Rarity Breeds Passion

Excitement crackles in the air whenever the news passes from one volunteer to the next about a flower--a rarely seen flower, and in an overlooked corner--that is blooming in the Botanic Garden. For example, Orobanche parishii, having bloomed once in 1997, came up again in May 2018. Several of us scoured the rocky beds of Southern California Desert Section, looking for a low-growing broomrape we had never seen before. Nobody found it. We went to the source of the information, Bart O’Brien, and sure enough, there it was! It was already shriveled, in rusty buff color, and just three inches high. But the fact that this little parasitic plant makes itself amenable to cultivation is already celebratory!

Photo of Parish's Broomrape by Wen Hsu, May 2, 2018.

Once I was roaming the less-visited paths of Canyon Section when a tiny plant caught my attention. It was white except for a pink stem, and several delicate ivory flower buds were forming. No chlorophyll, and growing in the shade—could it be living on nutrients provided by trees nearby? I was excited by discovering a parasitic plant unknown to me. I showed its photos to Joe Dahl. He thought for a moment, and said, “You know what, I think it’s an albino Epipactis gigantea.” Once he said it, I recognized every bit of Stream Orchid in it. Although being nutrient deficient, it may well be called pygmaeus. Not a rare plant, but it is a rare form!

Photo of albino Stream Orchid by Wen Hsu, June 4, 2015.

The same thrill exists for birders who find a rare bird (rarity being defined by location, season, or any other phenological yardstick). Having come to the Botanic Garden to watch birds for years, I am still surprised from time to time by a rare occurrence. The current prize is a female Belted Kingfisher. The garden staff has seen her displaying and rattling by the pond since the beginning of September. Kingfisher may not be a rare bird in the Bay Area, but previously appeared in our Garden only anecdotally.

In fact, any bird not in the Garden’s 4-year accumulated checklist of 81 is worthy of the title “rarity”. The year 2020, if nothing else, has proved to be fruitful for wildlife sightings. The tenacious bird survey volunteers of the Garden saw Willow Flycatcher, Lawrence’s Goldfinch, Hooded Oriole and Chipping Sparrow gracing us with their unusual presence.

I am particularly intrigued by Chipping Sparrow. It looked very much in its element in our Garden when I laid my eyes on it in disbelief early July, 2020, soon after the Garden reopened with a reservation system. The bird stood on a tree branch, hopped around, then dropped to the ground and disappeared behind shrubs and rocks. I happened to have been in Yosemite two weeks earlier, and saw Chipping Sparrows there in the open woodlands around 7,000 ft. I had come across the species in the Bay Area, too, but only on the east side of the Berkeley-Oakland Hills; such as Briones Park and Mount Diablo. Why did it come to the moist and wooded west side of the hills? I looked up eBird reports, and found two other records of Chipping Sparrow in the Garden in recent years. I can’t help suspecting that Chipping Sparrow must know a thing or two about the drying of our hills, and the corresponding change of plant community.

“Only once during my rambles about Berkeley have I discovered the strange Townsend’s solitaire.... It is much like a fly-catcher in general appearance, but in structure more closely allied to the thrushes. It is rather larger than a sparrow in size, decidedly longer and more slender, and is colored a plain, slaty gray all over, becoming lighter upon the under parts of the body. It usually inhabits the mountains and is a rare, shy creature, very easily overlooked on account of its severe coloring.” Written a hundred and twenty years ago by Charles Keeler, a poet and naturalist who called Berkeley home, this passage describes my own encounters with Townsend’s Solitaire perfectly. When a Solitaire looked me in the eye as it sat in Santa Cruz Island Ironwood at Channel Island Section one October day, I was in shock. I texted fellow birders cum docents and urged them to come witness the rare moment. I had never done it before or since.

The Botanic Garden is made ever more attractive by its rare gems that don’t stay long. It evinces an irresistible pull to birds, amphibians, mammals (including me) and more. And who’s gonna resist?

Magical Garden, a composite picture by Wen Hsu, using photos taken by Allison Kidder and Minder Cheng.

(Printed in Manzanita, Fall 2020, with several changes and different illustrations.)

Look, a Hawk!

When a hawk is called out, bird-watcher or not, everybody turns their head and wants to see it. Even a botanist who is concentrated on plants will oblige and allow him/herself to be distracted for a minute. Perhaps being both prey and predator in our evolution history makes us feel simultaneously threatened by and attracted to a ferocious hunter on wings.

