Rowdy Research

How Studying Denver Zoo’s Asian Elephant Bachelor Herd Is Shaping the Care of the Species Around the World

By Maura Davis, Curator of Large Mammals 

“Where are your females?” 

“Why don’t you have babies?” 

These are among the most common questions we get at Denver Zoo about our Asian elephant herd, and while our answer isn’t always what a guest is looking for (we don’t house females, so no babies here!), the way we take care of elephants in Toyota Elephant Passage is part of a larger goal to better understand male elephant socialization in the wild, and in human care.  

Toyota Elephant Passage opened at Denver Zoo in 2012 and was specifically designed to hold bulls.  In 2016, we started socializing male Asian elephants and our team of elephant care specialists  dedicated their time to learning as much about the integration process and consequences of those interactions as possible. Many zoological institutions that are housing male elephants often experience difficulties in socializing them as they get older due to numerous changes that occur as they mature, the most significant being their annual hormonal cycle called musth.   

The social structure of the herd in Denver was specifically designed to have a mature male (Groucho, age 53), who can teach and lead with patience and appropriate dominance, and a range of younger bulls who recently left their family groups to come and learn from Groucho’s teaching. As these younger males mature, they could be recommended to move elsewhere to a breeding institution to continue working with the Association of Zoos and Aquariums’ Species Survival Plans efforts to keep genetic diversity within the AZA’s Asian elephant population. As more male elephants are born, there will be a growing need for other institutions to house multiple male elephants, so learning best management practices and the importance of social hierarchy are important to set those other facilities up for success in the future.  

Denver Zoo has been working with researchers over the last several years to study multiple aspects of male management, and recently published a study titled “Age and Social History Impact Social Interaction Between Bull Asian Elephants at Denver Zoo.”  In this study, we found that behavior significantly changed when the mature male was present and that including at least one mature male in social groupings may reduce competition between adolescents. This has helped us understand how to best set up introductions of new elephants into our herd by starting with the the most mature male to help guide appropriate interactions when a new bull is establishing himself in the group. 

While this research helps us understand our own herd better, it will also be used worldwide to support the care of elephants in their native ranges, and in other accredited institutions. In India, the research is able to help guide governmental policy regarding the removal of adult males from groups of younger males in wild herds. Young males without the guidance of an adult bull show more tendencies to raid crops and cause damage in populated areas.  

We were able to see this research in practice with the arrival of our newest juvenile, Duncan. Duncan has only been at Denver Zoo for two weeks, but is already acclimating well with members of our herd, thanks to the work of our elephant care specialists. He spent his first day with Groucho to ensure Duncan had the mature male as support to help guide appropriate introductions to the younger elephants.  He has since met 14-year-old Chuck and 13-year-old Jake while under Groucho’s guidance. Our animal care specialists will continue to introduce him to other members of the group as he settles in.  

Research is a time-consuming process, but the insights gained, and the ability to share them with other organizations caring for Asian elephants, are invaluable. And thanks to our dedicated team, we now know more about male Asian elephant socialization than we ever have.