By Jim Burns

Our current quiz again features a family of birds in the from of your books, a family barely out of the primordial soup.  Though some are long distance migrants, these birds are weak fliers with no tails to speak of.  Their feet and legs, so close to the rear of the body as to make travel on land almost impossible, can be extended backward in flight to help with steering.  But, as you can see in the first photo, those feet are lobed making this family, like the loons before them, wonderfully evolved for their water world, and any human with a fear of the water may find the live of a grebe harder to fathom than that of an albatross or buteo.

A)  Good Photo, Easy Bird

Except for its remarkable bill, this grebe in black and white and shades of gray looks very similar to our second quiz bird in the January/February issue.  But the bill length here is indicative of overall size and the diver supporting this veritable spear is from the genus Aechmophorus which translates from Greed as “spear-bearer.”  The two large grebes of this genus are nearly twice the length and three times the weight of the Horned Grebe of our previous quiz and are further distinguished from their smaller family relatives in the Podiceps genus by proportionately longer, thinner necks.

In the field, of course, the real question lies in separating our large grebes, Western and Clark’s, from one another.  Bill color and facial pattern provide the answer.  Although bill color is much the more reliable of these a non-breeding bird bobbing around in the distance, here in black and white it is of no help.  However, in a close view such as this we can readily see dark facial feathering completely encompassing the eye.  This is diagnostic of Western Grebe.  In the color slide this grebe’s bill is the dull yellow-with-olive tones also indicative of Western.  Other useful, corroborative, but not clinching differences between the two Aechmophorus species are dorsal color and voice.  Westerns are typically more uniformly dark, Which makes them appear darker overall, and they have a two syllable call, the second syllable higher or accented.  Clark’s call is an ascending single syllable.

B) Good Photo, Difficult Bird

At first glance our second grebe shows the same long, thin neck and the same long, thin spear as our Western, but it has a decidedly different facial pattern, so it must be a Clark’s?  Perhaps, but we need to slow down a bit.  Ornithologists split Western and Clark’s grebes into  

Older field guides treat the Aechmophorus grebes as color phases of the same species, Western the dark phase, Clark’s the light.  Newer books, after the split, show us the eyes of breeding adults, Western encompassed by dark, Clark’s by white.  The most recent guides such as Sibley and the third edition National Geo also show us winter adults…with a caveat.  In winter Westerns, the dark facial feathering fades somewhat like that in our first photo.  In winter Clark’s, the white facial feathering smudges and darkens…beginning to resemble that in our first photo.  If this were not enough to give us pause, not that our second bird is obviously much darker overall than our first bird.

We don’t yet have a date for the second photo.  Could this second bird be another winter Western of even be the same bird?  Since we cannot discern bill color, the short answer is “yes, it could be.”  Several times in this quiz we have spoken of sight angles and the play of light and shadow changing perceptions.  Sibley gives us a better reason-“Intermediate  birds, seen regularly, especially during winter, are unidentifiable.  Some may be hybrids.”  So, if you see a large grebe reasonable close during breeding season you should be able to identify it by facial pattern, but remember that identification of large grebes out of breeding season should be based on bill color.  Facial patterns can be very similar at this time of year.

Our second photo bird is, indeed, a Clark’s Grebe photographed in November 1995 along the lower Colorado river.  In the color slide this grebe’s bill is the deep, bright orange-with-tones of red indicative of Clark’s.  The bird’s back appears uniformly black because it is perfectly shadowed from the bright sunlight by the head and neck.  This photo seems identifiable as a Clark’s because there appears no hint of dark feathering below the eye or above the lores, but the point of this exercise has been twofold- don’t’ assume every large grebe you see in Maricopa County in winter is a Western, and don’t assume every large grebe you see in Maricopa County in winter can be positively identified.

C) Bad Photo, Easy Bird

One of the many anomalies in bird photography is that a great slide does not always translate into a good print and, conversely, a crummy slide can sometimes be manipulated into something pleasing on paper.  Birders and photographers mumble the same foul letter words when a great bird appears backlit.  Our third grebe was photographed with the sun behind it, the bird’s nice color and sharp markings muddy and obscured against the bright water background.  Overexposure in Adobe Photoshop created this rather stunning black and white, but the color bring left much to be desired.

This grebe’s dark over light head pattern is similar to the Aechmophorus grebes, but both its bill and neck are shorter and thicker, lending a chunkier, less elegant jizz reminiscent of the Podeceps genus of medium sized grebes.  Although the head pattern does closely resemble our Horned Grebe in last winter’s quiz, note that this bill

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RUFOUS-BACKED ROBIN

By  Jim Burns

Turdus rufopalliatus is now an almost annual winter visitor to Arizona since it was first recorded in 1960, often found in more than one location simultaneously.  On its breeding grounds, Rufous-backed Robin favors deciduous forest edges, suburban gardens, and plantations, and in winter can be found in flocks much like our American Robin, utilizing fruiting trees and berry bushes, moving on when this food source has been depleted.

The reasons for the occasional northward movement of individual Rufous-backed Robins in winter are poorly understood.  Drought and poor berry crops south of the border are primary suspects.  There are scattered records from the lower Rio Grande Valley, southwest Texas, New Mexico, and California, but here in Arizona a winter without a Rufous-back has become the exception rather than the rule and the species is no longer included on the Arizona Bird Committee's review list.

Sometimes but not always seen in loose association with American Robins, the winter vagrant Rufous-backed Robins in our state are usually discovered coming to Pyracantha and Hackberry.  Despite the fact that this strikingly marked thrush will linger in one area for several days or several months as long as the berry supply persists, in Arizona it is a secretive and elusive species which can require several trips and much patience on the part of the birder.  Stories abound of groups of birders deployed around a small hackberry grove or even a single tree, one or two lucky souls rewarded with drop dead close-ups while those on the other side never even glimpse the bird.

Logically because of its abundance of fruiting trees, Boyce-Thompson Arboretum State Park just west of Superior was the hot spot for Rufous-backed Robin in Arizona during the 90's.  At least one Rufous-back and sometimes two were seen there for four consecutive winters, primarily in the vicinity of the herb garden.  In 1990 an obliging Rufous-back spent the entire winter in an Ahwatukee backyard, and in 2001 another spent the entire winter in a very public area of downtown Phoenix.  In the southern part of the state there are multiple records from Patagonia Lake State Park, River Road north of Nogales, and the Arizona Sonoran Desert Museum in Tucson.

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This is a breeding plumaged Red-necked Grebe, the larges of our three Podeceps grebes, photographed in Alaska, July 1994.  This bird was presented in breeding plumage to illustrate again the intriguing seasonal reversals of the light and dark head patterns which this genus undergoes.  As much as this summer Red-necked seems to mimic a winter Horned, winter Red-neckeds are identified by dark cheeks delineated by a light stirrup running from below the base of the bill up to the 

back of the crown, a pattern not unlike that of winter Eared.

Red-necked Grebes, rare in Arizona in winter, could easily be overlooked or mistaken for larger or smaller relatives by birders unaccustomed to seeing them in the desert.  There were confirmed sightings in the ‘90s from Lake Powell and Lake Pleasant and several rumors from the lower Colorado, but Red-necked Grebe is by no means an annual occurrence in our state.

If, like most birders, you word associate “bird” with the medium of air and the marvel of flight, keep a closer watch for some of our “lower” species.  For those of us uncomfortable around water, grebe in the next life could be a wonderfully satisfying experience.

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