RESTORATION TRAJECTORY

Behavioural responses of varanids to mine site restoration’

By Sophie Cross

Globally increasing rates of mine site discontinuations have brought the issue of restoration to the forefront of research interests. To date studies have focused primarily on floristic responses to mine site restoration, with little attention paid to faunal responses, especially in terms of behavioural responses and selective habitat use. Understanding the behavioural responses of animals to habitat change and restoration is key to determining the success of current and past restoration practices in returning degraded sites to a state approximating pre-mining conditions. PhD student Sophie Cross is undertaking research to assess whether current mine site restoration practices are effectively facilitating the return of fauna to these systems. 

Background

Many criteria are required to maintain a healthy, sustainable ecosystem, however vegetation surveys remain the most common method of assessing restoration progress. Responses of animals are often overlooked, despite their importance in the provision of essential ecosystem services (e.g. seed dispersal, pollination, and nutrient cycling). Animals are often assumed to return to pre-disturbance abundances following the return of vegetation. This is perhaps more aptly known as the Field of Dreams hypothesis, as in practice recovering animal biodiversity and community structure are some of the most difficult components to achieve following the restoration of degraded sites to pre-mining conditions.

 

Australia is a land of lizards, yet very little is known about their responses to habitat degradation and restoration. Varanids are important predators in many Australian ecosystems, occurring in almost every habitat type. Varanids present an excellent study species as the range in body sizes (~30cm to 3m), and therefore likely home ranges, provides an opportunity to study the effects of habitat change over varying spatial scales. This study proposes to study the behavioural responses of varanids to habitat degradation and restoration as a result of mining. Understanding animal behaviour and habitat use is key to determining both the ecological role animals play in restoration and the effect restoration has on species dynamics and community structure, and will offer novel insights into the effectiveness of current restoration practices. 

Aims and significance

This study aims to determine the behavioural responses of varanids to habitat degradation and restoration, specifically in terms of changes in home range size, habitat use, activity patterns, and population density. Results of this study will aid in the development of targeted, effective guidelines and indicators to increase mine site restoration success and effectiveness.