BIRDING BY HINDSIGHT: A Second Look at First State Records (Part I)

[Author's Note, August 2010 – A Hindsight article with updated lists of potential first state records was published in 2010; see http://mbwbirds.com/foresight.html.]

Or would it more instructive to take a first look at second state records? No, come to think of it, now that we're stuck in the middle of winter without a whole lot of birds around to look at, we could use something more interesting to look forward to, something to daydream about. Assuming that spring eventually gets here, what better fantasy to have now than finding Minnesota's next first state record when migrants start stirring in a couple months?

Trying to predict what species might be the next additions to the Minnesota list is mostly a matter of looking over the lists of neighboring states and provinces to see what birds they have recorded which are missing from our list. For example, it should have been no surprise when the first records of Curlew Sandpiper, White Ibis, and Glaucous-winged Gull turned up, since all three had already been found more than once near Minnesota. On the other hand, the Crested Caracara and Calliope Hummingbird in 1994 were quite unexpected since neither species had ever been recorded near here.

But another consideration to take into account when making these first-state-record predictions would be the difficulty involved in identifying these species. In other words, it is safe to say that some birds have already shown up here, and have actually been seen by someone, but they remain unrecorded in Minnesota because their identifying field marks are hard to determine.

It probably didn't take long for the observers involved to figure out the identity of that Curlew Sandpiper (which was in alternate – i.e., breeding – plumage), Crested Caracara and White Ibis. But, on the other hand, if that Curlew Sandpiper had been in basic (i.e., winter) or juvenile plumage, it may well have been overlooked and still missing from Minnesota's list. If it hadn't been for the specimen along with a series of photographs, the Calliope Hummingbird never would have been identified with any certainty. And without careful study by a number of observers and some identifiable photographs, last fall's Glaucous-winged Gull would not have been accepted on the state list.

So, which species are the best candidates for being future additions to the Minnesota list? Of course, any selection would be subjective and would vary from writer to writer, but most of the species are included below because they have already occurred in at least two or more states or provinces adjacent to Minnesota (i.e., Ontario, Manitoba, North Dakota, South Dakota, Iowa, Wisconsin and Michigan), so there is some precedence for their tendency to wander in this direction. Some of these selections are long overdue in Minnesota, others will seem more surprising and less likely, but that discussion is a subject for another article.

For the purposes of this article (it's supposed to be about identification, remember?), I would then divide them into two groups. Those in this first half are 22 species with relatively straightforward identifications; that is, they are adequately covered in the field guides, especially in National Geographic's Field Guide to the Birds of North America. This is not to say these are all easy identifications, however. Many will not be noticed and identified unless the observer is first aware of their field marks and potential for occurring in Minnesota, most have other species similar to them in appearance, and of course all of them would need to be carefully documented, hopefully with identifiable photographs.

Some of these species (e.g., Heerman's Gull and Black Skimmer) have already been reported in Minnesota, but they have not been accepted on the state list: [Author's Note, August 2010 – Since 1996, several of the species below have been now been documented and accepted on the Minnesota list.]

•     Northern Gannet

•     Brown Pelican

•     Roseate Spoonbill

•     Wood Stork

•     Smew

•     White-tailed Kite

•     Spotted Redshank

•     Wandering Tattler

•     Heerman's Gull

•     Royal Tern

•     White-winged Tern

•     Sooty Tern

•     Black Skimmer

•     Thick-billed Murre

•     Black Guillemot

•     Inca Dove

•     White-throated Swift

•     Gray Kingbird

•     Cave Swallow

•     Pinyon Jay

•     Phainopepla

•     Virginia's Warbler

The second group of potential first state records includes 22 species (or species groups) that pose potential identification problems, some so difficult that it will take a banded bird or specimen to gain acceptance on the Minnesota list. Because of this, most of these birds would tend to be more difficult to detect if they ever did show up – indeed, it seems likely that some of these have already occurred in Minnesota but were simply overlooked, unable to be identified. Also, unlike the species in the first group, several of the birds below have never actually been recorded in adjacent states/provinces, but it is reasonable to speculate they may have already occurred undetected.

