Opossum, Virginia

Didelphis virginiana
Order: Marsupialia

Documents

Husbandry Information

Housing Requirements

Enclosure

  • Park Zoo – tall, rolling cage 3x3x6 with shelves and a crate or box for a hidey hole. Our female liked to curl up in blankets and towels.
  • Zoo Atlanta- We house our opossums outdoors year round. We have one 10x10x8 enclosure and one 9x6x8 enclosure. Animals are housed seperately. Climbing structures are provided and utilized regularly.
  • EcoTarium – In their housing we often have movable furnishings of ramps, branches, stumps and their favorite bedding is either a “catgloo” where guests can still see them when they are on display or a pile of blankets behind the scenes where they burrow in.

Temperature Guidelines

Opossums are prone to frostbite on their ears and tail and should be provided shelter from freezing temperatures.

  • Zoo Atlanta: Heat lamps are provided at temperaturs of 25 F or lower. At temperatures of 35 F we provide extra bedding material (towels for our off exhibit animals, leaves for our on exhibit animals). Our opossums are provided with a nest box that is about 4 feet long to enable to choose to sleep directly under the heat or away from it.
    • We provide a frozen water bottle wrapped in a towel at temperatures of 85 F and above.

Nest Boxes

  • Zoo Atlanta: Our opossums are provided with a nest box that is about 4 feet long to enable to choose to sleep directly under the heat or away from it.

Co-Housing

  • Denver Zoo: We housed brothers together with no issues at Denver Zoo. They were neutered, and I think that helped. As long as they had space to eat in separate locations, they seemed to do fine!
  • Birmingham: We house to males together. They were not siblings but we successfully introduce them with no issues. I think as long as you get them at a young age you should have no problems
  • Rolling Hills Zoo: We have housed both female siblingss and male siblings as well as 1.2 siblings in the past.  All seem to do fine in our experience.  Personalities can go either way between pairs – one more workable than the other – but with consistent handling (and giving them time to wake up before handling) they have been overall great ed animals.  I prefer females to males as we have had more health and behavioral issues with males more than females. 
  • Zoo Atlanta: Our 2 girls were great together until about 6 months, we initially one sleeping in a different area than normal and then saw the scabs from bites after a very thorough fur search. They were well hidden. We separated them at that time and they now live apart and will not be reintroduced. We never attempted to house our males together since we keep them intact we just assume it would be a problem at some point.

Litter boxes

  • Zoo Atlanta: They consistently use a litter box with mulch in it as well which reduces the need for frequent substrate changes.

Diet Requirements

  • In the wild, Virginia opossums eat lizards, frogs, mice, rats, rabbits, invertebrates, carrion, fruits, nuts, seeds, and grasses.
  • Diet at Happy Hollow Park and Zoo:
    • 3 oz. maintenance (i.e., low fat) premium brand dog food (like Nutro) and 4.5 oz. chopped mix daily. The mix is whatever is available at the commissary, and can be any combination of fruits and veggies.
    • 3 mealworms or crickets and half a hard-boiled egg three days a week
    • 1 mouse once a week
  • Diet at Nashville Zoo:
    • Mazuri omnivore — 30 to 50 grams, total. In the past, we have given Mazuri exotic feline small and dry dog food as well, but omnivore is preferable
    • variety of produce, including turnip greens, sweet potato, papaya, grapes, melon, broccoli, kiwi, apple, and any other seasonal produce available, offered in small amounts, for variety — 70 to 90 grams, total
    • nightcrawlers
    • Enrichment food: small amounts of egg, crickets, wax worms, or mealworms
    • Training food: VERY small amounts of Bird of Prey mean, peanut butter, honey, crackers, cereal — 2 to 10 grams for both training and enrichment foods
    • If we have young animals that are growing, we will also offer fish and yogurt
  • Diet at Zoo Atlanta
    • Mazuri omnivore chow (18%), frozen crickets (15%), squash and zuchini (15%), and sweet potato and carrots (50%). We also offer about 1/4 can of science diet cat food two times per week.
    • Our younger opossum finishes his food daily so we use his regular diet for training. We use the insects, omnivore chow, and cat food for training for our older opossum.
  • Diet at Blank Park Zoo
    • 0.1 Virginia Opossum
      Monday, Wednesday & Friday AM & PM
      18g Science Diet Light Adult Dog Food
      ½ of a Capelin
      1 Cricket AM; 1 Mealworm PM
      1 tsp Canned Dog Food (Science Diet Light)
      3g Kale
      5g Banana or Apple
      5g Melon or other low sugar fruit
      2g Cucumber
    • Same diet on Sunday, Tuesday, Thursday and Saturday except replaced banana or apple with 10g Romaine lettuce and replaced cucumber with 2g carrot
    • ENRICHMENT – 6 g of vegetables 3X a week, Once a week boiled egg (if given, do not give canned dog food), Fruits and Vegetables – cantaloupe, orange, coconut, onion, tomato, watermelon, pumpkin, yam, strawberry, broccoli, corn; other enrichment items – jello, honey (very small smear), night crawler, mixed nuts(if given do not give canned dog food), pinky, 1 grape
  • Diet at Minnesota Zoo ( Our opossums are fed different diets due to one of them coming to us as an adult and keeping her on a similar diet to what she was being fed before arriving at the Zoo. )
    • V. Opossum (0.1) M
      • 30g canine senior
      • 35g mixed veggies
      • 25g various fruit
      • 6g omnivore (soaked)
      • 2g hard boiled egg – no shell
      • Split into AM & PM bowls
    • V. Opossum (0.1) O
      • Mix All together like an unformed meatloaf
      • 25g canine senior *
      • 45g mixed veggies *
      • 6g omnivore (soaked) *
      • 2g hard boiled egg – no shell *
      • 20g of toronto *
      • 2 pinkies
      • 2 fuzzies
      • 1 mouse cut in 1/2
      • Split into AM & PM bowls
      • pull all mice put in fridge

