Understanding and managing connectivity across habitat types: the case of avian pollinators with altitudinal movement in the tropical Andes mountains

Are you interested in spatial ecology and in developing methods that can inform the next generation of conservation approaches for marine, terrestrial and freshwater systems? Do you want to work with a dynamic team on a project that you can lead in your own direction?

Connectivity has become a key concept in ecology and conservation. There is now broad recognition that species have more robust spatial population dynamics when there is connectivity between patches of suitable habitat. There has been a rapid increase in management that focuses explicitly on increasing connectivity across terrestrial, marine and freshwater systems. Current understanding and management of connectivity focuses on connections between patches of the same type of habitat. Typically, people are interested in how well-connected forest patches are across a landscape or how well reefs, and thus fish populations, are connected by ocean currents. For species that live their whole lives in a single habitat type this is likely to be a sufficient consideration of connectivity.

However, many species have more complex life-histories and, for these species, connectivity is much more complex and is poorly understood. Many species spend part of the year in one habitat and another part of the year in another habitat. This seasonal migration can occur over huge distances or be more local in nature as, for example, in altitudinal migrations. Many other species are dependent on a different habitat as a juvenile to that which they require as an adult. An excellent example of this is in marine systems where many fish species that inhabit reefs as adults are dependent upon mangroves or seagrass habitat as juveniles (Mumby et al. 2006). For these species we need to understand not only connectivity between breeding habitat patches but also between habitat used in different seasons or in different life-stages.

This PhD project will address this knowledge gap by developing novel methods for assessing connectivity in species with these more complex spatial life-histories. These methods will then be used to determine how we should manage landscapes (or seascapes) for connectivity where we need to account not only for connectivity between areas of habitat where a species breed, but also for connectivity between habitat used in different seasons or at different life-stages. Substantial data already exist so a fully desk-based project is possible. However, depending upon the student's interest (and the situation with COVID), there is also the potential for field work to gather novel data for parameterising and validating the models. We are flexible on which system the field work might be in; possibilities include altitudinal migration of birds or bats in the Andes (Hsiung et al. 2018) and reef fish connectivity in the Indo Pacific. Training will be provided in individual-based modelling (Bocedi et al. 2014), statistics and fieldwork.