Rufous vs Allen’s -Addendum II

For readers in need of a basic primer on the Rufous/Allen’s ID issues, see Sheri Williamson’s post from Life, Birds, and Everything:

http://fieldguidetohummingbirds.wordpress.com/2010/09/06/rufous-vs-allens/

More interesting notes from Sheri on the Guilford, CT female, who kindly took the time to add the following:

Not only do molt patterns in other families not translate well to hummingbirds, but even generalizing from one hummingbird species to another in the same genus can lead you down the wrong track!

Like most highly migratory northern hummingbirds, Rufous normally undergo the most important parts of the molt (flight feathers and gorget) in winter. My first-hand experience with overwintering Rufous is limited, but the BNA account indicates that primary molt takes place mainly from late December through March, with females running 10+ days behind males. (Calder didn’t distinguish between age classes, but juveniles often average later onset and completion of primary molt than same-sex adults.) For a juvenile female, primary molt at P6 inmid-November (more than halfway along) would be ~8 weeks down the early side of the bell curve for Rufous, though apparently consistent with our limited understanding of molt in Allen’s.

Outlier characteristics often catch our attention, but attaching too much importance to them too often results in unproductive detours. As an extreme example, focusing solely on this bird’s primary molt would make HY Anna’s and Costa’s, both of which replace primaries mainly from early summer through late fall, stronger candidates than Rufous.

The diagnostic “pinched” tip of R2 is subtle, but it would be extremely unusual to find on a juvenile female and unusual *not* to find on an adult female or juvenile male. Here’s a new addition to my Flickr gallery that illustrates this difference: http://www.flickr.com/photos/tzunun/6385547925/in/set-72157619893017097/

Had R2 not been visible in any of the photos of the CT bird, the contrast in the gorget feathers would still have suggested a juvenile female, though with less confidence.

Within the “bee” hummingbird clade that most Americans and Canadians are familiar with, juvenile females are typically most “generic” in feather shape and pattern, while juvenile males and adult females tend to be more similar to each other than either are to juvenile females. This is one reason that I encourage birders to familiarize themselves with the broader aging and sexing criteria for hummingbirds before taking on the more challenging species.

If you know of any local/regional organizations that might be interested in a workshop on hummingbird identification and natural history, I’d be delighted to hear from them.

 Good birding,

 Sheri

 

Rufous/Allen’s – addendum

I emailed Sheri Willimason (well known and respected birder with a penchant for hummingbirds) about selasphorus hummingbird identification, as it pertains to Rufous/Allen’s types and the ageing and sexing. With regards to my post on the CT bird, she corrected some information and kindly wrote the following illuminating reply:

Hi, Julian,
Though primary molt is often helpful in hummingbird identification, in this case it’s a red herring. The “generic” shape and narrow white tip of R2 (cp. Peterson Field Guide to Hummingbirds, pl. 24-25) are characteristic of a juvenile female, though in this case one in precocious primary molt (early even for an adult).

Gorget pattern is highly variable in female and juvenile male Rufous and Allen’s. Juvenile females may have nearly immaculate gorgets with no orange iridescence and bronze-green spangling concentrated at the margins, heavy bronze-green “five-o’clock shadow” typical of juvenile males, lightly marked gorgets with small central patches of adult-like iridescence, and anything in between. The presence of extensively iridescent gorget feathers next to predominantly white ones with small, drab spangles is strongly suggestive of a juvenile female acquiring her first adult gorget, which would not be surprising considering the condition of her primaries.

The amount of rufous in the uppertail coverts is highly variable within and between age/sex classes of Rufous/Allen’s, but I’m unaware of any evidence suggesting consistent species-specific differences that would be useful in identification.

Both probability and tail characteristics argue in favor of Rufous, but juvenile females are the most difficult age/sex class to identify. Even their measurements overlap extensively; a few individuals remain ambiguous with the bird in one hand, calipers in the other, and Table 1 in Stiles 1972 available for reference. To rephrase what I wrote to Nick: The options supported by the existing evidence are “probable Rufous” and the more conservative “Rufous/Allen’s.” The only practical ways to absolutely confirm the ID beyond a shadow of a doubt are in-hand measurements by a bander or new photos after she replaces her tail.

Hope this helps.

Sheri L. Williamson

Thanks to Sheri, it seems that the matter of identifying these two species is even more dire than I thought!

19th November – Selasphorus Saturday, Rufous or Allen’s?

