Tag Archives: San Joaquin Wildlife Sanctuary

A Common Ringed Plover in Orange County California

While birding at San Joaquin Wildlife Sanctuary in southern California on 31-AUG-19, we found a plover with an unusually heavy black breast band. This bird was feeding on the mud of the ponds beside a handful of Semipalmated Plovers, and other shorebirds. Compared to nearby Semipalmated Plovers, this plover seemed slightly larger – just a tiny bit huskier and longer-winged. Further observation of the bird suggested we had found a wildly out-of-place Common Ringed Plover, Charadrius hiaticula. We sent word out to the local birding websites and hotlines, and at that point, the circus began!

What Makes It A Common Ringed Plover?

The male Common Ringed Plover showing the heavy black breast band.

The male Common Ringed Plover showing the heavy black breast band. Photo © Jeff Bray, 2019

Many features that distinguish Common Ringed from Semipalmated Plovers (Charadrius semipalmatus) are minute and subtle. They can be very hard to observe, let alone document. There were seven Semipalmated Plovers clustered around the pond where the mystery plover was foraging. All of them were either females or juveniles; not a single adult male Semipalmated Plover was present. This was, in itself, a little odd. The unknown plover male really stood out with its very wide, black breast band.

Subtler Differences

Common Ringed Plover (above) with Semipalmated Plover (below)

Common Ringed Plover (above) with Semipalmated Plover (below). Photo © Jeff Bray, 2019

Other less obvious differences became apparent with more prolonged observation. First, this bird had almost no visible eye ring. The “Semi-plovers” all sport orange, fleshy eye rings. This Common Ringed Plover showed a narrow black eye ring, only visible in direct sunshine. Second, where the Semipalmated Plovers had limited white arcs in the hind portion of the supercilium. The Common Ringed Plover had a longer white supercilium that extended from just about the middle of the eye to well behind it.

Through most of our observations of this bird, clingy mud coated its bright orange legs.  Still more mud obscured the shape of its bill. Eventually, we were able to obtain photographs showing a little more of the subtle bill differences. The base of the bill was not quite as thick as that of nearby Semi-plovers, and it was slightly longer too. Both species showed plain and bright white underparts from the bill all the way to the vent. But one subtle and clinching difference concerns how the white chin of the Semi-plovers extends up to just above the gape. This differed from the black face of the Common Ringed Plover which clearly dropped down to just below the gape.

About Those Webbed Feet…

Common Ringed Plover showing reduced foot webbing

Common Ringed Plover showing reduced foot webbing. Photo © Bruce Aird 2019

The literature also claims several other marks for separating these two very similar species. First, we address the eponymous palmation of the Semipalmated Plovers. Yes, these little plovers have webbing between their long central toe and the toes on either side. In Common Ringed Plover, this webbing is absent between the inner and middle toe and reduced  between the outer and middle toes. It took a long time to document this on the Common Ringed Plover. Eventually the bird waded into the water, and then walked around, showing us its feet. This provided an opportunity to document its foot webbing. The facial black of this Common Ringed Plover extended through the auriculars all the way back to the brown nape. In a male Semipalmated Plover, the black would go to brown in the auriculars, well short of the nape.

Some sources claim that Common Ringed Plover is slightly paler on the crown and nape upper, compared to Semipalmated Plover. The difference is very slight however, and it may not be true of all Common Ringed Plovers. In fact, the Orange County bird seemed to be slightly darker than the Semipalmated Plovers nearby. It’s possible that the Common Ringed Plovers of western Europe, Great Britain, Iceland and Atlantic Canada are, on average lighter, while those of Eurasia are slightly darker.

