What’s an Opossum, Anyhow?

Merriam-Webster defines an opossum as “any of a family (Didelphidae) of small- to medium-sized American marsupials that usually have a pointed snout and nearly hairless scaly prehensile tail, are typically active at night, and are sometimes hunted for their fur or meat

especially : a common omnivorous largely nocturnal mammal (Didelphis virginiana) of North and Central America that is a skilled climber, that typically has a white face and grayish body and in the female a well-developed fur-lined pouch, and that when threatened may feign death by curling up the body and remaining motionless and unresponsive”

The plural of opossum is opossums.

The ‘O’ is not silent. 

Virginia Opossum 

What about a possum?

“any of various small to medium-sized, nocturnal, chiefly arboreal marsupial mammals (especially families Phalangeridae, Pseudocheiridae, and Petauridae) of Australia and New Guinea that have thick, soft fur, a prehensile tail, and a rounded head with protruding eyes and that are mainly herbivorous”

The plural of possum is possums.

Common Brushtail Possum

Put simply, the difference between possums and opossums is primarily based on location (US and Canada have opossums whereas Australia has possums). There are physical differences, as well. Australia has 23 species while the only ones on our side of the water are the Virginia opossum.

Basic Facts About the Virginia Opossum

-The ONLY marsupial in North America

-Gestation period is only two weeks 

-Sexual maturity occurs at around one year of age

-Female opossums can have two litters a year

-Newborns remain in the mother’s pouch for about two months 

-Lifespan in the wild is only two-three years

-Grow to about two-three feet long and weigh six-thirteen pounds

-They are nocturnal (primarily active at night)

-Have existed since prehistoric times

-They have fifty teeth, the most number of teeth found in any land mammal

-They are omnivorous scavengers and eat pretty much anything, to include carrion and ticks which helps control the spread of diseases in the ecosystem 

-Much like fainting goats, they have an involuntary self-defense mechanism. Opossums will play dead to avoid prey.

-They have opposable thumbs. This helps them with climbing.

Myths About Opossums, Debunked  

-They do NOT hang from their tails to sleep

-They are VERY unlikely to contract rabies due to low body temperature and amazing immune system 

-They are NOT a nuisance species. They are an important part of the ecosystem and do not cause property damage 

-They do NOT make good pets. These are wild animals and trying to domesticate them will do more harm than good to their survival.

Prepping for Baby Season

I'm going to cover some of the things I'm starting to get together in preparation for baby season. Opossums typically breed 2-3 times a year, starting in the spring. They're super unique because their gestation period is only about 13 days or so. Once the babies are born, they climb up into their mother's pouch and find a nipple to latch on to. Opossums typically have 13 nipples (give or take a couple depending on what they're born with and depending on how many actually produce milk). Although they have many nipples, they often give birth to more than 13 babies. They've actually been known to have up to 25 babies at once but only the ones that locate a working nipple will survive. 

Once they've located a nipple, their mouths (which are pretty much shut) will open enough to swallow a nipple. Once the nipple is in place the baby's mouth will seal shut around the nipple, so the babies stay attached while they grow. They stay in the pouch for about 3 months before they get large enough to detach and start exploring with their mom. Opossums are solitary creatures, so the babies really only rely on their mother for their care. When they get big enough to start exploring, they'll wander out of the pouch while their mom stops to eat. They'll stay near her and learn how to forage for food. As the babies outgrow the pouch they will start to climb on to their mom's back for transportation. This stage is where many babies find themselves lost and on their own. If the mother gets spooked (by a dog or a person) she will run off. She doesn't notice when a baby falls off of her or gets left behind. Some of the babies that are brought into rehabbers are ones that were abandoned in such a manner. If you see one that looks to be less than 6-7 inches long, it is quite possibly too small to be on its own and it's a good idea to get the baby to a rehabber so it can grow a bit before being released back into the wild. 

