A tusk-less elephant phenomenon led a University of Idaho professor to research in Gorongosa National Park in Mozambique.
Ryan Long, an associate professor in wildlife sciences, along with researchers from Princeton University, began their study on tusk-less elephants in 2018. Long, a large mammal ecologist, had already been working with elephants in Gorongosa, starting in 2015.
“I got a project going with some of my startup funds studying crop-raiding behavior by elephants in Africa and how to prevent it,” Long said. “That’s kind of what got me started into the world of elephant research.”
A few years after, Long and his Princeton colleagues grew an interest in the existence of several tusk-less female elephants. Long said the initial idea was to grasp what genetic factors could play a role in creating the trend.
After receiving a grant from National Geographic in 2018, Long and his team were able to pursue the research necessary to understand the tusk-less phenomenon among female elephants. They darted three elephants with tusks and three without. The team collected genetic samples and placed trackers on the elephants to monitor their activity.
The next couple of years consisted of continually retrieving additional specimen and analyzing their findings. This led to their data, which was published in Science in October 2021. Long not only returned to Gorongosa because of his established presence from prior projects, but because of the area’s high rate of tusk-less elephants. Alarming amounts of elephants in Mozambique were poached during the Mozambican Civil War.
The research from the study found that after the high rates of ivory poaching during the Civil War, female elephants without tusks had a five-time higher chance of survival. Long said after the war, over half of the females in Gorongosa didn’t have tusks. It became a hereditary trait.
“It produced this sort of evolutionary shift towards tusk-lessness because being tusk-less was advantageous,” Long said.
Long said after the war, a rise in tusk-lessness continued into the next generation. After collecting the samples, they found a similar genome producing this physical difference, that is also found in humans.
Since concluding the initial study, Long and his fellow researchers plan to learn the behavioral consequences involved without a tusk. Long presently has a PhD student observing differences in their movement and dietary selection.
“They (tusks) are an important defining feature of elephants, but the tusk-less females in Gorongosa seem to be doing fairly well,” Long said. “And so there has to be some behavioral adaptations that they’re using to cope without tusks, right?”
Rita Walker, a PhD student in Behavioral Ecology, assisted the researchers in collaring the elephants while in Gorongosa. Walker said the study is interesting to observe how humans influence wildlife.
“What these guys find is that their declines have not just numbers of effects, but actually change what elephants look like in the park,” Walker said. “And there’s evidence that’s happening in other places as well.”
Sierra Pesnell can be reached at [email protected]
Erin Fanning
This was fascinating! Thanks for sharing!