T = 7.25° Baja land birds (Cody 1983)

Fig. 6. Idiosyncratic species. Idiosyncratic species may be identified by an idiosyncratic temperature higher than the system temperature of the matrix. System temperature is denoted with a horizontal line. Because the idiosyncratic species elevate the temperature of the matrix of the whole, an idiosyncratic temperature at or greater than system temperature implies that the species is in some manner disconnected form the system-wide biogeography of the archipelago. The species shown are the land birds of the northern and southern islands of the Sea of Cortéz. The majority of species occur in both island sets, but some appear only in one or the other set of islands. That disjunction in species composition creates the idiosyncratic species temperatures shown.