Taxonomy and Speculation

Common Ringed Plover comprises three sub-species, per the website, “Birding Newfoundland with Dave Brown” (see link below). These are:

  1. Eastern form: Charadrius h. psammodroma, which breeds in Arctic Canada, the Faroe Islands and Iceland,
  2. Central form: Charadrius h. hiaticula, breeding in Northern and Eastern Europe, southern Scandinavia and Britain, and,
  3. WEstern forms: Charadrius h. tundrae, which breeds in Northern Scandinavia across through Russia to offshore Alaska.
Common Ringed Plover at San Joaquin Wildlife Sanctuary

Common Ringed Plover at San Joaquin Wildlife Sanctuary. Photo © Jeff Bray, 2019

All three sub-species typically winter along coastal Africa, but they take different routes to get there. This raises the question of where birds found in North America come from. Birds appearing in Atlantic Canada are likely of the type sub-species, hiaticula, or the western Europe sub-species, psammodroma. Whereas birds appearing on the Alaskan islands and the west coast of the United States probably represent the tundrae sub-species. Almost all birds occurring in the lower 48 states appear during August and September.

Per the article cited, there were nine previous records of Common Ringed Plover in the continental United States. The article is no longer current in this regard. A bird at Point Reyes National Seashore in 2018 and this bird, bring that total up to eleven. Those birds that don’t stray too far from their normal range might retrace the route they followed. But those that stray as far south as North Carolina or southern California may winter with Semi-Plovers. What the 2016 Common Ringed Plover in Illinois did is anybody’s guess!

Just a Short Stay

Common Ringed Plover (left) and Semipalmated Plover in flight

Common Ringed Plover (left) and Semipalmated Plover in flight. Photo © Bruce Aird 2019

Piecing together the story, some birders saw the bird (but didn’t identify it) on 28-AUG-19. This happened again on 30-AUG-19, with birders noting its strangeness but not identifying it to species. You can sort of understand why. Heavily marked male Semi-plovers and male Common Ringed Plovers show some overlap in the width of the breast band. The rest of the identifying features for Common Ringed Plover are quite subtle. Females and juvenile birds of both species are even harder to tell apart.

Making matters worse, some experts cite “distinguishing” features that don’t actually distinguish, the two species. Some experts claim that Common Ringed Plover has more white on  the upper wing surface than does Semipalmated Plover. We looked at this character in the field but could not find a consistent difference either way. The calls of the two species are fairly distinctive. Many people heard the Semi-plovers vocalize. The Common Ringed Plover, however, never made a peep – perhaps an unfortunate word choice there!

The Common Ringed Plover didn’t remain long at San Joaquin Wildlife Sanctuary. On 03-SEP-19, a disturbance on the pond the bird foraged in, flushed it and it never returned. So, sadly, this bird was with us for only a little over five days. Still, due to eBird and birding websites, many people saw it. This resulted in hundreds of happy people and lots of work for the regional reviewers! Overall, it was a wonderful bird to find and a spectacular first record for Orange County.


“The Shorebird Guide” by O’Brien, Crossley and Karlson
“Shorebirds of the Pacific Northwest” by Paulson

The Black Skimmer

Sub-adult Black Skimmer close-up

A sub-adult Black Skimmer close-up over a pond at San Joaquin Wildlife Sanctuary in Irvine, California

The Black Skimmer (Rynchops niger) is a  wonderful weird bird that breeds across the southern half of North America. Black Skimmers live and forage almost exclusively at coastal locations or within about 20 miles of the shore. They are primarily year-round residents here, though some winter as far south as the Yucatan. A large population of Black Skimmers resides year-round in a range roughly corresponding to the entire Amazon drainage basin.

