Swainsons Hawk Kettle by Mary Freeman

Swainson’s Hawk Kettle at Anza-Borrego, CA | Photo by Mary Freeman

By Read Howarth, LAAS Member and Field Trip Participant
Photos by Read Howarth

March 18 and 19 were the dates for Los Angeles Audubon’s Field Trip to see the Swainson’s Hawk Migration and other birds in Anza-Borrego. In other years the wildflowers have been well past their prime, but the late rains this year made for wildflower viewing at its peak coinciding with our visit. Having signed up months ago, I was excited to experience the super bloom at the same time as the Swainson’s Hawk migration, and so was everyone else.

Some were able to arrive Friday in time to watch the hawk migration come in for a landing in the desert. Different from other migrating raptors, Swainson’s Hawks migrate in large flocks. Friday afternoon and early evening over 300 hawks were counted in the “kettle” of birds, that some described as a “tornado” because of the number of birds. As the hawks descend in the evening and ascend in the morning they form a shape loosely described as a kettle, narrower at the base and wider at the top.
The hawks visit the Anza-Borrego Valley to eat the caterpillar of the White-line Sphinx Moth as they migrate north. The caterpillar eats the wildflowers before burrowing into the sand of the desert to pupate. Kurt Leuschner informed us that the moths particularly like the Brown-eyed primrose.

Hal Cohen leads the Hawk Watch in Anza Borrego and his a blog announces numbers counted as they arrive in the evening to feed on the caterpillar. As the desert heats up in the morning, the Borrego Hawk Watch records the numbers that leave in the morning as the hawks rise in “kettles” on the thermals that develop as the sun warms the desert. The morning of Saturday, March 18, they recorded 3,713 hawks migrating out of the valley, continuing on their journey. That was a new record for the Hawk Watch.

From Hal’s entry in the Anza Borrego Hawk Watch blog:
http://borregohawkwatch.blogspot.com/
March 18 (3,713) Swainson's Hawks
Discussion
Today started off as any other day with kettles beginning to form around 8:30a hawk time. By the end of the first hour hawks began to stream. By the end of the second hour over 800 Swainson's Hawks had passed us. The next hour went crazy. We spotted a large kettle to the east. It finally emerged closer and as we clicked off the SWs another kettle formed to the east. Rose raised the cry that hawks were streaming in at an alarming rate. As one kettle formed near Pyramid and streamed away, another kettle formed in the same area. This continued for more than an hour. At times the stream was too dense to count. We believe we missed a few hundred hawks! With a cramped hand from clicking, I had to switch to my other hand. This figure surpasses our previous record by over 2,000 hawks.

If you search on YouTube you will find some of Hal Cohen's videos. Understandably, they were too busy counting to videotape the exodus Saturday morning.

4 looking for sheep

Watching for Sheep

Our group was led by Kurt Leuschner, Professor of Natural Resources at the College of the Desert, in Palm Desert, California. Kurt has a broad knowledge base in natural sciences and was equally able to identify the many blooming flower species, along with the birds. Besides his regular college curriculum on birds, reptiles and entomology, he teaches a number of seminars or workshops during the year at ZZYZX, Joshua Tree, in Arizona, and at the Channel Islands and the Salton Sea, and other areas. If you email him he can send you a list of the extracurricular classes: This email address is being protected from spambots. You need JavaScript enabled to view it.

Red-winged Blackbird

Red-winged Blackbird

On a beautiful Saturday, we used the back way out of the valley to avoid the worst of the traffic drawn to Anza Borrego by the wildflowers. Our first stop was the Borrego sink, a sewage overflow pond, where we saw a Black-tailed Gnatcatcher and three Sora. Birds, and so Birders, love these sewage fields wherever they are. We also saw Red-winged Blackbirds, Costa's Hummingbird and my first Yellow-headed Blackbird.

Verdin

Verdin

Next stop was the Tamarisk Campground where two of the birds we saw were an early migrant Western Kingbird and a Verdin. The Verdin was particularly beautiful with its yellow head on a grey body with rusty red accented shoulders.

Though Borrego Bighorn Sheep had been reported in the hills across the road from the campground, we scanned the hills with our binoculars without luck.

Bigelow's Monkey Flower

Bigelow's Monkey Flower

We headed toward Julian, stopping at Yaqui Well where we saw many Phainopepla, Tawni saw a Scott's Oriole that Kurt had heard. Kurt later described how some seeds are germinated after being deposited in the tetraskata (pyramid shaped scat) of the Phainopepla. It was here that Kurt pointed out my first view of a pink Bigelow's monkey flower. It is strikingly different from the yellow Sticky Monkey Flower of the Santa Monica Mountains.

