The use of a sniffer dog for amphibian conservation ecology
Abstract
Amphibians are threatened by a variety of factors, of which habitat loss (due to urbanization) and infectious diseases are a few of the largest contributors. Urbanisation and land development is one of the biggest threats to wildlife populations. Species that are particularly vulnerable, for example, burrowing species, are not easily detected by conventional survey methods, due to their cryptic lifestyles. The Giant Bullfrog (Pyxicephalus adspersus) is one of two amphibian species that are listed by the South African National Environmental Management: Biodiversity Act 2004 under the category Protected Species. Because Bullfrogs are fossorial (aestivate for up to 11 months at a time) and active for only a few weeks of the year, an area can easily be misidentified as not having any Bullfrogs during conventional surveys. This misidentification can then lead to the approval of construction work within their habitat. Thus, there is a need to find a way to locate these frog species without harming them in the process. It seems, however that scent detection dogs can help with locating and therefore, also protecting these species. Due to their heightened sense of smell (between 1 000 to 10 000 times higher) dogs have the ability to detect more diluted scents than humans can. Because of this sensitivity, Canines have been used for a variety of scent detection jobs. Using dogs for research and conservation purposes is a fairly new practice and therefore requires its own techniques. We made use of a sniffer dog to detect a burrowing species using a method called operant conditioning. This type of conditioning reinforces a natural behaviour in the dog. The ability of the sniffer dog to detect the Giant Bullfrog scent in amphibian conservation was tested, as a precursor for using this technology later on. Clicker training, in combination with operant conditioning, was used to prepare the dog for the detection of frog scents. This setup required three phases: 1) familiarizing the dog with the target scent in exposed containers; 2) introducing the training platform with diluted target scent and disturbances; and 3) training in simulated natural environments. After training, the dog could locate and indicate on containers with live frogs inside, and achieved 100% accuracy on a 1:100,000 dilution of the scent she was trained on. The results for this project indicated that human and amphibian scent disturbances are not a major distraction for the sniffer dog. The dog was able to detect scents, above and below the surface, under a variety of conditions. Our sniffer dog was also able to detect wild buried Bullfrogs and track the scent of live frogs over a body of water (in their natural environment), but digging to confirm the presences of the frogs was not always possible. Ultimately, the successful application of this research could result in a mutual beneficial collaboration between the scientific community and industry partners to the means of environmentally sustainable development. Additional work was also done to condition the dog to detect other critically endangered South African amphibian species and also train the dog to identify pathogens such as Batrachochytrium dendrobatidis(Bd). The sniffer dog was able to detect all of the Bd targets (cultures) in the experiments. Even though a minute amount of false indications were made during all plank experiments, most of the false indications could be explained by the position of the target and/or the setup of the experiment on the plank equipment. One of the factors that were applicable to our experiments with regards to missed indication was the way in which plank equipment was used. It could be concluded form our experiments that the two best methods for preservation of frog scent was a 1:1000 dilution and a swab that were both kept under the same conditions (4°C) only if the swab was diluted before each test. During this study we also looked at historical and spatial data (using geographic information system) and compared the results with sampled data. Comparing the datasets revealed a correlation between three condensed soil patterns and Bullfrog distribution. A vital component of this research project was informing and educating the public on amphibians and conservation. Mainstream- and Social media, along with scientific platforms, were used to convey the applicability of this study to conservation ecology. By using the sniffer dog, a lot of public interest and awareness was generated for the duration of this study.