Chameleon Spends Most of Its Life in Its Egg

“Life is short” isn’t just a witty saying for a certain species of chameleons that live in southwestern Madagascar. For the Labord’s chameleon (Furcifer labordi), life really is short. And, to make it even more interesting, the majority of its shortened life is spent within the confines of an egg. After hatching from its egg, the chameleon only lives another four or five months before its life is over.

An Accidental Discovery

The unusual natural history of these chameleons was discovered by researchers by accident. Kristopher Karsten, a graduate student based at Oklahoma State University, arrived late in the season. Although he expected to find many recently-hatched juvenile chameleons, he didn’t find any. Then, several months later in February, he discovered something even more unusual–the carcasses of many Labord’s chameleons, apparently dead from natural causes.

A male Labord’s chameleon. (Credit: Ken Preston-Mafham/PREMAPHOTOS/naturepl.com)

At the time of Karsten’s observations, not much was known about the life history of Labord’s chameleons. Since his initial observations, more than 400 individuals have been studied over a period of five field seasons and scientists now know much more about the species’ remarkable life history.

Shortest Lifespan, Fastest Growth Rate

Because of its short life span outside of the egg, it is imperative that the chameleon matures quickly–and that it does. Labord’s chameleons have the fastest growth rates of any tetrapod species. After hatching during Madagascar’s wet season in November, the chameleons grow at a rate of up to 2.6 mm (0.1 inches) per day. In fact, in less than two months, the chameleons increase in body size by 300-400 percent. To put that another way, if a human grew at the same rate, an infant that was 51 cm (20 inches) at birth would grow to a height of 1.5 meters (five ft.) over a period of only two months.

After reaching maturity, the chameleon population reproduces. Females dig burrows in the desert sand and bury their eggs about 138 mm (5.4 inches) below the surface. Following reproduction, all of the adult chameleons die. Meanwhile, the developing chameleons remain in their eggs underground for eight to nine months, where they wait out the dry season.

A female Labord’s chameleon. (Credit: PREMAPHOTOS/naturepl.com)

Ecological Constraints

So what accounts for such an unusual life history? Scientists point to several factors that may have led the species to evolve such a short lifespan. One factor is size–Labord’s chameleons are the smallest of its genus. Perhaps due to their size, the chameleons are a favorite snack of desert predators such as birds and snakes. A second factor is climate. The southwestern Madagascar desert climate where the chameleons live is harsh and unpredictable. In addition, the rainy season is short, which further limits the amount of time the chameleons have to grow and reproduce.

Questionable Future

Though scientists have learned a lot about Labord’s chameleons, many questions remain. While the short lifespan of the Labords chameleon lets it successfully survive the constraints of its ecology, scientists wonder how long-term changes in the climate–or even a short-term event like a longer-than-normal dry season–might affect the species.

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