Why travel to Baja California if you are a naturalist? What is unique to the peninsula? What should you understand before traveling there to appreciate better what you will see?
Fog/low cloud impacted environments
Extreme Rain shadow deserts
climate shift with latitude along the peninsula
relative emptiness and lack of development of the landscape
good accessibility for the driving naturalist
access to diverse coastal and oceanic environments
What the peninsula lacks:
truly moist environments (wet forests etc)
A diverse tropical fauna and flora compared with “continental” locations. The eastern side of the Gulf of California, including the states of Sonora and Sinaloa have a much richer reptile, amphibian and bird fauna – even if you exclude the higher elevation portions of these two states. There is unrestricted migration of tropical species northwards along the lower elevation strips, unimpeded by the barrier of the Gulf of California. Thus, a seasonal deciduous forest in the foothills of the Cape region near 23.5˚N will have fewer reptiles, amphibians and birds than a comparable forest in southern Sonora (27-28˚N) which is at a more poleward latitude.
While there are fewer vertebrates in Baja California than on the mainland, there are a number of reptile species restricted to Baja California, and in particular southern Baja. In fact, there is a section specific to Baja California endemics in the Peterson Field Guide to Western Reptiles and Amphibians.
There are about 15 lizards and 5 snake species found in Baja California, but not in the US or on the mainland of Mexico. These include a colorful Rock Lizard (Pterosaurus thalassinus) in the Cape region and an Black Iguana (Ctenophora hemilopha). The Cape Region has the greatest number of endemic reptile species.
Besides the book by Rebman and Roberts about the Baja California flora there are many technical articles in journals about the flora of specific parts of the peninsula or about specific plant groups. For the Sonoran Desert plants, which includes much of Baja California, the easiest reference is by Turner et al and can be purchased here. To see actual distributions of particular plant species one can go to several online sources.
Endemic desert vegetation and succulents
There are five widespread palm species found in Baja California (plus many more introduced around resorts). Four of these are native, while the Date Palm is native to Africa and the Middle East but has been naturalized in certain moist areas around human habitation since the arrival of the Spaniards. The figure below, taken from an article by Minnich et al, 2011 (probably not easily accessible to most people), mapped the distribution of these palms using the Google Earth imagery available by 2010. Palm clusters are evident on such imagery at the highest resolution as shown here. (Download the kmz file for display on Google Earth). I identified some of the more obvious palm clusters (appear to be Brahea brandegeei from the map below) in the central part of the peninsula to relate these to the climatology of summer cloudiness/rainfall here. Most of these dense palm groves are in isolated canyons far from paved roads and not easily accessed by normal tourists – even naturalists.
some epiphytes (Tillandsia recurvata)
Birds that are novel for northern travelers: frigatebirds,
Some reptiles of note: some rattlesnakes, sandsnakes, a few lizards of note
Underwater fauna: We don’t discuss except to say that coral reefs are not easily accessible in Baja… fish and rocky habitat yes. Whales yes, but we don’t really discuss.