Musings on the Passage of Hurricane Hilary, and a Wedge-rumped Storm-Petrel Departs Lake Palmdale

On August 20, 2023, Hurricane Hilary made landfall at San Quintin, Baja California Norte, at about 6 pm, some 345 km south-southeast of San Diego, California. By dusk, it had reached the eastern portion of the San Diego region. As the center of the storm was now and would remain inland, its strength diminished as it moved rapidly north. By dawn the next day, it had reached central Nevada. Some storm birds were noted in the San Diego area by dusk, and by early the next morning, pelagic birds were noted at a number of places both from the coastal slope and in the interior deserts of Southern California. This ornithological event will be well chronicled in the months ahead in the scientific literature, notably North American Birds, and likely elsewhere.

Here in the Owens Valley, Inyo County, we monitored the storm and its path. On the evening of August 20–21, it looked like the center of the cyclonic system might move through the Panamint Valley east of the Owens Valley and the Inyo Mountains. Based on the historical record of other tropical disturbances, Paul Lehman advised us on August 20 that the place to be was the center of the storm, or to the east.

The Owens Valley, where there is a small birding community, is to the west. The place to be then would be the Panamint Valley or Death Valley, but we worried that road closures might leave us stranded. We learned before dawn on the 21st that US 395 was closed at the south end of Bishop. So, we headed north to Crowley Lake in southern Mono County. We found no storm-driven birds there, and we returned to check ponds in the Bishop area. Russell Kokx independently birded south of Lone Pine at Diaz Lake and reached the north end of the Delta Ponds at the north end of Owens Lake on foot as the roads there were mostly flooded.

Soon, we heard reports of “storm birds,” overwhelmingly storm-petrels, at inland bodies of water in Southern California. These reports included some 30 storm-petrels, of three species, at Lake Palmdale in the southern Antelope Valley, Los Angeles County. Although we wanted to head south for those birds, road closures prevented it, and we continued to search ponds in the Bishop area. We were able to talk our way through the road block in Bishop and headed south to the Big Pine area where there were several large bodies of water. The serious flooding was near Independence.

During the day, we did see an interesting variety of species, notably lots of swallows (Debbie House found a Purple Martin at Crowley Lake that morning), an alternate plumaged Cattle Egret at Warren Lake near Big Pine, and a Dusky Flycatcher (unlike spring, it is a scarce fall migrant here in the lowlands of Inyo County) at Farmer’s Pond. Later we heard that Adam Otten, a California Highway Patrol officer and on patrol, found a “white-rumped” storm-petrel under his CHP vehicle at Panamint Springs on August 21. In-hand photos revealed it was a Wedge-rumped Storm-Petrel (Oceanodroma tethys).

Adam Otten in Panamint Valley. Photo: Adam Otten

In talking to Adam two months later, he relayed that he was on duty that day in the remote Panamint Valley because of the storm. He had stopped at the Panamint Springs resort at about 7:40–7:45 am to warn those there that they might soon get stranded due the heavy rain and anticipated road washouts. As he got out of his CHP cruiser, he noted an unfamiliar small dark bird flying around close by. After warning the folks at the resort and returning to his vehicle, Adam noted a small blackish bird sitting under his cruiser. He picked it up for careful study and then released it after photographing it. He tentatively identified it as a Wilson’s Storm-Petrel, but his excellent photos enabled a correct identification later. The roads into Panamint Valley and Death Valley were closed later that day and would remain closed for eight weeks! Some stranded folks were airlifted out.

Closed roads in Panamint Valley. Photo: Adam Otten

Wedge-rumped Storm-Petrel found on August 21 by Adam Otten under his CHP vehicle. Photo: Adam Otten

The evidence, so far, is that all of the interior “white-rumped” storm-petrels and those from the coastal lowlands were Wedge-rumped Storm-Petrels from this tropical storm. Least Storm-Petrels (O. microsoma) were equally, or perhaps more, numerous than wedge-rumped. Early on August 21, a few Black Storm-Petrels (O. melania) were seen at Lake Palmdale and Lake Isabella in Kern County.

