had the opportunity to work with many different bird species that we don’t usually catch.

After a bird was captured, we identified its species, banded it, determined its age and sex, and took standard morphometric measurements. Determining the age of birds can be very difficult, and in many cases you can only say that a bird is a juvenile of that year (a hatch-year bird) or an adult (an after-hatch-year bird). We learned how different feather wear and molt patterns can be used to determine the ages of the birds we caught. We also assessed body condition by looking at fat deposits on the breast and hips (birds have very thin skin, so it is easy to see the fat layer just below the skin). Over the course of the weekend, we captured and banded almost 300 birds! We also recaptured birds that were banded in the past and recorded their band numbers. All of the data collected will be given to the Federal Bird Banding Lab (part of the US Geological Survey) and used to look at trends in bird populations across the country.

Steve Myers (instructor) bands and takes body metrics of lesser goldfinches.

Steve Myers (instructor) bands and takes body metrics of lesser goldfinches.

This experience will help me in the permitting process and proved to be an invaluable opportunity to learn new skills and get lots of practice with banding and mist netting. I can’t wait to get out and put my new skills to use. Watch out, cactus wrens, here I come!

Colleen Wisinski is a senior research technician in the Applied Animal Ecology Division at the San Diego Zoo Institute for Conservation Research. Read her previous post, A Sense of Wonder for Wildlife.


No Night-lights for Kangaroo Rats

Alicia sets up the test site.

Anthropogenic light pollution due to man-made artificial light sources such as streetlights, car headlights, businesses, and even homes is common throughout the US. Artificial light can cause disorientation and ineffective foraging and/or escape behavior for many animal species. Impact studies have been conducted on sea turtles, bats, and insects, but little research has been done to understand the effects of artificial light on nocturnal ground mammals. The nocturnal Stephen’s kangaroo rat has eyes adapted for sharp nighttime vision. Studies of other kangaroo rat species have suggested that bright moonlight may decrease foraging and activity rates due to increased visibility to predators such as owls or coyotes.

Bug light array

This summer, Alicia Bird, our Frabotta Summer Fellow in Applied Animal Ecology, examined the impact of anthropogenic light pollution on Stephen’s kangaroo rat foraging behavior. The kangaroo rats are endangered, and they only persist in a few remaining fragmented habitats throughout San Diego and Riverside counties. Their preferred habitat is open temperate grassland. As their habitats are encroached on by human development, it is important for us to learn how our activities and further development might affect this species’ survival.

Alicia set up multiple arrays on our research site at Lake Skinner, just outside of Temecula, California. This site has previously been home to several of our ‘roo rat studies, including translocations (see Roo Rats Released!). Each array contained a series of cardboard trays set in a row at increasing distances from an artificial light source. Trays were level with the ground and covered with dirt.

The flood-light treatment is powered by a solar panel and car battery.

Over a period of about a week on a new moon night, Alicia placed 12.5 grams of seed on each tray and turned on the lights just before sunset. We used three light treatments: a low-watt bug light, a flood light, and a “no light” control. Alicia returned to the site just before sunrise to collect, sift, count, and/or weigh the remaining seeds. ‘Roo rats are granivores, or seed collectors, that use their cheek pouches to carry seeds to caches in their complex burrow systems.

Tracks and tail drags in the sand where used to assess their foraging presence. Cottontail rabbits were also found at this site; however, their presence did not affect the amount of seed foraged. The rabbits did have fun chewing on the wires of the lights, so Alicia had to bunny-proof them with wire mesh!

Significantly more seeds were collected from the control arrays compared to the bug and flood light arrays. There was little difference in the amount of seed foraged between the bug and flood light treatments. However, there was a difference in the distance at which each artificial light treatment impacted foraging activity. The bug light reduced foraging activity within 15 meters of the light source, whereas the floodlight affected foraging up to 35 meters away. Overall, this project suggests that kangaroo rats reduce their foraging levels under artificial night lighting.

Kangaroo rat tail drags are visible in a foraged tray.

Currently, there are no regulations on development near Stephen’s kangaroo rat habitats. They are often described as keystone species in grassland communities; therefore, the disturbance created by artificial night lighting may have far reaching influence over predator-prey relationships and species competition at the community level. Further study is needed to understand if these little mammals can habituate to artificial light and if it ultimately affects their survival in areas with ecological light pollution.

