San Joaquin kit fox, photo by G. Warrick
The San Joaquin Valley is a highly developed area - with agriculture being the main reason for loss of native habitat. Since the 1940s, when the Tulare Lake was drained and “reclaimed,” agro-development exploded. Native habitat was tore up and planted in crops nearly overnight. Near Fresno, the hardpan vernal pool systems were actually dynamited so that fig trees could be planted in the blown-out holes! Kit foxes don’t do well in agricultural crops – these parcels are tilled each year (more than once sometimes) which prevents a stable denning system that kit foxes need to survive (escape from the heat and other weather elements, raise pups, and escape from coyotes - their main competitor on the landscape). Native rodents, like kangaroo rats, don’t do well in agricultural fields either, which support kit foxes as a food item. With agricultural development came canals, aqueducts, and the channelization of rivers. In turn, road infrastructure and highway systems were created as the human population increased. These growth-inducing activities led to even more people and more cities (or at least city growth). Growing cities led to urban sprawl which, ironically, eats up the best farmland!
Bottom line – kit foxes are in trouble not only because of roads, but also because of loss of habitat. What’s left? The few native parcels of land are fortunately locked away as wildlife areas and refuges. But these remaining lands are far from adequate in keeping kit foxes and other endangered plants and animals from going extinct. [Incidentally, kit foxes are considered “umbrella species” – that is, setting aside land for the kit fox will concurrently preserve a whole suite of other plants and animals that live in the same type of native saltbush scrub habitat]. The next best thing is to retire farmland and convert it back to pre-European condition. One problem is that no one really knows what California looked like back then – but whatever the habitat was, obviously kit foxes were able to survive. Regardless, the farmland to be retired should be some sort of native California grassland intermixed with saltbush – kit foxes are currently doing well in these habitats in Kern County, hence providing a good restoration model. The reason the farmland has “gone bad” in the first place is human-caused. The constant irrigation practices have led to high concentrations of salts and selenium in the soil which makes the land un-farmable. Restoring these millions of acres of unusable farmland may be the saving grace for endangered species once widespread in the San Joaquin Valley.