My last visit to Del Puerto Canyon was almost three years ago and after all the rain that came this winter, I figured it was time for a visit to the area. It is quite an interesting location and is much, much different from Stebbin’s Cold Canyon. There is a good-sized, fast flowing, permanent stream that goes through the main part of the canyon and in that area is where most of the unique insect diversity is found. Species like the giant darner (Anax walsinghami), the giant salmon fly (Pteronarcys californica), and the ruby-spot damselfly (Hetaerina americana), can all be found here, sometimes in good numbers. I was very glad to be back and explore this area once again, with the hopes of finding something new or very interesting.
A Tree Filled Landscape
This area had changed dramatically from my last visit a few years ago and it had changed for the better. The hills that surround the canyon were filled with many species of trees including blue oak (Quercus douglasii), California sycamore (Platanus racemosa), valley oak (Quercus lobata), canyon live oak (Quercus chrysolepis), and juniper (Juniperus sp.), as well as large numbers of blooming wildflowers. Sticky monkey flower (Mimulus aurantiacus) was by far the most abundant flowering plant in the area, beating the blooming asters by a large margin. A number of other flowers were blooming in the area that I had not seen at Cold Canyon, but those species I will have to determine after I visit the area a second time. The insect activity however, was well into the amount that I was expecting to be out and about.
As I followed the creek looking for an area to cross over to the other side, I found a number of blooming seep willows that were all buzzing with a multitude of different insects. There were various flies visiting the flowers, including tachinids, syrphids (hover flies), tabanids (horse flies), stratiomyids (soldier flies), and dolichopodids (long-legged flies). Other insects stopped by these flowers including butterflies, beetles, and wasps, making for a full range of insects to be seen. Before moving on to another part of the canyon my friend Alex and I collected a few of these different insects to record the diversity of species that were present at this time of the year. We eventually moved to a drier part of the canyon and found more interesting groups of insects and plants.
The drier side of the canyon held a surprising amount of diversity that I had not seen previously. There was a surprising number of different flowers blooming in this area, including some I had never seen previously in the canyon and one I have never seen ever. The plants and insects I encountered included the Butterfly Mariposa lily (Calochortus venustus), California buckwheat (Eriogonum fasciculatum), yellow lupine (Lupinus sp.), flower beetles (Cleridae), blister beetles (Meloidae), and narrow-winged damselflies (Coenagrionidae). Another group of organisms that were very abundant in the canyon was lichen, displaying a number of different colors and textures throughout the area. Lichens are an indication that the air quality of the area is very good and that the ecosystem is also very healthy.
Predictions of a Great Season Ahead
Parts of the canyon that I had explored a few years back looked completely different now and we have the rains to thank. I noticed that the areas where milkweed (Asclepias sp.) had grown in the past was covered in it now. The patches of milkweed also held some small but wonderful surprises because these plants were covered in monarch butterfly caterpillars (Danaus plexippus). I had not seen this many on these plants before and was very excited to see them because I knew that meant that upon my return to the area I would eventually find the adult butterflies. After this discovery I followed the side of the creek in search of more milkweed patches, but instead of finding the plants I found some Pacific tree frogs (Pseudacris regilla). They were thankfully not as skittish as they are usually and I was able to get close enough for some photos.
As my friend and I moved further into the canyon we ended up in a more open part of the area and this place had also changed dramatically after the winter rains. The creek was now much wider than before, and the shrubs and grasses that once lined the creek were now completely washed away. This change in scenery didn’t change the insect activity much from previous years but I know it will change how the remainder of the season progresses. Once we had decided to move back across to the side of the creek that we started on, we encountered a very large and very loud rattlesnake. I am not much of a herpetologist when it comes to reptile identification, but I definitely know what a rattlesnake’s warning sound is like. So, we ended up leaving that area and found another spot to explore instead, this time with less rattlesnakes and more insects/flowers.
Once my friend and I were able to explore a majority of the upper canyon, we decided it was time to head back and pick up where we left off in the canyon in a few weeks time. By the time I return, the area should have received enough warm days to allow for new plants and insects to become in season. There are other insects and plants I am anticipating to be appearing in the canyon soon, so the next time I visit I will be on full alert. It will be interesting to see what early May will look like in the canyon, especially after a number of days of high temperatures and no precipitation.