Selasphorus hummingbird reports are now an annual occurrence in CT. Most of them are Rufous/Allen’s types, but  since the identification of Allen’s is almost impossible without banding them, proving one in CT is an uphill task. That many of the state’s selasphorus can be attributed specifically to Rufous is due to the banding efforts of Mark Szantyr and Jayne Amico. However, they can’t band them all, and so many reported birds are left as selasphorus sp. There are several records of Allen’s in the mid-atlantic states and New England (my only Allen’s was at Cape May in November 2000), so there is a good possibility that one will occur in CT sooner or later and each report should be checked out if, possible, to ensure we don’t overlook a potential Allen’s.

With this in mind, Nick Bonomo and I visited a bird coming to the feeder in nearby Guilford to see if we could slap a moniker on it, or at least try and get spread tail shots to help determine it’s identity – in Allen’s, the outer three tail feathers are narrower than in Rufous, so it was our mission to try and photograph the bird’s spread tail.

 Rufous Hummingbird, adult female, Guilford, Nov 2011. The obvious moult contrast in the primaries, with worn outer primaries and new inners, combined with some iridescent throat petals, made us age it as an adult. Juveniles would show more uniform wings with a spotted throat. The face was rather cold, lacking any rufous-wash, with a uniformly green back.

 Note prominent white forecollar, rufous flanks, fresh inner primaries and reduced rufous fringing to uppertail coverts

I confess to being confused with some of these birds, it’s a group I’m not that familiar with and so each time we get one of these it’s quite a learning experience, not only identifying them, but especially trying to age and sex them. Howell’s excellent Photographic Guide to Hummingbirds of North America was our reference.

We saw the bird well and photographed it from a distance, but unfortunately in the time we had, we were never able to get shots of the open tail, so it was destined to remain unidentifiable. According to Howell, one feature of adult female Allen’s is a propensity to have the uppertail coverts strongly fringed rufous. Our bird had some obvious rufous fringing , but without a baseline, our lack of experience left us asking “how much is enough?”. With Mark out of town, banding at present wasn’t an option, so it seems destined to fall into the selasphorus sp bin until Mike Moccio got  great shots of the spread tail which confirmed the bird to be a Rufous.

 Note in this fantastic shot, the relatively broad outer tail feathers compared with the narrower feathers that would be expected in an Allen’s. Also note the rufous on the uppertail coverts is limited to the fringes and is not that predominant. (Photo courtesy of Mike Moccio)

A cool bird, and as usual a challenging and educational experience! For instructional photos of an Allen’s banded in PA in 2009 see here: http://home.earthlink.net/~pomarine/id93.htmlLooking at these images the narrow pointed tail when seen from behind seem rather different from the broader, full tail of our bird. Also, in the flight shot note the obvious rufous uppertail coverts, perhaps two features to key into?

Here’s two shots of a (AHY female?) Rufous that was banded by Mark and Jane back in 2006.

Alterus race Nelson’s Sparrow in CT

Nelson’s Sparrow (alterus), Hammonassett, CT, Nov 2011. Very bright and contrasting bird, note strength and color of facial triangle and contrasting back pattern. Flanks show well-defined streaking.

Nick Bonomo and I came across two Nelson’s-type sparrows at the west end of Hammonassett. One of the two gave nice looks and showed itself to be a quite bright and striking individual.

Subvirgatus, the Atlantic coast race, breeding in Maine and occurring here during fall and winter is the expected species, generally separated from the interior races, nelsoni and alterus by virtue of its rather drabber plumage and blurry-streaked flanks.

Nelson's Sparrow (subvirgatus), Milford Point, CT, winter 09. Note blurry flank streaking, lack of clear buff breast band and subdued facial 'triangle'.

Individual variation across the races, combined with a lack of knowledge of the status of the interior races compounds the identification issues of non-subvirgatus Nelson’s in CT.  Clearly this bird appears to be alterus/nelsoni rather than subvirgatus due to:

- clean, unmarked crown pattern

- intensity of the back pattern

- quite well-defined flank streaking

- brightness and clarity of the supercilium (with muted grey auriculars)

- underpart patterm showing a well-defined whitish belly and buffy breast band

Nelson's Sparrow (alterus), Hammonassett, CT, Nov. Same bird as above. Note underpart pattern consisting of a nice buff breast demarcated from white belly

Separating these two races can be tough, and being wary of trying to shoehorn each Nelson’s Sparrow into neat little boxes, the following features do seem to be good for alterus:

- broad gray crown stripe

- quite well-defined flank streaking

- very bright, clean orange facial triangle with ill-defined gray center

- white belly contrasting with streaked, buff breastband.

