Special Topic: Erin- Species Spotlight
White-Tufted-Ear Marmoset Callithrix jacchus
The White tufted ear marmoset is a small-bodied New World Primate, with mottled gray fur, and large white ear tufts. Their faces are quite pale, but will darken with exposure to the sun. These tiny primates weigh under a pound, and typically live around 12 years. Pacific Primate Sanctuary is currently home to 30 White tufted eared marmosets.
These marmosets are endemic to Brazil. They are found in the northeastern and central forests from the Atlantic coast to as far inland as the Rio Grande (see the red area on the map). The forests they live in are characterized by having an abundance of gum-producing trees. A home range must have at least 50 gum trees to support these gum-loving primates.
White tufted eared marmosets are diurnal (active during the day) and arboreal (live in the trees). They live in extended family groups with all the members helping to rear the offspring. Additionally, large groups provide protection by helping with territorial defense. They tend to be most active in the mornings and evenings, and spend much of the daytime hours grooming and taking naps.
Marmosets have several unique adaptations. For one thing, they have claw-like nails, whereas most primates have flat nails. Marmosets spend much time clinging vertically to tree trunks, the claw-like nails allows them to accomplish this. The reason for clinging to the trunks has to do with their major food source; White-tufted-ear Marmosets are exudate (gum from trees) feeders. They cling to the side of the trunk, and then use their specialized teeth (their lower incisors are the same length as their canines!) to gouge holes in the tree. This causes the tree to produce an abundance of nourishing exudates! The marmosets also have a special digestive system to help process this particular source of nourishment. These special features provide the marmosets with a unique and abundant food source that allows them to live in large family groups with little or no competition.
Resources:
-Cawthon Lang KA. 2005 May 18. Primate Factsheets: Common marmoset (Callithrix jacchus) Taxonomy, Morphology, & Ecology.
- Rowe, Noel. 1996. The pictorial guide to the living primates / Noel Rowe; foreword by Jane Goodall; introduction by Russell A. Mittermeier Pogonias Press, East Hampton, N.Y.
Intern Alli Special Topic: A Tale of Two Monkeys
Prior to coming to the Sanctuary, Intern Alli gained experience with marmosets by working as a caretaker in a research laboratory. She then came to PPS as a resident Intern, and is already entering into the final month of her one-year internship. Through this experience of working with the same species in opposing settings, Alli has a very unique perspective. She is able to share this perspective with us in the following, very moving, essay.
A Tale of Two Monkeys: Brenda and Charlotte
Anyone who has walked the corridor at Pacific Primate Sanctuary has known and loved Brenda. She is a 15-year-old female White tufted ear marmoset with a sweet demeanor, a love for the outdoors, and her devoted mate named Bruno (a once solitary male who she helped socialize). She is the oldest female monkey in the corridor, although her activity level would tell you otherwise, and she spends as much time outside with Bruno as possible. As well as we all know Brenda here at PPS, many people don’t know that she was born “CJ0396” at a large, well-known national research facility in the Midwest. Why she was lucky enough to be sent to Pacific Primate Sanctuary at 6 months old is unknown. Up until January of 2009, she had lived a parallel, but completely opposite life to another female marmoset born in the same year at the same research facility.
Brenda in her lush greenroom at PPS
“CJ0130”, or Charlotte as her caregivers knew her, was nearly 15-years-old already when I first met her while working at the lab. She stuck out like a sore thumb in a room of 20 marmosets because of her missing ear tuft, her calm manner, and her sweet face. She was a favorite among the animal techs and vet staff alike because she had out-lived almost all of the monkeys born within 5 years of her. She had been through countless studies, behavioral and invasive, and had managed to survive to old age (despite the missing ear tuft). Grapes were her favorite fruit, since they were easy to juice with her uneven teeth, and I would often sneak her and her partner an extra grape at snack whenever I could. And I was there that day in January when she was anesthetized and brought to the necropsy room to be euthanized because her weight had dropped below 300 grams. It will remain a mystery how two monkeys born in the same year at the same national research facility could live out two completely different lives nearly 6,000 miles apart, however they didn’t have to be so different. While an animal’s life in a research laboratory versus a sanctuary is fundamentally different because the purpose, goals, and objectives of the two institutions are diametrically opposed- an animal’s life in a lab can be greatly enhanced by making small changes in daily care.
In a Biomedical Research Facility, the main goal of colony management is to provide the ideal research subject to potential researchers. The mental health of the subject is not necessarily always a factor as long as they are physically “healthy”. The more “healthy” subjects a facility can provide, the more researchers they will attract and therefore, the more money they can bring in. It is for this reason that White tufted ear marmosets, at a large lab in the Midwest, are kept in small metal portables lining every room. Within each portable is a metal carrier and two wooden dowels used as perches. Enrichment is given once a week in the form of treats hidden in plastic toys, frozen cubes, or cereal stuck in toilet paper rolls. Because of the smaller size of the enclosures, adolescent monkeys are pulled from family groups in order to make room for newer siblings. And finally, because a colony must be cared for as a whole using “herd health”, marmosets at this particular lab are euthanized when their weight drops below 300 grams. These types of policies allow a research facility to operate with maximum output (more monkeys) with minimal cost (smaller housing, and little daily enrichment). These facilities operate in this way because their definition of “humane” colony management is based on and serves their goals and financial objectives.
