Recently, despite wiser heads counseling otherwise, I ran in an ultramarathon in the San Dieguito River Park. The 50k race (31.1 miles) traced the boundaries of the San Dieguito River, including Lake Hodges and the San Pasqual Valley, where the San Diego Zoo Safari Park is located. All through the day I had the great fortune to see the results of our skilled scientists and conservationists in creating habitat for threatened local animals such as the California coastal cactus wren. Now, you may not wax as happily as I about running for six hours, but I’ll tell you, it was a magical day full of inspiration.
San Diegans may remember that in 2007, the Witch Creek Fire burned much of the San Pasqual Valley, including some of the 800 acres of coastal sage scrub that we protect and care for on the grounds of the Safari Park. Fortunately, the Safari Park was not reduced to a pile of embers. Much of the surrounding habitat was not as lucky. This epic fire sent a huge percentage of the mature stands of prickly pear cactus in the San Pasqual Valley up in flames. These stands can get up to almost seven feet tall and are the essential breeding habitat for cactus wrens. No mature cactus stands, no wren breeding.
The wrens are not the only animals that benefit from these large cactus stands, but because their populations are declining, my colleagues from the Applied Plant Ecology Division, led by Dr. Bryan Endress, at the Institute for Conservation Research and our collaborators, including the San Dieguito River Park, are working to restore the habitat on their behalf. They are planting prickly pear cactus pads, grown in our nursery, and many of the other forbs and grasses that are important food sources for the wren.
During the run, I passed through unplanted areas in the San Pasqual Valley that had been burned and saw the charred innards of what must have formerly been majestic cactus stands. These stood in mute testimony as lost habitat where cactus wrens, and many other species, may have cavorted but are now absent.
Fortunately, I also shuffled my way (I am not the fastest runner) through huge areas where the replanting efforts have clearly been hugely successful. Entire south-facing slopes were covered with burgeoning stands of prickly pear and associated food plants for the wren. In a few years, they will be bustling with boisterous birds breeding and creating healthy cactus wren populations. How great it is to see the fruits of our conservation labors so clearly manifest right in front of me!
This exemplifies hope for the future: conservation scientists actively and successfully conserving important habitat.
Most of the animals we encountered through the run were insects. This makes sense given that insects are over half of all named species (including plants, animals, bacteria, fungi, etc.), and beetles alone comprise 21 percent of all named species! Every few steps I saw black darkling beetles of the family Tenebrionidae, commonly called pinacate beetles. If you’ve ever been out on trails in the Southwest, I’m certain you know them, as they are the ones that do headstands if you touch them, pointing their abdominal terminus (or butt, of sorts) up at you. I love these slow-moving and clumsy beasties, because they threaten to spray you during their headstands with a nasty chemical if you persist in bothering them. Entomologists like myself find that endearing.
These beetles are part of a new citizen science effort that you could get involved with! We have just begun working with the San Dieguito River Valley Conservancy, the University of California, San Diego, the Canadian Government, and the International Barcode of Life to identify all the insects in the San Dieguito River Park. We’re collecting insects to sequence a section of their genome (the Cytochrome Oxidase I gene, if you would like to know!) to be able to identify the species. This section has been designated as the “barcode” of life for animals. It seems that nearly every species has a different DNA sequence in this section that also seems to be consistent within each animal species.
Most insects are tremendously difficult to identify due to the huge number of species and their small size. In contrast, once the barcoding process has been completed, it will be MUCH easier to identify all of the hundreds, or even thousands, of insect species we have around the Safari Park and throughout the San Dieguito River Park. As we develop this process, we need people to help us out in the field and in the laboratory identifying the insects we collect.
With these barcode-derived biodiversity data, we can test whether biodiversity in the sites where the cactus has been restored has increased relative to comparable areas without restoration efforts. We should also be able to trace seasonal and altitudinal changes across the entire San Dieguito River Park, from Volcan Mountain to the San Dieguito Estuary at Del Mar. Importantly, we will be able to assess areas that are of great conservation value and advise the San Dieguito River Valley Conservancy in their efforts to conserve this biologically important area!
All of this was going through my head during the run. I felt overjoyed and inspired by all the great work that we and our conservation collaborators are doing on behalf of coastal cactus scrub and the species living in it. It was an epic day filled with hope, wonder, inspiration, beauty, and yes, of course, lots of suffering. I’m lacing up my shoes. The trails are calling.
James A. Danoff-Burg, Ph.D., is the director of the San Diego Zoo Institute for Conservation Research’s Conservation Education Division. Read his previous post, I Ran for Wildlife.