Clay-colored Sparrow in Trinity Bellwoods Park

On my Bird Walk in Trinity Bellwoods Park this morning I experienced a mini-fallout of song birds. During two hours of birding I found 13 species of warblers, including Northern Parula, American RedstartOvenbirdBlackburnian, Magnolia, and Chestnut-sided Warblers. There were also several Scarlet Tanagers, Lincoln’s Sparrows, Rose-breasted Grosbeaks, and dozens of White-crowned and White-throated sparrows.

The best bird of the day, however, was a singing Clay-colored Sparrow. This species breeds in shrubby open areas across central Canada and central northern United States, and is an uncommon visitor on the northern shore of Lake Ontario during migration.

Unfortunately I didn’t have my camera with me, but I was carrying my new Remembird audio recorder. Here is a sample, including also the song of a Chipping Sparrow. Sibley describes the Clay-colored’s song as “a series of two to five rasping buzzes on one pitch zheee zheee zheee“.

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Trinity Bellwoods Park Bird Walks

Gates at the entrance to Trinity Bellwoods Park

Image via Wikipedia

Last May I did a daily bird walk in Trinity Bellwoods Park to find out to what extent migratory songbirds use the park as a resting spot during spring migration. The park’s breeding bird species are very few, including Red-eyed Vireo, American Robin, Yellow Warbler, American GoldfinchNorthern Cardinal, and Chipping Sparrow. Yet, throughout the month I managed to find 61 species in the park, including 4 Flycatcher species, 5 Thrush species, 20 Wood Warbler species, and 4 Sparrow species. Quite impressive, considering that the park does not have a lot of natural protective habitat suitable for song birds. I posted a full summary on the Toronto and Southern Ontario Birding Forum.

This high number of migrants encouraged me to start my 2011 bird walks in the park already in April. My first walk this year was on 8 April, and I hope to continue most days of the week until early June. The first signs of spring migration appeared already in March; Some early spring migrants included American Robin (first appeared on 14 March), American Tree Sparrow (17 March), Cooper’s Hawk and Red-winged Blackbird (19 March). Moreover the Black-capped chickadees that had spent all winter around the feeders in the park disappeared by the end of the month.

Last year’s walks were reported on the Toronto and Southern Ontario Birding Forum. This year I will try something new; I will post the species totals from these walks on eBird, and highlights on Twitter, using hashtag #TBPBirdWalk. Please follow my user (sonofjon) or subscribe to the #TBPBirdWalk hashtag to get a daily update. Of course, if I find anything unusual, I will report on the regular channels as well.

Edit: A history of updates is available here.

The route of the walk (see image below) is a mile long and takes roughly 30-60 minutes to walk, depending on bird availability. It includes four hot spots where song birds tend to aggregate (red crosses).

The marked route starts and ends on Dundas Street West, and passes by four hot spot areas (red crosses) where song birds tend to aggregate.

If you are birding in the park, please consider reporting you sightings; Either to me directly, on the Toronto and Southern Ontario Birding Forum, or on Twitter (please tag your post #TBPBirdWalk).

Comparison of Northern Waterthrush and Louisiana Waterthrush

Waterthrushes

From left to right: Specimens 1-3: Northern Waterthrush; Specimens 4-6: Louisiana Waterthrush

This will be the last post from my recent visit to the ROM Ornithological archive. The Northern Waterthrush and the Louisiana Waterthrush are New World warblers preferentially foraging on the ground in wooded areas. Hence they are difficult to spot, and often noticed only by song. To make things worse, the two species are quite similar-looking. The photographs displayed here, showing skins from the underside, reveal a few useful characters that separates the Northern and Louisiana Waterthrushes. The perhaps most commonly used character, however, details of the supercilium or “eyebrow”, is not discussed. Waterthrushes don’t have a pronounced change in appearance between breeding and non-breeding plumage (as many other warbler species do); these images include both specimens in breeding and non-breeding plumages.

First, note how the breast streaking is denser and stretch further down the side and belly on Northern than on Louisiana. The chin and throat on Louisiana are largely unmarked (although, note that the second bird from the right is an exception), while the throat on Northern has fine spots. Also, the tail on Northern extends further beyond the undertail coverts than on Louisiana (very subtle character). Furthermore, Louisiana is often pictured as having a disproportionately large bill. However, note that in this sample set, this character is not diagnostic; the bill of the first Northern specimen is as thick as on the second and third Louisiana specimens, and the bill of the first Louisiana specimen is as slim as on the second and third Northern specimens. Breast streaks are also said to be browner on Louisiana (black on Northern), but I find this character very variable, and not reliable in the field.

The Northern and Louisiana Waterthrushes were recently moved from the Seiurus genus to the Parkesia genus, effectively separating the waterthrushes from the Ovenbird. I compared specimens of Northern Waterthrush and Ovenbird in a previous post.

Waterthrushes

Same specimens as pictured above. From top to bottom: Specimens 1-3: Northern Waterthrush; Specimens 4-6: Louisiana Waterthrush

Comparison of North American Spotted Thrushes

Spotted Thrushes

Wood Thrush (top left pair), Veery (top right pair), Gray-cheeked Thrush (bottom left pair), Swainson's Thrush (bottom middle pair), and Hermit Thrush (bottom right pair).

