News from the Cape » Field Identification and Photo Quiz by Michael O’Brien

Glossy and White-faced Ibis

Marleen — Wed, 01 Apr 2009 14:00:45 +0000

Over the past two decades or so, White-faced Ibis, a predominantly western species, has been showing up with increasing frequency along the East Coast. Here in southern New Jersey, it seems that whenever there is a flock of 50-100 or more Glossy Ibis to carefully sort through, there is a reasonable chance of finding a White-faced among them. Often, because these birds tend to hide in tall marsh vegetation, or keep their heads down for long periods, the biggest hurdle is simply getting a good enough look at each member of the flock. If you are one who enjoys the challenge of sorting through flocks of birds to find a rarity, maybe this spring is a good time to seek out a flock of Glossy Ibis to try and pick out a White-faced.

To pick out a White-faced Ibis among Glossies, it is most critical to get a good look at the face pattern. A breeding plumage adult White-faced is easy to spot, with it’s broad band of white feathering wrapping around the bare facial skin and continuing behind the eye. A subadult or nonbreeding adult, however, requires a better look. Color of the eye and facial skin are critical field marks. And if you want a real challenge, you could always search extra hard and try to spot a hybrid – a rare but real possibility. The photo captions below highlight the key features to look for.

Figure 1) Breeding Glossy (left) and White-faced Ibis, April, Colorado. This photo nicely illustrates the typical face patterns of these two species in breeding plumage. On the Glossy, note the dark eye and slate-gray facial skin, crisply bordered above and below by pale blue skin. These pale blue borders can be quite broad, but they do not wrap around behind the eye. The legs on Glossy Ibis are typically gray but can sometimes have a pinkish cast. On the White-faced Ibis, notice the red eye, pink facial skin, and broad white band of feathers that wraps around behind the eye. The legs on White-faced may be just like those of Glossy Ibis, but often the joints are distinctly pinkish. Photo by Tony Leukering.
Figure 2) First summer (right) and molting adult White-faced Ibis, July, California. As the summer wears on, much plumage variation may be seen in White-faced Ibis, and many individuals will show little if any white feathering on the face. Note that all of these birds (all about a year of age or older) show red eyes, and all the adults show pink facial skin. The bird at center, and the one probing at bottom-left, both show just enough light facial feathering to make the eye stand out against a paler background – a very distinctive look compared to Glossy. On some breeding adults (and still just visible on the center bird), the presence of a bronzy or reddish tinge on the tertials, contrasting with greener wing coverts, is a good indication of White-faced. Glossy has more even-toned wings. The first-summer (one-year-old) bird at right is distinguishable from Glossy only by its red eye and pink-edged facial skin. Nonbreeding adults have a similar look. Photo by Steve Howell.
Figure 3) Breeding Glossy x White-faced Ibis, April, Colorado. Along with the increase of White-faced Ibis within the range of Glossy (and vice versa), there has been an increase in the number of hybrid ibis being reported, though they are still very rare. On this typical hybrid in breeding plumage, note that the facial skin is pinkish gray, edged in pale violet, exactly intermediate between Glossy and White-faced. The eye looks reddish, like White-faced, yet there is no white facial feathering, thus like a Glossy. Hybrids in nonbreeding or first-summer plumage would be much more difficult to distinguish from White-faced, and they likely would go unnoticed. Photo by Bill Schmoker.

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Swan Tails (and bills)

Marleen — Sat, 28 Feb 2009 16:30:03 +0000

In most of New Jersey, swan identification is not a big issue. Most of them are Mute Swans. Mute Swan is generally not a favorite among local birders and naturalists. A native to Europe and Asia, this species was first introduced into North America back in the late 1800s, though fossil evidence indicates it’s natural presence here in relatively recent times. In any case, the current, growing population of Mute Swans is considered highly invasive. Their large size and aggressive nature disrupts or displaces other wetland species, and their consumption of submerged aquatic vegetation has been shown to cause declines in several native waterfowl species. But despite the negative side to their presence here, they are certainly beautiful birds that are worth admiring from a purely aesthetic standpoint. And while you are looking at them, you may as well see if you can find a different species of swan hiding among them. The only other swan species likely to be seen in Cape May and elsewhere in New Jersey is Tundra Swan. They are fairly common but local in the state, though they are seldom seen in large numbers in Cape May. Small groups pass through in November and December and a few birds may remain through the winter and early spring. A third swan species, the Trumpeter Swan, has been seen in Cape May and elsewhere in the state on several occasions. This primarily western species historically occurred along the Atlantic Coast and has been reintroduced in the Great Lakes and Upper Midwest regions. This reintroduced population is growing and some of these birds have been showing up in the Mid-Atlantic states.

Identifying swans can be very tricky. Bill color in adults is usually distinctive and often settles the issue quickly. (Note, however, that some Tundras may show minimal yellow on the bill, and a few even may show a trace of fleshy color to the gape, a character more typical of Trumpeter.) However, structural features are sometimes necessary to really nail down the identification of an odd individual. The photo captions below cover the most useful features in adults. Immature swans can be much more difficult and are beyond the scope of this article. Structural features, much like on adults, are often the most reliable clues. Voice is also a helpful feature on both adults and immatures.