Between Yaqui Well and Julian we stopped at Sentenac Canyon, where we heard a Nuttall's Woodpecker and saw a Cooper's Hawk through the trees. Listen here:
https://www.allaboutbirds.org/guide/Nuttalls_Woodpecker/sounds

Cowbird remediation trap

Cowbird Trap

On to Scissor's Crossing where Kurt showed us a Cowbird trap, described the invasive nature of the Cowbird which lay their eggs in other birds' nests and, in turn, the larger cowbird chicks monopolize the food meant for the nesting bird's chicks. A Ladder-backed Woodpecker made an appearance.

More on the Brown-headed cowbird at The Cornell Lab of Ornithology – Nest Watch
http://nestwatch.org/learn/general-bird-nest-info/brown-headed-cowbirds/

In Julian we stopped at The Birdwatcher to use their facilities and do a little shopping in their terrific store. Linda bought some bird earrings. I headed down the block to pick up a sandwich for lunch from the market and after a half hour we all headed to Kurt’s secret lunch spot, a home owned by friends with daffodils and bird feeders. We had our lunch break at their beautiful home, made by his friends. I would gladly live there. The feel of the home and location was peaceful and beautiful.

After lunch we stopped at the Volcan Mountain Preserve where we saw Mule Deer, a Coot and a Mountain Chickadee. From there we went to Lake Henshaw, on the way back to the valley, where we saw White Pelican, a Red-tailed Hawk, Red-winged Blackbird, Western Meadowlark (singing away) and a Bald Eagle surveying his kingdom from a high perch on a tall spire of a bare tree trunk.

Peninsular Bighorn Sheep

Peninsular Bighorn Sheep

Peninsular Bighorn Sheep

We drove back past the Tamarisk Campground looking for the reported Peninsular Bighorn Sheep herd. We didn't see any across from the campground above the Cactus Loop Trail but, farther along in Yaqui Pass, Tawni spotted a white sheep up on another ridgeline. Once we stopped, we were treated to a view of at least 6 ewes and four young on the hillside above us.

Next was a visit to the Hawk Watch for the afternoon arrival of the Swainson's Hawks. While we were waiting, Rhonda found some of the White-lined Sphinx Moth caterpillars for us to photograph.

White-lined Sphinx Moth caterpillar

White-lined Sphinx Moth caterpillar

Returning to Borrego Springs we stopped at the Anza-Borrego Desert Natural History Association - Desert Nature Center. They have their own wildflower report and reference an app that is available: http://www.abdnha.org/pages/03flora/reports/current.htm .

Many purchased books. — I did.— I’m hoping Botany in a Day, the Patterns Method of Plant Identification, may help with my botanical pursuits; but I doubt it will only take a day.

Dinner that evening was Mexican at the very friendly Borrego Grill, just off Christmas Circle. Participants came from near and far; Glendale, San Diego, Riverside, Santa Monica, West LA, Palm Springs, San Francisco Bay Area and Seattle. After some camaraderie, we split up, early to bed to be ready for the next day.

Great Horned Owl with Chicks

Great Horned Owl with chicks

The next morning Kurt had another treat in store for us at the Club Circle Resort and the Borrego Springs Country Club. A friend and resident pointed out a Great Horned Owl on a nest with two chicks.

Also there was a Sora, Cinnamon Teal, Wigeon, a Kestrel, Boat-tailed Grackle and an uncommon Common Ground Dove among others. Of course I had turned away from the Cinnamon Teal in the pond to just miss seeing the Roadrunner....running.

By then it was time to get over to the Hawk Watch area to see the kettles form. They were developing on the far eastern and southern area of the valley. We posited the crowds of wildflower viewers had caused them to overnight farther away from the usual morning Hawk Watch area on DiGiorgio Road. They saw over 500 lift off that morning.

Wildflower viewing Henderson Valley Road

Wildflower viewing, Henderson Valley Road

Wildflower viewing, Henderson Valley Road

After watching hawks rising on the thermals, we headed out to Henderson Road for prime wildflower viewing.

Desert Lily

Desert Lily

Among other flowers, Kurt found us a Desert Lily.

Desert Sand Verbena

Desert Sand Verbena

The rest of the group headed out to find LeConte's Thrasher and possibly Badger at Old Springs Road while Rhonda, Tawni and I headed back to try to beat the worst of the crowds on the roads. On the way out I couldn't help stopping to take a few more pictures of the cactus including the Ocotillo, Beavertail and Fishhook.

Beavertail Cactus

Ocotillo Cactus

Ocotillo Cactus - detail

Beavertail Cactus, Ocotillo Cactus

It was another terrific Los Angeles Audubon field trip. Thank you Mary and Nick for organizing it.

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