Black Skimmers are easily recognizable by their bizarre asymmetric bill, longer below than above. Black Skimmers have clean white underparts, throat, neck collar (non-breeding only) and around the bill. Their feet and the inner bills are bright orange; the tips of both mandibles are black. Juvenile Black Skimmers are more brownish-gray on the upper surface, and have relatively dull orange feet and inner bill parts. At birth, juvenile skimmers mandibles are of equal length. But by the time they fledge four weeks later, the lower mandible is a centimeter longer than the upper one. Continue reading

American White Pelicans Feeding Behavior


American White Pelicans Group

American White Pelicans preening

The American White Pelican (Pelecanus erythrorhynchos) is one of two species of pelican in North America, along with the Brown Pelican (Pelecanus occidentalis). While occasionally seen in the same locations, American White Pelicans and Brown Pelicans prefer different habitats and their manner of feeding is as different as their plumage.
Continue reading

Vermilion Flycatcher

Male Vermilion Flycatcher

Male Vermilion Flycatcher, Mazatlan, Mexico

The Vermilion Flycatcher (Pyrocephalus rubinus) is a small tyrant flycatcher in the family, Tyrannidae. Vermilion Flycatchers live in the New World, ranging from central Argentina and covering much of South and Central America. Ornithologists recognize at least 12 sub-species of Vermilion Flycatcher. Some experts think the Galapagos Island Vermilion Flycatchers may be a full species on its own.

In the United States, we find Vermilion Flycatchers mostly in the desert southwest, where their range extends to southern Nevada.  Their California range includes much of the Mojave Desert, in San Bernardino County. Additionally, it extends across most of Riverside and Imperial Counties and into Los Angeles, Orange and San Diego counties. In coastal California, we see Vermilion Flycatchers increasingly often though more likely as winter visitors. However, their range is expanding and there are indications that their breeding range is expanding towards the coast. Here in Orange County, Vermilion Flycatchers often use edge habitat like golf courses and athletic fields. Continue reading

Yellow-crowned Bishops


Male Yellow-crowned Bishop in San Diego Creek

A male Yellow-crowned Bishop (Euplectes afer) recently made news in Orange County. Part of what makes this unusual is that Yellow-crowned Bishop isn’t a wild bird. It undoubtedly is a released or escaped cage bird. Originally, Yellow-crowned Bishops come from Africa, and inhabit nearly every sub-Saharan country. So what’s all the fuss about? Well, for starters, he’s a cracking bird!

Where to Find Him

Moreover, this bird is just fun to watch! Present in San Diego Creek just upstream of Audubon House at San Joaquin Wildlife Sanctuary, this Yellow-crowned Bishop is very territorial. He perches high in clusters of sedge and aggressively chases virtually anything that comes near – Scaly-breasted Munias, Common Yellowthroats, House Finches… whatever! He doesn’t just chase them though; he puts on a show! First he puffs his feathers up and half opens his wings, about doubling in size. Then he launches at the intruders with rapid shallow wing beats looking like an angry little quail in hot pursuit. All the time, he utters a high-pitched, metallic, plinking call. His turf protected, he returns to his previous perch high in the sedge.

Almost any exotic escaped cage bird can become established in the southern United States. People who said the Pin-tailed Whydah would never become established in California are looking a bit foolish right now! You just never know. Continue reading

A Yellow-crowned Night-Heron in Orange County

Sub-adult Yellow-crowned Night-Heron

Sub-adult Yellow-crowned Night-Heron

We recently visited Bolsa Chica Ecological Reserve to look for the reported juvenile Yellow-crowned Night-Heron. This is one of those location, location, location things. In Florida, a Yellow-crowned Night-Heron excites nobody. But in California, where for decades the nearest breeding population of these night-herons was down in Baja somewhere, it’s a pretty uncommon bird. In recent years, a small Yellow-crowned Night-Heron population has become established in an apartment complex in Imperial Beach, CA, in the shadow of Tijuana. Even so, a Yellow-crowned Night-Heron away from there is newsworthy in southern California.

At the time, this immature bird constituted the second confirmed record for Orange County. The first one showed up in 1977 at San Joaquin Wildlife Sanctuary. We see Yellow-crowned Night-Herons regularly now. This suggests the presence of a more local breeding population. But back then, a lot of local birders chased this bird.