After several years of watching birds in the Botanic Garden, we have come to realize that Alnus (Alder) growing on the west bank of Wildcat Creek at the edge of Sierran Section is a favorite perch of Sharp-shinned Hawk (Accipiter striatus) and Cooper’s Hawk (Accipiter cooperii).

A juvenile Cooper's Hawk on Alder tree, September 3, 2018. Minder Cheng.

These two hawks are small in size, and skilled in weaving in and out of dense woods to catch songbirds for meals. Foliage and branches of broadleaf trees are great cover for the stealthy snipers. Once they strike, successfully or not, they do not linger, but fly away immediately to either finish the job or find another hideout.

Although every hawk discovered is a cause of elation, the larger it is, the more excitement it arouses. Red-shouldered Hawk (Buteo lineatus) is much bigger than Cooper’s and Sharp-shinned Hawks; moreover, it is photogenic. Our local subspecies (elegans) has orange-red breast and belly, so distinctive and conspicuous once you locate it in the tree. On a memorable day in November 2019, we spotted an adult Red-shouldered Hawk sitting in Fraxinus velutina (Velvet Ash). We were mesmerized by its beauty, and it didn’t seem to mind our goggling. It was silent for maybe half an hour, then suddenly burst into calls. We didn’t know what caused it to announce to the world its existence, but we were thrilled to have a magnificent hawk displaying its full regalia and its vocal talent.

Adult Red-shouldered Hawk, November 5, 2018. Bill Thomas.

In fact, we hear Red-shouldered Hawks more than we see them. Their sharp and penetrating kee-ah series have a ringing quality, and often continue for some time before stopping. Listen to this recording made by Denise Wight in Tilden Park.

The wildlife harbored by the Garden makes it a great hunting ground for Red-shouldered Hawk, whose varied diet includes small mammals, birds, amphibians, insects, and crayfish. Several times during our surveys we saw this large raptor flying quietly down the canyon of Wildcat Creek, moving from one tree to another along the water course. And more than once did we see the carcass of crayfish lying on the rail of the wooden bridge crossing the creek. No witness came forward to identify the killer, but Red-shouldered Hawk is definitely a suspect in these unsolved murder cases.

Red-tailed Hawk (Buteo jamaicensis) is even larger than Red-shouldered, and is by far the most commonly seen raptor in the Garden. It usually appears as a fly-over that circles above us, glides effortlessly in the thermals or drifts along the horizon. Imagine our surprise when an immature Red-tailed Hawk showed up on the roof of the nursery next to the solar-powered well pump. It was on a weekend, and many visitors of the Garden walked by oblivious to its fierce gaze. The young hawk seemed just as unconcerned by people, paying its full attention to movements on the grassy meadow below.

Juvenile Red-tailed Hawk, intent on movements of rodents in the meadow. September 9, 2018. Minder Cheng.

Judging from its deflated crop (a pouch in bird’s gullet where food is temporarily stored after being swallowed), the fleet-footed voles and gophers that lived underground had largely evaded its talons.

Using sounds for bird identification is the game of experienced birders, and sometimes the only recourse to successful identification (especially so for Empidonax flycatchers). However, here birders encounter the challenge of mimicking. Steller’s Jay often throws me off by a bewildering array of sounds it is capable of making, which includes the masterful mimicry of hawks. And Red-tailed Hawk seems to be its favorite target of imitation.

Go to the second to the last recording on this page for a Steller’s Jay’s excellent parody of Red-tailed Hawk.

Why does a jay want to sound like a hawk? Donald Kroodsma says in Birdsong for the Curious Naturalist (2020): “Ornithologists have no solid answers, but are prone to speculate, of course. Maybe the jays are trying to scare other birds, or trying to warn their jay companions of a hawk or other danger nearby. Then I wonder, how often do jays call like hawks when we humans are not there to hear them?”

Next time you hear a hawk calling from somewhere in the trees, take note of the vocal quality. If it is a little too scratchy, not forceful enough, and doesn’t repeat a good number of times, then the calls may not come from a hawk. Try to follow the sound to its source, you may find a hidden jay singing away.

Extra:

Do you want to test your Accipiter ID skills? The difference between a Cooper’s Hawk and a Sharp-shinned Hawk is the perennial puzzle faced by hawk watchers. The following pair of photos were taken in the Garden; one has a Cooper’s and the other a Sharp-shinned. Please tell us how you decide which is which in comments. The answer will be posted after 3 days.

Note:

Jerry Ting and Bob Lewis, two esteemed birders in our area, helped me with Sharp-shinned Hawk and Cooper’s Hawk identification in many photos.

