Posts Tagged ‘lemur’

Internship Weeks 6 & 7: Are the Lemurs Reading?

by | August 29th, 2012

Intern Stephanie Lo

Gripping a stopwatch, pen and clipboard in the palms of my hands, I walk up towards the Oakland Zoo‘s lemur deck to conduct observations. Typically directly after serving one of their meals, the other intern and I will pick two lemurs and record their behavior for up to an hour. The behavior categories include interacting with enrichment, which we vary throughout the week. By recording how much time a lemur spends on a particular activity, we can construct a graph of their “typical day.” When I first began interning on String 7, it was difficult to identify and tell apart any of the lemurs. Now, I am able to distinguish the animals apart by their physical characteristics and personality.


Ring tailed lemurs interacting with phone book enrichment item.

“Are the lemurs reading?” one visitor asked me after I served their lunch. No, the phone books were one of the manipulative enrichments used this week. Stuffing pieces of produce between the phone book’s pages encourages the lemurs to manipulate the item to reach the food. By conducting observations of the lemurs, I can later analyze the data and compare the effectiveness of each enrichment item. Even though PVC pipe connectors, cat litter containers, and cardboard boxes sound like an odd combination, they are other examples of manipulative lemur enrichment. Both the plastic cat litter containers and cardboard boxes contain holes into which the lemurs must reach, and we sometimes use clips to hang up two of the plastic containers.


Eugene and Anthony, the two blue-eyed black lemurs, slowly approached me while eyeing the dried cranberries in my hand. I felt the smoothness of Eugene’s palms as he reached out to grasp the cranberry. His aquamarine eyes darted around as he chewed the sliver of cranberry. On Wednesday morning, I got the chance to assist the zoo keeper with cooperative feeding out on exhibit. Cooperative feeding rewards the dominant individual for letting the subordinate individual to eat in its presence. The male ring tail lemur, Jeager, is subordinate to the three female ring tail lemurs; the two blue-eyed black lemurs are also subordinate to the females. Every time the dominant female saw me feed the blue-eyed black lemurs that were about 10 feet away, the zoo keeper would reward her for not chasing them away. Helping with cooperative feeding is an opportunity to work closely with the lemurs and observe how it shapes their behavior.


One of the Oakland Zoo’s vet technicians led this week’s behind-the-scenes tour  of the Veterinary Care Center (VCC). I got to see some of the portable equipment the VCC staff uses, such as the anesthesia and x-ray machines. The vet technician showed us the various sizes of tracheal tubes used for anesthetizing the zoo animals, which range in size from a small bird to an elephant. She said that the VCC sometimes will coordinate with other veterinarians for major procedures. For the larger animals, such as elephants and lions, the VCC staff can exam or treat them in their night house because they will not fit into the surgery room.

Wooden feeders are an example of manipulative enrichment.

Plastic cat litter containers have holes cut in the sides. They can be hung up in the exhibit so lemurs must balance and reach inside for food items.

Cardboard boxes can be filled with straw and the lemurs’ food.



Internship Week 5: Pig Walking and Lemur Watching

by | August 15th, 2012

Intern Stephanie Lo

Throughout this week of my internship, I got to both learn more about operant conditioning and participate in training a few zoo animals.


We turn on a misting hose in the guinea hogs' exhibit on warm days.

The week began with walking Jason and Sara, the two Guinea Hogs, up to the Oakland Zoo‘s Veterinary Care Center to weigh them. Three other interns and I worked to harness them and continue the training we started last week. Two of us were in charge of delivering the reinforcement; in this case it was a variety of chopped produce. The other two held the leash, harness and clicker. It was important the rate of reinforcement was not too low or the Guinea Hogs might lose interest and turn to foraging. When training any animal, especially one that is as large and strong as a Guinea Hog, it is imperative to be alert to your animal. For instance, Sara is afraid of large and loud trucks so we remained aware of our surroundings while leaving the Children’s Zoo. In this week’s intern class on operant conditioning, I learned that escape is a primary reinforcer and permanent associations about something can last for years.


Patrick, one of the Nubian goats, in the main stall of the contact yard.

As part of the routine animal husbandry, zoo keeper Alan works with the goats and sheep to trim their hooves. During this week, I got to give out the reinforcement, which was food, to the sheep during the training session. Although the zoo keepers oftentimes use clickers to mark the behavior, Alan whistles instead because he uses both his hands to hold the animal’s leg and to hold the pair of hoof trimmers. The sheep appeared more skittish than the goats about hoof trimming. Alan had them stand on a mat during the training session, and he also worked to desensitize one of the sheep to touching its hind legs in preparation for the actual trimming part.