Since good numbers were still present at Lake Palmdale at the end of the day, and we had received news near dusk that US 395 had opened, we decided to drive south if the storm-petrels were still there at dawn on the 22nd.

Sure enough, at least some (but fewer than the day before) Least and Wedge-rumped Storm-Petrels were seen the next morning, so three of us headed south. It was about a four-hour drive from Bishop, the drive being a little longer due to a heavy flow of water across the highway just north of Independence. When we arrived, a number of birders were present and fortunately so were a handful of storm-petrels. Due to the kindness of the staff of the Palmdale Fin and Feather Club, birders were permitted entrance to this private site, enabling us to get much better views of the storm-petrels. Several Least Storm-Petrels were present and were sitting on the water or were flying around off the spit, and one distant Wedge-rumped Storm-Petrel was sitting on the water along the southwest edge of the lake just off a few short private fishing piers. From the spit, we were able to note some white in the rump area, but we desired much better views, so more than a dozen of us headed down to the area.

Wedge-rumped Storm-Petrel at Lake Palmdale, August 22. Photo: Larry Sansone

We soon spotted the Wedge-rumped sitting on the water through openings in the trees. Even better views were obtained when a couple of fishermen allowed us access to their private piers. Shortly afterward, the bird got up and flew around, giving all of our group excellent views (see Larry Sansone’s photo) for a short time before it landed on the water again. The bird got up and flew around and landed at least one more time, before it got up and headed more purposely and directly to the southeast end of the dam on the opposite side of the reservoir. From here it turned and flew north along the dam while gradually gaining altitude, and then turning northwest along the north edge of the lake. At one point, I noted that it was nearly halfway up the huge windmill behind it and commented that we were likely witnessing its departure. I was reminded of a plane gradually ascending after takeoff in steady and direct flight, not circling to gain height.

Once the bird reached the northwest end of the reservoir, it continued on northwest in a direct and ascending flight, passing high over the freeway (Highway 14). It was now easily at 1,000 feet and was likely much higher. I was trying to explain to others where it was and ultimately said, “It’s above the highest cumulus cloud high in the sky to the north.” One observer later said to me that it looked like a “fleck of pepper against the sky.” Gradually we lost it in the sky, but Christine (Chris) Dean kept on it for perhaps another minute before it vanished for her too.

Since the bird was flying towards the Tehachapi Mountains and perhaps Gorman to the west, it was hard to be optimistic about it ever finding an ocean again. Such is the fate of many, likely most, of the storm-petrels that are storm-driven into the interior. Indeed, as we were watching the Wedge-rumped Storm-Petrel depart, a dead Least Storm-Petrel was retrieved from just off the spit. Later we heard that single Wedge-rumped Storm-Petrel specimens were retrieved from the Victorville area in San Bernardino County, Lake Isabella in Kern County, and Stovepipe Wells, Death Valley National Park, Inyo County.

The specimen from Lake Isabella was retrieved from within a small boat on August 23 by John Schmitt. He had hired the boat’s owner to search for storm-petrels on the lake. The previous day he had told John that he was out on the lake and at times he could have reached out and grabbed the storm-petrels as they were that close to him! He had been chumming with mackerel bait in the hope of catching fish.

Morphometric (measurement) data and perhaps also molecular data should indicate whether these specimens of Wedge-rumped Storm-Petrel are the expected smaller kelsalli subspecies, which breeds on islets off the Peruvian coast and moves in the nonbreeding season north to off the Cape region, southern Baja California Sur, or the nominate tethys, which nests on the Galápagos Islands and perhaps is more sedentary. There are, however, two specimen records that were assigned (by Alexander Wetmore) to the nominate subspecies, from western Mexico: one from Melpomene Cove at the south end of Guadalupe Island on January 31, 1950, and one from Roca Partida in the Revilla Gigedo Islands (Huey 1952). Both involved birds taken on land. Lawrence Huey had sent both specimens to Wetmore at the Smithsonian Institution in Washington, DC, and he determined that both were tethys, but said (ibid) they were at the small end morphometrically and were “borderline” to subspecies designation.