Another way that baby opossums find their way to rehabbers is after a mother opossum has been hit by a car. Many times, when the mother has been hit by a car there will be babies in her pouch. Sometimes crazy people, like me, will get out to check an opossum on the side of the road to see if there are any babies that need help. Babies can technically survive up to about 5 days in their mother's pouch after she has died. The longer they remain in there and drinking her milk, the less likely they are to survive even if they're brought to the most amazing of rehabbers. Once the mother is dead her milk becomes contaminated by her slowly decomposing body and that releases chemicals into her milk.

If for some reason you ever see an opossum on the side of the road and feel the need to check the pouch, make sure it's safe to do so. Some roads are just too dangerous to pull over on so I definitely don't recommend it. You really have to use your best judgement. It's also important to note that you have to be super careful when you remove the babies from their mother's nipples. The nipples will swell when they're in the baby's stomach, so they have to be pulled off the nipples very gently. If it is done too fast it could fatally wound the baby. 

Now that I got all that background information out of the way, I'll start detailing some of the stuff I'm getting ready in anticipation for baby season. 

One of the first things I need to have on hand are some incubators and a scale. The incubators need to keep the babies at a constant temperature and humidity. They're taken out only to eat and potty. Depending on how big they are when they arrive, they might need to eat every 2-3 hours, day and night. When they get big enough that they can start to regulate their own temperature, they will get moved to a tank which has a heating pad under it. The heating pad needs to stay on 24 hours a day. Only half the tank should be heated, and it will stay on the lowest setting to keep the opossums from overheating. 

It's also important to keep little nests on hand. I crochet and sew so I make mine in my free time in the winter (NOT during baby season....no time for crafts during baby season!). The nests (or pouches) are used to keep the pouch siblings together and simulate their mother's pouch. 

I also have to keep many of these animal carriers on hand in order to keep different pouches of opossums separated. They're absolutely fantastic for transporting babies in and make life a lot easier when it comes time to feed them. 

It's also important to have a special, separate fridge for opossum food and formula. Right now, this little fridge is what I'm using. It's the perfect size to hold formula (which only lasts for a day or so in the fridge before it goes bad). From the fridge I will put it into baby bottles and use an opossum designated bottle warmer to warm up their formula before feeding them. 

Speaking of formula, opossum formula can get stupidly expensive. I know there are a few different types of formulas that are suggested for opossums, but I stick to the one recommended by the National Opossum Society. It consists of added calcium, brewer's yeast, high calorie puppy supplement, egg yolks, and goat's milk Esbilac puppy formula. All of it needs to be measured out precisely with filtered water. It needs to be mixed up in advance and left to sit for a few hours before it can be used. This makes sure that the formula breaks down certain elements and allows it to be digested properly by the babies. It's also super important to run the formula through a strainer multiple times. Any clumps at all can clog the feeding tube and it sucks. It can take a ridiculous amount of time and energy to unclog the tubes. They're super tiny and in order to unclog them I have to sit with a piece of fishing line and try to maneuver it through the tube. When I encounter a clog, I have to continually ram the fishing line into it until it manages to pierce through chunk of formula and allows liquid to pass again. It's a nightmare to deal with. And before you say, just throw the tube away and use another, each tube is $15. They're expensive. Especially when you have to feed babies multiple times a day and run into clogs quite often. 

Baby opossums need to be fed by tube due to the fact that they don't suckle. If you give them a nipple like you would for a squirrel or raccoon, they won't eat from it. If they do for some reason attempt to, they're more likely to aspirate the formula which can cause them to get sick and die. It's also a very delicate thing to tube feed a baby opossum. It's important to determine that the tube is in the right place before you start pushing slowly on the syringe to introduce the formula into the baby's stomach. They're only able to get a small amount of formula at a time and it depends on their body weight. There are a lot of calculations that go into feeding them. I typically note every baby's weight at least twice a day to make sure that I'm feeding them the correct amount of formula and to make sure that they're gaining weight. 

