# Light Paths and Dark Valleys: Topographic Complexity and Mammal Occupancy in a Semi‐Arid Mountain Landscape

## TL;DR

This study explores how mountainous terrain features influence mammal habitats in a semi-arid region of South Africa.

## Contribution

The study introduces detailed topographic metrics into multispecies occupancy models to better understand biodiversity patterns in complex landscapes.

## Key findings

- Floodplains and low ruggedness areas are biodiversity hotspots with high species richness.
- Steep and rugged areas serve as refuges for specialized species like leopards and klipspringers.
- Topographic complexity significantly affects species-level habitat use but has limited impact on community-level biodiversity.

## Abstract

Topographically complex mountainous regions are widely recognized as important for biodiversity conservation due to their environmental heterogeneity, which can promote species turnover, niche differentiation, and the persistence of specialized taxa. Such landscapes are often associated with high biodiversity value and provide critical resources and connectivity for wildlife and human communities. In this study, we deployed 131 camera traps to assess the occupancy of 34 mammal species in relation to key topographic variables in a semi‐arid mountain catchment in South Africa. Multispecies occupancy models were used to evaluate the probability of habitat use concerning topographic complexity, characterized by features such as catchment aspect, slope, ruggedness, solar gain and landscape units. The results identified floodplains, valleys, low slopes, and areas with low ruggedness as biodiversity hotspots, offering critical resources like water and forage and supporting high species richness. Conversely, steep slopes, rugged terrains, and high solar gain areas, while supporting fewer species, served as critical refuges for specialized taxa such as leopard, klipspringer, caracal, and grey rhebok. While topographic features like ruggedness may have a limited impact at the community level, their importance becomes more pronounced at the species level. This study underscores the value of incorporating detailed topographic metrics into ecological research, particularly in mountainous landscapes where these features govern species distribution. Conservation strategies should integrate both community‐level and species‐specific monitoring approaches to safeguard the unique biodiversity and ecological dynamics of topographically complex mountain landscapes.

Topographically complex mountainous regions are critical for biodiversity conservation, supporting high beta diversity, endemic species, and essential ecosystem services. Despite their importance, the fine‐scale effects of topographic metrics such as slope, ruggedness, and solar gain on mammal habitat use remain poorly understood. This study aimed to assess how topographic complexity shapes mammal occupancy patterns in a semi‐arid mountainous landscape by integrating detailed digital elevation model (DEM)‐derived metrics with multispecies occupancy models.