- upperparts quite contrasting with well-defined white “tramlines” (though lacking any blackish in the scaps shown by nelsoni)

 

Nelson's Sparrow (alterus), Hammonassett, CT, Nov. Note back pattern and broad, clean gray median stripe.

Nelson's Sparrow (subvirgatus), Milford Point, winter 09.

This synthesis was aided by a topical and educational article by Fletcher Smith, published in North American Birds, whose photo-essay showed an educational array of photos of the various races. See here: http://www.aba.org/nab/v65n2sparrows.pdf

Fletcher was kind enough to offer the following comments on this individual.

“Julian,
I agree that this bird is likely a nelsoni/alterus type bird rather than a subvirgatus for all the reasons you mention.  Subvirgatus (as you know) is a really dull looking bird, and this bird has a good bit of color to the face and pattern in the dorsum, along with black streaking in the cap. 

I think that nelsoni would have more black mottling in the cap, but the view here is not complete.  Alterus tends to have distinct streaking in cap, not mottling like nelsoni, and this bird looks like it has streaking not indistinct mottling.  The dorsum is also not strongly patterned and has no dark centers suggesting alterus not nelsoni.  The cheek patch looks like it is mostly gray, not infused with ochre color.  This is typical of alterus.  I tend to lean alterus on this bird, I see no characters that suggest nelsoni at all. 

Very little is known of the migratory routes of these birds, and my hope is that the article I wrote will push subspecies ID to the forefront on these birds and allow for a more complete knowledge of the migration routes. “

Late Push at Lighthouse

Snow before Halloween..local die-hards braving the weather!

With a Nor’easter laying down a foot of snow in north-central CT, we escaped with just 1 1/2″ of slush! Such snow levels are  of this early! The breezy NW winds bode well for a hawk flight, but so it was getting late in the season, so I was expectant but didn’t have high hopes.

Juv. Cooper's Hawk

Adult Cooper's Hawk - a barred-breasted individual. According to Jerry Liguori, these types of adults are more common in the east than in the west.

A total of 485 raptors. Over 200 Sharpies. Highlights were a great look at a Northern Goshawk, 9 Bald Eagles, 29 Northern Harriers, of which at least 9 or 10 were adult males, 2 Peregrine Falcons, and 7 Broad-winged Hawks. Factor in Cooper’s, Red-tailed and Red-shouldered’s, plus Merlins, American Kestrels and a bunch of TV’s and it was a great day.

Peregrine at lunch

We also had 5,000+blackbirds,50+Bluebirds, 2 Rusty Blackbirds, 25+ Pipits, a Cattle Egret, a Cackling Goose (likey hutchinsii) and a Vesper Sparrow.

Juv. Goshawk - a beast of a bird that gave brief, but close looks as it powered out over the harbor towards my house! A scarce bird at LHP

Setting Black and White Points

Do you want to make this….

RAW capture

Look like this….

Post-processed using Adobe Raw Converter and Photoshop CS3

Or make this….

Original RAW capture

Look like this….

Arches National Park, Utah, converted with ACR and PS CS3

Click for Larger Images

Since some people have asked me how I post-process images,  I’ll attempt to sporadically post some of my basic workflow steps that I use when processing my images in Photoshop. I always capture in *RAW format (rather than Jpeg)

The above image of a juvenile Cooper’s Hawk eating a pigeon was made at a local boatramp. The bird allowed a close approach and I managed to get quite a few images. As you can see the original is all washed out. This is because I exposed “to the right”, which basically means that I try to get my histogram on the back of the camera to have most of the “peaks and valleys” to the right of middle (the highlight end) of the histogram without overexposing the whites (i.e no flashing “blinkies” in the LCD).  Most of the tonal detail resides in the right 2/3 of the histogram and exposing to the right ensures that you capture as much tonal information as possible as well as reducing digital noise. There is less tonal information in the left (shadow) side and that is also where most digital noise is likely to manifest itself.  Anyway, since this image has a lot of highlight tones and not a lot of dark tones, the original RAW capture looks rather washed out. But, since I have captured most of the tonal details by exposing to the right, I know I can add in the contrast when I process the RAW file.

The scenery images where made at Arches National Park, Utah. I wish I would have had more time..awesome scenery!

