By Jon Fisher

Published by Los Angeles Audubon Society in the Western Tanager, Vol. 86 No. 6 , July-August 2020

The latter half of April saw the passage of large numbers of passerines and other migrants.  Within a few weeks, this movement began to wane significantly.  Often, the upside to this slowdown is the appearance eastern vagrants, and a satisfying variety of these did show up this year.  Though most vagrants are never seen by birders, the increasing army of observers in the county ensure that a greater percentage are detected.

There were remarkable movements of western migrants through Bear Divide in the western San Gabriel Mountains.  This location is unique in that it is the terminus of a long wide canyon that funnels migrants to a low divide.  Birds take the flight path of least resistance and observations easily made, often at or below eye level.  In late April, mornings of birding there produced up to 13,000 individuals. 

The impressive numbers of birds were made up of a variety of vireos, warblers, tanagers, grosbeaks, thrushes and others.  As this spot is readily accessible by car, it attracted quite a few interested birders.  There are certainly other similar spots in our local mountains that funnel migrants, but access is problematic; limited largely by the extent of public roads.

Another interesting phenomenon occurred this spring, as it did back in 1992.  California saw a spring invasion of typically southeastern passerines.  This year there were Yellow-throated Vireos (six recorded), Kentucky Warblers (a half dozen), Hooded Warblers (about a dozen) and Northern Parulas (over two dozen) among them.  Los Angeles County saw few of these birds, but did garner its share of parulas. 

Nearly as interesting as the vagrants are the potential or confirmed breeding records of scarce, unusual and local species.  Finding these can add some fun to what is otherwise generally a slow period following spring migration.  Black Swifts, Northern Parulas and Summer Tanagers figured into that equation this year. 

While there were no new records this spring, species recently increasing in the county- including American Oystercatcher, Neotropic Cormorant and Yellow-crowned Night-Heron- continued in small numbers.

Two Common Mergansers at Castaic Lake on May 11 (Jane Stavert) and one in San Gabriel Canyon above Azusa on May 25 (Luke Tiller) may be indicative of local breeding, as has been documented in recent years.

The tiny population of Inca Doves in Lake Los Angeles in the east Antelope Valley continues, with at least two birds present there from May 16-June 6 (Kimball Garrett).  A few Common Ground-Doves continued along the San Gabriel River in Bellflower with as many as three being reported through June 17.

From one to three Black Swifts were seen intermittently above Claremont Wilderness Park and Palmer Canyon from May 21-June 19 (Tom Miko, Chris Dean).  Breeding undoubtedly takes place in the area, with nest sites often being located behind waterfalls.

Late inland Common Loons were at Ken Malloy Harbor Regional Park in Harbor City on May 5 (Kiera Carvalho), over Diamond Bar on May 10 (Keith Condon) and at Bonelli Regional Park in San Dimas on May 15 (Rod Higbie).

Up to three American Oystercatchers continued off and on at Royal Palms Beach in San Pedro through June 18.

Rare inland was a Heermann’s Gull at Bonelli Regional Park in San Dimas on May 24 (Michael San Miguel).  What may have been the same bird flew over Peck Road Park in Arcadia on June 1 (Jon Fisher).

A few Glaucous-winged Gulls were noted late in the season, with single birds at Franklin Canyon Park on May 3 (Calvin Bonn), one near downtown Los Angeles on May 6 (Brad Rumble) and up to three along the LA River in the Maywood area on May 10, with one lingering as late as June 17 likely to summer locally (Richard Barth, Brad Rumble).

Neotropic Cormorants included a continuing bird at Santa Fe Dam in Irwindale through April 27, one at MacArthur Park on April 29 (Brad Rumble) and two at the spreading basins below Hansen Dam near Lake View Terrace from May 3-7 (Brad Rumble).

Up to eight American White Pelicans were late on the Los Angeles River in Long Beach from May 21-31, with one still there through June 18 (Kim & Jeff Moore).

Yellow-crowned Night-Herons included at least one continuing in the Playa del Rey area through May 30 and up to two at Sims Bio Pond in Long Beach from May 25-June 13 (Becky Turley).

A California Condor was northwest of Castaic Lake on April 28 (Aaron Kreisberg) and two were above Echo Mountain above Altadena on June 19 (Molly Hill).  The continuing Zone-tailed Hawk in Monrovia was reported through May 11.

The wintering Dusky-capped Flycatcher at Heartwell Park in Lakewood remained through May 4.

Lingering wintering Tropical Kingbirds were at El Dorado Park in Long Beach through May 13 and at Ken Malloy Harbor Regional Park in Harbor City through May 16.  A nice find at Apollo Park near Lancaster was an Eastern Kingbird observed on June 6 (Becky Kitto). 

