Prolonged adolescence in the giant panda

(writing in progress)

The giant panda reproduces slowly owing to its nutrient-poor diet of bamboo, and it is on this that its aposematism (see previous posts) is partly based.

The point of this Post is to show that this species has has a peculiarly long adolescent period.

Please see basic information at http://www.4panda.com/panda/pandatips/reproduction.htm and http://wwf.panda.org/what_we_do/endangered_species/giant_panda/panda/panda_life_cycle/

Since humans reach sexual maturity early in the teenage period, I now see that the thinking I used below was rather fuzzy. Using humans as a model, ‘teenage’ refers to a period mainly after, not before, sexual maturity, but before full body mass is attained. In female humans the teenage period, thus defined, would be only 13-17, because girls certainly reach full body mass by 17 years old. So I guess (bearing in mind that the female is the standard gender) that female ‘teenagers’ in the human species are really 13-17 years old, a period of 5 years.

Coming back to the giant panda:

I’ve so far not found information on when the female giant panda reaches full body mass. However, assuming that sexual maturity (which occurs at 4-8 years old but usually at ca 6 years old, about half the human value) occurs before full body mass is reached (which is a common pattern in mammals), then let’s assume that the female giant panda grows in body mass until about age 8 years. If so, then ‘teenager’ in females of the giant panda would be defined as 2-8 years old, a period of 6 years, which is impressively long for a member of a non-primate and as long as in the human species.

Please note that the giant panda achieves independence from its mother at about age 18 months (after being weaned by about 9 months), so we can certainly regard any age above 2 years as ‘teenage’, not so?

Out of date?So the answer is: the giant panda is adolescent at about 2-6 years old, which is a relatively long period for a member of the Carnivora. A growing giant panda can be described as adolescent for at least 3 years of its life whereas a growing wolf could be described as adolescent for hardly more than one year of its life, and the lion is more similar to the wolf than to the giant panda in this respect.

So, the bottom line, on second thoughts, seems to be this:

The human species has a female teenage period of about 5 years, ages 13-17.

The giant panda has a female teenage period of similar length, ages 2-8 years.

Despite being faster-growing and shorter-lived than the human species, the giant panda manages to have a prolonged adolescent period.

Although felids and canids are different, in growing faster and having brief adolescent periods of only ca 2 years, another lineage of Carnivora that would be worth looking at for comparison with the giant panda is the hyenas, which live long and may grow more slowly than cats and dogs. And of course we already know of the fossa (Cryptoprocta) of Madagascar, which has a prolonged ‘tween’ period, in its case pre-sexual maturity. I suspect that, although giant panda and fossa both take many years to mature, the difference is that the giant panda reaches sexual maturity earlier (relatively and possibly absolutely) than the fossa, hence has a longer ‘teenage’ period than the fossa.

As you can see, ‘teenage’ female humans are more or less always sexually mature, ‘teenage’ females of the fossa are not yet sexually mature, and ‘teenage’ females of the giant panda straddle sexual maturity. So the word ‘teenage’ hardly stands up to scrutiny as a useful way of referring to the growth stage of the giant panda that you observed in China, being too hard to define satisfactorily, not so? Nonetheless, I can see where people are coming from in applying this term to the giant panda, because (compared with felids and canids) it does have an extended period of playful adolescence.

Humans are adolescent at 13-19 years old, a period of 7 years of life.

but what does ‘teenage’ mean in terms of the life history of the giant panda, a species that lives at most 30 years and more usually only 20 years? And why describe the giant panda at this age as ‘teenage’ given that such terms are not usually applied to, for example, the wolf?

Well, sexual maturity in the female giant panda is at ca 6 years old, and sometimes as early as 4 years old.

whereas it is at <3 years old in the lion (Panthera leo) and <2 years old in the wolf (Canis lupus). Although weaning occurs within the first year in the giant panda, the animals grow for another >5 years before starting to breed. The giant panda certainly grows more slowly than does the lion or wolf, and possibly lives longer. I presume that even at 6 years old, the time of sexual maturity, the body is still not fully grown in the giant panda. I’ve not heard the term ‘teenager’ applied to adolescents of the wolf, presumably because that canid grows so fast that ‘teenagers’ would be limited to the age range of 1-3 years at most.

(writing in progress)

Posted by milewski milewski, June 04, 2022 02:03

Comments

There are reports of the surprising playfulness of ‘teenagers’ of the giant panda at the breeding centre for this species in Szechuan, which may be reminiscent of juvenile baboons. This aspect of the behaviour of the species does not come out strongly in the literature.

Posted by milewski 4 months ago (Flag)

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