8/13 - Some More Results

 Hi everyone,

    I thought it would be worthwhile to give an update about our results with the tick and understory project. We have come up with a final model: a zero-inflated Generalized Linear Mixed Model with a Conway-Maxwell Poisson distribution. This type of model helps with count data, where there are many zero values and some underdispersion. Underdispersion occurs when our observed data's variability is less than the mean or theoretical variability. The results tell us how ticks increase/decrease in abundance with given parameters, or how likely they are to be present/absent given similar parameters. This model ended up fitting the best with our data and gave some interesting results.

    Concerning understory data, our models tell us that ticks are more abundant in areas with more flowering plants and more litter relative to other types of plants. The other important parameters were the time during the summer, altitude, and the distance from the trail. Ticks are more abundant in late spring/early summer months, lower altitudes, and close to trails. Our model also tells us that ticks are more likely to be present when there are fewer woody plants like shrubs or saplings, and when varied grasses are present. All this information comes from the data taken in northern Colorado, and only the tick species Dermacentor andersoni, so it's important to understand that the results are under those constraints. These results can be useful for our specific area, however, and can inform recreationists where to be careful in Colorado forests. 

    It has been awesome working with this data, and hopefully, there will be more information to come out of it. We are planning on working with it more, but these results tell us a lot about our data and the relationships between ticks and forest conditions.