PARENT SESSION
Friday, August 11, 8:00-11:30 am
COS 104 - Invasive species VII: prevention, control, and models
Ballroom E, Ballroom Level, Cook Convention Center
Presiders: T Langkilde
Using integro-difference equations to model the effect of growing season length on the spread of the Eurasian collared dove in North America.
Fuller, Michael*,1, Asano, Erika1, Whittle, Andrew1, 1 University of Tennessee, Knoxville, TN
ABSTRACT- The Eurasian collared dove (Streptopelia decaocto) established breeding populations in Florida in the mid-1980s and is now spreading across North America. Records from the Christmas bird count suggest that the collared dove spreads via discrete dispersal events of varying distance (i.e. jump dispersal). Ecologists use integro-difference equations to model this type of invasion pattern. However, integro-difference models typically assume that population-level parameters, such as growth rate, are spatially homogeneous. We extend the integro-difference approach by explicitly considering the effect of spatial heterogeneity on the velocity of the invasion wave front, the density of local populations, and the ultimate boundary of the species' range. Our model incorporates information on life history (mating system, breeding period, number of offspring fledged) and the observed distribution of dispersal distance. We consider the effect of spatial heterogeneity by setting the breeding period to the 30-year mean length of the growing season recorded at different latitudes for a series of longitudinal transects. Our model indicates that the latitudinal gradient in climate can impose strong directional variation in spread rate, such that southern regions are likely to be colonized earlier and support populations of higher density. Our model links the ultimate northern limit for the species range to variation in long term climate trends. Using our model and observations on the post-invasion population trends of native dove species, we discuss the potential future distribution of the collared dove and the consequences for native species.
Key words: invasive species dynamics, Eurasian collared dove, integro-difference models