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Gull Identification in Puget Sound

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Whether you want to nerd out on gull molt or argue over Olympic vs Glaucous-winged Gull criteria, this is your one-stop shop. This is my primer on gull identification and frequency in Puget Sound, from the perspective of Port Townsend. Most of these pics are from Port Townsend or elsewhere on the Olympic Peninsula, though a few are from farther afield.

I present them roughly in order of abundance. I start with the forms I see in numbers at various times through the year: Olympic, California, Short-billed, Heermann’s, and Bonaparte’s.

Then I move onto others I see in small numbers: Glaucous-winged, Ring-billed, Thayer’s Iceland, and Herring.

These regularly-occurring forms can practically be identified by bill, head, and body shape. These are all first cycle birds here. A word of caution: there is some variability in bill shape – and it can really change from one still photo to another based on angle and lighting. Also, male gulls are 15-20% larger than females, so size can be a moving target.

Finally, I cover some I rarely see: Western, Cook Inlet, and Glaucous.  

Gulls take several years to reach adulthood – three for the smaller gulls, four for the larger ones. During this time, they molt and fade and molt and fade. Season is everything. Gull identification in fall, when the birds are fresh and crisp, is completely different from spring and summer, when they are a faded, tattered mess. With each of these taxa, I’ll present the photos in order of age, so we’ll follow them as they age thru the months and thru the years.

Western x Glaucous-winged Gull (“Olympic Gull”)

Let’s start with the most common gull year-round – by far (with a few exceptions as noted below). When I’m birding, my default position is that all large gulls are Olympics until proven otherwise. (Personal shoutout to Shonn Morris for educating me about Olympic vs Glaucous-winged identification.) The nickname Olympic Gull was possibly first coined by Bob Boekelheide on a Tweeters post on January 13, 1997. Puget Sound Gull was another term batted about at the time.

Hybridization between these two species has been documented since 1908. A nice summary of the early observations, entirely on the outer coast from British Columbia to Oregon, can be found in Scott (1971). Bell’s thesis in 1992 described “a broad zone of introgression” from Haida Gwaii to Coos Bay. The colony at Protection Island, just around the corner from Port Townsend, has been described as the largest Olympic Gull colony in the world (Megna et al 2014). As described in that paper (see Figure 2 at right), the gulls in Puget Sound are decidedly toward the Glaucous-winged end of the spectrum, and “few individuals” appear to be pure Glaucous-winged. Note this is base on appearance, not DNA testing. This implies a hybrid swarm that has been going on for many generations. We are way past F1 hybrids. We’re more at F50 or more. In this context, Megna et al found evidence of assortative mating, meaning that paler birds were more likely to mate with paler birds, and darker birds with darker birds.

In my experience, and in keeping with Megna’s observations at Protection Island, most of the large gulls in Puget Sound (over 90%) appear to be hybrids at the Glaucous-winged end of the spectrum. That is my default assumption when using eBird. For those not comfortable with that, eBird also offers the option of “Western/Glaucous-winged Gull,” meaning the bird could be either parent species or a hybrid between the two; it’s the catch-all option. Simply calling dozens or even hundreds of birds “Glaucous-winged Gulls” is not correct, though that practice is widespread. That said, my limited observations in the San Juan Islands and Victoria, BC suggest less Western influence up there.

Aug 15 – Mid-August is when the first juveniles descend from the rooftops and appear on the beaches. They are crisp, with uniform brown-gray scaled scapulars and coverts. Their primaries are not jet black as in Western, Herring, California, and most other dark-winged gulls; they are dark gray. The color tone of the wing tips varies, as does the darkness of the entire bird. Like Western, the face has a uniform sooty auricular (cheek) patch, and the bill is black, large, and with a bulbous tip (see the head shots above).

Sept 18 – A month later and they haven’t changed much. This one is a bit paler and browner, which could be a function of sun exposure as well. The scapular pattern varies a bit. Note the overall robust and stocky structure, with short primary extension past the tail (i.e. short wings).

Sept 18 – Here’s another example from the same day. This one has a nearly pale greater covert panel. California Gulls in the background.

Sept 24 – A delightfully coffee-cream version, very Thayer’s-like in appearance. However, the heavy bill, stocky structure, tiny eye on a large head, and short primaries rule out the more sleek and dainty Thayer’s.

Oct 4 – Changes are afoot. It’s October and the juveniles are already molting. The telltale sign are the molting scapulars (the back). (These are actually 1st alternate scaps which they will keep a long time.) Note that the upper half of the brown checkered feathers have been replaced by rather messy patterned ones with some gray tones. Also the head and body are molting in paler feathers, though the sooty cheek remains.

On the right-hand edge of the pic, you’ll see a second cycle bird with a pure white primary sticking out (what’s left of it). This old feather is being replaced by a fresh dark (nearly black) primary. More on that as we move thru the calendar.

Oct 11 – The molting back and scapulars are obvious here as a pale gray-blue patch on the bird’s back. This bird has neat oak-leaf patterned scapulars (very Herring like, though these are rather pale), but they will be molting out soon.
Some may be tempted to call this one Glaucous-winged, as it is paler, less sooty gray, overall, and the primaries are nearly concolorous to the body. Yet the overall darkness, the dark belly, and dark auriculars suggest Western influence.
That’s a 3rd cycle bird in the back. Note the primaries are obviously darker than the mantle.

Nov 1 – This darker bird has completely molted its back and scapulars.

Nov 1 – This bird is more delayed in its molt cycle; it still has a lot of checkered juvenile scapulars. All the birds in this pic appear to be Olympics.

Nov 12 – Some more late fall examples with molted back and scapulars. How dark or light they appear can change with light and the angle of the bird. These birds are definitely reflecting some sunlight.

June 8 – And now we’re in June. Gull identification in spring and summer is a mess because the birds get quite faded and tattered. Exhibit A in this is the late 1st cycle bird on the right. This bird is now about 10 months old and desperately in need of molting to replace these primaries, which have now faded to nearly white. But that does not make it a Glaucous-winged Gull (same for the adult behind it). The rest of the bird, particularly the face and belly, are still rather dark.

June 23 – Another formerly sooty 1st cycle bird that looks like it’s gone through the wash.

June 23 – As summer wears on, many Olympics will have tertials and primaries that fade to white. This happens even in some dark-winged gulls (e.g. Short-billed). This bird has many Glaucous-winged features, though the dark below and large bulbous bill suggest some Western influence.

July 3 – With birds like this, it becomes impossible to use plumage to separate them from pure Glaucous-winged. The heavy bill with a rather sharp hook and gonydeal bulge are a better fit for Olympic.

July 6 – Here’s another summer bird that is a bit darker, and thus more obviously an Olympic. The exposed primary has a dark shadow on it where it was once covered by another feather.

July 8 – More examples of faded summery Olympics. Note the heavy dark bills and dark bellies.

July 12 – At last, molt has begun. They molt their secondaries and primaries from the inside out. The fresh feathers here are more gray; the old feathers more brown. The old primaries – the last three or four feathers on each wing – are also warn to pin points. Note, on the left wing, the new dark-tipped primary starting to grown in. This is P5 (the 5th one in from the tip, which is P10).

