posted September 12th, 2012; last edited September 13th, 2012 –– David Sibley

Quiz 53: Eastern Sparrows in early September

Below are three sparrows photographed in Concord, MA on 11 Sep 2012. Can you identify the species?

Today’s quiz features a bonus

Everyone who submits a perfect score by noon Eastern Time tomorrow – Thursday September 13th – will be entered in a drawing to win a prize. And we have a winner! Congratulations to Tim, and thanks to all who entered.

The prize this week is donated by Acopian BirdSavers – the best way to prevent birds from hitting your windows. The winner will receive a window protector custom-made to fit their window. Of course, even if you don’t win, you can still order your own BirdSavers from Acopian BirdSavers (or even make your own).

Scroll down to take the quiz, and good luck!

….Continue reading Quiz 53: Eastern Sparrows in early September →

posted September 11th, 2012; last edited September 12th, 2012 –– David Sibley

In search of Spoon-billed Sandpiper

Spoon-billed Sandpiper. Original gouache painting copyright David Sibley.

Join me on a WINGS/Heritage Expeditions cruise 21 June to 4 July 2013 to search for nesting Spoon-billed Sandpipers in Siberia.

I’ve always been fascinated by Siberia. Growing up in the lower 48 states I dreamed of seeing birds like Steller’s Sea-Eagle, Siberian Rubythroat, even Middendorff’s Grasshopper-Warbler, and the crowning jewel of the Siberian specialties was Spoon-billed Sandpiper. My fascination increased as the population of Spoon-billed Sandpiper declined, and in Feb 2010 I made a trip to Thailand where I could see a few individuals on the wintering grounds. That trip was very successful, and I learned a lot about identification and behavior of the species.

I really wanted to see them on the breeding grounds, but at that time there was simply no practical way of getting to the right locations. Since 2011, however, Heritage Expeditions along with BirdLife International has offered a cruise designed specifically to see Spoon-billed Sandpiper in summer, and I am thrilled to have the opportunity to go along in 2013, which is the last year they plan to run this trip.
….Continue reading In search of Spoon-billed Sandpiper →

posted September 11th, 2012; last edited September 11th, 2012 –– David Sibley

Quiz 52: More numbers

Here are three more “flocks” of lentils that need to be estimated. If you need an extra challenge, give yourself a time limit to come up with each number.
….Continue reading Quiz 52: More numbers →

posted September 10th, 2012; last edited September 10th, 2012 –– David Sibley

Quiz 52: Trees for birders


The quiz below shows four photographs of the leafy crowns of trees, as you might see them while looking for birds through binoculars or telescopes. Differences in leaf “posture”, arrangement, and color are just as obvious as differences in leaf shape, and all of these species are readily distinguishable at a glance, even in silhouette.

Just like beginning birdwatching, you can start by learning to recognize a few common and distinctive species of trees that you see every day, and as those become familiar you will add more species to your “repertoire”.

These photos were all taken with a Canon digital camera held to a Swarovski telescope at The Nature Conservancy’s Mashomack Preserve, Shelter Island, New York, on 27 August 2012.
….Continue reading Quiz 52: Trees for birders →

posted September 8th, 2012; last edited September 8th, 2012 –– David Sibley

Juvenal plumage of songbirds: Gray Catbird

Most Passerines only hold juvenal plumage for a few weeks, quickly molting to a more adult-like plumage soon after they fledge and before fall migration. It’s a plumage that is seen almost entirely on the breeding grounds, but the breeding grounds (and fledging time) of many birds overlaps broadly with the fall migration of others, so it’s common to see a mixture of juveniles and fall migrants of various species. Learning to recognize juvenile songbirds, and appreciating the things they all have in common, can help avoid confusion in the late summer and early fall.

Juvenile (upper) and adult (lower) Gray Catbird. Original pencil sketch copyright David Sibley.


….Continue reading Juvenal plumage of songbirds: Gray Catbird →

posted September 6th, 2012; last edited September 7th, 2012 –– David Sibley

Quiz 51: Estimating Numbers

Another quiz to test your skill at estimating numbers of birds in flocks.
….Continue reading Quiz 51: Estimating Numbers →

posted September 5th, 2012; last edited September 6th, 2012 –– David Sibley

Quiz 50: Bird topography – upperside

Here is a new quiz about the topography of the upperparts of a large songbird.

….Continue reading Quiz 50: Bird topography – upperside →

posted August 21st, 2012; last edited August 21st, 2012 –– David Sibley

Quiz 49: Estimating numbers of birds

This time the answers are arranged randomly, instead of sequentially, and I think this makes it a little harder, since it’s harder to use the range of possible answers as a clue. Suggestions are always welcome.

….Continue reading Quiz 49: Estimating numbers of birds →

posted August 18th, 2012; last edited August 16th, 2012 –– David Sibley

Distinguishing immature (white) Little Blue Heron from Snowy Egret

These are the only regularly occurring herons that are truly difficult to identify, as immatures of these two species are variable in bare-parts color and distinguishing them can require very careful study. The best clue is foraging posture, which can be seen at any distance and is very reliable. Most individuals are fairly easily separated by leg and bill color, and those differences become more obvious and more reliable over time in late fall and winter. It is perhaps only the youngest immatures in July to September that cause confusion. At least as early as March, the presence of a few new gray body feathers will distinguish most immature Little Blue Herons from the always-white Snowy Egrets.