I’ve posted several short articles about bird specimens at the Royal Ontario Museum in the past couple of days. See here, here, here and here. This post will be about identification of  spotted thrushes. Ignoring American Robin, the five most common thrushes in North America are Wood Thrush and four species of the Catharus genus, including Veery, Gray-cheeked Thrush, Swainson’s Thrush, and Hermit Thrush. These are all common birds occurring across large parts of North America every migration season.

In Ontario, Hermit Thrushes are the first species to arrive in the spring, by early April. Veerys, Swainson’s Thrushes and Wood Thrushes follow by middle to late April and Gray-cheeked Thrushes arrive somewhat later, by early May. During migration these birds only sing quite sparsely, so oftentimes identification has to be based of visual characters.

The five species are superficially similar, having variably spotted chests and upper sides ranging from rufous brown to gray. In this post I’ll point out some characters that are helpful for accurate identification of these thrushes. Note, however, that the text is by no means exhaustive. I will focus on characters that are visible in the photographs, which generally picture the specimens from the underside. For further details on identification please see links provided above.

Wood Thrush:

The Wood Thrush is the easiest species in the group to recognize. It is slightly larger, has a chunkier appearance (larger head, thicker bill), than the Catharus thrushes. The distinct triangular-shaped breast spots, covering large parts of the creamy white breast and belly, are stunning compared to the other thrushes.

Wood Thrushes

Wood Thrush: Two male specimens collected in Ontario in May 1936 and September 1936, respectively.

Veery:

The Veery has a weakly spotted breast (belly largely plain). The breast base colour is warm beige and spots are comparably diffuse.

Veerys

Veery: Two female specimens collected in Ontario in September 1961 and June 1929, respectively.

Gray-cheeked Thrush:

This species is very gray (hence the name), but note that it is not just the cheek that is gray, but also the breast, face and overall appearance; compare to Swainson’s Thrush, below. Gray-cheeked Thrush is slightly larger than other Catharus thrushes, see title image, and has slightly denser breast spotting.

Gray-cheeked Thrushes

Gray-cheeked Thrush: Two male specimens collected in Ontario in May 1920 and May 1941, respectively.

Swainson’s Thrush:

The Swainson’s Thrush looks similar to the Gray-cheeked Thrush, but has a warmer base color on breast and upper sides (see comparison below). Spots are slightly bolder and stretch down further on the sides than on Veery.

Swainson's Thrushes

Swainson's Thrush: Two immature specimens collected in Ontario in September 1929 and September 1939, respectively.

Hermit Thrush:

This species is slightly smaller than the others, has a breast with a dingy base colour, and bold, somewhat smudged, spots.

Hermit Trushes

Hermit Thrush: Two male specimens collected in California in December 1952 and August 1895, respectively.

Gray-cheeked Thrush versus Swainson’s Thrush:

I generally find that Gray-cheeked Thrush is the most difficult species to identify, perhaps partly because it is the least common species in my area. Size has never been a very useful character (oftentimes it can be misleading) and its gray colours are only subtly different from those of the Swainson’s Thrush.

The key character to look out for is the “spectacles” on the Swainson’s Thrush (buffy lores and eye-ring). However, on atypical individuals the lores are not very distinct, which could mislead you to think that you are looking at a Gray-cheeked Thrush. Moreover, the presence of an eye-ring can be difficult to detect, and often requires optimal viewing conditions.

The image below compares side views of Gray-cheeked Thrush and Swainson’s Thrush. Note the bright lores on the Swainson’s specimens (note that eye-rings are not preserved well on stuffed specimens) and the steel-gray overall appearance of the Gray-cheeked specimens compared to the more beige and brown tones on the breast, wings and upper back of the Swainson’s Thrushes .

Gray-cheeked Thrush versus Swainson's Thrush

Left: Gray-cheeked Thrush; Right: Swainson's Thrush.

That’s it for this time. I hope this comparison was useful to some of my readers. Finally, I just want to reiterate that many useful characters, including upper part colour and face details were left out in this comparison. Good birding.

Acknowledgement:

Thanks to Mark Peck and the Royal Ontario Museum (ROM) for giving us access to the ROM Ornithological collection.

Comparison of Mourning Warbler and MacGillivray’s Warbler

Mourning Warbler versus MacGillivray's Warbler

Mourning Warbler (top) and MacGillivray's Warbler (bottom). Male specimens collected in Ontario in June 1936 and in British Columbia in June 1931, respectively. Royal Ontario Museum Ornithological Collection.

Last fall I wrote about a side by side comparison of Mourning Warblers and Connecticut Warblers. Today I’ll compare the Mourning Warbler with another species of the same genus (Oporonis), the MacGillvray’s Warbler. The MacGillvray’s Warbler is in fact the Mourning Warbler’s closest relative. The two forms originally used to be considered as a single species. Now they are believed to form an east-west species pair complex, with MacGillvray’s in the west and Mourning in the east, and with minimal overlap of the breeding ranges.