Veterinary Concerns

  • This species has a strong tendency toward obesity so careful diet management and regular exercise are important to maintain a healthy condition.
  • This is a short-lived species, with typical longevity around 2-4 years.
  • Blank Park Zoo we did not have a problem with biting but our vet recommended/ required us to use gloves due to leptospirosis.

Notes on Enrichment & Training

  • Our female loved to go outside and take long walks. Because of her weight we let her our in a grassy area behind the scenes and let her walk as we followed. She was partially or mostly blind so we did not worry about her getting away from us. We did have to watch her in the grass because she liked to find and eat rabbit poop.
  • Due to their limited vision, target training can be difficult. Some facilities have used some scent, or a rattle integrated into the target stick.
  • Zoo Atlanta: All food is offered in feeder toys for our younger opposums.

Programmatic Information

Tips on Presentation

  • Zoo Atlanta presents opossusm in the hand. We use a flat hand/arm presentation and allow the animal to stand on the forearms.
    • We do not allow public to touch opossums due to the variety of potentially zoonotic parasites they are known to carry
  • Zoo Atlanta uses a top-loading kennel for removing an opossum from the carrier so that no one is reaching toward their face. The alternative we use is to allow the opossum to leave the crate on its own and pick it up as it exits the crate (we do this only indoors).
  • Zoo Atlanta has harness trained one opossum who did not tolerate being handled when he was younger and he can now presented on leash or in the hand.

Tips on Handling

Socialization:

  • Little Rock Zoo – We have hand reared our last to sets of opossums and they have been amazing ambassadors. We do hand feed ours (very carefully) and just spend a lot of time with them (We will take them to novel areas or just let them explore). We use hammocks and not pouches, but there really isn’t a reason other than its easier to clean/get them out. They are also in our training program and now how to target, circle, station and crate.
  • Birmingham Zoo – We start socializing our opossums right away with our quarantine keepers upon arrival to the zoo. They spend time picking them up and holding them on the arm in accordance with our handling guidelines for these animals. We steer clear of having them sit on our laps or allowing them to investigate above arm level. They also play the radio and music for them and set up a staff radio so that they are fairly comfortable with the rustle and bustle of zoo life when they come down to our department. When they get to us after quarantine, we try and make sure they get three sessions each day for the first few weeks. We don’t hand feed them or have food on us while handling them to avoid too much interest in our fingers or arms. We’ve had many opossums come through our department and love using them as ambassador animals!
  • EcoTarium We have received opossums as young as 6 weeks and as old as 1 year.  While in quarantine (located within the keeper office so it works for socializing) we introduce them to name recognition and bridging.  The first three behaviors we work on as soon as we initially socialize with them for about one week are target, kennel, and scale. From there we build on station/ tactile/ nail trims/ spins/ paint/ follow/ harness/ other engaging behaviors.
    We use food as reinforcement but have never hand fed.  We use a silicon long handle spoon for delivery. With the bridge established it allows us to have a little “forgiveness” with delayed reinforcement it a keeper is slower to get food on the spoon.

Handling:

  • Variation in temperament has been noted at several institutions. Some animals seem to have a more easygoing temperament and tolerate handling well while others gape and sometimes bite while being handled. This did not seem to be strongly tied with sex or if an animal had been neutered. It may be best to look for animals that are less reactive when young and then desensitize them to the presence of humans and with positive reinforcement training.
  • The bite delivered by an adult opossum is potentially very damaging. It is important to wear thick gloves if handling an animal that may be likely to bite. Even with thick gloves on, expect bruising.
  • Seneca Park Zoo we have had both rehabbed adults and hand raised ones. The rehabbed adults needed gloves to be handled but, rarely attempted to bite. The hand raised ones were very imprinted and tamed. There was no need to where gloves. We also found that females are more friendly than males.
  • Blank Park Zoo we did not have a problem with biting but our vet recommended/required us to use gloves due to leptospirosis (sp?).
  • Zoo Atlanta we use gloves to handle one animal that was a biter when he was younger
  • Zoo Atlanta offers treats to our opossums as we pick them up. We have found that they now usually wake when their names are called and aproach the handlers readily. This is not generally the case if it is very cold out and they are snuggled in their nest box though.
  • EcoTarium Our opossums are not held but presented on a table or in a plexi corral depending on the location/age of the observers.  They are very adaptable to being presented in a variety of locations and in situations like loud crowds, fast moving children, etc.