Sugar Thieves

Have you seen birds with feathers sticking up around their beaks as if they had a bad facial hair day? It happens often in late winter in our area to small birds with short and thin bills, such as Ruby-crowned Kinglet, and a number of warblers. These birds are insectivorous for the most part, but when there is nutrient-rich plant food around, they don’t hesitate to tuck into it.

Ruby-crowned Kinglet, near Jewel Lake. Feb. 8, 2016. By Minder Cheng.

When warblers pick bead-like berries, such as fruits of Pacific Wax Myrtle (Morella californica) and exotic palms, both favorites of Yellow-rumped Warblers, they swallow them in whole, and no feathers are messed up. The irresistible sugary tree sap, on the other hand, is a treat that leaves tell-tale sign on the guilty parties.

Yellow-rumped Warbler, Tilden Nature Area. Feb 1, 2016. By Minder Cheng.

Coming upon sap wells drilled by sapsuckers (and sometimes by other woodpeckers, see for example Kozma 2010), warblers and kinglets have to press their heads against the holes, and thrust their short beaks as deep as they can, in order to lap up the sweet liquid inside. That’s because the circumference and depth of the holes are made by bills much bigger than theirs, and if the sugary residue around the hole touches the base of a small bill, it can gum up the feathers surrounding the bill.

Orange-crowned Warbler, Valley-Foothill Section of Regional Parks Botanic Garden.
May 7, 2019. By Minder Cheng.

Here is a blog post that documents a Townsend’s Warbler visiting a Red-breasted Sapsucker’s handiwork in Fort Mason, San Francisco.

Hummingbirds, well-known for their love of sugary drink, actively pursue, and even defend, sap-producing holes (Sutherland et al 1982). I once saw an Anna’s Hummingbird dipping its bill into a sap well, then it got excited and zapped a Red-breasted Sapsucker working on other sap wells in the same tree. The feisty hummer chased the rightful owner away in no time.

But we don’t see hummingbirds with any matted facial feathers. They maintain their immaculate look because they have longer beaks, plus very long tongues adapted for nectar drinking (watch this video for the way their tongue works. They simply hover outside the holes, and let their bill and tongue do the job cleanly.

Tree sap is such an important part of hummingbird diet that it’s believed that the northern limit of Ruby-throated Hummingbird’s breeding range is affected by the availability of the sweet sap provided by Yellow-bellied Sapsuckers. In the west, the same relationship likely exists between Rufous Hummingbird and two sapsuckers, Red-naped and Red-breasted. (Miller and Nero 1983)

Rufous Hummingbird and Red-naped Sapsuckers. Painted by William Zimmerman.
Life Histories of North American Woodpeckers, 1992.

In fact, many birds enjoy swiping the sweet drink that the hard-working sapsuckers make available by drilling down to phloem or xylem tissue of trees. According to The Audubon Society Encyclopedia of North American Birds (1980) by John K. Terres, American Goldfinch, Pine Siskin, White-crowned Sparrow, Evening Grosbeak, Northern Cardinal, nuthatches, waxwings, and juncos are all sugar thieves. If we know there is free syrup out there in the woods, won’t we flock there, too?

Note:

Another source of matted facial feathers is the viscous nectar of Eucalyptus flowers. Let me quote David L. Suddjian (2004) “Birds and Eucalyptus on the Central California Coast: A Love–Hate Relationship”:

The great attraction of flowering eucalyptus for foraging birds may have its downside, though. As the birds spend time feeding amid the flowers, the feathers on their faces become matted with a black pitch-like residue (or gum) from the nectar. This affects their ability to maintain those feathers, and in some cases the gum may plug their nostrils or bills, and prevent breathing or feeding. Australian birds that regularly feed at Eucalyptus flowers in native settings have longer bills than North American species that feed at eucalyptus flowers, apparently permitting them to feed there without being affected by the gum.

Articles published in the Point Reyes Bird Observatory newsletter (Stallcup 1997) and in Audubon magazine (Williams 2001) have suggested that the effects of this black pitch cause substantial mortality among the North American species that feed at eucalyptus flowers. It seems to be a reasonable conclusion, and Stallcup (1997) cites some instances of mortality. But in my experience, and the experience of a number of other long time field ornithologists, we have seen very little evidence of such mortality. It has been argued that the bird carcasses do not last long on the ground before they are scavenged. However, when observers spend hundreds of hours under these trees over many years but find hardly any evidence of such mortality, then it seems fair to question whether the incidence of mortality is as high as has been suggested.