July 12 – A close-up look at P5 coming in.

July 14 – Another individual molting in fresh gray primaries to replace the tattered faded ones.

July 25 – And another individual. Even this rather dark-faced bird had its primaries fade to white. The new one is dark gray.

July 27 – Finding molting birds like this in late summer is fun. This bird is in the process of changing from a white-winged gull (which some might confused with Glaucous) to a nearly black-winged gull (approaching Western)!

July 27 – Taken on the same day as above, this bird is much slower in its molt cycle.

July 30 – Another bird molting from white-winged to dark-winged.

Sept 27 – September again. This bird is now a year and a few months old. It still has one long thin old faded white primary left. It’s new 2nd cycle primaries are dark enough to clearly put this bird in the Olympic camp.

Oct 4 – Another individual with a single white primary left, but new dark gray ones coming it. The other birds are juvenile Olympics, just a few months old.

Oct 11 – And voila, a fully molted fresh 2nd cycle Olympic Gull, ready for the winter.

June 8 – Now approaching it’s third birthday, this late 2nd cycle bird is ready for molt again. Note the bill had changed from black to incorporate the classic school bus yellow of Western.

Sept 20 – A juvenile begs from its parent. You can tell this adult is an Olympic because it’s child is an Olympic (with rather dark primaries). The adult has some faded primaries which are being replaced by a feather with a much darker gray band.

Oct 26 – A fully molted adult with dark gray in the primary pattern.

Jan 17 – Some more adult mid-winter. While the front right bird has rather medium gray primaries, only a little darker than the mantle, note the bill lacks any dark mark (as seen in the bird to the left), which Glaucous-winged should show in winter. The clean yellow bill is a Western feature.

Feb 17 – Thanks to David Estroff for this photo from Port Townsend. This is not a pure Western Gull because: 1) the underside of P10 (the folded wingtip in the back) is not black, but a silvery gray, especially on the inside of the white mirror. In a pure Western, this would be nearly black. 2) the orbital ring is reddish. In pure Western, it should be mustard yellow. Pure Western Gulls are rare in Puget Sound. I usually encounter them after strong west winds in winter. The clean white head is because it’s coming into breeding plumage.

Apr 19 – This adult is in full breeding plumage. When breeding, the bill and legs get brighter and more colorful. Note the primaries are too dark for Glaucous-winged, but too light for Western.

California Gull

California Gulls are abundant in Puget Sound June thru October, when a wave of post-breeding migrants pulse through the region. Especially in the Strait of Juan de Fuca, they can outnumber all other species combined in late summer. They can be found at other times of the year, though in much smaller numbers.

June 29 – I love it when the first juv Calis show up – little checkered gems on the kelp-covered cobble. They are typically rather skittish, so hard to get close pics. This June bird is my earliest record; usually they show up around July 11. Olympic in the foreground.

July 16 – Here’s another one among the Heermann’s, compared to which they are only slightly larger.

July 25 – Juvenile California Gulls can be confusing because many have all black bills. This one is already turning pale at the base. Compared to Olympic, note the long primary projection past the tail, the jet black primaries (blacker than any Olympic), and more horizontal and sleek posture.

July 27 – Two different juvenile California Gulls, now with the more characteristic dirty pink bill with black tip.

Aug 9 – These birds can look like juvenile Herring (which aren’t expected for another two months), but note the solid dark inner primaries, lacking a pale inner primary window.

Aug 27 – Though they vary from dark to light, this is a very typical juvenile California Gull.

Aug 27 – Taken on the same day as the previous pic, this is what is colloquially called a “cinnamon morph,” rather pale juvs with warm brown tones and whitish underparts. Given the all black bill, it must be quite young as well. These are more regular in California than in the Pacific Northwest.

Sept 18 – Another gorgeous juv. The feathers can often have a cinnamon brown tone.

Sept 29 – California on the left; Olympic on the right. Both of these birds have started molting scapulars. They both have pink legs in first cycle, though Calif Gull legs are paler pink.

Sept 29 – Two California’s on the left; two Olympics on the right. All juveniles. Note the left California Gull still has an all-black bill. The California Gulls stand out by their smaller size, more horizontal backs, and long, black wingtips.

June 26 – We’re now through spring into summer. This bird is approaching its first birthday and is showing the classic tri-color pattern of relatively fresh gray scapulars, faded white coverts, and tattered primaries, now faded from black to brown.

July 6 – A similar late 1st cycle California Gull. Note the legs can turn rather blueish.

July 11 – This fly-by bird reveals it has begun molting its inner primaries – the fresh gray ones.

Aug 2 – This bird is probably a year more ahead, molting from 2nd to 3rd cycle. The legs are still rather bluish gray.

Dec 9 – This bird is a full adult, with black and red near the tip of the yellow bill. The blue legs will turn yellow by spring. Olympic back left; Short-billed Gulls back right.

July 15 – Finally, a full adult California Gull with yellow legs. Note the dark eye with red orbital ring and red gape (where the bill meets the face). The adult in the background with the messed up head feathers especially shows the red gape. Heermann’s back right. The black mark on the bill is much reduced when breeding.

Short-billed Gull

These petite beauties arrive in the fall to spend the winter, departing by May to breed in Alaska and Canada.

Oct 4 – The fresh juvs look like miniature Thayer’s Gulls, but are as dainty as fairies. Note the tiny thin bill and dove-like head with a relatively large eye. Also bantam chicken-like chest and very long tapered wings.

Nov 12 – Because this is a three-year gull, the 1st cycle birds quickly resemble 2nd cycle in large gulls, in that they have “adult gray” back and scapulars. This contrasts with the brown coverts.

Jan 9 – In flight they have a rather solid tail (unlike Ring-billed Gull).

Apr 25 – Here we are in spring. The brown coverts have faded to white, and head and body molt has also created a paler appearance.

July 14 – Occasionally, some late 1st cycle birds will over-summer. These often bleach to a nearly completely white, baffling birders. The bill seems longer than usual because the head feathers are molting.

Sept 18 – This is an adult just arrived from the north. Note the tiny unmarked yellow bill, somewhat unique in the gull world. California, Olympic, and Heermann’s tower over this tiny gull.

Jan 8 – Winter adults are beautiful in flight, with considerable white in the primary pattern: mirrors on P10 and P9, and a white “string of pearls” between the gray and black in Ps 4-8 (the Slaty-backed pattern). The exact pattern is variable.

Mar 25 – The amount of head and neck smudging in variable. Note that some birds will show a yellow eye.

Apr 25 – As spring gets on, the head markings resolve to a clean white head and the bill brightens as the breeding season approaches. This means they’re about to head north.

Heermann’s Gull

A striking and unique gull, nearly the entire world’s population emanates from tiny Isla Rasa in the Gulf of Mexico. After breeding, they migrate north. About 400 typically spend the summer and early fall around Port Townsend.

