The last full day of summer has arrived. Tomorrow, the Autumnal Equinox occurs at 11:21 PDT. The celestial sun will be directly above the equator and no shadow would be cast at 12:00 PM if someone put a stake in the ground. We are in a transitional period… the longest day of the year in the northern hemisphere was three months ago, the summer solstice, on June 21, now we are half-way to our shortest day of the year on December 21st, the winter solstice in the northern hemisphere.
In the Mission Bay Channel, just outside of where we started in Quivira Basin, we saw three Coast Bottlenose dolphins and a California sea lion foraging and finding prey and/or playing with each other. The sea lion being an imposter, pretending to be a dolphin, was porpoising next to the dolphins. It may have been that the sea lion was surprised by the dolphins.
We went way offshore, experiencing a bit of light rain, to deeper water and got over the Coronado Escarpment or 9-Mile Ridge and found a pod of about 30–40 Offshore bottlenose dolphins. They were breathing heavily and were involved in some ritualized courtship behaviors. We saw a really young calf and one of the likely bulls had an old wound or birth defect, missing a dorsal fin. Two of the dolphins had raw wounds in which the top of their dorsal fins were bit-off with rake marks beneath the wounds, so some rough play involved for sure.
Later, we came across a pod of long-beaked common dolphins, around 1,200 of them, forming a super-pod. They seemed to exhibit exuberance, a joyful, playful demeanor with some curiosity, as they came over to participate in the dolphin equivalent of a “human-watching” tour. This sighting was exceptional. Seeing this many wild animals up close is a spectacle we rarely witness on land. Perhaps the wildebeest migration in East Africa in the Serengeti might be equivalent or seeing large herds of charismatic megafauna in the Yellowstone ecosystem biome.
On our afternoon trip, we had coastal bottlenose dolphins feeding in the Mission Bay Channel entrance and several miles offshore, we had a large pod of long-beaked common dolphins. We followed the dolphins to the northwest to LaJolla off of the Scripps—San Diego submarine canyon. We’ve had some great sightings so far this September, hope to see some of you soon on a San Diego Whale Watch. —Naturalist Greg McCormack
