Explorations in bird-land geometry

Abstract

The spatial distribution of woody vegetation in areas of residential development is analyzed in terms of the conflicting demands placed on such vegetation by people and wildlife. Human needs favor one-layer-deep plantings which provide the maximum visual surface area for the minimum ground space occupied; most forest bird species prefer clumps and larger “islands” of vegetation providing not only encircling visual cover but a more spatially compact resource base. On larger housing lots in North America, the tendency to extreme dispersion of woody vegetation can be traced historically to a preference for rectangular over triangular lot boundaries and for rectangular grid street patterns over street patterns oriented to circles or to polygons with more than four sides. Several examples are offered of triangular lot designs and of non-rectangular street patterns. These allow small patches of woody vegetation on private lots to be clumped effectively together into small and medium-sized woods which are capable of supporting significant subsets of the forest avifauna.