July 27 – The fresh juveniles are brown with mostly dark bills. The pale feather edges wear off quickly.

Aug 15 – This is a four-year gull. This photo features two brown juveniles in the back (molting their scapulars), a 2nd cycle front left, and an adult front right. Heermann’s Gulls have black legs at all ages.

Aug 26 – This 2nd cycle bird looks a lot like 1st cycle. It has a more orange bill.

June 29 – Breeding plumage adults are remarkable for their bright red bills, clean white heads, and smoky gray bodies.

Aug 26 – Adults in the August conspicuously molt their flight feathers and tails.

Oct 5 – Adults in complete basic plumage, with mottled dark heads.

Oct 4 – A small percentage of adults show “jaeger-morph” wing patterns, with variable amounts of white in the primary coverts. This adds to their jaeger habits of chasing other gulls.

Bonaparte’s Gull

Even smaller and daintier than Short-billed, Bonaparte’s Gulls are easy to identify and a joy to watch. I’ll leave it to other sources to help you pick out a Black-headed or Little Gull among them. Suffice it to say, the former is more larger, and the latter slightly smaller, than Bonaparte’s. These northern breeders are present throughout much of the year – except summer – with pulses during spring and fall migration. Hundreds can be found at Point No Point, often harassed by jaegers in the fall.

Aug 3 – A gorgeous freshly-arrived juvenile with the characteristic black year patch.

Aug 3 – Newly arrived adults, one still with an all-black head.

Aug 3 – An adult in flight, molting its primaries.

Nov 29 – An adult in full basic (winter) plumage. It appears to have an injury in the shoulder area.

Glaucous-winged Gull

Pure Glaucous-winged Gulls are challenging for me to find among the crowd of Olympics. At best, they are uncommon in winter and rare in summer, largely limited to a few over-summering subadults. That said, an influx in winter can match Olympic numbers at some roosts between Sequim and Neah Bay.

Oct 5 – Given the dusky auriculars and rather bulbous bill, this bird probably has some Western in it. Nevertheless, note the even pale tones throughout.

Oct 28 – There’s no question about this bird. The primaries are as pale as they come, as is the tail. The auriculars have no indications of a sooty wash. The coverts are intricately patterned. Note the scapulars are fully molted.

Nov 1 – Olympic on the left; Glaucous-winged on the right. At this date, fading is not an issue.

Nov 6 – This bird shows no auricular patch. The primaries are almost patterned as in Glaucous and Iceland. Note the bill, while heavy, is less blob-ended than Western or Olympic, with a shallower gonydeal angle. The tomium (upper edge) often begins a gentle curve about 2/3 of the way out, rather than a strong hook ¾ of the way out, as is typical in Western and Olympic.

Nov 7 – This bird shows a hint of subterminal arrowhead patterns in the primaries. Note the straight bill without a contrasting blob ending.

Nov 12 – Note the whitish head on this fall bird. The primaries on this one are quite pale. Olympic in foreground.

May 7 – By spring, Glaucous-winged Gulls can fade to nearly all white. Note the bill is beginning to pale.

May 12 – Another spring adult, though this one seems less faded. Again, the bill is paling and more straight than Olympic.

June 29 – As they molt coverts, Glaucous-winged Gulls often produce this striking pattern due to fresh dark coverts.

July 6 – Over-summering late 1st cycle birds often stand out in Puget Sound. Feathers with less melanin (paler feathers) are more prone to wear and fading than darker feathers.

July 14 – This bird could be confused for Glaucous, but a Glaucous would never have dark in the middle of the bill. Given the time of year, this bird is typical of an over-summering one-year-old Glaucous-winged Gull.

July 27 – Another over-summering 1st cycle Glaucous-winged, in desperate need of molt.

June 8 – We’re now a year later. This bird is late 2nd cycle, with a bill that is already acquiring yellow tones.

Jan 17 – A presumed pure adult Glaucous-winged Gull in mid-winter. Note the icy gray mantle and nearly matching primaries (though they are more slate gray than blue-gray), the purplish legs, the rather straight bill, and the straw yellow bill with the dark mark thru the red spot.

Ring-billed Gull

Ring-billed Gulls are rather rare to uncommon around Port Townsend. I only see them in small numbers (usually three or less) in late summer and fall. Apparently they are more common in the South Sound.

Aug 25 – Compared to California Gulls, the juveniles are smaller, whiter, and with brighter pink in the bill.

Nov 15 – In flight, 1st cycle birds have a tail with a messy band. California and Short-billed Gulls have much more solid brownish/blackish tails. Also note the very contrasting wing pattern with very pale window in the inner primaries.

Aug 19 – Adult Ring-billed Gulls have very pale mantles. They can be told from Short-billed Gull at a hundred yards by the lack of a contrasting white tertial crescent between the gray mantle and black primaries. The pale gray just fades into the black with only a small white fringe.

Thayer’s Iceland Gull

Gulling is traditionally best in the winter, when Arctic breeders such as Thayer’s Iceland Gull arrive. This is difficult in Port Townsend, as there are few high tide roosts nearby. In winter, there are rarely low tides during limited daylight hours. Thus, I usually only see a few Thayer’s, if any, on any given day. They are much more regular at the Elwha River Mouth, which also has suitable high tide roosts for midday viewing.

Nov 7 – Of the large four-year gulls, Thayer’s is amongst the smallest. Fresh juveniles resemble fresh Olympics with their checkering and coffee with cream tones, but their structure is very different. Note the thin bill and long primaries, almost always darker than the body and with pale edges.

Jan 9 – Thayer’s on the left; Olympic (or possibly Glaucous-winged) on the right. The main differences: Thayer’s is smaller, longer winged, has a much tinier bill, and generally retains its scaled juvenile scapulars through the winter; the Olympic has already molted them.

Sept 22 – From left to right: Heermann’s, Thayer’s, California, and Olympic. On the Thayer’s, note the dark eye, bright pink legs, and primary pattern with the pale underside of the far primary. This is actually P9 we are looking at. P10 is missing due to molt.

Oct 11 – Thayer’s often appear petite and squat, though they are slightly larger than a California Gull. Note the small bill. Many individuals show a gold eye.

Oct 11 – This is the same bird as above, showing off their unique primary pattern. P10 has a large terminal mirror (all white tip). P9 has a mirror that swirls open toward the inside of the wing.

Nov 15 – Here’s another view of the primary pattern, which produces a striped effect.

Feb 26 – How to pic a Thayer’s out of a flock of Olympic Gulls. It’s the small one in front. Note the jet black in the primary pattern, the thin bill, and the overall petite structure (it probably weighs 30% less than the Olympics). Note also the underside of the far primary on the folded wing is pale — this rules out Herring. The dark eye also rules out Herring (though some adult Thayer’s have somewhat pale eyes). The back left bird is a 2nd cycle Thayer’s — note the thin bill.

Herring Gull

Sept 18 – I see even fewer Herrings than Thayer’s, usually just a few each winter, unless I go to Elwha. Compared to Thayer’s and Olympic, note the black primaries and very dark tertials. The coverts are usually very checkered and contrasting. The bill can vary from all black to dirty pink with a dark tip.