Reflections on birds of 2019

Reviewing the data collected last year, we are happy to report five new species being added to our checklist compiled through 2018. Carrying out a pre-dawn birding operation in January, Kitty and Ellen nabbed a Northern Saw-whet Owl in the dark. May and June brought us respectively a male Yellow Warbler in Canyon Section and a White-Throated Swift flying over the Garden. Two large-sized and unmistakable species joined us in the latter half of 2019: ten beautiful White Pelicans shone in the blue October sky; a Great Egret granted the Garden staff an exclusive view in December as the graceful bird checked out the pond, the small pool, the creek, then departed for the golf course.

Survey data of 2019 with the complete list of 74 species can be found here.

If you are an avid eBird user, you know that Regional Parks Botanic Garden is a birding hotspot. Searching through 2019 eBird reports by birders who visited the Garden, you will come across quite a few interesting species that were not sighted during our surveys. Since these reports were submitted nearly all by reputable birders, they are worth our attention. Let’s look at, first, a number of birds that are in our checklist, but were not seen in last year’s surveys.

What we missed in 2019: Lazuli Bunting, Lincoln’s Sparrow, Red-breasted Sapsucker, Willow Flycatcher, House Wren, Red Crossbill, Pine Siskin, and American Goldfinch.

The most glaring miss is perhaps Red-breasted Sapsucker. There are active sap wells on several trees in the Garden. In fact, one winter weekend I had a glimpse of the bird in Channel Island Section, but alas, it was outside the survey time. So even though we did not have the bird in our 2019 data, we know it was in the Garden.

Second, there are five reported species that are not even in our checklist: Western Screech Owl, Chipping Sparrow, White-breasted Nuthatch, MacGillivray Warbler, and Brown-headed Cowbird.

Now that we have been alerted to their occurrence in the Garden, albeit transiently, we will keep an eye (and ear) out for them!

In addition to numbers and lists, below are some memorable moments we had in 2019.

Ellen:
One morning our intrepid surveyors ventured into the Canyon Section where the tall redwoods have been living for a very long time. Here it feels truly wild. Traversing the west facing hillside, we heard it: the Pacific wren. The song is pure liquid music.

On this particular morning we were well above the creek. The bird seemed intent on coming to investigate these tall bipeds. Although the song seemed somewhere down the slope, suddenly the bird was just in front of us, skulking around in a sword fern cluster. This wren is a trickster, making his voice appear in places he is not, and sounding oh-so-big! But this bird is tiny and dark brown, with a short cocky tail. Its movement is reminiscent of a mouse. Instead of running on the ground, this wren flies low between clumps of vegetation to investigate upturned roots and decaying logs for food.

We were lucky that day to see the Pacific wren, and we are always delighted to hear its liquid song.

Pacific Wren, November 13, 2019. By Minder Cheng.

Idell:
Near the Channel Island section remains one of my favorite survey spots. The unmistakable cheery calls and twittering of the Lesser Goldfinch fill the air, and on overcast days their bright yellow breasts appear to be tiny globes of sun--but fluttering ones!

Bart (from two email messages):
A huge flock of Cedar Waxwings spent several hours in the garden today (April 27). They seemed to be flying in a large circle–arriving over the Visitor Center and landing in the alders. From there they went down to the flowering Amelanchier (next to the button willow), then off into the aspens and points south. They kept going in this circuit for a few hours. I think there were probably 100 in the flock.

This evening (May 8th), the Cedar Waxwing flock is back. As I am with this, there are a lot of them perched at the top of the alder that is right across from the Visitor Center deck. There are only about a quarter to half as many as last time (probably between 25 and 50 right now) and they don’t seem to be as “flighty” as they were. Most of them just few off toward the southwest, after a small group flew in from the southeast.

How to Find a Pacific Wren

“If a Pacific Wren turns up at this time of year, it won’t be singing, but calling,” said Wen as the bird survey team set foot in Canyon Section on October 16, 2019. Everyone turned to Kitty, expecting that our ear-birder extraordinaire would know the calls. She took out her iPod without hesitation and began to play Geoffrey Keller’s recordings of Pacific Wren. After the long and dainty songs, came the thin and scratchy calls of tschet, tschet, tschet.

“Is that what the calls are?” Ellen asked rhetorically. We all tried to imprint the calls in our heads, and walked farther into the shady forest of Canyon Section. Suddenly a small shadow darted to the left, 50 feet below us; the sharp-eyed Allison called out, “Wren!” We heard the tschet-tschet calls that accompanied this bird, but not everyone had a good look because the bird had already hidden itself behind a clump of Sword Ferns (Polystichum munitum). We trained our binoculars to the ferns, focusing our attention on any movement of the fronds that would be indicative of something taking cover there.

