Please consider the elephant if you or someone you know has gone through a pregnancy that lasted for what felt like an eternity. It has a nearly two-year gestation period making it one of the longest in the animal kingdom.
And now, the elephant in the room…
The Sick Pachyderm
As the largest land mammals on Earth, elephants also have the longest pregnancy of any living mammal lasting an average of 22 months in Africa and anywhere from 18 to 22 months in Asia. You could blame their massive size for the extended gestation period but you’d be wrong.
Due to their massive size, elephant calves do take their time maturing in the womb. However, this isn’t the only reason for their sluggish progress, their massive brains play a role too.
An Elephant Never Forgets
It takes time for an elephant to develop its intelligence but once it does, it is an exceptionally intelligent mammal. The brain is the largest of any land animal and has a structure very similar to that of the human brain.
This is further evidence of their intelligence. However, it has three times as many neurons as the human brain (250 billion) and is three times larger.
The old adage, “an elephant never forgets,” is mostly accurate. Their memory-processing region (the temporal lobe) is unusually developed with more folds than in most people’s brains.
Because of this, elephants are able to remember important information such as where and how to access life-sustaining resources like food and water. The herd matriarch can access intricate mental maps covering hundreds of kilometers to guide her family to watering holes.
Elephants are just as smart as dolphins and chimpanzees. In order to get to their food, they stack blocks and use tools made from branches and rocks. Their trunks give them the dexterity of human hands, allowing them to pick up, carry and manipulate objects with ease.
They are one of the few animal species to comprehend the meaning of pointing. Many dogs, for instance, do so but chimpanzees do not. Elephants are also among the few animal species capable of recognizing their own reflection in a mirror, only great apes, crows and bottlenose dolphins show similar ability.
Also, they show compassion by tending to injured members of the herd and mourning the loss of a loved one. The gentle giants have been observed burying their dead or covering them with leaves. They can mimic the sounds of other elephants and even some human words, in case that wasn’t impressive enough.
Understanding Pregnancy For Conservation
The illegal ivory trade and poaching have led to a dramatic decline in elephant populations around the world. Populations in much of Southern Africa are stable or increasing but poaching is a growing threat in the region’s eastern half.
The IUCN Red List of Threatened Species lists both savanna and forest elephants as endangered or critically endangered respectively. Elephants’ lengthy gestation periods contribute to the population decline crisis.
When compared to other animals, they have a significantly longer gestation period (around four to five years) and typically only give birth to a single calf at a time.
Even though zoo breeding programs play a crucial role in elephant conservation, adult male elephants who are reproductively active can exhibit unpredictable behavior and there may be issues in finding a suitable mate. Understanding elephant pregnancies is essential for the successful application of “assisted reproduction” techniques.
The method behind the production of such exceptionally smart animals has been shrouded in mystery for quite some time. However, in the last couple of decades scientists have been able to take a closer look thanks to advancements in ultrasound technology.
The elephant’s extended pregnancy and unusual ovulation cycle have been traced to a hormonal mechanism that has not been observed in any other mammal. LH (luteinizing hormone) surges twice to initiate pregnancy and hormones secreted by multiple corpus lutea in the ovary keep the baby growing.
This insight into the mechanisms that keep the pregnancy going is crucial for conservation efforts in the wild and in zoos. Artificial insemination must occur after the second surge of luteinizing hormone (LH) but timing is crucial because ovulation and fertilization are only likely to occur within a two- to a three-day window.
Scientists monitor hormone levels with weekly blood samples or by measuring hormone metabolites excreted in urine and feces in order to be prepared for the first LH surge. Artificial insemination pairs animals that may be separated by hundreds of kilometers so that their gene pools can expand.
An increasingly healthy and stable population is a direct result of a larger and more varied gene pool. Because of this, the female elephant can remain with her herd, which is crucial to its well-being.
Obviously, that’s not the final chapter.
Calves that have endured a marathon pregnancy have fully formed brains by the time they are born. Observing the adults, they quickly learn which plants to eat and how to access them and this skill is used both to recognize the matriarchal social structure around them and to help them feed themselves.
Yet they are not completely isolated. If there are any calves in the herd, the older females will help care for them and slow the herd down so the calves can keep up.
Without those 680 days in the womb, however, none of that would have been possible. They were given a head start in life thanks to the complex neural development that takes place during this time.