Because of space considerations, only the first 11 of these 22 are discussed below; the others will be covered in a second installment of this article in a future issue. Some brief comments on the identification of these species is given below, and in some cases the reader is referred to other sources for more information:

• articles in North American Birds and Birding (both published by the American

  Birding Association)

• A Field Guide to Advanced Birding by Kaufman

• Waterfowl: An Identification Guide to the Ducks, Geese and Swans of the World by

  Madge and Burn

• Shorebirds: An Identification Guide to the Waders of the World by Hayman,

  Marchant and Prater

• Gulls: A Guide to Identification by Grant

[Author's Note, August 2010 – Since 1996, in addition to these references and those cited below, several other identification references have been published.]

Arctic Loon

No, this species has not been recorded anywhere near Minnesota, but the Pacific Loon is now practically regular here in fall. The problem is that the two, which were formerly considered the same species, are so much alike that who's to say some of our "Pacific" Loons weren't actually Arctics? While it's hard enough for many birders to just separate Pacific Loon in juvenile or basic plumage from Common Loon, if you actually find one, take a second look to see if it might possibly be an Arctic and start taking notes and photographs.

Compared to Pacific Loon, an Arctic in juvenile/basic plumage might appear larger overall with a larger bill; its hindneck might not appear quite as pale, contrasting less with the crown and back; and it will lack a complete "chinstrap" and "ventstrap" (i.e., a dark line across the under tail coverts, visible only when the loon is preening or flying). However, if you're looking at a possible Arctic Loon, it is unlikely a Pacific will also be there for direct comparison. Also, some juvenile Pacifics also lack a chinstrap, and both Pacifics and Arctics may have only an incomplete or pale ventstrap (which is hard enough to see in the first place).

A better Arctic Loon field mark, which also works on birds in alternate plumage, is the greater amount of white visible along the water line on the sides of a swimming loon, with this white area widening and more extensive on the flanks. Be aware, however, that it is entirely normal for a Pacific Loon (or a Common, for that matter) to also show white along the water line, especially when preening, but it is less extensive and it does not widen on the flanks.

If an Arctic Loon ever made it to Minnesota, it would not likely be in alternate plumage, but a few Pacifics here have been in this plumage. Accordingly, just as head color alone is not reliable in separating male scaup, it is important to note that throat color is not diagnostic on alternate Pacifics and Arctics. More than once in Churchill, Manitoba, I have seen Pacific Loons with green, not purple, throat iridescence.

Since there is no precedence for an Arctic Loon appearing in this part of North America, it would probably take some good photographs or a specimen to include this species on the state list. It is also recommended that birders refer to three articles in Birding (20:12-28, 21:154-158 and 22:70-73) for more information.

Anhinga

There are documented records of this species near Minnesota, and its identification would seem straightforward enough, so this is a strong candidate for addition to the state list. Indeed, some would claim they have already seen this species in Minnesota since there have been four documented, but unacceptable, sight records – three of these were initially accepted on the state list but later reconsidered.

The problem is even experienced birders are unaware that cormorants often soar at unexpectedly high altitudes, sometimes in a "kettle" in the manner of soaring raptors. And when a cormorant does this, its neck may appear perfectly straight, its wings held flat and stiff as it circles, and its tail can look longer and even be fanned out somewhat in order to catch the thermals. In other words, if you've never seen a soaring cormorant high overhead, it would be easy to mistake one for an Anhinga.

Tufted Duck

Here we have another species that has not only been seen before in this region but also reported in Minnesota. In this case the birds were adult males and identification was not the issue, but they were considered unacceptable because of their probability of being escapes from captivity. However, identifying this species remains a problem if it is a female or immature without a conspicuous crest or tuft, and great care and extensive documentation would be necessary to separate it from a scaup or Ring-necked Duck. Space considerations preclude any useful identification analysis here; therefore, be sure to consult Madge and Burn's Waterfowl book for more information.

Black Vulture [Author's Note, August 2010 – This species has now been recorded and accepted on the state list.]