Christine Slocomb is a senior research technician at the San Diego Zoo Institute for Conservation Research. Read her previous post, Kangaroo Rats and Pocket Mice Burrow In


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.


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.


Are Wild Areas a Luxury?

A critically endangered white-winged guan in Peru's northwest

There was some disturbing news from northwest Peru, near where we’ve been working in the dry forest on Andean (spectacled) bear conservation research in collaboration with the Spectacled Bear Conservation Society: some local hunters had poached white-winged guans within a private, protected area. The white-winged guan, a bird somewhat similar to a wild turkey, was thought to be extinct until rediscovered by scientists in 1977. Efforts to breed it in captivity and reintroduce it to the wild have been ongoing for the last few decades, but although the population has increased, it is thought there are less than 300 adult white-winged guans in the wild. The species is listed as critically endangered by the International Union for Conservation of Nature (IUCN), the world’s largest global environmental network.

It would be easy to simply condemn poaching of white-winged guans as a shortsighted, illegal act, but this wouldn’t address the question of why the guans were hunted. One of the long-standing threats to guans has been hunting, and now poaching, for their meat. Like turkeys in North America, guans are large birds that taste good to humans. I wonder, then, whether the guans were killed for food. If so, this should lead us to consider a contributing factor in poaching: poverty and the lack of options that go along with it.

A camera-trap photo shows several white-lipped pecarries in the humid transitional forest of Cusco, Peru.

Every year there are many instances around the world (including North America) of wildlife poaching for trophies, for the commercial trade in their body parts, and for the commercial trade in wildlife as bushmeat. But there are also many instances of poaching for consumption by local residents living next to protected areas. This type of poaching illustrates the need to engage local residents in conservation actions and the need to work toward the sustainable development of local economies. If local people are struggling to make ends meet, and they don’t see benefits from conservation, don’t you think they might consider it a luxury to set aside wild areas and wild animals for conservation?

A camera trap photo shows a collared peccary in the humid transitional forest of Cusco.

I’m not sure, but I suspect that past over-hunting of peccaries in the dry forest might explain why they’re rarely detected by our camera traps. Two species of peccaries, the white-lipped peccary and the collared peccary, have been frequently photographed by camera traps in humid forests of Cusco at the same elevation as the dry forest of Lambayeque, but it’s rare for camera traps in the dry forest to take photos of peccaries. Perhaps the dry forest is not good habitat for peccaries, but given that collared peccaries range across a wide variety of habitats, including other dry forests, I wonder whether their scarcity at our study site reflects past predation by hungry humans.

It’s nothing new to say that most conservation challenges arise from human actions, but it seems clear that we can’t address those conservation challenges without also considering the challenges facing the humans who live where we work. I don’t know much about how to manage the human component of conservation, so I’m glad that Samantha Young (see post Scientific Concepts for Non-scientists) and the rest of our Conservation Education Division are starting to work with us in the dry forest. We can use all the expert assistance we can get!

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, The Bear Necessities.


Pandas: Unraveling a Mystery

A wild panda rests in a tree in China's Foping Nature Reserve.

A male panda sits, hour upon hour, lazily grabbing bamboo stems, pulling them to his mouth, where powerful jaws and crushing teeth make short work of it. A few hours later, it comes out the other end, changed little by the passage through his intestines. After a few days of this routine, intermittently sleeping and eating in a circumscribed area, the panda rouses and begins heading up the slope. He pushes through the dense bamboo, slow and shuffling but somehow graceful.

Upon reaching the ridge, he enters a different world—the dense bamboo gives way to open understory beneath a towering canopy of ancient spruce and fir trees. It’s a pleasant enough place for a picnic, but for pandas, the picnicking is better below in the valley. This panda has come here not to eat but to communicate: this ridge is like a community bulletin board, and scent messages are posted on these ancient trees.

Every move a panda makes is calculated to conserve energy. Even his placement of scent marks is efficient. He walks past a smooth-barked tree in favor of one with rough bark, lifts his tail, and rubs his gland in a circular motion. His scent is spread across little crevices that increase the surface area, maximizing the “odor field” of his scent. He approaches another tree and sprays urine over the trunk while doing a handstand.

