Invasive species as vectors of disease and amphibian population declines

Emerging infectious diseases have far-reaching consequences for human health, agriculture and biodiversity. One of the most devastating diseases to emerge for wildlife is that caused by the fungus Batrachochytrium dendrobatidis (colloquially known as 'Bd'), a fungal infection of amphibians that has caused population declines and species extinctions on four continents. In the last two years this disease has reached the UK, and is currently known from three sites. At all three sites introduced amphibians are present and carry Bd infections, and the disease appears to have been transmitted to native amphibians. This studentship will focus on two of these sites, both of which are in SE England. At one of these sites (Site A) the suspected source of the infection (introduced bullfrogs) has been eradicated, but the disease remains in native species. At the second site (Site B), the suspected source of the infection (alpine newts) is still extant. The research will address the question of whether introduced amphibians are the cause of disease introduction in the UK, and examine the potential role of both native and non-native amphibians as vectors of the disease. This will be carried out by surveying all ponds within 2 km of Sites A and B for amphibians, and carrying out comprehensive screening of amphibians for Bd. This will be combined with GIS analysis of landscape variables to identify correlates of amphibian and disease dispersal, spatial epidemiological modelling, and if necessary, pathogen challenge experiments. These data will then be used to determine (1) if there is a relationship between the incidence of Bd and non-native species; (2) whether non-native species are more effective carriers of Bd than native species; and (3) if there is a relationship between the presence of Bd and the absence of common toads - a species for which the disease is usually fatal. The project combines the wildlife disease expertise of the Zoological Society of London (ZSL) with the amphibian population assessment expertise of DICE, complemented by the spatial epidemiological expertise available through the collaboration with Imperial College. This complementary collaboration provides a unique opportunity for the student to work at the interface of these disciplines, while capitalizing on the long-term research standing of both teams in amphibian conservation research. At the ZSL, full training will be provided in biosecurity protocols, Bd screening, post-mortem and gross morphological and histological analysis. At DICE full training will provided in amphibian population assessment methods, GIS, and occupancy modelling of animal populations (with support from the National Centre for Statistical Ecology, Institute of Mathematics). Spatial epidemiological training will take place in collaboration with Imperial College. As part of their personal development plan, the student will also be required to take relevant modules from the well-established postgraduate programme in conservation biology at DICE, including those dealing with research design and data analysis, science communication, personal development and other generic and transferable skills.