BIRDING BY HINDSIGHT: A Second Look at Herons

In case you felt the previous "Birding by Hindsight" installment seemed to end abruptly as printed in The Loon, that's because it did. It seems the original article included an additional three paragraphs at the end, but someone apparently felt this section was inappropriate, or off-topic, or that some things are above criticism....or something – actually, I'm not sure why it was deleted. (If you're curious what all the fuss was about, see http://www.mbwbirds.com/internet-iii.html.)

Anyway, at the risk of offending those readers who have pet herons at home, this Hindsight will present some identification issues involving that group of heron-like birds I'll simply call waders. ("How dare he refer to Lulu Belle, my precious pet Least Bittern, as a simple wader!") There are 15 of these species which have occurred in Minnesota, representing three families: Ardeidae (bitterns, herons, egrets), Threskiornithidae (ibises, spoonbills), and Ciconiidae (storks).

It may seem curious that it took so long for this 15-year-old column to get around to discussing this familiar group of birds perched conspicuously towards the beginning of your field guides and checklists. It's mostly because there are relatively few ID difficulties here, with only the ibises presenting some serious challenges. But finally, after 15 years, appropriately enough, here are the 15 waders as they appear in standard checklist order.  

American Bittern

About the only source of confusion with this bittern would involve an immature night-heron, since both are brown overall and similar in size. But given a decent view of a standing bittern, it's not hard to see its black malar/neck stripe, the longer and thinner neck, and the more upright posture with bill typically pointed skywards. By contrast, a standing night-heron lacks a black neck stripe, has a hunched posture, and usually holds its bill level.

Even in flight, the ID usually isn't too difficult. The bittern's longer neck/head profile and neck stripe are still often noticeable, but note especially its contrastingly black flight feathers (brown with no contrast on a night-heron). The calls are also quite different: a flying bittern seldom calls (I can't recall ever hearing one in flight), while that's about the only time you hear the night-heron's low-pitched quork. Of course, the bittern's strange ooon-ka-choonk emanating from a swamp is hard to confuse with anything else.

Least Bittern

Size alone will serve to separate Lulu Belle and other members of this hard-to-see species from everything else, except perhaps the somewhat larger and more widespread Green Heron. With any decent view, of course, this bittern's buff-and-black plumage and conspicuous buff wing patches are quite different from the Green Heron's uniformly dark plumage – which hardly shows any trace of green, by the way.

Given the Least Bittern's secretive nature, it's more often heard than seen, so it's useful to learn its muffled, rapid, low-pitched (and easily overlooked) call, which sounds very much like the coo coo coo of the Black-billed Cuckoo. (I still recall the time years ago when I played a Least Bittern recording by this marsh. No bittern, but instead a responsive Black-billed Cuckoo flew in from the aspens across the road.) They also give a similar but higher-pitched kah kah kah vocalization, plus a brief, low-pitched tr-r-r-r-r-r trill.

Great Blue Heron

This most widespread heron in Minnesota seldom presents any ID confusion. About the only difficulty I've noticed is when a poorly seen or partly obscured Great Blue is hunched over and conceals its long neck: it then can resemble either of the night-herons.

And, abruptly, that's about it for this section. But rest assured nothing was edited out this time: there's just nothing much to say about this heron's ID. (It would be tempting, though, to be critical of its name, since it's really gray rather than blue – but, while there's little to fear from Lulu Belle, an angry Great Blue Heron is nothing you'd want to trifle with.)

Great Egret

Here's another account which may appear truncated, but this is another species providing little reason to say much about its identification. The combination of large size, yellow bill, and dark legs serve to separate it from the smaller white waders, and the only real issue to keep in mind is the same thing mentioned in the previous section: i.e., it often hunkers down and can then appear smaller, shorter-necked, and possibly be mistaken for another species.  

Snowy Egret

The ID of this relatively rare and local Minnesota wader would seem straightforward enough. After all, no other species has the combination of an all-black bill, yellow lores, all-black legs, and yellow feet. But the problem is that many birders fail to realize that these distinctive features consistently apply only to adults; when confronted with a juvenile, their confidence in making a correct ID often wanes.