Dec 2 – Here’s another Herring. Note the black primaries and contrasting pale head, a common feature.

Jan 30 – An adult in flight. They always have a very pale straw-colored eye, producing a fierce look. The mantle is pale icy blue. The typical primary pattern has only a single mirror on P10.

Western Gull

Sept 16 – Pure Western Gulls are rare in Puget Sound. I usually only see them in fall or winter after strong west winds. This juvenile shows a dark sooty face (similar to many Olympics) but also jet black primaries. Note also the more contrasting coverts, not the uniform muddy tones of Olympics. That’s a juvenile Olympic back right.

Sept 29 – This 3rd cycle Western shows a fairly dark mantle and jet black primaries.

July 27 – This summer adult is a classic Western: a clean white head (which they keep year round), a thick bulbous school bus yellow bill, a darkish mantle, and jet black in the primaries. Note also the yellow orbital ring. The eye varies from yellow to dark.

Herring x Glaucous-winged Gull (“Cook Inlet Gull”)

I only report a few of these each winter, usually at Elwha or Neah Bay. They are probably regular but rare in Puget Sound, but they are really a pain to pick out amongst all the Olympics!

Nov 6 – This one is easy to separate from Olympic – it has a pale version of the Herring Gull bill, pale with a black tip. The dark gray primaries rule out black-primaried gulls and imply either a Thayer’s or Gl-W hybrid. The molted scapulars, structure, and gray color tones rule out Thayer’s. Olympic in the background.

Nov 12 – A likely Cook Inlet, with a straighter and more paling bill than found on Olympic. Cook Inlets often retain juvenile scapulars later in the winter, as this one has. Note also the longer-winged structure.

Jan 8 – Another potential Cook Inlet with unmolted scaps (in January!) and a longer-winged structure than Olympic. The more squared off and contrasting pale head also suggests Herring influence. 2nd cycle Olympic in the background.

Glaucous Gull

Large and white, these are rare winter visitors.

Nov 9 – Most Glaucous Gulls in Washington are 1st cycle birds, like this one. I took this on the beach at Ocean Park. It is accompanied by adult Ring-billed and Western Gulls. The bill is always pink with a well-demarcated black tip. Glaucous-winged never approaches this at any age. Note the bill is also straight and not blob-ended.

Rarities: These species, listed roughly in order of probability, occur less than annually:  Franklin’s Gull, Lesser Black-backed Gull, Black-legged Kittiwake, Black-headed Gull, Little Gull, Slaty-backed Gull, Black-tailed Gull, Ross’s Gull

Probability by season

It always helps to know which gull species are around at any one time during the year. eBird data for gulls in Puget Sound is of little use due to widespread misidentifications. This graph is based on my personal eBird data from Pt Wilson and Pt Hudson near Port Townsend. Frequency may vary around the Sound and at other gull roosts. For example, Ring-billed Gull is quite regular in the South Sound earlier in the year, and Thayer’s and Herring are regular at the Elwha River Mouth in winter.

Heading south for winter, more birds are choosing the Pacific Northwest

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Many papers predict that bird ranges will shift northward with a warming climate (Wu et al 2018, Langham et al 2015).

Many studies have already documented that this is happening (Illán et al. 2014, Virkkala, R. and A. Lehikoinen 2014, Hitch and Leberg 2007, and La Sorte and Thompson 2007).

And some have documented poleward range shifts specifically for wintering ranges (Saunders et al 2022, Hampton 2019, Paprocki et al 2017, Prince and  Zuckerberg 2016, and Paprocki et al 2014).

I’ve previously written about an increase in insectivore bird species in winter associated with a warming climate in the Sacramento Valley. As the Putah Creek Christmas Bird Count (CBC) compiler, it was hard not to notice the trends. Cassin’s Vireo, Black-throated Gray and Townsend’s Warblers, and Western Tanagers were becoming more expected in winter. We had crossed a threshold; we didn’t get freezes anymore. My bougainvillea and cape honeysuckle, which previously clung to life in winter, were now growing and blooming year-round. Fruit and insects were available to these birds.

Now in Port Townsend, Washington, we set a local CBC record for Yellow-rumped Warblers last year. This caused me to take a closer look at the data, focusing on Passerines that are rare or uncommon, and at the northern edge of their wintering range. They are: Hermit Thrush, Cedar Waxwing, Lincoln’s Sparrow, White-crowned Sparrow, Orange-crowned Warbler, and Yellow-rumped Warbler. For each of these, the PNW is at the northern limits of their wintering range.

I looked at their numbers and trends on the Portland, Olympia, Seattle, Bellingham, and Vancouver BC CBCs since the 76th CBC (winter 1975-76). I’ve got more notes on my methodology at the end.

Results

All have increased since 1975, generally with the uptick beginning in the 1990s. Here are the results of my inquiry.

The range maps are from eBird’s Abundance Maps. Red=summer; blue=winter; purple=year-round; yellow=migration. The graphs show the birds per party hour across the five CBCs, taking the total number of birds and dividing by the total number of hours across all five counts.

Hermit Thrush

Hermit Thrush has been increasing at a rate of 4.2% per year across all the CBCs. It has been increasing across all five of the counts, most strongly in Vancouver (4.1% annual growth) and most tepid in Seattle (0.6%). It is most common on the Portland count, which has averaged 26 Hermit Thrushes per count since 2009.

Cedar Waxwing

Of the six species I focused on, Cedar Waxwing showed some of the most erratic growth, averaging only 2.5% per year. That said, it has been above average 8 of the last 9 years. To illustrate the unpredictable nature of waxwings, they have actually been declining on the Olympia (-2.3%/yr) and Vancouver (-4.1%/yr) counts. They are increasing the most on the Portland count (3.0%/yr).

Lincoln’s Sparrow

Lincoln’s Sparrow has been increasing steadily, from near zero, at an overall rate of 3.6% per year. To put this in perspective, these five CBCs tallied 5 or fewer individuals, summed across all counts, in each of the first five years of this analysis. In each of the last five years, these counts, in aggregate, tallied between 34 and 52 individuals. Growth has been strongest on the Olympia count (4.6%/yr) and weakest on the Bellingham count (1.7%/yr).

White-crowned Sparrow

Despite the eBird map, White-crowned Sparrow is a regular overwintering species in the PNW. The five counts, in aggregate, tally between 100 and 750 individuals each year. They’ve been increasing at a rate of 1.8% per year, strongest in Seattle (3.1%/yr) and weakest in Vancouver (-2.5%/yr, the only count with declining numbers).

Orange-crowned Warbler

Orange-crowned Warbler has seen dramatic increases, averaging 5.0% per year, highest in Olympia (7.2%/yr) and lowest in Bellingham (3.2%/yr). The numbers, however, are still small. Aggregate numbers across all counts were zero five of the first eleven years of this analysis (easily seen on the graph). Double digits were not reached until 1999. The last ten years, however, have averaged 15 individuals across all the counts, making this an expected species in winter now.  