Charlotte’s life and death were a result of this distorted philosophy. I remember about a month before Charlotte was euthanized I was sitting with the Associate Director of Veterinary Services, who was inquiring about my upcoming internship at PPS. I told him how excited I was and I asked him if there was any way that I could take Charlotte with me, since she was no longer considered an ideal candidate for research. He laughed the question off and said there was no way a monkey her age would ever manage the trip successfully. A month later, I sat in an anteroom and watched as Charlotte went to sleep for the last time. I couldn’t help but wonder, if Charlotte had made it to the sanctuary and only lived one day in a lush green enclosure, wouldn’t that have been better than bleeding out in the necropsy room of a research facility? And more so, how would it have been a loss to the research facility?
In a sanctuary setting, like that at Pacific Primate Sanctuary, the main goal is rehabilitation and restoration of the monkeys’ birthright. Monkeys are provided food, shelter, and enrichment by volunteers, but are otherwise “free” to do what monkeys should do. They spend their days foraging in their jungle enclosures, grooming family members and partners, basking in the sunlight, and playing in their natural worlds. Monkeys at Pacific Primate Sanctuary always have access to browse or greenery in which to manipulate, tear, rip apart, and play with. In fact an adolescent male was once observed using a large green leaf as a trampoline, bouncing from the leaf to a branch above. Most importantly, monkeys at Pacific Primate Sanctuary are given individualized care addressing each of the monkey’s needs. They are not euthanized when their weight drops. In fact, there are a handful of White tufted ear marmosets (mostly females) at Pacific Primate Sanctuary who have lived almost their entire lives weighing less than 300 grams and are healthy and active- Brenda being one of them.
Brenda arrived at Pacific Primate Sanctuary on March 29, 1995 along with six other White tufted ear marmosets from the same research facility. She adjusted extremely quickly to sanctuary living, having been sent at a young age. She was paired with Bruno, a lone male sent from a different research facility. He was un-socialized and didn’t share food well. With Brenda’s patience and a caregiver’s gentle 3 month conditioning, Bruno soon became an ideal mate. (This time consuming endeavor might not be pursued in the laboratory where he would have lived a solitary existence.) While he is still enthusiastic about his food, he no longer hoards or monopolizes the food bowls. He now loves to groom and play-wrestle with Brenda and they are rarely seen apart. Brenda has had two serious health issues that have resulted in her having to be to be moved from her enclosure into the infirmary for intensive, personalized care. This occurred once in December of 2004, when she was treated for a GI issue, and again this year when we found she had tooth infections. Both times she was cared for until she was well again and returned to Bruno as good as new. Even though she has lived almost her entire life weighing less than 300 grams, her weight is still monitored very closely and she is given extras (avocado, sweet potato, Nutrical, oatmeal, etc.) in her breakfast daily to keep her calorie intake high. This type of specialized care is one of the main reasons she has lived such a long, high quality life. If Brenda were living in a research laboratory, she would have been euthanized years ago.
Because of the fundamental differences between a biomedical research facility and a sanctuary, the lives of the monkeys housed in each could never be the same. However, there can be vast improvements in the living situation of those housed in research facilities that could even be cost effective to the labs. First, implementing weekly environmental enrichment in the form of natural greenery, in Hawaii we use Ti leaves, palm leaves, hibiscus flowers, etc., can elicit more natural behaviors and has also been found to be a way for the monkeys to relieve stress. It can be difficult to understand just how enriching foliage can be until you’ve watched a monkey tear it apart/carry it around/manipulate it for the first time. The cost of this type of enrichment could be kept down by making a partnership with a university greenhouse.
Another beneficial practice would be allowing the monkeys to live with their natural families for a longer period of time. While I recognize that there are limits to how many monkeys can live in a small laboratory enclosure at once, I have also seen first hand the benefit of allowing offspring to help rear their younger siblings. The first set of marmoset babies born while I was at the research facility died within two days of each other because the mother had never reared infants before (siblings or her own). Having experienced mothers and fathers would decrease the amount of infant mortality in a laboratory setting.
Finally, implementing a more tailored herd health practice (rather than just euthanizing all monkeys at a set weight) would allow for a more diverse and less homogeneous colony of primates. Dr. Cathy Johnson-Delaney, President of the Association of Exotic Mammal Veterinarians, established an alternative policy for a lab colony that catered more to each individual marmoset’s weight. Extreme illness was defined as a monkey losing 15-20% of their adult body weight. This way, monkeys who usually balance around 300 grams are not euthanized because they lost 10 grams (which would only be 3% of their adult body weight, but would make them eligible for euthanization at the Midwest lab.) Another option would be sending those monkeys considered less ideal for experimentation (i.e. under 300 grams) to sanctuaries where they can have more personalized care. The research industry might also consider that euthanizing a monkey in a lab setting can be extremely costly. There is the cost of drugs to first sedate a primate, then the cost of the personnel to perform the necropsy and necropsy report, then the cost of blood tests and tissue tests (depending on why the monkey needed euthanasia), and finally the monkey must be properly disposed of. These are all costs that could be avoided if the euthanasia is deemed unnecessary in the first place.
It is my personal hope that one day primate research will be a thing of the past and will soon be considered an UNnecessary evil. That day, unfortunately, is not today. So instead we need to cooperatively work towards improving the lives of those still living in a world of metal bars and constant fear. I am extremely thankful for each and every monkey that Pacific Primate Sanctuary has been able to save over the past 30 years, however, I am constantly thinking about the hundreds of thousands of primates still living compromised lives in biomedical research facilities across the world. We need to once again expand our philosophies, but this time to accommodate a species other than our own. In fact, Dr. Jane Goodall considers this the next step in human evolution. She writes:
"If only we can overcome cruelty, to human and animal, with love and compassion we shall stand at the threshold of a new era in human moral and spiritual evolution and realize, at last, our most unique quality: humanity."
"An animal's eyes have the power to speak a great language."
~ Martin Buber
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