When do elephants get their tusks

In the s, aerial surveys showed about 2, elephants lived in the park. Related: Genetics by the numbers: 10 tantalizing tales. In , the aerial surveys stopped due to the outbreak of the Mozambican Civil War, which lasted until Arnold suspects much of the population decline during the war was a direct result of poachers killing elephants, since both sides relied heavily on the ivory trade to finance their war efforts.

However, elephants migrating away from the area could have also contributed to the overall decline, he said. Tusks are typically important for an elephant's survival, as they help them dig for underground water sources and strip the bark from trees, which is an important part of an elephant's diet. But when elephants are hunted for their tusks, this beneficial trait becomes a death sentence.

As they sifted through data, the researchers noticed an interesting pattern: All of the tuskless elephants are female. To understand why, Arnold and colleagues observed the first generation born from the war survivors. For each calf, they recorded whether it had tusks, and then whether its parents had tusks.

For African elephants, tusks can be found on both males and females compared to Asian elephants where tusks are mainly seen only on males. About half of Asian female elephants have short tusks known as tushes.

The tusks on elephants can be used for many purposes. African elephant tusks are mainly used for protection, digging, lifting objects, and gathering food. African elephants will use their tusks as a defense mechanism against other wildlife predators or when another elephant charges toward them. During the dry season elephants will use their tusks to dig water holes in dry riverbeds to get water.

To help gather food, elephants will use their tusks to strip bark from trees to eat. Also, elephant tusks are used to protect their sensitive trunk. Interestingly, just like humans tend to be right-hand or left-hand dominate, there is evidence to believe elephants tend to be right-tusked or left-tusked with the dominate tusk being known as the master tusk.

The more worn-down tusk is an easy way to tell which tusk an elephant prefers to use. Unfortunately, an African elephant only grows one set of tusks during its lifetime. Elephant tusks are rootless similar to human baby teeth and therefore cannot regrow. Douglas-Hamilton adds that if left alone, these big elephants, which typically bear the larger tusks, will father the majority of calves.

Centuries of poaching and overhunting, however, have relentlessly cut down big elephants at the height of their reproductive power, with an observable impact on the size and weight of elephant tusks. Tusks are teeth—upper incisors to be exact. According to Dr. Male tusks can grow to be seven times the weight of female tusks as they age. Those males then no longer pass on their genes for large tusks. Poole notes that even if younger, smaller males with the potential to develop large tusks remain in the population, they will not be the primary breeders given that age, body size, and musth—a frenzied, sexually charged state for male elephants during which hormone levels are elevated—determine how often and successfully a male elephant breeds with females.

Smaller tusks are not the only genetic consequence faced by elephant populations in Africa and Asia due to heavy poaching. Over several decades, researchers have documented an increase in the percentage of tuskless males and females in a number of elephant populations.

A elephant conservation plan in Uganda reported a higher-than-normal percentage of tuskless elephants in Queen Elizabeth National Park and singled out poaching as the main cause. Whereas a normal level of tusklessness in an elephant population is somewhere between 3 percent and 4 percent, according to the Ugandan report, a survey of Queen Elizabeth National Park revealed tusklessness in the elephant population to be between 9 percent and 25 percent.

For African elephants, tuskless males have a much harder time breeding and do not pass on their genes as often as tusked males. In heavily poached populations, says Poole, the ratio of tuskless animals in the population increases as poaching continues.

You can see this in almost any population that has experienced a wave of heavy poaching, in Gorongosa [in Mozambique], for example, or Selous [in Tanzania]. One might go a step further and contend that wiping out elephants—be they big tuskers or not—amounts to ecological sabotage as well.