Anza Borrego Desert State Park has become an immensely popular destination of late, and this past weekend I joined my fellow Southern Californians to witness the super bloom in full effect. As I drove into the park from the west, winding down into the Borrego Valley from the Cleveland National Forest, the landscape changed dramatically from oaks, white salvia, and ceanothus to low scrub and tall ocotillo branches tipped with red flower buds. The scent of creosote and the blast of heat through the open windows were signs that we’d transitioned to a very different landscape.
The proximity of two very distinct biomes – noted by the quick change in temperature, elevation, smells, and colors – is one of the unique features of California.
The desert flowers were everywhere, and plant species and patterns varied with the geography of the valley. Hillsides were mostly spotted with yellow Encelia and valleys were filled with orange desert poppies. The evidence of water – a weaving of dry washes and vegetation across the desert floor – could be seen from the road above. It wasn’t until we got out of the car at Plum Canyon that we could grasp the diversity of plants. The washes were full of color from lupines, phacelia, chuparosa, lilies, and primroses.
The desert blooms every year, but this year was exceptionally lush due to the record amount of rain this past winter. Patterns of drought and wetter years are part of the California climate, although climate change is making those patterns less predictable and/or more extreme. Ecosystems wax and wane with these fluctuations, and this year’s explosion of flowers means more than just a pretty display of color. An entire ecosystem is set into motion by the abundant rain.
Looking closer at the flowers, I noticed a large number of fat caterpillars with a single horn eating away at the juicy stems. These were Hyles lineata – larvae of the well-known White-Lined Sphinx Moth aka Hummingbird Moth that hovers over flowers and is often mistaken for its namesake bird. Population explosions coincide with years of large desert blooms, and the bounty moves up the food chain to birds, amphibians, and mammals. Owls, lizards, and bats feed on these caterpillars. Swainson’s Hawks are currently flocking to the valley in record numbers to gorge on them.
If they survive the larval stage, H. lineata pupate underground before emerging as moths. They are key pollinators for local plants. Their long proboscis, or tongue, is necessary to reach the nectar of the desert primrose. They are one of the only pollinators of the rare lemon lily. Sphinx moths are very common, but with a wingspan of up to 5 inches, seeing one always feels special.
The ephemeral desert bloom will soon morph into seasonal dormancy and harsh summer conditions. The moths will be metamorphosing underground and the Swainson’s Hawks will continue their migration to Canada. This weekend may be your last chance to see the desert bloom at its peak. If you go, be sure to take a minute to absorb the bustling ecosystem around you.