From beeps to big cats: tracking lion energetics and physiology in the Kruger National Park

Estimated reading time: 6 min, 45 sec

Published: 28 Nov 2025
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From early-morning telemetry beeps to rare sightings in the Kruger bush, this story follows two researchers as they track collared lions to uncover how these apex predators move, cope and survive in a changing environment, all with the help of their trusty Suzuki Jimny.

In pursuit of lions, one beep at a time

 

Many visitors have driven through the Kruger National Park searching for lions, scanning the bush hoping to catch a glimpse of a golden coat or the flick of a tail. When that moment finally comes, it’s unforgettable: a mixture of excitement, awe and respect for one of Africa’s most iconic apex predators. Ashleigh Donaldson and Kiyana Rehnema of the Wildlife Conservation Physiology team at the University of the Witwatersrand feel the same thrill, and relief, when they hear “beeps” from their telemetry equipment, signaling that one of their collared lions is nearby. For them, each beep represents an opportunity to observe and study this charismatic species - a privilege that is essential for advancing lion conservation. 

A collared lioness walking through grass

Credit: Ashleigh Donaldson

Life is not that easy for the mighty ‘king of the jungle’

 

Lions contribute significantly to ecotourism and play a critical role in maintaining ecosystem balance. Yet, lion populations across Africa are in decline with the most recent 2023 estimate suggesting that only 23,000 individuals remain on the continent. Lions in Kruger face many threats, including disease and climate change. Kruger is experiencing increasing air temperatures, unpredictable rainfall, and extreme weather events like drought—conditions that put extra physiological pressure on lions. As part of their research, Ashleigh and Kiyana are studying how lions function, move and behave under varying environmental conditions and disease pressures. Their work involves collecting fine-scale GPS movement and body temperature data alongside a suite of climatic variables from a weather station in Satara. 

 

Two lionesses sitting in the middle of the tall grass in the rain

 Credit: Ashleigh Donaldson

WhatsApp Image 2025-11-17 at 13.40.55_46a3164b-min

Credit: Kiyana Rehnema

 

A day in the life

 

Every couple of months, Ashleigh and Kiyana head to Kruger National Park in their Jimny on a mission: to locate their study lions and observe their behaviour. Since lions are mostly nocturnal and most active between sunset and sunrise, they focus their tracking efforts on early mornings and late afternoons. Along the way, they often attract attention from curious tourists who notice the antenna sticking out of their vehicle. When told they’re tracking lions, the usual response is, “Ah, so we should just follow you!” - a suggestion that always earns a laugh, because more often than not, it feels like a game of hide-and-seek with their elusive subjects! 

Kiyana listens for the telltale beep of a collared lion

 Credit: Andrea Fuller

When Ashleigh and Kiyana finally locate a collared lion, the real work begins. They record precise GPS positions and make detailed behavioural observations - everything from resting and feeding to social interactions. These data will help link movement patterns to environmental conditions and energy use. Occasionally, they witness something extraordinary, like a lioness perched high in a tree - a rare and delightful sight that adds excitement to their tracking adventures. 

A lioness lounging in the branches

Credit: Ashleigh Donaldson

Researchers driven by curiosity, and a Suzuki Jimny

 

Finding specific lions in a park that’s almost 20,000k is quite a challenge, even with the help of telemetry equipment. The Suzuki Jimny has been a great help to Ashleigh and Kiyana - allowing them to safely travel to their study site, tackle bumpy dirt roads and being compact enough to squeeze through crowded sightings. 

Navigating Kruger’s roads in a Suzuki Jimny

Credit: Ashleigh Donaldson