Once the babies have their formula it's important to potty them. When they're little and still in the pouch their mom will lick them, much like a cat or a dog, which will encourage them to void their bladder and bowels. When I take in baby opossums, I take on that role (but I don't lick them!). I use a slight damp cotton swab (with warm water) and rub it over their parts until they potty on the puppy pee pads I use. I also have to keep a close eye on their bowel movements to make sure they're not too loose or too hard. It's also a good idea to make sure that they're not getting dehydrated. If for some reason they start to, it's important to get them started on some Pedialyte or plain water to make sure their little systems are up and running like they should be. 

It's also good to note that I buy a ridiculous amount of disposable exam gloves. Any time I handle the babies or their enclosures I need to make sure that I have gloves on. I also need to switch gloves any time I switch between pouches of opossums. It's a sanitary issue. I make sure to keep a ridiculous amount of hand sanitizer on hand too. 

Taking care of these little hissy monsters is expensive, time consuming, stinky (their poop smell SO BAD) and many times the babies hate me and hiss at me (which is a good sign they'll be good on their own when they get released) but I honestly wouldn't want to give it up for the world. I love them, even when they don't love me. 

Opossum Profile: Lady Nubbington

 This is the first iteration of the “Opossum Profile” series of posts where we will highlight one of our rehabilitation success stories.

Name: Lady Nubbington, Duchess of Stubblefield, the Tailless Terror AKA “Nubbs”

Favorite Food: Fresh broccoli  

Favorite Activity: Showing “Alligator Mouth”

Nubbs came to us as a part of a litter that survived in their mother’s pouch after she became a roadkill victim. Unfortunately, it was soon discovered that her tail was broken and mangled and she seemed very runty compared to the other pinkies. 

After a late night visit to the emergency vet, she came back to us with her tail amputated but she didn’t let that slow her down.

Against the odds, this little lady was one of two littermates that ultimately survived and was rehabilitated to release. 

Her balance was a little off as she adapted to the lack of a tail, but it didn’t stop her from growing up happy and healthy.

Let us know in the comments how you liked the first ever Opossum Profile, feel free to ask any questions, and offer any recommendations for information or content you’d like to see added.

Upgrading Opossum Paradise

Apologies in advance for the abrupt nature of this post. We just got the blog set up and haven't even fully built profiles, introduced ourselves, or told the story of how we got here, but I didn't want to miss an opportunity to get an update out there on current events and share the progress of my current construction project to perhaps give folks some ideas on how to set up their own outdoor rehab enclosures when other family pets are involved.

So...skipping the story that leads up to today:

I've been racing the sunset each day after work for the past few days to get a newer, more professional looking fence around to expand the area around our old enclosures and add the larger pre-release enclosure to be used. State law requires a fence to separate our dogs from any outdoor enclosures. It's also going to help with our sanity because our two basset hounds LOVE talking to the opossums outside at odd hours.

My goal was to have something that was actually installed in a straight line and didn't look like it was cobbled together with found items like the makeshift chicken wire fence that I initially set up to get my wife started on this adventure. You can see the existing monstrosity in the background of the photos below. It's not pretty and I have hated it since day one. I hated it even more once I put a bunch of time and money into the large pre-release enclosure that ended up finding a home outside the fenced-in corner that I lovingly (jokingly?) refer to as "Opossum Paradise."

The end results are a little wonkier than I would have liked when it comes to the goal of "straight lines" but the tree roots are the ones in charge of this project right now. That being said, I still REALLY highly recommend the Zippity Outdoor Products vinyl fence kit from Home Depot. They have been incredibly easy to assemble and install and provide an easy no-dig option to get something up relatively quickly. 

Still some work to do yet, but it's getting there!

Here's the list of items that I ended up getting, if you'd like to build a similar shopping list:

All American Picket Fence Panel Kit with No-Dig Anchor and Cap
All American Vinyl Picket Fence Gate with Stainless Steel Hardware
No-Dig Vinyl All American Finishing Fence Post with Anchor and Cap

I would like to note, however, that the placement on the pre-drilled screw holes on the gate and the accompanying hardware is rather poorly thought-out and caused me to strip out one of the screws for the hinges because it hit another one that I drilled in from the adjacent side and also severely limits the placement of the hinges so they can sit flush. A minor inconvenience in the grand scheme of things.