Potential Messaging

  • Only marsupial in the United States.
  • Great defense mechanisms.
  • Important scavengers.
  • Plastic/Styrofoam – Reduce, Reuse, Recycle: Conventional plastic and Styrofoam (That’s pretty much all plastic and Styrofoam) do not biodegrade. Whether items made of these materials are thrown on the ground as litter or thrown away in the trash, they tend to end up in our rivers and oceans, each piece staying in these ecosystems for decades or centuries. Large pieces of plastic float in the water or wash up on the shore, often animals. Smaller pieces are mistaken for food and eaten by many species. Please ask zoo guests to avoid disposable plastic and Styrofoam packaging, opting for re-usable alternatives: cloth tote bags instead of plastic grocery bags, filtered tap water instead of bottled water, re-useable plastic food storage (like Rubbermaid containers) instead of Styrofoam boxes. Ask them to recycle plastic rather than throwing it away and to purchase products that are made of recycled materials. Participating in a beach or river clean-up is also a great idea. http://www.nrdc.org/oceans/plastic-ocean/[[http://kids.nationalgeographic.com/kids/stories/spacescience/water-bottle-pollution/]]

Acquisition Information

  • Local rehab centers. GA law requires releasable animals to be released so we are notified of young animals that cannot be released due to human habituation. We also have acquired while caught youngsters from other states.
  • Zoo Atlanta uses both a neutured male and an intact male for presentation.

Comments from the Rating System

  • CuriOdyssey: Clear messaging (defenses, habitats, food web, adaptations); Easy to train but most “show behaviors” consist of A to B travel.
  • Henry Vilas Zoo: Large enough for large audiences to see; native mammal; native marsupial; ours are non-contact for the public.
  • Natural Science Center of Greensboro: Males can get bitey.
  • Philadelphia Zoo: Not long-lived enough to get the time investment back; tendency towards obesity; some individuals have a biting tendency
  • Zoo America: We’ve had biting issues with males, so we prefer females.

Natural History Information

Range and Habitat

Virginia opossums are found in North America, New Hampshire west to Colorado, southern Ontario south to Coats Rica. They prefer moist wetlands or thick brush near streams and swamps.

Physical Description

The coloration can be gray, black, reddish, or (in rare cases) white. The pelage consists of under-fur and white-tipped guard hairs. The prehensile tail is about 12 inches long. Each hind foot has a clawless, opposable thumb.
Average length is 30 inches, head to tail. Virginia opossums can weigh anywhere from 4 to 15 pounds.

Life Cycle

Usually, two litters are produced each year – one in February and one in June, although young opossums have been observed as early as January 24th and as late as August 15th. Each litter can number 5 to 21 young, which are born after a gestation period of 11 to 12 days. The young are about the size of a bee when they are born; they will each crawl up to a fur-lined pouch on their mother’s abdomen. Once in the pouch, each baby opossum will find a nipple and begin to nurse. As soon as nursing begins, the nipple will swell and completely fill the baby’s mouth, thereby firmly attaching it to its mother. The young will stay in the pouch, drinking milk and continuing to develop, for about 2 months. Since most female opossums only have up to 13 teats, young born in larger litters need to quickly find a nipple – those too slow are left without and will quickly die.
Average lifespan is 2 to 3 years.

Behavior

Virginia opossums are nocturnal, solitary, and anti-social, either avoiding others of their kind or acting aggressively towards them. Virginia opossums do feign death as a defense mechanism.
Vocalizations include hisses, growls, screeches, clicking and lip smacking. The latter two are used by females to communicate with their young, and by males in aggressive displays during mating season. The lip smacking does seem to start at sexual maturity.

Threats and Conservation Status

Common predators include foxes, coyotes, great horned owls, and barred owls. Humans hunt Virginia opossums for their fur (which is not considered particularly valuable but can still be used for trimming) and for their meat (which many consider a delicacy.) They have no special conservation status.

Did you know…

  • The Virginia opossum is the only living marsupial in North America.
  • Opossums are not the same thing as possums. Opossums range from North America to southern Argentina and contain 15 genera with over 60 species. Possums are found in Australia with over 20 species. They are all marsupials, but opossums and possums are only distantly related within the same subclass.
  • Virginia opossums have 50 teeth – more than any other land animal.
  • Virginia opossums are only able to hang from their tails when they are young – full-grown adults are incapable of supporting themselves by their tails.

Photographs

Contributors and Citations

  • The Philadelphia Zoo
  • Happy Hollow Park and Zoo, San Jose
  • Nashville Zoo at Grassmere
  • Atlanta Zoo
  • Houston Zoo, Natural Encounters
  • Ecotarium
  • Birmingham Zoo
  • Little Rock Zoo