A ring tail lemur interacting with enrichment. The PVC connector stuffed with food and straw is a form of manipulative enrichment.

As I mentioned in my Week 2 blog post, the lemurs get daily enrichment, which I mark on the calendar. String 7 zoo keeper Liz organized the list of possible enrichment into categories, such as manipulative, environmental or sensory. Manipulative enrichment includes putting food into containers with holes so the lemurs have to manipulate the object to retrieve their meal. One day this week, I helped fill plastic PVC connectors with their lunch and straw. After doing a thorough scrub of the lemurs’ night house in the morning, the other interns and I did a little interior designing. We rearranged the “furniture” inside the night house, which is a form of environmental enrichment.


A ring tail lemur eating a piece of Romaine lettuce, one of the leafy greens in their diet.

A major part of this week included conducting observations of the lemurs. Depending on the type of observations, the time intervals range from every 30 seconds to every 2 minutes. Usually I pick an easily identifiable lemur to observe while another intern keeps track of the time. The categories on the observation sheet comprise of social behaviors, like huddling with another lemur or being groomed, and also of agnostic behaviors like marking with scent glands or chasing. The observations can be done any time of the day and inform the zoo keepers on how the lemurs interact with enrichment and with each other. The data collected can be used to make ethograms or to determine what percentage of the day a particular lemur does a certain activity.


One form of enrichment is scattering their diet throughout the grassy areas of the exhibit. Three of the ring tail lemurs foraging for their food and sunning themselves.

Internship Week 2: Candy wrappers, clicker training and ring-tailed lemurs

by | July 26th, 2012

Intern Stephanie Lo

After becoming familiar with the daily routine during my first week, String 7 Zookeeper Liz allowed me and the other interns to do many of the animal feedings and exhibit cleanings on our own.  In addition to the daily pellets, the meals of the domestic pigs and rabbits consist of specific amounts of fresh produce and greens.

The Oakland Zoo‘s Veterinary Care Center, the commissary and the string’s zookeeper work together to ensure each zoo animal has an appropriate diet. Sometimes, I help prepare the diets of the lemurs, pigs and rabbits by selecting produce from the commissary’s walk-in refrigerator and cutting up the correct amounts for each animal. Although slicing pieces of sweet potato or cantaloupe isn’t a physically demanding portion of my job, it is extremely important to pay attention to detail because each animal has unique nutritional needs. There is even a scale located in the Children’s Zoo kitchen to help us measure out grams, if necessary.

Blue-eyed lemurs Eugene and Anthony interacting with enrichment. The "candy wrappers" are made from newspapers filled with their food.

Each primate night house contains a calendar to mark each day’s enrichment. One of the lemur enrichments I did this week was configure pieces of newspaper into “candy wrappers” that contained their meal. The other interns and I wrapped chunks of cut produce into sheets of newspaper. At first, the lemurs did not approach the newspapers, but then a Ring Tailed Lemur picked one up and began opening it. Other forms of enrichment include piles of straw with scents mixed in and wooden bird toys hung with fruit in them. Besides stimulating their senses, the daily enrichment encourages the lemurs to forage for their food, much like they would in their natural environment.

Ring Tailed Lemur foraging for food in the enrichment item.

One of the most interesting opportunities this week was watching Liz do clicker training with the Ring Tailed Lemurs. During the individual training sessions, some of the lemurs acted more relaxed than others, allowing the zookeeper to trailer the training to the lemur. The goal of much of the training revolves around veterinary and husbandry purposes, such as having the lemur sit quietly on a mat while the keeper holds a stethoscope to its chest.  The zookeeper also worked on having the lemur sit still while waving a pretend chip scanner over its back, which could be done to identify an unknown or escaped lemur. One of the new commands Liz began was “stand.” She used a small target ball on the end of the stick, and she first rewarded the lemurs for showing interest in the target and then worked her way up to having them touch it with their hands. It was amazing to be able to observe how quickly some of the lemurs caught onto new commands and how sensitive they were to the trainer’s body posture.

Read more about what I have learned regarding operant conditioning and the use of clicker training during my upcoming Week 4 blog post.

One of the Ring Tailed Lemurs eating food from an enrichment item. The plastic container has holes for the produce to fall out.