Both of these specimens are at the San Diego Natural History Museum, which is convenient. The Victorville specimen is there, and I believe the Stovepipe Wells specimen will end up there too. Philip Unitt, the museum’s curator of birds and mammals, is in an ideal position to pursue the subspecies issue further. Tissues have or will be sent to Kevin Burns at San Diego State for molecular analysis. The specimen from Lake Isabella has gone to the Santa Barbara Natural History Museum, where molecular data will be analyzed as well. I do not know if there are identifiable molecular markers that identify the two subspecies. The one previous specimen of Wedge-rumped Storm-Petrel for California, housed at the California Academy of Sciences, San Francisco, was found in a backyard on January 21, 1969, in Carmel, Monterey County. It was assigned to kelsalli (Yadon 1970).

While much has been written about storm-petrels inland, most of the accounts offer details while observing the birds flying over water. I don’t believe I have ever read an account about a bird actually departing the scene. Many of these storm waifs, sadly, likely don’t leave and die at the site. Others just seem to disappear. A dozen or so of us were able to chronicle this Wedge-rumped Storm-Petrel depart Lake Palmdale to a most uncertain fate. Beyond how this one left, it got me thinking about how they arrive. Perhaps they are at a high elevation in the center of the cyclonic system, then spot water below and gradually descend.

Long ago, Brainard Palmer-Ball Jr. and I drove down from northern Kentucky to south-central Tennessee, arriving in the afternoon of August 29, 2005, at Pickwick Lake in Hardin County. That morning Hurricane Katrina had gone right through that tristate meeting of Tennessee, Mississippi, and Alabama. A number of storm birds were recorded that day by the birders present. Brainard and I managed to see a few Sooty Terns, a juvenile Long-tailed Jaeger, and an adult male Magnificent Frigatebird along with the adult Black Skimmer on a tower found earlier. Laughing Gulls were numerous. Several birders on the east side of the lake alerted us to the presence of one, or more, Band-rumped Storm-Petrels, and we managed to see them as they foraged low over the water.

As we were watching the storm-petrels near the end of the day, my attention was drawn to a tiny dark dot high in the sky. It was descending slowly like a hot air balloon and eventually dropped down and landed on the center of the reservoir, where it remained until dark. My first thought was it was likely a dark morph Pomarine Jaeger, but commented that to me it actually looked more like a South Polar Skua. It was a conflict between what was “most likely” and what it looked like. Photos taken at the time were later determined to show that it indeed was a South Polar Skua, one of only a few confirmed interior North American records. The lesson for me then and now was that during one of these events scan in all directions. Loreena McKennitt (“Dante’s Prayer”) sang in the refrain, “Cast your eyes on the ocean, cast your soul to the sea . . . .” I am also reminded to “cast your eyes to the skies.”

—Jon L. Dunn



I thank our small cadre of birders who birded Inyo on August 21, some of whom headed south to Lake Palmdale the next day; the staff at the Palmdale Fin and Feather Club, who allowed many birders into their private club on August 21; John Schmitt for passing on to me the account of obtaining the Lake Isabella specimen of Wedge-rumped Storm-Petrel; Adam Otten for contacting me and giving a firsthand account of his Panamint Valley sighting of his storm-petrel and for providing in-hand photos of the bird along with a selection of photos documenting the major flooding that day; and Larry Sansone for his outstanding photo of the Lake Palmdale Wedge-rumped Storm-Petrel shortly before its departure, and for always freely sharing his photos with me, many of which have been published.

Literature cited

Huey, L. M. 1952. Oceanodroma tethys tethys, a petrel new to the North American avifauna. Auk 69:460–461.

Yadon, V. L. 1970. Oceanodroma tethys kelsalli, new to North America. Auk 87:588–589.

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  1. Great story, Jon. Amazing event last August. The well organized CA birders did a grand job of checking as many places as feasible for waifs. –Jay S.