Talk Putting the citizen in science: using volunteerbased data to determine the effect of vehicular traffic on endangered western leopard toad Amietphrynus pantherinus in Noordhoek Cape Town

Amphibians are one of the most impacted vertebrate groups at risk from roads during breeding migrations and feeding events, in particular wildlife-vehicle-collisions (WVCs). The last 20 years have seen a dramatic increase in efforts by volunteers and scientists to mitigate the negative effects of roads and traffic on wildlife globally, including fencing to prevent WVCs and wildlife crossing structures to facilitate landscape connectivity and reduce road mortality. WVCs have been identified as one of the main threats facing the endangered Western Leopard Toad (Amietophrynus pantherinus), found endemically in coastal suburbs in Cape Town, South Africa. Due to the desirability of coastal land for residential homes, there has been an increase in WVCs on A patherinus.

In 2008, a volunteer group consisting of local residents Toad NUTS (Noordhoek’s Unpaid Toad Savers), was established to rescue migrating toads off roads and to record observations and locations.  A ‘rescue and record’ protocol was created whereby volunteers were trained to drive the roads bordering the breeding ponds and remove toads off the roads. A photograph of each toad was taken and size and sex recorded. Data are collated per season and used to track roadkill numbers, identify road hotspots and breeding ponds and to help motivate the volunteers.

Our protocol identified A. pantherinus road mortality hotspots, prompting Toad NUTS to seek alternative methods to reduce the number of fatalities and to make the rescue process safer for the volunteers. As the first experiment of its type in South Africa, Toad NUTS in collaboration with The Endangered Wildlife Trust pioneered shade cloth drift fences and pitfall traps erected on the roadside verges to reduce road mortalities of A. pantherinus on their migration routes on a main road in Noordhoek, Western Cape. The design of these fences was based on recommended international practices, but also took into account developing world conditions such as: severe budget limitations, possibility of theft, potential for human interference, and erection and patrolling by non-scientifically trained volunteers.

The road kill numbers reflect the success of the barrier erected for 900m along Noordhoek Main Rd. Before the barrier was in operation 29.5% of 105 toads collected were found dead on the road in 2011. Similar figures were noted in 2012 and 2013 with 29% of 155 toads followed by 27.1% of 70 toads collected on the road.

The barrier was erected after the first week of the 2013 breeding season with 0% of 88 toads collected found dead on the road; further decreases in road mortalities were noted in 2014 (3.6% of 138 toads collected) and 2015 (1.9% of 106 toads collected).

The Toad NUTS initiative has been a self-started, community-funded project involving ~100 local residents in nightly road patrols over eight breeding seasons (2008-2015). This has resulted in increased public and driver awareness of A. pantherinus as well as the successful adopting of a roadkill-reduction measure. The data collected over eight years of road patrols and for three years of barrier patrols, has been essential. These data further reflects the value that volunteers can contribute to citizen science. However, it is clear that a single strategy to conserve this species is not enough; conservation strategies need to be site-specific and community awareness and participation in the form of volunteerism and financial support is essential. Together, with appropriate levels of support provided by the scientific community, local volunteerism may be the most important and enduring strategy for an African country such as South Africa with limited financial resources available for continuous conservation projects.

Cape Peninsula, citizen science, roadkill, Western Leopard Toad, wildlife-vehicle-collisions