Research in the Maritz Lab aims to understand the functional role that snakes play in African ecosystems.
Foraging Ecology & Dietary Analyses
Information regarding the diet and feeding ecology of snakes is lacking for most snake species, especially in Africa where quantitative descriptions of diet are exceedingly rare. Given the importance of diet and feeding ecology in understanding inter-specific interactions and autecology, we use multiple approaches (including the dissection of museum specimens, citizen science initiatives, field observations, and molecular techniques) to quantify snake diets. In combination, we aim to better understand the diversity and abundance of prey consumed by snakes and the ecological implications of those interactions.
On-going projects include:
- Investigating the evolutionary origins, behaviour, and ecology of a specialist feeder, the rhombic egg-eater (Dasypeltis scabra).
- Using the social media group, Predation Records of Reptiles and Amphibians (Sub-Saharan Africa), to understand temporal, spatial, and species-specific dietary habits.
- Quantifying geographic, ontogenetic, and sexual variation in the diet of the brown house snake (Boaedon capensis) using museum specimens and social media.
- Examining the diets of cross-marked whip snakes (Psammophis crucifer) and spotted skaapstekers (Psammophylax rhombeatus) using molecular techniques.
Resource Utilisation & Competition
The availability of resources, both food and shelter, in a landscape can alter both inter- and intraspecific interactions. How seasonal changes in food availability or gravitation towards certain habitats affect competition and coexistence is a fascinating and unanswered question for most species of snakes in southern Africa. The two study systems that relate to this topic are:
- Cape Cobras and Boomslang at Tswalu Kalahari Reserve
Naja nivea and Dispholidus typus are known predators of Sociable Weaver eggs and chicks. However, little is known beyond this fact. In our work at Tswalu, we are characterizing competition and resource utilisation for both species using radiotelemetry. With our data, we will be able to address: 1) whether visits to nests are synchronous with bouts of breeding, 2) how snakes are navigating their landscape, 3) if snakes engage in resource guarding, and 4) what other resources are important to these species.
This project is conducted in collaboration with Prof Graham Alexander, Wits University.
- Cross-marked whip snakes and Spotted Skaapstekers at Koeberg Nature Reserve
Psammophis crucifer and Psammophylax rhombeatus are psammophine snakes that occur at Koeberg Nature Reserve in relatively high numbers. Both species are diurnal and are documented eating similar types of prey suggesting they are each other’s biggest competitor. Since 2015, we have been conducting biweekly reptile surveys at Koeberg using more than 200 cover boards placed throughout the veld. The long-term mark-recapture data will allow us to quantify population sizes, demographic traits, and vital rates for the two most abundant snake species, P. crucifer and P. rhombeatus. Additionally, we have begun utilising molecular methods to examine prey identity throughout the season and rates of feeding for both snake species.
Impacts of Local and Global Change
Even the most pristine environments cannot escape the effects of environmental change. Today, many animals are subjected to changes in climate, vegetation, and even ambient light. Our work aims specifically to understand if and how these changes influence reptiles at the individual- and population-scale.
On-going projects include:
- Evaluating the short- and long-term impacts of climate change on cape cobras and boomslang in an arid environment
- Developing a framework to detect and assess changes in reptile populations and communities
- Investigating the effects of habitat transformation on reptile populations across South Africa
- Exploring the influence of artificial light on snake activity patterns
Multi-scale Community Ecology
The magnitude of the ecological effects a species, or group of species, can have within an ecosystem depends, in part, on their community structure and respective population sizes. In addition to our long-term mark-recapture study at Koeberg, we have on-going projects involving:
- Examining the impact of predator and prey abundance and diversity on snake communities
- Assessing reptile community composition across the Kruger National Park
Tswalu Kalahari Nature Reserve, Northern Cape
Situated in the Northern Cape province just south of Botswana, Tswalu spans more the 100 000 ha comprised of pristine arid savanna habitat. The aridity and temperature extremes contribute to the interesting biology of the local organisms, and animals must be able to deal with temperatures exceeding 40C in summer and temperatures approaching freezing in winter. Our main focus at this site is to understand the interactions between Cape cobras, boomslang, and sociable weavers.
Find out more: Tswalu Foundation
Koeberg Nature Reserve, Western Cape
Situated North of the city of Cape Town, Koeberg is a 3000 ha reserve comprised of West Coast Strandveld and Coastal Duneveld. Using a variety of survey methods, we have a produced a nearly complete list of the animal species at Koeberg. Our research interests at this site include understanding the interactions between P. crucifer and P. rhombeatus and building a comprehensive understanding of snake community dynamics.