Like the Anhinga, while there have been unacceptable Black Vulture records in Minnesota, the species has been recorded a few times not far from our borders, and it seems only a matter of time before we have an acceptable record. Also, Black Vulture identification is normally not much of a challenge, and, like the Anhinga, it could almost have been listed above in the first group of species. But one problem is that some observers are still fooled by vultures with black heads, even though some field guides show that immature Turkey Vultures also have black heads.

However, these same field guides, Geographic included, do not adequately deal with two other field marks. One is that the Turkey Vulture has white feather shafts on the outer primaries, and the upper surface of these outer primaries is paler than the other flight feathers. These two features in combination could easily suggest the Black Vulture's pattern of whitish outer primaries. However, this patch is much whiter on the Black Vulture and is also present on – and limited to – the under surface of the outer primaries.

The other problem is it has long and inexplicably been stated that Turkey Vultures glide with wings held in a dihedral while Blacks glide with flat wings. In reality, Black Vultures typically hold their wings in a dihedral as well! Therefore, when you actually do see and document a Black Vulture, don't let its dihedral make you or anyone else doubt the record. By the way, there is a difference in the way the two vultures flap, not glide: Turkey Vultures have slow and labored wing beats, unlike the Black Vulture's much more rapid wingbeats.

Pacific Golden-Plover

The status of this species is similar to the Arctic Loon's, which is discussed above. It was formerly conspecific with American Golden-Plover, so it is only in recent years that birders would be looking for it, and, while there are no records anywhere near Minnesota, its identification difficulties would make it easy to overlook.

One difference is, unlike the loon, relatively little has been written about Pacific Golden-Plover identification. If one did wander this way, it would likely be a juvenile in fall, which should appear brighter and buffier overall than an American Golden-Plover, especially on the breast and supercilium. Also, in any plumage, Pacifics at rest are said to have a shorter primary extension, with only 1-3 primary tips visible beyond the tertials (Americans should show 4-5 primary tips). A possible difference on flying birds would be the feet projecting beyond the tail on a Pacific, something not visible on an American Golden-Plover.

As with the Arctic Loon, it would probably take some good photographs to accept such an unprecedented species on the Minnesota list. For more information on Pacific Golden-Plover identification, be sure to consult the Hayman et al. Shorebirds guide; there are also some helpful photos and captions in Birding 25:322–329, and there is an article in the journal Birding World (4:195–204) which I have not yet seen.

Mountain Plover

Normally the identification of this species is not thought of as much of a problem. However, there have been two sight records of Mountain Plover which were initially considered acceptable (The Loon 46:115 and 58:154-158) and later removed from the state list (The Loon 60:146-148). What even seasoned shorebird watchers are unaware of is that both Black-bellied Plovers and American Golden-Plovers can appear during spring or summer in worn basic plumage, which means their back and wings appear relatively "smooth" overall, lacking the more familiar patterned appearance of white-edged feathers on the upperparts. As a result, a bird in such plumage, especially the golden-plover, strongly resembles the Mountain Plover in overall appearance.

Red-necked / Little / Temminck's / Long-toed Stints

Many Minnesota observers are already having enough trouble with the identification of peeps, especially the enigmatic Western Sandpiper, so what chance do we have in trying to detect the presence of one of these Eurasian stints? None of these has been successfully documented in or near Minnesota, but any of them could conceivably occur here and easily be overlooked.

Certainly their identification is beyond the scope of this article, and clear photographs would certainly be necessary before any of these stints could be admitted to the state list. But birders interested in this challenge should not only consult the Shorebirds guide, but they should also be sure to study the outstanding article on peeps and stints in American Birds (38:853-876; it was also reprinted three years later – 41:212-236).

Sharp-tailed Sandpiper

This is considered to be one of the most overdue species yet to appear on the Minnesota list, and its absence from our list is probably due to its resemblance to the widespread Pectoral Sandpiper. The most likely time for a Sharp-tailed to appear here would be in September or October, and it would probably be in juvenile plumage.

Compared to a Pectoral, look especially for a "smoother", buffier and less streaked breast which lacks the Pectoral's sharply defined cut-off from the white belly; a wider and whiter supercilium, especially behind the eye; a more conspicuous white eye ring; and a more uniformly dark bill (Pectoral's bill bi-colored, paler on the basal half).