He chooses a large tree, lest he miss his target and let the golden message fall to the ground. He needs his urine mark to be up high; it will waft farther through the air where it is more likely to capture the attention of a passing panda. The height of his mark also conveys his status; other pandas will read “dominant male,” at least in this neck of the woods. For a urine mark, he chooses a tree with ultra-rough textured bark that captures the urine, keeps it from trickling down the trunk, and perhaps keeps it from washing off easily in the frequent rainfall characteristic of these Chinese mountains.

Other pandas will be able to read his urine mark for about two weeks, but the mark from his gland will last four months! This way he does not to have to climb back up to the ridge again for a few weeks. He ambles further down the ridge path, stopping to sniff the marks left by pandas that have come before him. This one, his nose tells him, comes from a young male that came here and left his scent several weeks ago; it represents no threat.

The next one, however, came from another large dominant male. He has tangled with him before, he remembers, and two years ago this male bested him in a long, drawn-out contest for access to a fertile female. The next mark encountered really gets his attention: it’s from that same female, and she is again nearing her fertile period. After leaving the scent ridge, he will expand his range in search of signs of this female. She will be marking frequently now, and several males will catch her scent and track her down. There’s bound to be trouble.

Such is the life of a giant panda. I can be relatively certain about my scenario only because of years of study, working with many partners and colleagues at breeding centers in China and wild pandas at the Foping Nature Reserve. Our collective effort allows me to paint this picture and begin to unravel the mystery of this rare and difficult-to-study species.

We now know, for example, that pandas require very different habitats for communicating with one another than what they need for foraging. We must work to protect all the panda’s habitat, including the palette upon which they paint their scent messages.

Ron Swaisgood is the director of Applied Animal Ecology, San Diego Zoo Institute for Conservation Research and co-head of the San Diego Zoo’s Panda Team. Read his previous post, Cocha Cashu: Exploring Uncharted Territory.

Author’s note: The story described here is derived from years of collaborative research with many partners, most prominently Professor Wei Fuwen’s Key Laboratory for Ecology and Conservation Biology at the Institute of Zoology at the Chinese Academy of Science and the China Conservation and Research Center for the Giant Panda.

Photos courtesy of the Institute of Zoology, Chinese Academy of Science.

Visit San Diego Zoo Global’s Wildlife Conservancy website for photos, videos, and great stories of our work to help wildlife near and far.


Pacific Pocket Mouse: Help Is on the Way

An adult Pacific pocket mouse

Back in 2006, at the beginning of my postdoctoral fellowship with the San Diego Zoo Institute for Conservation Research, I began a project to translocate the critically endangered Pacific pocket mouse. Like many San Diegans, this pocket-sized mouse lives in Southern California’s coastal zone. It’s actually endemic to the region, meaning that it is found here and nowhere else.

Several years later, I am now our Brown Endowed Scientist in the Institute’s Applied Animal Ecology Division. I have translocated several hundred endangered Stephens’ kangaroo rats over three years but have yet to translocate a single pocket mouse. I learned a great deal about the species by studying them in the wild at Marine Corps Base Camp Pendleton, but our trapping efforts indicated that there were simply too few remaining in the wild to risk translocation.

Because of the status of the species, we have decided that we have reached that critical point with Pacific pocket mice where removal of individuals from the wild to establish a conservation-breeding program is necessary. The regulatory agencies and land managers have agreed, and we have secured funding to begin to breed this adorable mini-mouse in managed care. We have a lot of work ahead of us but are excited about facilitating recovery of the Pacific pocket mouse (PPM).

First, we have to design a facility for the species, which will be located on grounds but off exhibit at the San Diego Zoo Safari Park. In 2012, we will bring founders into the facility and begin behavioral experiments to better understand the species and, yes, hopefully, to breed them and produce lots of babies! We hope to grow the captive population to as many as 200 individuals and begin releasing groups of 50 annually. My valuable senior research tech, Maryke Swartz, and new graduate student, Rachel Chock, and I will be the core Pocket Mouse Team.

We will keep you updated on the status of the program and our journey as we attempt to use science and the Zoo’s longstanding “know how” to recover this critically endangered species.

Debra Shier is the San Diego Zoo Institute for Conservation Research Brown Endowed Scientist. Read her previous post, Kangaroo Rats Dig Mountain Lions!