Print PageMexico’s Peninsula of Baja California is about 1200 km long, spanning almost 10 degrees of latitude, although most of it is barely or less than 100 km wide, and ranges from sea-level to over 3000 m asl in its northern and 2000 m asl in its southern sierras. Furthermore it has multiple islands on both sides (Pacific Ocean and Gulf of California). This provides it with a high diversity of vertebrates, which have been the subject of scientific inquiry since the 19th century, mostly focused on inventorying its biodiversity. Three main zoogeographic themes regarding the peninsula have been addressed in detail: Island biogeography (in the Gulf of California), reptile historical biogeography, and the presence or not of a mid-peninsula waterway. Other zoogeographical issues, both historical and ecological, remain to be analyzed in detail. Here we will synthesize knowledge about the ecological zoogeography of ground-dwelling vertebrates (most reptiles and mammals), and speculate about some questions dealing with the influence of physical drivers on their regional and local scale distribution.
Results/Conclusions
Climate, especially rainfall, is probably the most visible driver of vertebrate distributional patterns, and derives from a complex set of interactions of general circulation patterns, topography (and rain shadows), and oceanographic features. The overall rainfall pattern causes the mediterranean-arid-subtropical transition of the western side of the peninsula, and the extremely arid character of much the eastern side, and is reflected in the phytogeographical patterns of the region. Fog is a particular case of climate and it influences some communities along the western side of the peninsula. The effect of topography, in addition to that of creating rain shadows, is exhibited clearly in the transition of coastal scrub to chaparral and forest in the northern sierras, and from subtropical scrub to forest in the southern Sierra de la Laguna, with according changes in composition of animal species. A related matter is that of substrate, due to the complex arrangement of sediment types along the peninsula. These affect micro-distributional patterns of vertebrates, but the issue has been explored little for the most part. Finally, ocean-land subsidies have been demonstrated, but their complete role in vertebrate micro-distributional patterns (essentially on islands) has not been explored fully. There are a number of questions that seem worthy of addressing in order to better understand the ecological zoogeographic patterns of terrestrial vertebrates and, also, to address conservation and, perhaps, taxonomic issues.