Juvenile Snowys can have a bicolored or mostly yellow bill, their lores may appear more greenish than yellow, their legs can be yellowish or both black and yellow. In other words, except for consistent yellow foot color at all ages, those diagnostic features on adults you always relied on may be missing on these disconcerting youngsters.    

One feature that can prove helpful in detecting a Snowy Egret of any age is its behavior. Most foraging waders are typically slow, deliberate, and often stationary as they patiently wait for some morsel to crawl, swim, or slither by. While Snowys often act the same way, they just as often act more Reddish Egret-like: i.e., actively and erratically running around in pursuit of food.

Last summer, for example, a distant egret came into view, too far away to see bill or leg colors or to determine its size. But it was noticeably more active than the other egrets around it, and I called out to the group that it was possibly a Snowy Egret. Several minutes later it flew much closer, and sure enough – and much to my relief – it turned into a definite Snowy.

Little Blue Heron

Like the Snowy Egret, the identity of an adult Little Blue Heron is seldom difficult to figure out. Even those mostly white sub-adults with a blue-gray patchwork are quite distinctive. But beware of juveniles whose plumage can appear entirely white and whose lores can be quite yellow: no wonder these are sometimes confused with Snowy Egrets. With real problematic birds, my recommendation is to study the bill shape: thicker at the base, gradually thinner towards the tip, and slightly downcurved on a Little Blue; it's straighter and more uniformly thin on a Snowy Egret.

And once you do figure out which one it is, odds are it will be a Snowy Egret. Of the three rare-regular "southern" waders which spread north into Minnesota in the 1970s (Snowy Egret, Cattle Egret, Little Blue Heron), the Little Blue is now the rarest of the three and teeters on the edge of Casual status. Records of the two egrets are about equal in frequency, but confirmed nesting records for all three have become virtually nonexistent in the last few decades, and we only have a vague notion of the distribution of these three waders during the breeding season.    

Tricolored Heron

This casual Minnesota species, with only about 15 (sound familiar?) state records, is not something which needs to be thought about that often in these parts, and even then the only similar species to consider would be Little Blue Heron. Indeed, in Texas and elsewhere I have seen birders casually view a Tricolored, not notice its contrasting white belly and underwing linings, and mistake it for a Little Blue. There are other minor differences, too, but that diagnostic white belly is the best and most visible field mark to keep in mind.     

Cattle Egret

Here is yet another species which is typically easy-to-identify as an adult but with clear potential for misidentification as a juvenile. Many birders are quite unaware that young birds have dark bills and dark legs, and consequently they are candidates for confusion with Snowy Egrets. When in doubt about which one you're looking at, it helps to consider the Cattle Egret's shorter bill and shorter-necked profile. Consider the habitat as well: Cattle Egrets seldom spend time foraging in wetlands and along shorelines like a normal wader, preferring instead to look for insects in pastures, roadside ditches, and even landfills.

Green Heron

As discussed above, the Least Bittern is about the only thing that vaguely resembles a Green Heron. Accordingly, since I've already criticized this heron's name (and got away with it!), the only other comment here would be to mention its call note. Though quite different from a Least Bittern, it is somewhat similar to a night-heron's call, although the Green Heron's skew! is louder, sharper, and higher-pitched.

Black-crowned Night-Heron

Yellow-crowned Night-Heron

At the risk of offending the powerful night-heron lobby, I'll lump these two species into the same section. As adults, their IDs are simple enough, but immatures resemble American Bitterns (see above), and telling one young night-heron from the other requires a careful look. I usually study the bill color first: all-dark on a Yellow-crowned vs. bicolored on a Black-crowned. Also note the Yellow-crowned's upperparts are darker above with small white spots, while the Black-crowned looks paler overall, and its spots are larger and somewhat teardrop-shaped.

It's often helpful as well to note the shape and calls of a night-heron of any age. The Yellow-crowned's profile usually shows a rounder crown, shorter bill, and longer neck, and its quark call note may sound higher-pitched than the Black-crowned's quork. But I find one oft-mentioned field mark difficult to use with much confidence. While a Yellow-crowned's legs are longer, with its feet extending farther beyond the tail in flight, this difference is pretty subtle and would require direct comparison with a Black-crowned for it to be a useful mark.