Yellow-rumped Warbler

Yellow-rumped Warbler wins the award for poster child of species increasing in winter at the northern edge of their wintering range. They’ve been increasing at a rate of 5.3% per year. Interestingly, this growth is concentrated in the south. Portland (3.7%/yr), Olympia (3.4%/yr), and Seattle (6.1%/yr) have seen the most growth, while Bellingham (-0.5%) and Vancouver (-5.0%) have seen declines. Perhaps those Fraser River winds are too cold for warblers. 

Methodology

The data includes bird per party hour for the Portland, Olympia, Seattle, Bellingham, and Vancouver BC Christmas Bird Counts from the 75th count (winter 1975-76) to the 120th count (winter 2019-20). The 121st count was impacted by the pandemic.

CBC (and Breeding Bird Survey) data is uniquely advantageous for looking at long-term trends such as climate change, as they both go back many decades with generally similar effort over time (for certain well-established counts). Nevertheless, there were some issues with this data:

  • I did not use the Portland data from the 76th thru the 82nd count, due to aberrantly low party hours relative to later counts.
  • The following data was missing entirely from the Audubon CBC database: Olympia 76th, 77th, 78th, 84th, 104th, and 110th counts; and Seattle 91st count.
  • The following counts had no (or obviously incorrect) data for party hours: Portland 104th count; Bellingham 111th, 112th, and 119th counts. Because they did have bird numbers, I approximated the party hours based on their counts in nearby years. I used 230 party hours for the Portland count and 200 party hours for the Bellingham counts.

Other climate-related bird changes in the Pacific Northwest

I’ve previously blogged about climate change and birds in the Pacific Northwest:

The invasion of the Pacific Northwest: California’s birds expand north with warmer winters looks at northward range expansions of Great Egret, Turkey Vulture, Red-shouldered Hawk, Anna’s Hummingbird, Black Phoebe, Townsend’s Warbler, and California Scrub-Jay, with some discussion of others as well. Note that Townsend’s Warbler, as a migrant that winters rarely in the PNW, fits with the group of birds described in this post.

The song of the Lesser Goldfinch: Another harbinger of a warming climate looks at increasing records in the PNW in summer.

Mapping the expansion of the California Scrub-Jay into the Pacific Northwest looks at the steady range expansion of this non-migratory species.

References

Hampton, S. 2019. Avian responses to rapid climate change: Examples from the Putah Creek Christmas Bird Count. Central Valley Birds 22(4): 77-89.

Hitch and Leberg. 2007. Breeding distributions of North American bird species moving north as a result of climate change. Conservation Biology 21(2): 534-9.

Illán et al. 2014. Precipitation and winter temperature predict long-term range-scale abundance changes in Western North American birds. Global Change Biology, 20 (11), 3351–3364.

Langham et al 2015. Conservation status of North American birds in the face of future climate change. PLoS ONE 10(9): e0135350.

La Sorte, F.A., and F.R. Thompson III. 2007. Poleward shifts in winter ranges of North American birds. Ecology 88(7):1803–1812.

Paprocki et al. 2014. Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends. PLoS ONE 9(1): e86814.

Paprocki et al. 2017. Combining migration and wintering counts to enhance understanding of population change in a generalist raptor species, the North American Red-tailed Hawk. The Condor, 119 (1): 98–107.

Prince, K. and B. Zuckerberg. 2016. Climate change in our backyards: the reshuffling of North America’s winter bird communities. Global Change Biology 21(2): 572-585.

Saunders et al. 2022. Unraveling a century of global change impacts on winter bird distributions in the eastern United States. Global Change Biology

Virkkala, R. and A. Lehikoinen 2014. Patterns of climate-induced density shifts of species: poleward shifts faster in northern boreal birds than in southern birds. Global Change Biology 20: 2995–3003.

Wu et al. 2018. Projected avifaunal responses to climate change across the U.S. National Park System. PLOS ONE 13(3): e0190557.

I try to maintain an updated list of references at the Birds and Climate Change Facebook group. At that page, click on Files to find the list.

A Nazca Booby, a tug, a barge, and a pit: A climate parable

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At 9:30am on August 17, that is, yesterday, I got a text from another birder. A Nazca Booby had just been seen from Discovery Point near Seattle. What’s more, we knew exactly where the bird was now; it was perched on the bow of a barge being pulled by the tug Seaspan Raider.

The Nazca Booby, atop the barge, photographed by Matt Stolmeier, captain for Outer Island Excursions.

The Nazca Booby is a tropical seabird that breeds exclusively on the Galapagos Islands. When not nesting, it occurs at sea in the eastern Pacific, generally between central Mexico and northern Peru.

Breeding (orange) and non-breeding (blue) range of the Nazca Booby.

This was Washington’s third record. The first, quite possibly the same bird, was on August 14, 2020, in pretty much the same part of Puget Sound. The second was a few weeks ago also off Seattle. That one was an immature, not an adult, so we know it was a different individual. It then showed up off Victoria, providing Canada with its third record.

The Nazca Booby first arrived in the United States in California in 2013. I actually played a role in that first record, a dead beachcast bird found in the aftermath of an oil spill. Working for the state’s spill response, I brought it to the attention of the California Bird Records Committee and had experts examine the carcass for identification. That bird was not a one-off event; it was the beginning of an invasion. There were a few scattered records in the following years, followed by an explosion of 26 records in 2018 and 21 in 2019. After that, California removed the species from its “review list”. While some of these records may have been the same individuals, it is remarkable that a tropical bird previously unheard-of in the US was suddenly widespread. Oregon got its first two records in 2018 and 2019.

Sea surface temperature (SST) of 66.1F off the Washington/Oregon coast.

Checking sea surface temperatures, I see that the water off the Washington and Oregon coasts is reaching 66F in places, only 4F cooler than on the south side of the Galapagos. Zooming out, it is easy to see a route from there to here where the bird never had to encounter sea surface temps under 60F. The Strait of Juan de Fuca is in the low 50s, but it does approach 60F near Seattle.

I opened the MarineTraffic app and quickly located the Seaspan Raider. It was southwest of Edmunds, northbound at 7.3 knots. I calculated it would arrive off Port Townsend between 1 and 2pm. Birders scrambled, heading to various coastal promontories on both sides of Puget Sound. I headed to Point Wilson, where Puget Sound effectively ends and meets the Strait of Juan de Fuca. The tug, bound for Canada, would have to pass by me here.

Reports came in. The bird had flown off the barge. It was in the water off Edmunds. It took off. It was seen from both sides. No one knew where it was.

Tracking the tug using the MarineTraffic app.

This wasn’t the only booby in the Salish Sea at the moment. A Brown Booby had been photographed a few days earlier near the San Juans. That was yet another tropical seabird that had already invaded the US, with records from over forty states, including Alaska. Two decades ago, this would have been unimaginable. And this summer, 2022, was already noteworthy across the Midwest and East Coast for the mass invasion of waterbirds typically found only in Florida or the Gulf Coast. Limpkins, Wood Storks, White Ibis, Roseate Spoonbills and many others were showing up hundreds of miles north of their previously known ranges.