After a couple of minutes, the wren moved again, now bolting to the right and uphill. No sooner had it landed at a low shrub, it disappeared into the dense foliage. “I saw its barred tail; it’s a wren all right!” exclaimed Kitty. Again, this wren let out an urgent series of “tschet”s.

The tiny, yet feisty, bird continued its island-hopping maneuver, getting closer and closer to us via stands of undergrowth of the forest, tschetting all the time. “Did we disturb it,” Wen wondered aloud, “or is it checking us out?” By this time the Pacific Wren had become too close to look through binoculars, and it stopped vocalizing. We caught glimpses of a typical wren profile: cocked tail, plump body, and brown plumage. Soon it crossed the trail we were on, and vanished uphill. We looked at one another, amazed by our good luck, except for Ellen, the demanding naturalist who said, “but I didn’t see it through binoculars.”

Listen to the calls of Pacific Wren recorded in Redwood Regional Park.

Pacific Wren (Troglodytes pacificus) is the smallest wren in North America, sharing this title with Winter Wren (Troglodytes himalis) with whom it was conspecific formerly, but now separated. In the field, the two wrens are distinguished foremost by their songs and calls. 

The occurrence of Pacific Wren is usually labeled as uncommon in field guides. Similarly, in our Checklist of the Garden, its sightings spread over many months, but are never frequent. Also in the Checklist, most of the time its habitat is Unknown (= Heard Only). If birding generally consists of equal parts of listening and watching, in the case of Pacific Wren, we rely more heavily on our ears than our eyes to recognize its presence.

The best bet to find a Pacific Wren in the Garden is go to the back of Pacific Rain Forest Section, or walk along Wildcat Creek in Canyon Section. Prick up your ears, and wait for the quick-shifting phrases of its bubbly song, or its scolding-like calls of tschet. Then track the sound using your eyes, and with luck, you will find moving leaves and a flitting shape near the ground. With more luck, you will see a partial or even a complete form of a dark bird. With utmost luck, you will catch a clear image through your binoculars, and declare to the world, “Pacific Wren!”

See photos on iNaturalist of adult and young Pacific Wrens.

My favorite guide book description of Pacific Wren comes from American Bird Conservancy’s Field Guide All the Birds of North America (1997). On Key 104, a general statement under “Curved Bills” goes: “Wrens have big, energetic voices for their small size...They typically scold intruders furiously from the security of their thickets. Wrens are as inquisitive as they are bellicose, and bird calls or simple squeaking noises often coax them into view.” On Key 107, the entry of Winter Wren (at the time of its publication, Pacific Wren was a subspecies under Winter Wren) says: “Scarce; in cool dense undergrowth of conifers in summer, esp. along streams and in boreal bogs...Very vocal, active, but furtive, hard to see.” 

Don’t these words capture vividly and succinctly all the bird’s characteristics revealed in the narrative above?

Townsend’s Warbler

Compared to the Eastern United States, we have relatively few species of warblers in Northern California. Considering that tackling the identification of 56 warblers in North America is worthy of its own guidebook, app and LPs (such as The Warbler Guide and Songs of the Warblers of North America), it is really in our favor that we can select from a small collection of species while craning our necks and arching our backs to identify these tiny birds flitting high up in tall trees.

One thing of note is that nearly all warblers found regularly in our area have some yellow feathers (Black-throated Gray Warbler being an exception). Among these yellow birds, Townsend’s Warbler (Setophaga townsendi) has the most striking facial pattern of yellow and black.

Female top, male bottom; taken respectively on November 24 and December 30, 2018. By Minder Cheng.

According to the checklist of the Garden, there are only two months of a year when we have no records of Townsend’s Warbler. It means that of the six warblers (family: Parulidae) that have been sighted in the Garden, Townsend’s has the honor of being here the longest. However, it is not the most abundant nor the easiest to see. And it does not even breed in our area.

Townsend’s Warblers nest in mature conifers in the Pacific Northwest, in the mountains of Oregon, Idaho, Wyoming and Montana, and in Alaska and the Yukon Territory. Some of them spend their fall and winter along the coast from Washington down to California, and some fly farther south to Baja California, other parts of Mexico, and even Central America. The reason we see them in all months other than June and July is that the Garden attracts both winter residents and those migrating through our area.