As most Minnesota birders are aware, it's typically safe to assume any unidentified night-heron here should be a Black-crowned, since the Yellow-crowned is barely Regular in the state and may eventually be demoted to Casual status. But that's not to say the Black-crowned is common and widespread: it's certainly down in numbers from previous decades, its breeding sites are now fewer and far between, and its summer status is poorly known.  

White Ibis

That first and only state record in Winona in 1995 was long overdue, considering that a handful of records exist from nearby states. Since it was an adult, I assume its ID was immediately obvious, but keep in mind that an immature bird may well provide Minnesota's second record. So, if you ever chance to hear about a brown-and-white ibis that someone thinks is a partial albino White-faced or Glossy, you'd better go check it out. Odds are it will have an orange or red bill and legs and turn out to be an immature White Ibis.

Glossy Ibis

White-faced Ibis

Until recently, it used to be a safe assumption that any Plegadis ibis seen here was a White-faced, even those juveniles which have no consistently useful field marks. After all, there had been only one Glossy Ibis record in Minnesota prior to 2005, but since then both ibis species have expanded their ranges, there are now two recent Glossy records (three total), and suspected ID-defying hybrids are turning up in several states. So now what?

One place to start is with a few over-simplified basics:

• Juveniles. Since there are no reliably consistent features visible in the field, don't fret over this too long: just leave it as an unidentified Plegadis.

• Facial border. If this border consists of actual white feathers and clearly extends completely behind the eyes and under the chin, it's an adult White-faced. If the white (or pale blue) border is a narrower facial skin edge (rather than feathers) and does not extend behind the eyes or under the chin, it's a Glossy. And if the white feathering looks narrow or limited in extent, it may well be a hybrid.

Note that adult White-faceds may retain these white feathers for only a relatively short time in spring and early summer, while the adult Glossy's whitish facial skin border is actually present all year (though harder to see in fall-winter).

• Facial skin color. If clearly deep pink or red, it's an adult White-faced, and note adults can retain this color year-round. If bluish, it's an adult Glossy. If the color is in-between or something else or unknown, it could be either species or a hybrid.

• Iris color. If clearly red, it's an adult White-faced – and, like the facial skin, eye color can be retained all year. If eye color is anything else, it again could be either species or a hybrid.

• Overall size, bill color, leg color? I tend to disregard these. Some references claim that the two ibises differ in these features (Glossy larger; White-faced with redder bill and legs), but there seems to be no consensus that any of these are consistently reliable.     

Especially since hybrid ibises are a real possibility in Minnesota, a complete analysis of Plegadis ID is beyond the scope of this article. To fully appreciate the complexities involved, I would recommend the article "Hybridization between Glossy and White-faced Ibises" (North American Birds 57:136-139); see https://sora.unm.edu/node/116022.

Wood Stork

Now here's a bird so obvious that even a three-and-a-half-year-old can identify it! Indeed, that's the age of the person who first spotted this first state record in 2004 near Grand Marais. In his words, the discovery was announced by: "Papa, there's a really big bird out there." Dad grabbed his video camera, and the ID was soon confirmed.

Like the White Ibis, this distinctive species was overdue here, with other records in adjacent states. Since other occurrences seem inevitable, take a second look the next time you see a presumed pelican (or Whooping Crane) soaring overhead that doesn't look quite right. That big black-and-white bird just might turn into Minnesota's second Wood Stork record. (And if you're not sure what it is, find a three-and-a-half-year-old to help you out.)

*          *          *

Now that you've mastered the identification of Minnesota's 15 wader species, keep in mind that other species could eventually appear here. Although the White Ibis and Wood Stork finally turned up, there is still opportunity for you to find a Reddish Egret or Roseate Spoonbill: both long-overdue first state records. There would then be 16 wader species on the list, and you'd then ruin our recurring theme involving the number 15 – although, just think of the proverbial Fifteen Minutes Of Fame you'd earn by your discovery.       

(And, finally, our standard disclaimer: "No proofreaders, editors, or animals were harmed during the making of this article." Not even Lulu Belle.)