Zoo scientists observe wild animals


Lincoln Park Zoo scientists have assisted the recovery of endangered black rhinos across Africa, which were nearly driven extinct during the 1990s by habitat destruction and poaching.



Lincoln Park Zoo scientists assisted the recovery of endangered black rhinos, which were nearly driven extinct during the 1990s by habitat destruction and poaching. Prior to the recovery effort, their population dropped from 65,000 to 2,000 individuals.

With help from conservationists, the rhinos have begun repopulating their historical range—recent surveys show 5,055 individuals—but because they are slow breeders, it’s important to understand the factors that naturally limit reproduction.

With more than 50 individuals, Addo Elephant Nation Park currently boasts South Africa’s largest breeding population of the southwestern arid subspecies of black rhino. To form a clearer portrait of their health, zoo scientists used non-invasive field techniques—the collection of fecal samples—to monitor hormone concentrations and the presence of parasites in this population. Sample collection is made possible by motion-activated field cameras that are used to track rhino movement and habitat usage.

Hormone and parasite data was combined with information on behavior, ecology, predation, competition, and tourism. The resulting information helped scientists better manage and conserve this amazing endangered species.

Black Rhino Background


Rhinos in Peril

The black rhino is a shy, secretive species that is difficult to observe in the wild. Rhinos have a good reason for being elusive; they are poached for their horns, which, in some cultures, are used in traditional medicine.

Rhino Pregnancy Test

The black rhino offers a charismatic reminder of prehistoric times, and it has also become an iconic species for conservation efforts. After a narrow escape from extinction, the black rhino is slowly repopulating its historical range.

However, continued reproductive success is critical for the species’ sustainability, especially given that it is a naturally slow breeder. Understanding the factors that naturally control reproduction will help managers—in the wild and zoos—ensure that all black rhinos reach their reproductive potential.

Toward this end, zoo researchers developed a field kit that diagnoses pregnancy using black rhino fecal samples. They can use this information to determine the breeding success of rhinos in Addo Elephant National Park. Specifically, they can monitor the inter-calving interval (the timeframe between births) to determine how the environment impacts black rhino reproduction.

Conversation Close-Up

What Can Be Learned from Feces?

Hormones can be extracted from fecal samples, providing information on an individual’s reproductive state and stress levels. Also, the presence of parasites in the samples can be measured to provide an indicator of health and well-being.


How Do Motion-activated Cameras Work?

These cameras take photos when a laser attached to the camera senses nearby motion. They were set up at rhino latrines (bushes where rhinos defecate to mark their territory) to help scientists match fecal samples with individual animals.


How Are Individual Rhinos Identified?

Each rhino in Addo Elephant National Park was immobilized at the age of dispersal from its mother (around 6 years of age) and given a name and specific pattern of ear notches that can be used to identify it in photographs. Rhinos can also be identified by anatomical features, such as their horn and the scars on their bodies.


Rachel Santymire, Ph.D.
Adjunct Scientist, Lincoln Park Zoo
Conservation & Science
Jed Bird
Wildlife Biologist
Jordana Meyer
Wildlife Field Technician
Elzabeth Freeman
Empty Playlist