Fine-scale habitat use of forests by human visitors:
developing an agent-based model of risk of tick challenge.

Jennifer Taylor, Oxford University

Link to project: Assessing and Communicating Animal Disease Risks for Countryside Users

                                                                                                    
Our hypothesis is that different sectors of the public vary in their use of forests and thereby suffer differential risk of tick bites, and may also perceive that risk differently.

To test this, we shall focus on the following specific questions:
1. Which off-path habitats are accessed by humans (and their dogs) and how frequently?
2. What types of visitors are likely to go off path, and what are their activities?
3. How aware are these visitors of the disease risks and impacts of such off-path use, and how amenable are they to adapting their behaviour to reduce these risks?
4. Can the diversity of visit types and routes be represented in spatially explicit agent-based  models?

RELU project RES-229-25-0007 aims to assess and communicate animal disease risks for countryside users and encourage appropriate precautionary responses. The model system is that of Lyme disease, which is acquired from bites of ticks carrying the Borrelia spirochaete. The risk assessment depends upon estimation of tick abundance, how this varies diurnally, seasonally and with habitat type, and to what extent the habitats are visited while ticks are active/present. The main project makes provision for estimates of tick abundance, and of visitor use from records held by visitor centres, etc. in sample forests. Many visitor surveys, however, record only numbers visiting a general location (e.g. Forest Park), or particular site (e.g. car park within a Forest Park). Relatively little is know about how visitors make use of the forest environment after they have arrived; how use varies with motive for visit, age, ethnic background, recreational activity etc; and how use of parts of a forest varies with season and time of day. These factors are important because :-

• The type of use and locations/habitats accessed can make a substantial difference to the risk of visitors (and their dogs) being bitten by ticks.
• The type and background of a visitor may make a substantial difference to their selection of routes (and habitats) and their preparedness for dealing with risks

Fine scale habitat type influences questing tick abundance, which can vary dramatically between vegetation types, associated with microclimate. In addition, the likelihood of encountering ticks can be affected by use of habitat, e.g. walking, cycling, horse-riding, orienteering, picnicking, playing, bird-watching, picking fungi and berries. Studies in eastern Europe have indicated that variable motivation for forest visits, associated with socioeconomic status, can affect disease incidence; visitors harvesting wild foods are at greater risk of acquiring tick-borne infections than those who visit solely for leisure pursuits . In Britain, new visitors are being encouraged to visit forests (e.g. Active England project stressing health benefits); there is also a rise in community participation in environmental activities, with incentives for community management of local open spaces (e.g. BBC Breathing spaces), and in environmental volunteering4. This population of new users will be at risk and may have less inherent understanding of precautionary measures.