Scrolling thru the American Birding Association Rare Bird Alert nationwide posts, limited to just mega-rarities, here is what pops up: Brown Booby in Oklahoma, Neotropic Cormorant in North Carolina, Brown Booby in Wisconsin, two Swallow-tailed Kites in Ohio, Limpkin in Wisconsin, Neotropic Cormorant in Michigan, White Ibis in New York, Wood Stork in Pennsylvania, Heermann’s Gull in Alaska, Limpkin in Illinois, Nazca Booby in California, White Ibis in Nebraska, etc. And that doesn’t even get us back to August 1. These are all birds, mostly aquatic birds, well north of their normal ranges.

Our current rate of climate warming hasn’t been seen since the Paleocene-Eocene Thermal Maximum (PETM) 55 million years ago. Then, there were alligators within the Arctic Circle. Kind of like Nazca Boobies are now a thing in Puget Sound. Actually, our current rate of warming is much faster than then. During the PETM, the climate warmed 5C in five thousand years. The current rate of warming is eighteen times faster. Then, no one would have noticed. Now, there is 1C of warming – and, with it, dramatic changes in climate and ecology – within the lifespan of a single bird. Some seabirds are showing us that they can keep up, thanks to their ability to fly long distances. I’m not sure about the alligators. Or birds that depend, say, on oak trees. The birds can fly, but the oaks can’t.

Two hours passed. I was ready to give up and head home, my only consolation being “MAMU CF”, a Marbled Murrelet making a provisioning flight across the Sound, carrying a fish to its single chick somewhere on a moss-covered Doug fir branch a hundred feet above the forest floor, probably in the Olympic Mountains. I’d only seen that once before. Much of their range in California has been lost to fires in the past five years, so this Olympic chick is important.

The original photo of the Nazca Booby on the barge, by Alex Meilleur.

One birder, who was unable to search for the Nazca Booby, called some of the local orca boats, as he worked on some of them. He let them know about the bird, as some were near it. About twenty minutes later, texts came in. They had re-found it! It was back on the same barge, now approaching Marrowstone Point. I spun my scope south. There, beyond the ferry lane, I could make out the red and white structure of the Seaspan Raider, pulling its barge, all blurry and shimmering in the distant heat mirage, slowly chugging toward me.

Taking advantage of the outgoing tide, the Seaspan Raider was now hitting 9 knots. It is powered by two Niigata 6m G25HX diesel engines. I don’t know what kind of gas mileage it gets, but, because it presumably refueled in Washington, most of its fuel is likely conventional diesel, but a small component may be renewable diesel.

Renewable diesel is not the same as biodiesel. Biodiesel can be mixed with conventional diesel, but only in very small amounts, like 2%. Renewable diesel, on the other hand, is molecularly identical to conventional diesel. It’s a relatively new invention. Made from non-petroleum sources, such as plant and animal material, it is to conventional diesel what corn syrup is to sugar; it is a “drop-in ready” alternative fuel. It can be mixed with or substituted for conventional diesel seamlessly, with no change in gas pumps, pipelines, or engines. In fact, it burns slightly cleaner, so engines last longer. It emits fewer particulates and, most importantly, its greenhouse gas footprint is up to 80% less. Its use is already widespread in California, where two of the state’s largest refineries no longer take petroleum crude.

This is the kind of thing that should have been developed thirty years ago, just after James Hansen of NOAA briefed congress on climate change in 1986. Now it’s late. We’ve already had more than 1C of climate warming, with more coming and probably ten feet of sea level rise built into the system. Stopping carbon emissions is no longer a suitable goal. We’ve already pushed the cart down the ramp. It’s rolling. We need to reverse climate change, to change that ramp so the cart rolls back to where it was. That will require actually sucking CO2 out of the air – negative emissions – which will certainly take a hundred years under the most optimistic scenarios. So get ready for more boobies, maybe even Limpkins and alligators.

Aside about Washington: Washington further delayed action a few years ago when the Department of Ecology required an Environmental Impact Statement from Phillips 66 to convert their refinery at Cherry Point to make renewable diesel. That is to say, Phillips needed to jump through major permitting hurdles because they were changing – that is, reducing — their greenhouse gas emissions. Phillips didn’t want to wait the several years required for this, so they promptly moved their operation to California. Governor Inslee tried to intervene and save the project, but it was too late. Now BP is picking up the baton in Washington.

Renewable diesel is already in widespread use in trucks, especially in California. The ferries in San Francisco Bay are powered exclusively by it. Because diesel is similar to jet fuel, and made during the same refining process, refineries also produce what is called sustainable aviation fuel (SAF). Aircraft are currently permitted to fly with up to a 50/50 blend of SAF and conventional jet fuel. Boeing promises jets that can fly with 100% SAF by 2030. We’ll be approaching 1.5C of warming by then. Nazca Booby will almost certainly be off the rare bird review list, at least in California. Brown Boobies will be breeding on the Farallones and prospecting further north.

I watched as orca boats came and went from the barge, photographing the Nazca Booby. I was told it was on the starboard side of the roof of the little structure on the bow. The tug and barge continued up Admiralty Inlet until it was straight out from me, as close as it would pass. Slightly more than halfway across the channel, it remained blurred in heat mirage. I could see fuzzy white dots on the described rooftop, but I couldn’t tell you if they were Nazca Boobies or gulls or volleyballs. In birder’s lingo, this was going to be a ‘dip’, even though I knew exactly where the bird was and was looking at it.

My view of the tug, barge, and bird.

Mathematically, this would be at least the sixth time a Nazca Booby had passed this point, my point, my sea watch. And this time I was here, ready and waiting, and still I couldn’t see it. Were it not for the texts and the orca boats, I’d never know it was there. I kept my scope glued to it, hoping it would lift off in a distinctive flight and head directly toward me, where it would join the Caspian Terns and plunge dive right in front of me as I clicked my camera in ecstasy. But it didn’t. The tug and barge chugged north.

The bird was last seen at Partridge Point on Whidbey Island, still riding the barge. It was off the barge by Rosario Inlet. I’m guessing it jumped ship and headed toward Victoria or Smith Island.

The barge’s destination was the Lafarge Texada Quarrying Ltd. limestone mine north of Vancouver. Limestone is critical to making cement. The cement-making process is responsible for 8% of the world’s carbon emissions. Part of that is from the energy used in production, which requires a kiln heated to 1,400 degrees Celsius. But most of the emissions comes from the limestone itself. Forty percent of the weight of limestone is CO2, and this is burned off in the process. There are efforts to improve the cement-making process, to make it less dependent on limestone, to reduce its carbon emissions. That’s all coming in the future.

The limestone mine at Beale Cove, the barge’s destination.

I’m wondering about the ancient Nazca civilization in what is now Peru. It was dependent on a remarkable network of underground aqueducts that delivered mountain water to their arid home. There’s a theory that they over-harvested a certain tree, which led to erosion of riversides during heavy rains, destroying their water delivery system. I wonder if they had meetings about the problem, if they had new policies in effect, at least at the end, when it was too late.

