A Glimpse into the First Few Days of Hand Rearing Marmosets

By Michelle Weatherford

In Dr. Wissman's Primate, Nutrition and Husbandry section you can find detailed instructions under Infant information. The following is an idea of how much time and effort goes into the first few days of hand rearing marmosets.

On Friday April 14, 2006 one of our marmosets had twins. Most marmosets and tamarins usually give birth in the early morning hours. Every morning I check each animal visually so if there are young they are found at the start of the day. This particular pair of Penicillata marmosets, Tiki and Jefferson, had not had babies together before but each raised one baby with other mates. They were watched throughout the morning to see if the twins were being carried by both the mother and father. It is customary for the male to do most of the carrying and the mother to take the babies to nurse them. Tiki and Jefferson were taking turns with the twins and occasionally they kept one each. We believed at least one of the twins had nursed but could not be sure if they both were nursing.

As the day went on we realized they were not nursing or Tiki didn't have enough milk. This is observed by the young riding lower on the parent or slipping lower without a tight enough grip of the parents' hair. We saw Tiki trying to rub (it looks like she was scratching her back on the wire) a baby off of her when it was crying, so the decision was made to pull at least that baby but maybe both. This was about 3:30 p.m.

Tiki rubbed the baby onto the wire when we put the net in to get it so the first baby was quickly removed from the cage. It was a girl who appeared slightly dehydrated. The male had the other baby and we wanted to check it for dehydration also. After taking the baby off the male we knew they both needed hand rearing.

I brought the fraternal twin girls into the house to weigh them and get them started on formula immediately. The girls both weighed 33 grams. I mixed up formula and they both readily accepted the syringe and ate about 0.5 ml. Then I gently rubbed both their bottoms with a newborn baby wipe to stimulate urination and defecation. The parents would lick the babies to do the same. At this time they went into a soft sided insulated lunch bag to keep warm. I use mini rice bags microwaved for 8-10 seconds for them to clutch onto. On the bottom of the bag is a larger warming pack. The one I use is by Petstages; it is made for cats, and has a removable microwave pack inside of a plush square pouch. Also a microwavable heat pack may be wrapped in a towel or pillowcase to have the same affect. Then the entire bag can sit on an electric heating pad to keep the microwave warmers warm until the next feeding. An electric heating pad should never be used inside with the babies because even on low it would be too hot if the babies crawled into the cloth cover. The temperature inside the lunch bag must be closely watched because too cold or too hot is deadly for the infants.

On the first day, I started the babies on feedings every 20 - 30 minutes. So by the time I would clean up from one feeding it was almost time for the next one. Since the babies were increasing the amount they ate at each feeding, I extended the time in between feedings to 30 - 45 minutes in the evening. For the first night the twins were fed every 45 minutes to 1 hour. I always set an alarm but they actually woke me up by scratching around in the bag when they were hungry.

By morning I decided to name the girls Lily and Mily since they were born on Good Friday, right before Easter. At 7 am I weighed them again and Lily gained 3 grams, weighing in at 36 grams. Mily gained 2 grams, weighing 35 grams. That is very good for the first day. Now they are taking anywhere from 0.4 to 0.7 ml per feeding. This can vary, as long as the babies are urinating and defecating properly and gaining weight each day. I always offer more formula after they urinate and defecate to make sure they have had enough. Then I packed everything up to take outside with me so I can prepare the marmoset diet for the day.

On day two I was able to gradually increase the time in between feedings to 1 to 2 hours. This is a big help for getting all the other animals fed. Some of the marmosets like to see the new babies so I showed them off in between feedings. I especially show the babies to the expectant mothers so hopefully it may help them when they have their babies. I also briefly showed Tiki and Jefferson so they knew their babies were well.

After I was done feeding outside I took Lily and Mily back inside and feed the animals at my house. I have a male Red Handed tamarin named Malachi that lives in my house. (picture 4) He was born May 12, 2005 as a singleton. His parents were first timers and spent so much time fighting over who got to carry him that no nursing went on. I pulled him that afternoon and quickly became attached! When penicillata twins needed to be hand raised 2 months later Malachi was very interested in them. They were fraternal twin girls as well, so I named them Mary-Kate and Ashley. After they were a few days old I carefully let Malachi interact with them. He quickly decided he needed to carry them even though he was still a baby himself. The three are still very close but the twins have their own cage so they don't continuously gang up on Malachi.