The Sibley “Guide to Birds” states that the MacGillvray’s “averages slightly longer-tailed and rounded-headed than Mourning”. It is “smaller and shorter-winged” and has “white eye-arcs in all plumages”. For the two male specimens I examine here, from the Royal Ontario Museum (ROM), the MacGillvray’s is indeed longer-tailed than on the Mourning, however, the most striking distinguishing character is the extent and structure of the black on the throat and chest: note that on the MacGillvrays’s this area is uniformly dark slaty gray while on the Mourning the area is gradually darker toward the lower chest.

This character is not mentioned either in Sibley or in the National Geographic “Field Guide to Birds of North America”, although the illustrations in both books suggest that it could be a diagnostic character. The Peterson “A Field Guide to Warblers of North America” confirms that the character is useful for identification of the two species. It is somewhat surprising that you have to go the specialist literature for such an obvious character. The Peterson guide also brought my attention to another important distinction between the two species, which is readily visible in the title image: spring adult male MacGillvray’s has dark lores while the lores on spring adult male Mourning generally has the same shade as the rest of the face.

Mourning Warbler versus MacGillivray's Warbler

Same two specimens as shown above: Mourning Warbler (left) and MacGillivray's Warbler (right). Royal Ontario Museum Ornithological Collection.

Side by Side Comparison of Empidonax Flycatchers

Flycatchers

From left to right: 1: Olive-sided Flycatcher; 2: Yellow-bellied Flycatcher; 3-6: Traill's Flycatcher; 7-8: Least Flycatcher. All spring/summer males.

At last week’s visit to the Royal Ontario Museum (ROM) Ornithological archives, we had the opportunity study some common groups of similar-looking bird species. One such complex is Tyrant Flycatchers within the genus Empidonax, often referred to as empids. These are small songbirds with olive upperparts, pale throats and bellies, and whitish wing-bars and eye-rings. In the field they are very difficult to distinguish visually, however, their songs and calls are distinct. So, to study skins of these species side by side was a useful exercise.

Flycatchers

Same specimens as pictured above. From top to bottom: 1: Olive-sided Flycatcher; 2: Yellow-bellied Flycatcher; 3-6: Traill's Flycatcher; 7-8: Least Flycatcher. All spring/summer males.

The photos above show three Empidonax species: Yellow-bellied Flycatcher; Traill’s Flycatcher; and Least Flycatcher; and for comparison, another widespread North American flycatcher species, Olive-sided Flycatcher. Traill’s Flycatcher has since the 1970’s been considered to consist of two unique species, Alder Flycatcher and Willow Flycatcher (these two are the most difficult to distinguish), however, at the time when these specimens were collected this distinction was not made.

After some close looks at the skins a few conclusions could be drawn. Disregarding from the Olive-sided Flycatcher (which is larger and have darker chest sides that the other empids) it appeared that Yellow-bellied Flycatcher and Least Flycatcher can be uniquely identified by visual characteristics; Yellow-bellied is uniquely coloured bright olive and Least is significantly smaller that other empids. Furthermore, the skull of Least is proportionally larger than Traill’s, and Least has a more distinct eye ring, a character that cannot easily be seen in stuffed specimens, and certainly not in these images.

We also had detailed looks at specimens of Acadian Flycatcher (another empid, not shown), and concluded that they are indistinguishable from Traill’s. I looked especially at the primary projection, which according to Sibley’s “Guide to Birds” is supposed to be particularly long on Acadian, but there was no significant difference between the Acadian and Traill’s specimens we had at hand. I also noted that bill width does not appear to be a useful character in separating empids in the field.

So, where does that leave us. Well, essentially when encountering an Empidonax flycatcher in the field, I would only feel comfortable identifying Acadian, Willow and Alder Flycatchers by sound, whereas the other species should be identifiable by visual means.

Now, I know that there are some advanced birding guides out there, detailing differences between empids, stressing for example differences in bill shape, and I’ve just ordered a copy of the brand new “Field Guide to Advanced Birding” by Kenn Kaufmann, so after having read that I may have reason reassess my conclusions.

Spoon-billed Sandpipers at the Royal Ontario Museum

Spoon-billed Sandpipers

Skins of Spoon-billed Sandpiper (Eurynorhynchus pygmeus)

At last week’s visit to the ROM ornithological archives I discovered some 20 skins of Spoon-billed Sandpiper (Eurynorhynchus pygmeus) in the collection. This shorebird species, with its unusually shaped bill, is critically endangered, so it was touching to see so many dead birds. These specimens of course were collected a long time ago, before the species was known to be endangered.

Spoon-billed Sandpipers

Spoon-billed Sandpipers in non-breeding plumage

Looking closer at the tags attached to the skins revealed that these specimens were all captured in Japan, many of them from the island of Hokkaido. Today the only know over-wintering sites are in Bangladesh and Myanmar. Only a few hundred birds are thought to be remaining in the world.

Spoon-billed Sandpiper Labels

Most birds were collected in Sep-Oct during 1904-1911 in Hokkaido, Japan

If you haven’t already seen this amazing video of this rare species displaying at the breeding grounds on the Chukotsk peninsula (Russia) in June 2010 I can highly recommend it.