Join us to learn about Schaefer and Medella’s transformative journey to health and fitness. This duo is one of the Lemur Conservation Foundation’s most unique pairs of endangered ring-tailed lemurs. Both individuals were born into the exotic pet trade, and this tragic start to life resulted in chronic dietary complications and hyper-aggressive behavior toward humans.
Lemurs, like other primates, never make appropriate pets. Ring-tailed lemurs live in complex social groups, but pet primates are often separated from their mothers much earlier than would normally occur in a natural setting. Removing a primate from its mother too soon prevents proper development, and can result in life-long psychological and behavioral problems.
The outstanding animal care team at LCF consulted with professional colleagues, dietary experts, and veterinarians to craft a specialized care plan for Schaefer and Medella. This plan included a carefully monitored diet, detailed training plans, and increased opportunities for exercise. Keepers are excited to share Schaefer and Medella’s physical and mental transformation thanks to their new routine.
Schaefer is a male ring-tailed lemur who joined the LCF family in 2010 after having been rescued from a private breeder in Florida. Our reserve is not a sanctuary for confiscated lemurs, but after discussions with the Ring-tailed Lemur Species Survival Plan (SSP) coordinator, availability of space at our reserve, and close proximity, LCF was able to make special accommodations for Schaefer.
Just days after his arrival, Schaefer began to show increased aggression towards keepers, frequently grinding his teeth and pinning his ears back. This quickly progressed to charging at keepers when they approached his enclosure and attempting to grab and scratch caretakers through the mesh.
Less than a month after his arrival, keepers determined that Schaefer would need to be managed in a strictly protected-contact setting. This means LCF staff only worked with Schaefer behind a secure barrier, and never went into the enclosure with him. Caretakers worked diligently to habituate Schaefer to shifting into a separate, secure area of his enclosure before entering to feed and clean.
Medella is a female ring-tailed lemur who joined LCF under similar circumstances. Originally rescued from a private breeder when she was just a couple months old, Medella began to show hyper-aggressive behavior toward humans as she matured. At two years old, the rescue facility did not have sufficient space to manage Medella, and that is when she joined LCF.
Having arrived just a few months after Schaefer, keepers planned to house the two together. The lemurs were introduced successfully, however keepers noted that the pair “seem to be reinforcing each other’s aggressive behavior towards humans.” Grabbing, charging, teeth grinding, and yawning (open mouth threat) became daily occurrences from both of these ex-pets.
Challenges of Ex-Pets
In addition to the pair’s abnormally high levels of aggression toward people, Schaefer and Medella also struggled with high weights. This was likely the result of poor diet early in life. Ingesting sugary snacks (e.g. candy, marshmallows) and other inappropriate food items offered by pet owners can be hazardous for lemurs. Much like people, obesity in lemurs can result in a variety of health concerns including abnormal blood pressure, diabetes, and even heart disease.
As part of LCF’s preventative veterinary care, keepers monitor and record all animal weights at least once a month. Unexpected weight fluctuations often provide the first indication of potential medical concerns. Schaefer and Medella slowly started to pack on the pounds despite slight alterations to their diet. At first, their daily fruit ration (which contains the most sugar) was decreased by 40%, then 50%, then a whopping 60%, and yet their weights continued to creep higher and higher.
Ideally, an adult ring-tailed lemur at their age should weigh no more than 6lbs (2.7kg). However, Schaefer peaked at a whooping 9lbs (4.08kg)—meaning he needed to lose approximately one third of his total body weight! Medella was over 8lbs (3.76kg) at her heaviest and also needed to slim down to live a healthier life. After a deeper dive into their weight gain history, LCF staff pulled out all the stops to create a specialized weight loss program tailored specifically to Schaefer and Medella.
Training for Weight Loss
Caretakers met to create a comprehensive training program with one specific goal in mind: convince these lemurs to move it, move it! Encouraging Schaefer and Medella to exercise every day was no easy task. Our team decided to reward the lemurs only with their daily fruit ration – no additional sugary raisins or grapes. With Schaefer and Medella each only receiving 16g of fruit daily (equivalent to one large strawberry), our trainers had to carefully plan each session to maximize progress.
“Target” was the first, and simplest, behavior the lemurs learned. The premise was simple: if the lemur touched his or her nose to the tip of a stick, they were rewarded with a piece of fruit. Once the lemurs understood the basic concept, trainers gradually increased the distance between targets, requiring the animals to move, climb, or even jump to successfully reach the target and receive a treat.
Progress was slow, and Schaefer and Medella showed very little interest in participating at first. The overweight pair preferred a sedentary lifestyle, and were most often found lounging on pillows inside. Staff started with micro training sessions, sometimes lasting just 30 seconds! With patience and consistency, the two ring-tailed lemurs are now eager to participate in every session sometimes remaining active and focused for 15 minutes or more.
LCF’s Curator of Primates consulted with colleagues, veterinarians, and nutrition specialists to create a dietary plan to assist with healthy weight loss. The lemurs were gradually transitioned to a low-starch chow, and we replaced certain starchy produce items (like sweet potato and corn) with more leafy greens. In combination with increased exercise, we saw wonderful results from the new diet.
Both lemurs continued a steady, healthy weight loss. Before the diet change, it wasn’t unusual to find leftover green beans and kale strewn across their enclosure, as if thrown on the ground in disgust. After adjusting to the changes, keepers now see the pair eagerly munching away on their veggies, rarely leaving any leftovers at all.
Both lemurs have shown a steady decrease in weight since keepers implemented these changes. Reaching their healthy target weight will take time, but they are on the right track.
Additionally, animal care staff have noticed a dramatic shift in Schaefer and Medella’s aggressive tendencies. After building trust and working consistently with dedicated keepers year after year, their aggression levels have dropped significantly in both frequency and severity. Instances of grabbing through the mesh, attempted scratching, and charging at keepers are minimal. While both of these animals will always be managed in a protected contact setting, they are now much calmer and relaxed during normal day-to-day activities.
Schaefer and Medella are living a more enriched life. Both graduated to a variety of more complex behaviors aimed to assist in their own health care. From positioning themselves on a scale for accurate weights, to voluntarily entering a crate in preparation for transports to regular check-ups, both lemurs have shown incredible growth and aptitude for learning.