Figure 1) Adult Mute Swan, December, New Jersey. This should be a familiar image to most of us. Adult Mute Swan’s orange bill with swollen black knob at the base is very distinctive. Note also the very long tail, a trait unique to Mute Swan. Although not evident here, territorial Mute Swans often take on a characteristic pose with wings lifted as a sail and neck curved in an S-shape. Contrary to their name, they are not entirely mute. They give an odd, relatively soft growling call, quite different from that of other swans. They also hiss at you if you get too close! Photo by Michael O’Brien.
Figure 2) Adult Tundra Swan, December, New Jersey. The black bill with yellow loral spot is distinctive. Note also how much shorter the tail is on this species than on Mute Swan, a helpful field mark on sleeping birds when the bill is tucked away. Formerly known as “Whistling Swan” (before being lumped with the Old World “Bewick’s Swan”), Tundra Swan’s voice is a beautiful, distinctive, deep whistle with a slightly descending quality, which may also be likened somewhat to the bugling call of a crane. Flocks of Tundra Swans flying high overhead are often heard before they are seen. Photo by Michael O’Brien.
Figure 3) Adult Trumpeter Swan, January, New Jersey. The most obvious difference from Tundra Swan is the lack of a yellow loral spot on the bill (always lacking in Trumpeter). However, a few Tundra Swans may lack this spot so careful scrutiny of bill structure is necessary to be certain of a possible stray Trumpeter Swan. In particular, note how the bill looks slightly heavier overall with a straighter culmen (upper edge) and a wider area of black where the bill meets the eye (on Tundra, the black looks “pinched” in front of the eye, so the eye often stands out more). Also note how the line from the eye to the gape is straighter on Trumpeter, and more curved on Tundra. As on Tundra Swan, the tail is distinctly shorter than that of a Mute Swan. As their name implies, Trumpeter Swan’s voice is a distinctive trumpet-like bugling (sometimes likened to the noise made by a French taxi cab) with lower, shorter, more resonant notes than Tundra. Photo by Michael O’Brien.
Figure 4) Adult Tundra Swan, December, New Jersey. In this head-on view, note how the bill meets the forehead in a relatively straight line, an important distinction from Trumpeter Swan. This bird is missing its right eye, making it difficult to judge the width of black at the lores. Photo by Michael O’Brien.
Figure 5) Adult Trumpeter Swan, January, New Jersey. Compared to Tundra, note the more V-shaped juncture between the bill and forehead feathering and also the wide area of black where the bill meets the eye. Photo by Michael O’Brien.
Figure 6) Adult Mute Swan, December, New Jersey. When the bill is not visible it is probably impossible to distinguish Tundra and Trumpeter Swans, but this Mute Swan is still readily identifiable by its long tail. Photo by Michael O’Brien.

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Was Your Eider Smiling?

Marleen — Sat, 31 Jan 2009 18:00:13 +0000

One of the pleasures of winter birding in New Jersey is grabbing a warm beverage and working up or down the coast, checking the various inlets and jetties for sea ducks. Scoters and Long-tailed Ducks are often numerous and well worth the trip by themselves. But, with a little luck, you may also come across an eider. Both King and Common Eiders occur regularly along the New Jersey coastline in late fall and winter. Commons are always more numerous and flocks of a dozen or more are sometimes encountered (though smaller groups are more frequent). King Eiders are much scarcer and are most often seen as singles, either by themselves or among Commons.

The flashy adult male eiders are easy to identify, but most of the birds we see here in South Jersey are females and immatures. The females are all brown (except for whitish wing linings) and the immature males are darker brown with white patches on the body. There are a variety of different field marks that are helpful in distinguishing female and immature eiders. For starters, King Eiders are a bit smaller than Commons. Though the difference may not be too obvious, if you see a flock of Commons, a King among them should appear to be on the small side. And if you see an eider flying with a flock of scoters, a Common should stand out as obviously larger, whereas a King will look only subtly larger. A more solid criterion is the structure of the head and bill. Common has a distinctively long-snouted look (like a greyhound) and an evenly sloping forehead with a rather straight line from crown to bill tip. King Eider does not look so long snouted, and it has a rounder head and a slightly swollen base to the bill (so no straight line from crown to bill tip). Also, the way the bill meets the face is different. One aspect of this difference that is particularly evident in the field has to do with where the gape line is. On Common, the gape line is barely evident because it lies along the bottom edge of the “snout”. On King, however, the gape line curves upward across the cheek, so the bird seems to be smiling. So if you look through a flock of eiders and find one that’s smiling, you have found a King!

These features, and others that may be helpful in distinguishing our two eider species, are illustrated in the figures below.

Figure 1) Adult female Common Eider, June, Alaska. This head-shot clearly illustrates Common Eider’s distinctive greyhound-like long-snouted look. Note the straight line from the bill tip to a little bump on the forehead. Also note how the juncture between cheek and nape feathering angles back from the eye, and how the gape line is very hard to see because it runs along the lower edge of the “snout.” The bill color is typically olive-gray. Photo by Michael O’Brien.

Figure 2) Adult female King Eider, June, Alaska. Compared to the Common in Figure 1, note the more rounded head and shorter “snout,” with a slightly swollen base to the bill and, thus, less even line from the crown to bill tip. Also note how the juncture between cheek and nape feathering angles down from the eye (like a clown’s tear), and how the gape line curves upward across the cheek, so the bird seems to be smiling. The bill is often distinctively black in adult females but more olive-gray in immature females. On this adult female, note the chevron-shaped markings on the flanks, distinct from the vertical bars on the flanks of an adult female Common. Note, however, that immature females of both species show much less distinctive flank markings. Photo by Kevin Karlson.

Figure 3) Immature male Common Eider, April, Norway.Structural features of the head and bill are the same as on female Common. Young males of both eider species are darker and more solid brown than females, and both have white patches on the body. On this individual, a few white feathers on the back are a telltale sign that this is a Common, not a King (adult male Kings have black backs; adult male Commons have white backs). Young male Commons in a less advanced stage of molt may not show these diagnostic feathers, but head and bill features are still distinctive.