It’s supposed to be 95F in the Seattle suburbs today. I’m not worried about missing this Nazca Booby. There will be more.

The Nazca Booby on the bow. I’m sure the scope views were better. Photo by Laura Brou.

Mapping the expansion of the California Scrub-Jay into the Pacific Northwest

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This blog post is merely to provide a visual illustration, by way of a map, of the expansion of the California Scrub-Jay across Washington, British Columbia, eastern Oregon, Idaho, and even Montana (one record so far). It is intended to complement my more detailed article, “Tracking Expansion of the California Scrub-Jay Into the Pacific Northwest”, in the Washington Ornithological Society (WOS) News, August-September 2021 edition.

California Scrub-Jays are often first detected at bird feeders in suburban areas. As aggressive nest predators, jays should not be subsidized by anthropogenic food sources. In short, please don’t feed the corvids. Port Townsend, WA. April 2021.

As becomes clear in the article, these are not hard lines. The jays are advancing gradually, not in a solid wave. Typically, a single jay will appear well outside the known range (e.g. Spokane). Within a year or two, there will be several. Then they’ll be breeding. Then they will begin expanding further. Meanwhile, a wave of jays will be backfilling the new territory, with densities increasing annually. The lines in this map are as much art as science, but are intended to show the primary region were jays were “regular and expected”. There were always outliers, pioneer dispersers expanding the range. Records beyond the 2020 line are shown as pale blue dots.

CLICK MAP TO ENLARGE

The expansion of the California Scrub-Jay mimics that of several other species, mostly non-migratory or short-distance migrants, rapidly expanding from California and Oregon into the Pacific Northwest.

The jay’s expansion has already surpassed that predicted by the Audubon Society’s climate model under a 3.0 degree Celsius scenario, shown here.

The jay’s expansion, when considered in the context of timing and trends in other species, is likely a function of a warming climate combined with suitable food sources. For more discussion of this, see the WOS article linked above.

They seem to be particularly taking advantage of warmer winters in the lower Columbia River Basin.

It will be interesting to see where the 2030 scrub-jay “contour line” will be. I predict they’ll be on Vancouver Island from Victoria to Campbell River, as well as up the Sunshine Coast, up the Okanagan Valley to Kelowna and possibly Kamloops, and east to Idaho, from Coeur d’Alene in the north throughout the Snake River Valley in the south.

After that, they face some formidable hurdles. The biggest obstacles to their expansion further north and east will be habitat with limited food sources (e.g. high mountains). That said, they’ve already shown some ability to travel up mountain valleys and potentially cross the Cascades north of Mount Rainier.

Like most corvids, California Scrub-Jays are big time cachers, storing extra food for future use. I took this photo in southern California, October 2017, when a family of jays were repeatedly stripping an oak, two acorns at a time, flying over a nearby ridge to cache them, and then returning again and again throughout the morning.

Goodbye California: Reminiscences of a climate refugee

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There are a lot of reasons why I’m moving from California to Washington, including family and other personal considerations. But one reason, one big reason, is California’s rapidly changing climate.

It was late February in the Coast Range of northern California when I was wearing shorts and a t-shirt. Dust swirled around my car in the dirt parking lot at Cold Canyon. The car thermometer, warmed by a sun that felt imported from Palm Springs, said 87 degrees; it was actually only 77. A hint of ash, omnipresent since The Fire last summer, remained in the air.

Its oaks torched with little hope of return, Putah Creek Canyon is quickly resembling a sun-scorched canyon in Arizona. Until 2018, only one fire in the area had burned more than 15 square miles. Then the County Fire burned 140 square miles. In 2020, the LNU Complex Fire burned 570 square miles.

The hillsides were green with the new growth of non-native grass, which was responding to a recent heavy rain. That was deceptive. More than half the rain we’d had in the previous eight months came in that single event. We had six inches of rain in all of 2020. Looking beyond the grass, nearly every tree – blue oaks and gray pines – on the hillsides was dead, burnt black and orange monuments to a previous era. For our local blue oak woodland, that era ended last year and, given that recruitment of saplings is unlikely due to heat, fire, and cattle, it was an era that will never return.

Massive die-offs are eliminating blue oaks from the southern third of their range. Black oaks are marching up the Sierra, displacing Ponderosa pine, which are marching up, displacing firs. Everyone is on the move. Oak woodlands are becoming oak savannahs, oak savannahs are becoming grasslands, grasslands are becoming rocky high deserts. Arizonification is happening quickly, thru heat, drought, and ultimately, thru fire.

Virtually all of the east slopes of the Coast Range between San Francisco Bay and the Trinity Alps has burned in the past ten years. In the Sierra, one can practically predict where the next fire catastrophe will happen, because it hasn’t burned yet (hint: Lake Almanor, Placerville, Arnold).

The Fire, the LNU Complex Fire, was part of 2020’s 4.3 million acres of scorched earth. The LNU Fire exceeded the total acreage of all previous fires that impacted my county over the last 50 years combined.

It was a beautiful day—for April. But February has become April, April has become May, and June, July, August, September, and even October and November have become unrecognizable. Every year more heat records are broken. Hottest summer, hottest month, most days over 100, most days over 90. The list goes on, each year breaking the records set the previous year. Weather data is normally highly variable; now it is a straight line—warmer and warmer. And smokier.

My cape honeysuckle and bougainvillea, both planted with a degree of optimism outside their recommended zone, used to die back so badly in the winter that each spring I was tempted to declare them dead and pull them out. Now they bloom year-round, looking like they’re in a courtyard at a hotel in the tropics. We haven’t had a real freeze in seven winters.

The songs of lesser goldfinches on my street are a depressing warning. I can’t take two steps outside without seeing or hearing a bird that reminds me that our climate has seriously changed. Western tanagers, house wrens, and turkey vultures are regular in winter now. The lesser goldfinches have come out of the arid hills and are quickly becoming one of the most ubiquitous nesting birds in Davis. (I know this definitively because one included an imitation of a canyon wren in its song.) What’s more, at least four Say’s phoebes, essentially a high desert species, are scouting for nests in town now. A fifth arrived on my block last week, singing as if on territory. They’ve been doing this for a few years and their numbers are growing.

The graphs of acres burned in California (and in other western states) and the expansion of some bird species into the Pacific Northwest (in this case, Anna’s hummingbirds in winter), are strikingly similar.

I’m leaving. I’ve lived in California fifty-five years but it’s no longer the state I grew up in.

We’re headed to the Olympic Peninsula in Washington. We are fortunate to be able to do so.

Besides the cooler summers, one of the best things about moving to a new place is that I won’t be reminded of climate change on a daily experiential basis. Because the ecosystem will be new to me, I won’t know what’s different, what is changing, except maybe for the brown boobies, a tropical seabird, that are now showing up in Puget Sound each year. Or the family of California scrub-jays that have just established residence on my new street. Like Anna’s hummingbirds, black phoebes, great egrets, red-shouldered hawks, and people like me, scrub-jays are moving north. I expect more of California’s birds to follow me, just as I follow some of them. Yes, lesser goldfinches are coming north too; they’re already established southeast of Tacoma.