Mary-Kate and Ashley are now 9 months old so it is important to introduce them to babies since they were not parent raised themselves and will probably not make good parents unless they learn some skills soon. Over this past winter we only had one baby that needed to be hand raised, a penicillata male but they did not want anything to do with him. A month ago we had Red Handed tamarin twins that had to be hand raised so I attempted to let Mary-Kate and Ashley meet them but they seemed too afraid of the newcomers. It would be too easy for an unwilling juvenile to harm a baby so caution is necessary. I was hoping Mary-Kate and Ashley would be ready for Lily and Mily. I only let one marmoset out of the cage at a time to prevent jealously or aggression over the babies. I held Mary-Kate in one hand and Lily in the other for the encounter. Mary-Kate sniffed the baby and seemed interested until the baby reached up and touched her hair. She was not aggressive towards Lily but wanted to get away from her. It was then Ashley's turn, I did the same thing but Ashley only leaned towards Lily quickly then wanted to go back to Mary-Kate.

Malachi liked Lily and Mily right away and on day two tried to get into the lunch bag with them but I did not let him carry them until day three. He gently stands over babies to let them crawl onto him. As you can see in the pictures he is not that good yet at getting them in the right spot but does not let them fall off. An adult marmoset with parenting skills will guide the babies with their hands to their back, up by the shoulders or on their chest. Malachi will learn more with each set of babies that I bring home. Since Malachi carried pencillatas when he was young he readily accepts them. When I had the red hand twins he did not like them. This could be because he was 10 months old before seeing red hand young. They went to a co-workers house after a couple of days so it is possible that he would have eventually accepted them. There is always next time. We always try to let juveniles learn parenting skills so when they become parents they will keep the babies. Marmosets that are parent raised learn from their parents when the next set of babies is born.

Lily and Mily weighed 38 and 37 grams on day 3. They are on every two hour feedings around the clock now until they are two weeks old. Sunday night Dr. Wissman took the babies overnight so my husband and I could get a solid nights rest. It is great if you have someone to share the responsibility with especially during the first two weeks. Those are the most crucial because the babies can't self regulate heat yet. After the first two weeks it is important for their development to carry them around on your head to stimulate the parents movements with the babies attached.

On Tuesday, day 4, Lily weighed 39 grams and Mily 38. During the first two weeks it is important the marmosets keep gaining weight. As they get older there might be a day here or there that the weight stays the same. This is alright as long as they do not lose weight. It is also extremely important to never let anyone else handle the babies. So many things could happen to the baby. The most important is the transmittal of the Herpes Simplex I or II virus; the ones that cause cold sores and genital lesions. This is deadly to marmosets and tamarins. Even if someone does not have symptoms they can still shed the virus. You will never know which friend or relative is potentially deadly to the baby so it's best to never let anyone touch your baby.

Lily and Mily are off to a good start. If you would like to help sponsor these twins or any others pictured please use the Pay Pal link on our homepage. Baby formula is expensive and soon they will be onto baby food and more. Mary-Kate and Ashley's parents just had their 2nd set of twins this morning, April 27. They are currently carrying the babies and are very gentle with them. Hopefully they will continue to nurse and care for them on their own. If not, Mary-Kate and Ashley will get a chance to help me raise their siblings.

Update on Mahogany and MS Bob's 2nd set of twins born on April 27, 2006

The twins were just as small as Mary-Kate and Ashley and while they were on Mahogany they held on tight. I was fairly sure they were both nursing. The next day MS Bob decided he needed to hold a baby and sit right up against the wire. The baby that he had was very outgoing and decided to try to climb the wire and almost climbed out of the cage by itself! Of course, I was right there watching. So I brought the whole family inside to let them try to raise these twins themselves.

I was able to interact with Mahogany and the twins much easier inside so it was nice to watch them develop. At 2 weeks of age I decided to try to take the twins out of the cage briefly one at a time to weigh them with the scale next to the cage. This worked out great, they are twin boys I named Zack and Cody. They weighed 50 and 47 grams. I gradually and age appropriately fed them formula, cereals, fruit, and oatmeal. This week the family will be moving back outside to the much larger cage. Today, June 6, 2006 Zack weighed 86 grams and Cody weighed 80 grams. The twins will have a new environment to explore but the boys will miss watching the Disney Channel I'm sure.

Small World Zoological Gardens
is dedicated to the captive conservation of marmosets and tamarins.
It is a non-profit charitable organization under IRS 501C3 status,
so all donations are tax deductible.

Photos: M. Weatherford & Derek Weatherford

Copyright 2006 Margaret A. Wissman, D.V.M., D.A.B.V.P.
All Rights Reserved

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