Discovering the in-between: the hidden network of the Agulhas Plain leopard corridors

[ORIGINALLY PRINTED IN SUIDERNUUS, 8 APRIL 2022]


A sliver of undeveloped land outside Bredasdorp may hold the key to the survival of a small leap of leopards that roam the Agulhas Plain. It is an invisible drama that plays out mostly at night, unbeknownst to most of us. Anri Matthee spoke to conservationist Bool Smuts about the critical importance of preserving leopard corridors.

 
A male leopard on the mountains between Bredasdorp and Napier. A sliver of undeveloped land outside Bredasdorp holds the key to the survival of a small leap of leopards that roam the Agulhas Plain. Photo: Supplied / Landmark Foundation

A male leopard on the mountains between Bredasdorp and Napier. A sliver of undeveloped land outside Bredasdorp holds the key to the survival of a small leap of leopards that roam the Agulhas Plain. Photo: Supplied/Landmark Foundation


Leopards are the last widely occurring free-roaming apex predators in the country. And the Overberg is home to one of these last remaining prides, according to the Landmark Foundation, an NGO focusing on leopard and predator conservation in Southern Africa.

“We’ve got leopards right up there above Bredasdorp in the mountains,” says Bool Smuts. “They do occur there. That’s been known for many years.” But in order to protect the dwindling leopard populations, their freedom of movement and habitat accessibility are critical.

Smuts is the director of the Landmark Foundation, which studied the movements of leopards in an area stretching from Cape Infanta to the Bot River lagoon.


Corridors – the leopards’ lifeline

Leopards navigate between different populations through passages of natural landscape – called corridors – that connect their habitats in a similar way that roads connect cities and towns.

Around Bredasdorp, however, these strips of natural land are few and far between in a landscape that has been “utterly transformed” by agricultural and urban activity, explains Smuts.

“Leopards do not set foot in transformed landscapes, so they rely on these connectivity corridors through natural landscapes.”

One such corridor is found along the coast between Arniston and Struisbaai, especially including the Heuningnes River in De Mond Nature Reserve.

The natural landscape of the coastal belt is mostly intact, which enables the area to act as an important connectivity corridor to the Nuwejaarsrivier wetland area and the broader Agulhas Plain.


Finding the facts

Because of this corridor and surrounding leopard sightings, there was a need to establish the scope of leopard activity on the Agulhas Plain.

From 2011 to 2015 the Landmark Foundation conducted research with wildlife cameras to capture leopard activity and collect data across the entire Agulhas Plain.

The remaining leopard population they discovered was “extremely low”, says Smuts – fewer than 20 territorial adult leopards roam the terrain from Kleinmond to Infanta. Leopard cubs are few and have a survival rate of only 25%.

The area of study also included Bredasdorp and its surrounding mountains. Leopard activity was found on either side of the town – in Heuningberg Nature Reserve on the west, and in the mountains of the Air Force Base Overberg in the east, which eventually form De Hoop Nature Reserve. As the town is situated between these two areas, the researchers started looking for potential connectivity corridors that would allow leopards to navigate between them.


Bredasdorp is nestled between the Heuningberg Nature Reserve in the west and the mountains of the Air Force Base Overberg on the east that eventually form De Hoop Nature Reserve. Besides the coastal belt corridor, the small strip of natural landscape south of the town is one of the only possible corridors that connects two leopard populations.

Bredasdorp is nestled between the Heuningberg Nature Reserve in the west and the mountains of the Air Force Base Overberg on the east that eventually form De Hoop Nature Reserve. Besides the coastal belt corridor, the small strip of natural landscape south of the town is one of the only possible corridors that connects two leopard populations. Graphic: Anri Matthee using Google Earth


On our doorstep

South of the town, behind the Bredasdorp Golf Club, runs a small strip of wilderness that is one of the few remaining natural landscapes in the area. This sliver of land could very well be a critical connectivity corridor, says Smuts. “Unfortunately, our cameras got stolen near Bredasdorp, so we never verified whether that corridor is used,” he said. “But on scientific analysis, that is a very, very important last remaining opportunity for connectivity between the De Hoop leopard population and the Napier-Bredasdorp mountain population.”


A matter of survival

Considering the low population numbers, this potential corridor could “probably [be] the most important” since it – along with the coastal belt corridor – are the only possibilities for contact between local leopard populations, as well as other populations to the north and northeast. This connection between different leopard populations is necessary for the genetic variation of the species. The isolation of leopard populations leads to “genetic bottlenecking” and negatively impacts the reproduction of natural populations. This has disastrous implications for their survival. “These last slivers of land are critically important for the persistence of the species,” Smuts says. “They are the last tiny little slivers of opportunity and are really the last chance for the species in the area.”