The Heron was Elusive

We went on a Saturday morning, with someone who had seen the bird only the day before. Thus, we were confident of success. Naturally, we couldn’t find the stupid bird! We circled the entire pond under the bluff there. We checked out every immature Black-crowned Night-Heron on the property, without any success. Finally, it turned out that the Yellow-crowned Night-Heron was actually roosting among a large group of Black-crowned Night-Herons in the trees right where we started. The night-heron cooperated, but only grudgingly. It gave us long looks at fairly minimal distance. But it perched in a dense tangle of branches that always obscured it . Eventually we got a few photos.

A Gift Burrowing Owl

Burrowing Owl

Wintering Burrowing Owl

Next, we searched the ground squirrel burrows around the mesa looking for returning Burrowing Owls. Eventually we found one bird. The didn’t get great views because the bird never completely emerged from its burrow. But at least we found it. Later in the day, someone else found a second bird. Burrowing Owls are often hard to locate. If you don’t know how or where to look for them, overlooking them is easy.

Burrowing Owls are tough to come by in Orange County. Widespread development pretty much gobbled up virtually all grassland habitat in the county. A small  breeding population of this species subsists in an area closed to the public. Also, scattered wintering birds pop up as winter migrants, like the Bolsa Chica birds. Hopefully, these two will stick around for the upcoming Coastal Christmas Bird Count!

The pictures were taken by digiscoping with a Kowa TSN-884 spotting scope and a Nikon CoolPix P6000 (Night-Heron) or a Kowa TSN-883 with a Nikon CoolPix P300 (Burrowing Owl). The optics were mounted on a  Manfrotto MT055CXPRO3 carbon fiber tripod with a MVH500AH pro fluid digiscoping head.

A New Bird Species for San Joaquin WS

imagehawkOn a routine weekend in late November, we went to look at a Harris’s Hawk reported recently at San Joaquin Wildlife Sanctuary in Irvine, California. The Orange County Bird Records Committee is unlikely to accept this bird due to questionable origins. Even so, you just can’t miss a bird that cool in a location like this. We arrived at about 8:45 on a sunny Saturday morning. At least 200 Cedar Waxwings were calling from the parking lot as we set up and headed out. We walked to the end of the boardwalk, and there was the hawk, sitting regally in a bare branched tree.

After taking numerous photos of him, we headed back towards the main pond area. A nice male Sharp-shinned Hawk interrupted our walk. It posed obligingly in a sycamore some 200 feet away. Next up was at least 7-8 Blue-gray Gnatcatchers, all fussing away like tiny, angry felines. As we got back to Pond D, one of the birders with us asked “Isn’t that the Vermilion Flycatcher?” He was right! It was, and a nice bright male at that.


Unexpected BlackbirdBlackbird-Rusty-2011-11-26-012

While we photographed that bird, one of us noticed what appeared to be a Brewer’s Blackbird, walking along the shore of Pond D. Upon closer examination we noticed that this bird had cinnamon plumage on the crown, nape and saddle. It also had a bright pale supercilium extending well behind the pale yellowish eye, and pale gray between the wings and on the rump. This was an apparent female Rusty Blackbird. It was a first for San Joaquin Wildlife Sanctuary and only the third for Orange County. As we observed further we noticed the handsome rufous edging to the flight feathers contrasting with the shiny black wings. The bird showed a paler brownish gray chest with faint, short vertical streaking across the chest and belly, all consistent with a female Rusty Blackbird.

Rusty Blackbird is a species of special concern in the United States at large. Its population has been in precipitous decline in recent years.

Blackbird-Rusty-2011-11-26-042All images were taken with a Kowa TSN-884 spotting scope with 25-60x zoom eyepiece and a Nikon CoolPix P6000 camera attached using a Kowa TSN-DA-10 digiscoping adapter. The optics were mounted on a Manfrotto MT055CXPRO3 carbon fiber tripod with a MVH500AH pro fluid digiscoping head. The Rusty Blackbird photos are of the same bird. One is in direct sun at 160 feet. The other is in shade at about 40 feet. The difference in these two photos illustrates how much lighting can alter the appearance of a subject.