Red-eyed Vireos were at Ken Malloy Harbor Regional Park in Harbor City from May 11-13 (Bobby Trusella), in Juniper Hills in the Antelope Valley on May 31 (Kimball Garrett) and near Big Santa Anita Canyon above Arcadia on June 19 (Darren Dowell).

Purple Martins, always a scarce migrant, were nearly missed entirely this spring with just two recorded at the Val Verde landfill near Santa Clarita on June 6 (Stephen Myers).

A very late Hermit Thrush was at Apollo Park near Lancaster from May 25-June 12 (Mark & Janet Scheel).  Even more interesting were at least six singing birds in the vicinity of Sturtevant Camp in the mountains above Arcadia on June 19 (Darren Dowell).  Several were recorded here last spring and summer and breeding seems possible, if not likely.Rancho Sierra Golf Course in the east Antelope Valley hosted a rare Gray Catbird on May 31 (Mark & Janet Scheel). 

A late gambelii White-crowned Sparrow- our expected wintering subspecies- was in La Canada on May 26 (Mark Hunter), while a White-throated Sparrow continuing at Crescenta Valley Park in La Crescenta through April 23 was the only one recorded during the period, though a number of others were in the area over the winter and well into spring.

Turning our attention to warblers, nine “vagrant” species were discovered between late April and late June in addition to our regular western types.  A Northern Waterthrush was at Peck Road Water Conservation Park in Arcadia on June 5 (Dessi Seiburth), a Black-and-white Warbler was at Buckhorn Campground in the San Gabriel Mountains on June 9 (Dessi Sieburth) and a Tennessee Warbler was found at Madrona Marsh in Torrance from May 19-20.

American Redstarts were at Rancho Sierra Golf Course in the east Antelope Valley from May 16-17 (Kimball Garrett), along the Playa Vista Riparian Corridor from June 11-12 (Sage Bylin) and at Blaisdell Park in Claremont on June 12 (Dan Stoebel).

Northern Parulas were at Rancho Sierra Golf Course on May 23 (David Bell), at Meadows Park in Claremont on June 3 (Dave Smith), along Little Rock Creek on June 5 (Kimball Garrett) and in Soledad Canyon on June 5 (Naresh Satyan), with a pair present there from June 6-7 (Andrew Birch).  The discovery of a pair in suitable habitat makes local breeding very possible.  Bringing up the rear was one at Ernie Howlett Park in Rolling Hills Estates from June 16-20. 

Two Magnolia Warblers were together in the east Antelope Valley on June 9 (Joseph Dunn) and a Chestnut-sided Warbler was in Beverly Hills on May 13 (Scott Logan)

A Palm Warbler was found at Hahamongna Watershed Park in Pasadena on April 24 (Darren Dowell) and the continuing Grace’s Warbler continued at Charlton Flat in the San Gabriel Mountains through June 12.  The latter bird has been present since April 16 and was also at this locale in the spring of 2019.  Charlton Flat is no stranger to vagrant southwestern warblers; long time county birders will recall the Red-faced Warbler that showed up here in June of 1978.  A handful of other vagrant warblers have turned up over the years as well.

A singing male Wilson’s Warbler along Little Rock Creek on June 9 indicated a potential for breeding in this area (Kimball Garrett).  

Ten Summer Tanagers were recorded during the period, with the most noteworthy being potential breeding birds.  A pair was at Pearblossom Park in the Antelope Valley from May 19-June 20 (Kimball Garrett, Kelsey Reckling) and one to two singing males were along Big Rock Creek on the north side of the San Gabriel Mountains from May 22-June 18 (Kimball Garrett). 

Rose-breasted Grosbeaks were at Malaga Dunes on the Palos Verdes Peninsula from May 27-28 (Jonathan Nakai), in Glendora on June 7 (Andrew Hulm) and at Cloudburst Summit in the San Gabriel Mountains on June 13 (Merryl Edelstein).

Now that spring migration has concluded and much of breeding season is also behind us, we turn our attention to fall migration.  The first southbound shorebirds- Wilson’s Phalaropes, as expected- were recorded by mid-June.  By early July the numbers and variety will have increased and continue to do so for another month or so.

Unfortunately, as of this writing, the Piute Ponds on Edwards Air Force Base- one of the premier shorebirding spots in the county- remain closed to entry.  But there are still many other places to watch shorebirds.  The lower Los Angeles River is always excellent, and Malibu Lagoon and the Ballona Wetlands offer good opportunities as well.  In addition, there are many other spots along the San Gabriel River, the Los Angeles River and even the Rio Hondo that are worth birding.

The game will truly be on in August when passerines begin heading south through the mountains and to a lesser extent in the lowlands.  The summer months will be uncomfortably hot, but the rewards of birding during this period can help make up for that.