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Determining the drivers and importance of scavenging behaviors in a changing world using agent based modeling approaches.

Periodic Reporting for period 1 - SCAVENGER (Determining the drivers and importance of scavenging behaviors in a changing world using agent based modeling approaches.)

Reporting period: 2017-09-25 to 2019-09-24

In the face of a rapidly changing world ecologists must understand the fundamental components of ecological systems. Unsurprisingly, much research has focused on the food web links of which ecosystems are constructed. However, despite this attention one particular type of food web link, scavenging, has been relatively ignored. This is despite estimates showing that scavenging accounts for more energy transfer through the food web compared to predation, demonstrating its crucial role in determining ecosystem dynamics. Yet scavenging is a still a poorly understood behavior as despite its prevalence across predators, little explanation is available for the enormous level of variation in the level of scavenging both across species and with them.

This is important not only from the viewpoint of understanding how ecosystems may change in response to global change but also how species of conservation interest, particular large predators, may respond or adapt to changes in scavenging opportunities as a result to global change. The SCAVENGER project aimed to develop an agent based model which could be applied to such systems to not only understand the drivers of scavenging behaviour in general, but also to predict the possible results of changing habitats for species which either have previously relied on scavenging opportunities or which may benefit from them in the future. These species include those that hold conservation and social value, such as polar bears, tigers and sharks, and also keystone species, such as top predators, which in turn drive the many ecological communities on which society depends upon. Understanding changes in scavenging will also aid in predict potential human-wildlife conflict risks such as recent seen in polar bear scavenging behaviour in urban areas.

The SCAVENGER project achieved its central goal of developing an agent-based model aimed at helping to understating the drivers of scavenging behaviour in general and also the role of scavenging in particular systems. The fellow will now build on the outputs of the MSCA SCAVENGER project by applying the agent based model to several specific systems of conservation and ecological interest.
Work performed and Main results achieved
The main work performed and the main result achieved during the reporting period was the development of the agent-based model of scavenging that is the main component if the project. This involved creating a generalised version of an agent-based model of scavenging which could be easily applied to various ecological systems. This model is hosted on the Github repository (https://github.com/healyke/SCAVENGER).


Other work performed during the action included identified appropriate systems of ecological and conservation interested which the model could be applied to and which have sufficient data to test the model. This main result with this regards to building collaborations relating to two systems of conservation and ecological importance. This include a collaboration with researchers in the Zoological Society of London to apply the model to an artic system centred around the scavenging of polar bears which has immediate conservation interested relating to climate change and human-wildlife conflict. A second system has also been identified through collaborations with the Marine Centre as the National University of Ireland Galway to apply the model to deep sea scavenging systems and compare it to data collected from remotely operated underwater vehicle (ROV) surveys.

The fellow also completed the expected training to date relating to Gender and Equality training and participating in the Passport to research futures training programme. This training aided in the fellow successfully securing a full time position in Academia as outlined the career development plan created at the start of the action.

The fellow also developed a data management plan in order to ensure data is appropriately stored and to increase the exploitability of the project outputs, such as through sharing the final code of the scavenging model to potential users through github.


Exploitation and dissemination
The main outputs of the action were presented at the Evolution 2018 meeting in Montpellier and at the British Ecological Societies Macroecology annual meeting in St Andrews. The fellow also developed a data management plan in order to ensure data is appropriately stored and to increase the exploitability of the project outputs, such as through the use of github. Dissemination of the project and scientific topics relating to scavenging was also carried out which included writing blog posts, such as for the journal Animal Ecology (https://animalecologyinfocus.com/2017/09/23/high-society-the-social-network-of-vultures/) and creating a website.
The main progress beyond the state of the art achieved during this action was the development of the agent-based model of scavenging. To date theoretical and empirical approaches to exploring the importance of foraging, such as scavenging, typically focus on using analytic methods which fail to capture the complexities of both top down and bottom up ecological process, such as may be introduced by competition between foragers. For example, while using analytical approaches can predict behaviors at the individual level these approaches fail to capture the emergent foraging behaviors of many ecological systems, such as seen in shoaling of fish. The agent-based model developed as part of the SCAVENGER can incorporate such emergent behaviors allowing the drivers of scavenging in multiple ecological systems to be understood within the context of the specific system.

The potential impacts of this action is in aiding in the understanding of scavenging in systems of high conservation, social and economic interest. Two such case studies have been identified which will demonstrate this impact and will be tested beyond the lifespan of the current SCAVENGER action. These systems include a model of scavenging in polar bears and the role of scavenging in deep sea environments. Polar bears are not only species of particular conservation risk due to climate change, but as a result of changing foraging behaviors are now more frequently coming into contact with humans in urban areas. The scavenger model will test how further changes in scavenging opportunities may impact polar bear foraging strategies. The second system identified is scavenging in deep sea environments. Deep sea environments are quickly becoming economically exploitable through opening mining opportunities. However, very little is understood of how deep-sea ecological communities operate. By applying the SCAVENGER model to data relating to a deep-sea community off the Irish coast the importance of scavenging to members of the deep sea community will be established along with the effects various impacts fisheries, whaling or commercial mining may have on these communities.
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