I feel like a frog in a boiling pot. I’m getting out. I’m saying goodbye to California, but I feel it has left all of us without saying goodbye to anyone.

The view from Point Wilson, a mile from my new home in Port Townsend, which has had only a few nights below freezing all winter. Climate change is occurring there too, but remains well within temperate ranges.

I do believe that Homo sapiens may ultimately win the climate battle and bring atmospheric CO2 back down to 300 ppm or something. But that’s a hundred years off. And there’s no guarantee we can stop the tide of Greenland and Antarctic ice melt to prevent sea level rise. In the meantime, in the next 50 to 100 years, it’s going to get a lot warmer. And we may ultimately lose New York City, Singapore, Mumbai, and every other low-lying coastal city. My new home is fifty feet above sea level. Well, probably forty-nine and a half now.

The song of the Lesser Goldfinch: Another harbinger of a warming climate

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As the climate warms, different thresholds are crossed for different species at different times. For the Lesser Goldfinch, that time seems to be now—both in the core and northern edges of its range, where the species is increasing, and in some parts of the southern arid regions, where it is decreasing.

As I prepare to migrate myself from Davis, California to Port Townsend, Washington, I’m serenaded by Lesser Goldfinches every time I step outside. This is a new thing, a warning of coming heat and smoke brought by a beautiful voice. A more open and arid country version of the American Goldfinch, until five or ten years ago, Lesser Goldfinches were sparse breeders in Davis. I would get a few of them mixed with Americans at my feeder in winter, but I’d have to go west to the more arid edges of the Sacramento Valley, or up into the hot dry foothills, to find them in the breeding season.

They arrived in my neighborhood as nesters about five years ago. This year, 2021, they seem to be the most ubiquitous singing bird, setting up terrorities throughout the town. Friends in Sacramento have reported the same. This comes after several years of record heat and lack of rain (only 6″ in all of 2020).

Here’s what the eBird data says. For comparison, Northern Mockingbird, one of the most common birds in town, is reported from about 20 eBird locations in Davis each June (ranging from 16 in 2015 and 14 in 2016 to 18-22 in the more recent years as eBird users and reports increased). Using mockingbird as a metric for Davis, it’d be fair to say that 20 sites represents close to 100% presence throughout the town, and that number was probably 25% lower (i.e. 15 sites) in 2015. Lesser Goldfinches have increased from reports from four sites in June of 2015 (representing about 20% of the town) to 17 sites in June of 2020 (representing 85% of the town). It feels like it will be 100% this year.

They are not the only arid-country species increasing in Davis as a breeder. Nesting Say’s Phoebes have expanded up from the south, with multiple pairs in Woodland each year (and it’s looking like Davis this year as well).

As with so many less-migratory species, Lesser Goldfinches are expanding north into the Pacific Northwest and beyond.  Their colonization of the Columbia River Valley began in the 1950s, with the first state of Washington record in 1951; they are now established around Portland, The Dalles, and in the vicinity of Clarkston on the Idaho border. They remain rare elsewhere, but increases in records have been dramatic in recent years. In the northern Puget Trough region (Chehalis north thru Puget Sound to Canada), June records have increased from 1 in 2015 and 2016 to 10 in 2020 (as reported on eBird). While they have clearly gained a toe-hold in Olympia and Puyallup in the South Sound region, in 2020 they made appearances in Victoria and Vancouver, Canada (not shown in the data because these records were in May, not June).

Lesser Goldfinches in British Columbia were limited to four scattered records until 2007. Since then, they have become nearly annual, with most records between January and June.

This is a pattern seen in other resident and less-migratory species. Many of those that were already growing before detectable climate change (around 1985) have expanded noticeably since then. Anna’s Hummingbird is the most dramatic example.

Further east, Lesser Goldfinches are moving due north from Yakima and Kennewick into the Okanagan Valley. June records in this region have increased from zero in 2015 to eight in 2020.

All this is predicted. The National Audubon climate prediction map for Lesser Goldfinch, under the 2C warming scenario, describes much of what we are witnessing.

In the Mojave Desert, Lesser Goldfinches have declined. Iknayan and Beissinger (2018) reported them from only 43% of 61 study sites, compared to 68% historically. This is part of a massive avian community collapse in the Mojave Desert, as extreme aridity is pushing many species beyond their limits.

UPDATE NOV 2022: eBird released its Trends maps, which illustrate where species have been increasing (blue dots) and decreasing (red dots) between 2007 and 2021. The map for Lesser Goldfinch show exactly what I’ve described above: increasing in around Sacramento and Davis, decreasing in the western foothills (probably due to fires), increasing in Washington, particularly in the Columbia River Basin, and decreasing in the desert Southwest.

The 2018 flight of the Buff-breasted Sandpipers: Data from the West Coast

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Buff-breasted Sandpipers breed on the Arctic tundra from western Alaska, across northern Canada, to Baffin Island. They winter eight thousand miles to the south, on the grasslands of the River Plate Basin in Argentina, Uruguay, and Paraguay. Their primary migration corridor is east of the Rockies, through the central United States. A secondary route is along the East Coast. They are always rare in fall migration along the West Coast, with four to fourteen individuals counted each fall between 2014 and 2017. In spring, they are almost unheard of (there is one record in eBird from Arcata, California in May, 1980).

Fall migration in 2018 was exceptional on the West Coast, with sixty-five individuals reported, five to ten times the norm. The figure below summarizes eBird data from the past five years in southern British Columbia, Washington, Oregon, and California.

CLICK TO ENLARGE.

BBSA

A few interesting points:

  • While fall migration generally spans from mid-August thru late September, the timing of records within that period are not strongly correlated with latitude.  That is, it does not appear that birds are moving from north to south through the period. Each season’s latest records, from mid or late September, may come from British Columbia or Washington as easily as from southern California. That said, in 2018, the latest records are indeed from southern California. Moreover, the very few October records over the years (not included in the graph) are from southern California.
  • They are most reliable in the Pacific Northwest, only reaching California in years of relative abundance, such as 2018. The only location with records from every year is Salmon Arm Bay of Shuswap Lake, in the interior of British Columbia. Other sites, with records in all but one year, are Boundary Bay, British Columbia, and the south coast of Washington (e.g. Ocean Shores, Gray’s Harbor vicinity).
  • The vast majority of records are of single individuals. The only time more than four birds were documented together during these years was in 2018, with five birds at once at Sauvie Island, Oregon, and a remarkable thirteen at Boundary Bay.
  • In the years 2014-2017, Buff-breasted Sandpipers first appeared between August 15 and 19. In 2018, they did not appear until August 23, and most were relatively later than birds in previous years.
  • In 2018, there were several records from offshore California: one from the Farallons, two from San Clemente Island, and two birds seen together from a pelagic trip one hundred miles off southern California. These were all relatively early in migration, between August 25 and September 1. In contrast, most 2018 records from the Oregon coast were from the first week of September.