next up previous contents ©Marino Gatto and Renato Casagrandi (2020) Models for conservation and management in population and disease ecology

Next: Problem SE8 Up: Problems on Spatial Ecology Previous: Problem SE6   Contents

Problem SE7

Since the beginning of 1900 the Eurasian collared dove (Streptopelia decaocto, Fig. 4) has expanded its spatial range from Turkey to the whole Europe so that in 1970 Scandinavia, British Isles and Russia have been reached by the bird. Fig. 5 displays the exponential increase of the total number $P(t)$ of doves in a sequence of successive years. Estimate the instantaneous rate of Malthusian increase $r$ of S. decaocto.

It has been further estimated that the range expansion speed for this dove has been 43.7 km year$^{-1}$. From this information estimate the diffusion coefficient $D$ of this alien species.

Figure 4: The collared dove Streptopelia decaocto.
\includegraphics[width=0.4\linewidth]{Collared_dove.eps}

Figure 5: Data on the diffusion of collared doves in Europe.
\includegraphics[width=0.5\linewidth]{Dove_growth.eps}