Since they do not nest here, we usually don’t hear their songs, but only their soft chip calls emitted as they glean insects in the foliage. If you are familiar with Yellow-rumped Warbler’s chip calls, Townsend’s call is less forceful than that and sometimes in a fast sequence.

When Townsend’s Warblers first arrive in early fall, or in late spring right before they leave for the higher latitude, occasionally we get to hear a male sing. I remember that on the day (August 29, 2015) we celebrated the 75th anniversary of the Garden with an open house, a Townsend’s Warbler broke into song in the morning drizzle as I walked past the shrubs by the pond. Perhaps the unusual chilliness and rain reminded him of his home up north.

For songs and calls of Townsend’s Warbler, Peterson’s Guide to Bird Sounds has a great collection of recordings. If you have the app of The Sibley’s Guide to Birds, check out their recordings of Townsend’s Warbler, which are completely different from Peterson’s. That demonstrates how much variation there can be in the vocal repertoire of a warbler.

Song of the Summer: Swainson’s Thrush

Around the summer solstice, one of the most acrobatic bird songs in the Botanic Garden comes from a thrush that is brown in plumage, and almost always hidden in vegetation. 

This virtuoso singer is Swainson's thrush. He starts with a sonorous and undulating voice, as if initiating a slow aria. After a short couple of turns of it (whose pitch outlines resemble small hills in a sonogram), he launches into an eerie fine thin line, quickening his pace, reaching higher and higher (outlines of steep mountains in a sonogram), until in ecstasy he goes out of range of our hearing (10 kHz is the upper limit for many human adults).

You can hear a variety of Swainson's Thrush's recordings made available through Peterson's Guide to Bird Sounds; the third song of the page, which is labeled Del Norte, California, best captures the description above.

Sometimes the singer stays at the low range of the song, and doesn't go up to the high range. In the same recording, the second series of notes demonstrate such a song (0:05-0:07). Apparently it takes an inordinate amount of energy to be a male sopranist!

A bird’s voice box is a double structure called syrinx, another novel evolution in this incredible flying animal with so many unique features. 

The New World thrushes in the genus Catharus, which includes Swainson’s, can maneuver two independent systems of musculature on the syrinx at the same time, producing vastly complex voices. That makes the dense growths of their preferred habitat never a hindrance to broadcasting urgent communications to either competitors or objects of desire. 

If we create a singing contest among the three most wide-spread North American Catharus thrushes,  Wood Thrush, Hermit Thrush and Swainson's Thrush, which one will get your vote as the top talent of the show? Listen to a short sample of each of them here. You can probably guess my choice, and surely the evidence is in the hearing!

In addition to songs, Swainson’s Thrushes reveal their presences aurally by short low-pitched whistles and other calls. But to catch sight of them, our best luck is find some ripe fruits at branch tips.

In early July along Wildcat Creek in the Garden, many plants growing on the stream banks and reinforced walls seem ready to take over the waterway. This is the prime time and spot to see a Swainson's Thrush. From the newly formed dense growths below, a thrush may suddenly flutter up and show itself above the green herbage. Dangling just barely on the slightly-bent sprig, it plucks quickly a blue currant with white bloom, or a thimbleberry in crimson red. Almost before you have time to train your binoculars and focus on any field mark, it is already out of sight, savoring its sweet taking behind foliage. We are left with a taste of short bursts of excitement, and a blurred image of Swainson’s Thrush.

Extra songs of the summer

If you are more taken by Swainson's song than its plumage, here’s another snippet that may interest you. It was taped by cellphone on June 12, 2019 at Jewel Lake, Tilden Nature Area, about two miles due north of the main pond in Botanic Garden. It's a soundscape with many voices knitted together, typical of a birdy area. Turning up the volume gives you a fuller range of sounds.

At 0:03, a Swainson’s thrush makes its entrance with a robust sound. He is often preceded and followed by a Wilson’s Warbler’s soft chet-chet-chet-chitchitchit. Our resident breeder Song Sparrow is nearby, emitting a song of trill and more (at 0:19, 0:28, 0:40). The sparrow is loud and forceful. From a high branch afar, an Olive-sided Flycatcher sings a neat phrase of three-note whistles (in a low-high-low pitch pattern, at 0:21, 0:39, 0:55). The flycatcher’s clear and familiar song is always a delight to hear in local woods from spring to summer. But in comparison with the Swainson’s song, wouldn’t you say it’s a little too plain?

Swainson's Thrush in Canyon Section, May 5, 2019. By Minder Cheng.