An adult Sharp-tailed in alternate or basic plumage would be most unlikely in Minnesota, but one in fall molting from alternate into basic plumage might be a possibility here. Since such an identification would be tricky, it would be best to consult Kaufman's Advanced Birding guide, the article in American Birds on Sharp-tailed Sandpiper (41:1356–1358), and, of course, Shorebirds by Hayman et al.

Rock Sandpiper

There are documented Purple Sandpiper records in Minnesota, right? Yes, but how do we know that some of them weren't actually Rock Sandpipers? We really don't, since no one seems to know how to separate these two as out-of-range vagrants, and it's only an assumption that all "Purple" Sandpipers seen in the Great Lakes region have actually been Purples. The Shorebirds guide mentions a few subtle differences between the two, but it would probably take a specimen before a Rock Sandpiper record could be accepted here. By the way, Minnesota's first Purple Sandpiper is a specimen (The Loon 39:64); perhaps a second look at it is in order?

Western / Slaty-backed Gulls [Author's Note, August 2010 – Slaty-backed Gull has now been recorded and accepted on the state list.]

You've found an adult "black-backed" gull with pink legs that looks as large as a Herring Gull, possibly larger. A Great Black-backed Gull, right? Probably, but not necessarily. Not when you consider the Western Gull has been recorded at least twice in the eastern U.S., and the Slaty-backed Gull is one of the most overdue additions to the Minnesota list, having been documented at least five times south or east of us.

And since we're dealing with gulls here, it goes without saying that the identification of these two when out of range would require careful studies, extensive written field notes, and a photograph or two. It would also help if the gull in question were an adult: certainly, there is no room here to discuss the identification of immatures.

Come to think of it, a meaningful analysis of adults is also beyond the scope of this article. But the place to start is to study Grant's Gulls guide and two articles on Slaty-backeds: American Birds 40:207–216 and Birding 26:243-249. Then, although everything on a suspicious gull is worth studying, attention to a few features would probably be the most useful.

First, though usually difficult to determine without photos, study especially the exact pattern of the outer primaries in flight, since the Great Black-backed, Western and Slaty-backed all differ from each other in the number and placement of white markings visible in the spread outer primaries. And be sure to note that the subterminal row of white spots, said to be diagnostic of the adult Slaty-backed, may be variable in extent on that species, and other species of gulls may even show a similar pattern.

Also consider the amount of darkness on the under surface of the flight feathers (paler gray and less extensive on Slaty-backed), the mantle color (averaging blacker on Great Black-backed, though these gulls – especially the Slaty-backed – are variable in mantle darkness), overall size and bill size (Great Black-backed largest on average, but there can be overlap), extent of head streaking in winter, and iris color (yellow on Slaty-backed; either yellow or brown on Western; normally yellow on Great Black-backed, but it may appear dark).

Roseate Tern

Like some other terns, the Roseate is declining as a breeding species in many areas, but it still could occur in Minnesota since there are at least a few Great Lakes records. The identification of a flying adult would be relatively straightforward, with its narrow and sharply delineated blackish area on the upper surface of the outer three primaries, and its lack of black on the trailing edge of the underside of the primaries.

When at rest, an adult Roseate's tail on average extends farther beyond the tail than on other similar terns (though overlap with Forster's is possible), and, like other adult terns, its bill color is variable – usually all dark, but also bi-colored with the basal half red in summer.

A juvenile Roseate would be more difficult to tell, of course, but note especially its white trailing edge on the primaries with no black present on either the upper or lower surface, the black legs (reddish on other similar juveniles), the barred back, the more extensive black on the head than on other juveniles, and the white upperside of the secondaries (also shown by juvenile Arctics). For more information, be sure to consult Kaufman's Advanced Birding guide (the tern chapter is perhaps the most useful one in the book); also see American Birds 41:184-187.

*          *          *

The second part of this discussion on the identification of potential first state records will appear in a future issue of The Loon, probably in the Winter 1996-97 issue. In the meantime, let's see if any of these predictions come true or if the next first state record is something that catches us by surprise. (Also, in the meantime, see if you can guess what the last 11 species or species groups will be covered in Part Two!)