Determining the age of a white egret can be helpful, since any white adult cannot be a Little Blue Heron, although adult Snowy Egrets have more distinctive bill and leg color than juveniles, and are less likely to cause confusion in the first place. If a bird in late summer or fall shows signs of molt (see my post on aging white egrets), or lacy plumes on the nape or back, then it must be an adult and therefore not a Little Blue Heron.

Habits and foraging posture

Little Blue Heron is a patient stalker, and walks with the neck stretched somewhat awkwardly up and forward, while the bill is pointed down at the water. This posture is distinctive. Generally solitary in shallow water, and shows a preference for grassy or weedy ponds. This species can often be seen quietly working the grassy edges of a pond while numbers of Snowy Egrets forage together in the more open water.

Snowy Egret forages in shallow water up to belly deep, rarely or never in grassy or upland situations. Typically quite active and gregarious, walking or standing with neck either stretched up or coiled, using a variety of techniques to attract or startle fish: striding purposefully through shallow water with the neck partly coiled, running through shallows with wings flapping, following flotillas of Cormorants or mergansers along creeks to catch fish that are flushed out by the diving birds. If water is too deep for standing the egrets will fly low over the surface and attempt to snatch fish from the air. This species will also crouch, with neck coiled ready to strike, and stir the water with one loot, or put the tip of the bill in the water and vibrate it to attract fish. Much of this behavior recalls Reddish Egret or Tricolored Heron, and is never engaged in by Great Egret or Little Blue Heron.

Little Blue Heron vs Snowy Egret

  • habits provide one of the best clues to the identity of foraging birds (see above)

  • wingtips show small dark gray tips on outer primaries (vs all white on Snowy Egret)

    This is variable and the gray tips can be very hard to see (usually invisible when the bird is at rest) but when gray tips can be confirmed they are diagnostic for Little Blue.
  • legs and feet pale, chalky pea-green with feet about the same color as the legs (vs leg color generally brighter lime green with at least some black and with contrasting brighter yellow feet ).

    Some young Snowy Egrets show dull green legs with no black, and even substantial amounts of black (usually on the upper front of the legs) can be difficult to see. Presence of black is diagnostic for Snowy Egret, as is contrasting yellow feet.
  • bill usually paler grayish with less contrasting colors, outer 30–50% of bill dark grayish, entire base of bill pale greenish-gray or fleshy gray, not contrasting much with greenish loral skin (vs bill usually darker, with blackish on culmen extending back close to forehead and pale area at base of bill clean pale gray, contrasting with fairly bright yellow-green loral skin)

    But both species are variable, in particular very young birds. Both species can have the entire base of bill pinkish, yellowish, or gray (more variable in Little Blue), and both species can have contrasting yellowish loral skin (more common and more typical of Snowy Egret). Note that nestling Snowy Egrets have dark gray loral skin and some still show this color briefly after leaving tlie nest. In summary, a mostly blackish culmen is diagnostic for Snowy Egret, any other pattern can be shown by either species.
  • bill shape slightly deeper at base and more tapered, appearing slightly downcurved at times (vs. slightly thinner, more even depth)

    This feature also leads to broader loral skin on Little Blue and more open face with staring expression (vs. narrower loral skin on Snowy Egret with more squinting or frowning expression).
  • Little Blue seems to have a larger eye, broader bare skin on the lores, and maybe a less pronounced eyebrow ridge above the eye; all of which leads to a more wide-eyed, “staring” expression

  • This is a consistent impression, but I haven’t been able to find any objective or measurable difference. Other things like bill thickness, lore color, or head shape may also contribute to the impression, and all can be very similar on young birds. For example, Little Blues average a higher and more rounded crown profile than Snowy, but very young Snowy Egrets also show a rounded crown.
  • Many immature Little Blue Herons show a short pointed plume or two on the back of the head (vs. immature Snowy Egret lacks plumes entirely, although very young birds retain fluffy down at the tips of some head feathers; and adult Snowy Egrets have a bushy tuft of lacy plumes on the back of the head)

posted August 17th, 2012; last edited August 17th, 2012 –– David Sibley

Identification of Waterthrushes

Northern (upper) and Louisiana (lower) Waterthrushes, showing differences in size and plumage. The impression of whiter underparts on Louisiana is partly the result of the very sparsely streaked upper breast, compared to the breastband of many small streaks on Northern. Also notice only two rows of streaks on the flanks of Louisiana, fading out at the rear and leaving a large area of unmarked white on the belly, compared to the many rows of dark streaks on Northern. Original gouache painting copyright David Sibley.

First Glance

A quick judgment of the ground color of the breast and eyebrow stripe will separate most waterthrushes: bright white on Louisiana, yellowish on Northern. A yellowish waterthrush is definitely a Northern, while a whitish bird could be either species. Next look at the shape of the eyebrow stripe, which broadens to the rear on Louisiana, and since it is also bright white on Louisiana this stripe can be very conspicuous (vs tapered behind the eye and usually yellowish on Northern).
….Continue reading Identification of Waterthrushes →