Short-Tailed Opossum Life Spans

About 4 Years, Not 8 Years

By Molly Kalafut

One of the most frustrating inaccuracies about short-tailed opossums is the supposed 8 year lifespan. This information is found all over the Internet on a variety of websites. I don't know where the 8+ years rumors first came from, but it has been copied over and over since then to different places.

For a long time, my own website said this about their lifespan: "While many websites report 8 as the average, from what I've noticed most people's seem to live until around 3-4." After 7+ years of research for my soon-to-be-published book on short-tailed opossums, I am finally confident in stating that 8 years is wrong. In fact, I haven't found any confirmed cases of a STO living to age 7, much less 8 as an average.

The fact of the matter is short-tailed opossums live about 2 years in the wild, generally about 3-4 years in captivity, and the longest recorded life span in captivity is 6 years. The book "Longevity Records" by Carey & Judge (2001) gives 6 years as the record for Monodelphis domestica in captivity. Tony Cueto, one of the original introducing breeders of STO as pets, stated his oldest STO lived to 6.5 years old. My mailing list for short-tailed opossum owners has had over 300 members and the oldest pet STO reported was 5-6 years old when they died. Most owners have reported their STO died around age 3-4, and not infrequently at 2-3.

It is a shame because many owners are heartbroken, feel like failures and wonder what they did wrong when their short-tailed opossum lives to a ripe old age of 4, yet they were expecting 8 years or more. Some people buy a STO happily hoping for 10 years to spend with their new pet, and then get a terrible shock later to learn they will probably die after 3-4 years instead.

This brings up a good point for anyone researching pets. Pay close attention to specific numbers - weights, ages, lengths - and see if those numbers conflict with other sources. If 6 sources give 5 different numbers for the same measurement, that's a sign that more in-depth research is needed!

Life Span Quote Examples

These are quotes from websites about short-tailed opossums. As mentioned above the actual average life span is 4 years. The examples aren't meant to embarrass the authors; STO have only been kept as pets since 1994 so a lot of care information has been speculation.

What I am trying to do is illustrate why you need to read a lot and pay close attention to the details when researching pets, since reading just 1 or 2 articles about a pet is probably not enough.

Conflicting Information On STO Life Spans:

1. "I was talking to one local 'possum owner who claimed that his was an adult when he got it and it had lived 7 years, and that several other owners he knew had short-tails that were 11 years old." (Source: http://shell.rmi.net/~amethyst/opossum.html)
2. "I have read they live 5-10 years on average." (Source: http://shell.rmi.net/~amethyst/opossum.html)
3. "They are gray to a tannish blonde in color, and they are thought to live for about 8 years, possibly longer with proper diet." (Source)
4. "Lifespan 8 years." (Source)
5. "Life Span 8 years" (Source)
6. "Short Tailed opossums can live to be 6 years or older." (Source)
7. "Lifespan: 5 to 8 years" (Source)
8. "They can live up to five years in captivity, and will readily breed with the right conditions." (Source)
9. "In any case, these animals are both unusual and captivating as pets with an average life span of five years." (Source)
10. "They are friendly by nature and grow to between 5 and 10 inches and will live about 4 years. " (Source)
11. "Short-Tailed Opossums (STO) are cool little creatures that live for about 4 years in captivity." (Source: http://www.geocities.com/beck4321/stocare.html)
12. "Average Lifespan: 4 year(s)" (Source)
13. They will live for approximately 3-5 years, with some individuals living to be 7 years old!" (Source)
14. "Lifespan: 3-5 years" (Source)
15. "Its lifespan is approximately 3-4 years." (Source)

Conclusions

No matter how many places you read that the short-tailed opossum life span is 8 years or more, it is actually closer to 4 years. The record longevity reported from universities, laboratories and pet owners is 6 years, with less than five confirmed cases total.

When researching pets - especially unusual and exotic pets - keep an eye on conflicting life spans. If some sources report "4 years" and others report "8 years", that's a sign that more reliable information is needed.