Matthew Van Dam
Natural history in environmental niche modeling
Predicted niche occupancy profiles for the sympatric species of Rhaphiomidas flies. The species displayed are sympatric but separated in time. The bioclim data for warmest month and quarter does not capture the subtlety different niches as the daymet data does (binned by day averaged over their know occurrence times). It seems to be an interesting result. As the flies live underground as larvae most of their lives I wanted to use only the temperature from the times when they are active. In addition to Bioclim variables showing values the flies do not actual experience, it is not exactly clear which one of the temperature variables is appropriate to use to know more about their ecologies and evolutionary history.
Rhaphiomidas acton photo Greg Ballmer
Rhaphiomidas hirsudicaudis photo Greg Ballmer
Climate binned by day (Daymet data) over known occurrence period, time slices to the left
Bioclim variables, binned by month
Rhaphiomidas pachyrhynchus photo Greg Ballmer
In order to see if species track niches and/or actively adapt to them, I first made predicted niche occupancy profile (PNOs see above) from our niche models and Daymet data. Next in order to examine whether colder daytime temperatures (when the adult flies are active) are correlated with a darker maculation on the body of the flies, we used a Bayesian quantitative genetics threshold model (Wright 1934; Felsenstein 2012). The results show that species both track an environmental optimum as well as adapt to local conditions by changing to a darker color (given light color ancestrally see below tree) to maintain optimal conditions.