Before Starting
It helps if your monitor is calibrated so that your brightness/contrast are accurate so that you have a solid foundation to start with.
Check this site out first to help:
http://w4zt.com/screen/

To create a grayscale stopwedge in Photoshop:
http://www.ohio.edu/people/schneidw/digital/step_scale.html

There are free basic calibration tools on the web tthat will get you in the ballpark, but if you are serious then you can purchase a piece of hardware/software such as a Spyder: http://spyder.datacolor.com/

This essential attaches to your screen and calculates the right calibration based off these screen measurements. Since I don’t have one, I use Adobe Gamma and that basically runs through a wizard-type set-up to adjust my monitor.  It’s not as accurate, but I have seen many of my images printed in magazines that look comparable to how they appeared on my monitor, so I am happy.

Tip#1 – set black and white points

To adjust the image for contrast and eliminate color shifts/casts we want to set the darkest and lightest parts of the image. We want the shadows to be dark enough without being muddy and the whites to be bright without being burnt out. Once we set the black and white points, the mid-tones will fall into place automatically.

RGB values of 0, 0, 0 equal true black and 255, 255, 255 equal true white. By setting the darkest pixels in the image to R=10, G=10, B=10 you retain shadow detail. Setting the lightest pixels to 245,245,245 will retain detail in the whites. Since RGB values dictate color in our images, setting each of these color channels to the same value will neutralize unwanted casts in your image.

1. Open your image in Photoshop (File > Open…).

2. Add a Levels adjustment layer by clicking the Create Adjustment Layer icon (the split circle at the bottom of the layers palette) and selecting Levels.

3.Double-click the Black Eyedropper and set the RGB values to 10,10,10. Press OK.

4. Double-click the White Eyedropper and set the RGB values to 245,245,245. Press OK.

5. Select the Black Eyedropper tool, hold down the Opt (PC-Alt) key and move the Black slider to find the darkest pixels in the image.

6. Click the darkest point in the image with the Black Eyedropper tool. It is now set to 10,10,10.

7 .Repeat the process while holding the Opt (PC-Alt) key and moving the White slider to find the lightest pixels. Avoid specular highlights. Click the lightest pixels with the White Eyedropper. White is now set to 245,245,245. Click OK.

If you have any questions, or are interested in learning how to improve your digital images, I can be available for one-on-one instruction. Contact me for  at: jrhough1@snet.net

*RAW vs JPEG

Although I shoot in RAW, many people shoot jpegs since the images saved to the memory card are smaller and allow you to capture more images per card than with shooting RAW. There are plenty of sites that discuss the pros and cons of each, but for me, RAW is the way I shoot since I feel I have a lot of latitude when processing images that jpegs do not give me.

The following steps assume you are using jpegs straight from the camera. Once these native jpegs are downloaded to your computer and a file is opened in photoshop, immediately do a “Save As” and change the file format to either .TIFF or .PSD (essentially the same). This ensures that your original jpeg remains intact as your untouched digital ‘negative’. Another reason to make the conversion is that jpeg format uses lossy-compression (which basically means that it loses information when its compressed or saved) which allows jpegs to achieve their small file sizes compared to .TIFFS or PSD files. Each time you open a jpeg file, make changes and then resave it, you essentially are dumping information from the file. Will it be perceptible to you on a monitor or on a print?..perhaps not in many cases, but why not maintain the integrity if at all possible?

Down at the Beach

Just wanted to share a photo from last week of Alex at Sandy Point on a beautifully clear October evening. Enjoy!
(Click for larger image)

Nikon introduces 85mm EDG scope with Vibration Reduction Technology

Nikon just announced an 85mm EDG scope containing the VR technology they use in their camera lenses.  For further details see here:
http://www.nikon.com/news/2011/1006_edg_01.htm
Nikon Vision Co., Ltd., a subsidiary of Nikon Corporation, is pleased to announce the release of its EDG Fieldscopes 85 VR and 85-A VR, new models in the Nikon Sport Optics flagship EDG series.

These new EDG VR Fieldscope models are the world’s first*1 fieldscopes to incorporate the lens-shift type VR function. The vibration reduction algorithm, based on Nikon’s sophisticated VR mechanism used in NIKKOR VR lenses, has been optimized for these scopes.

The VR function accurately compensates external vibrations caused by wind and operations such as focusing, panning and tilting. The VR function makes composition easy by reducing vibrations to approximately 1/8*2 of image blur caused by vibrations during normal observation. This also enhances focusing accuracy even when manual focus is used during super-telephoto digiscoping. The system provides an effective equivalent to a shutter speed approximately two stops*2 faster and is especially effective when digiscoping in bad conditions such as windy weather.

Surinamensis Black Terns

Juv. American Black Tern, South Carolina, August

UK birder Graham Catley, fine photographer and a sharp field birder discovered this typical American Black Tern (surinamensis)on the East coast of the UK..only the fourth record for the UK.

Check out these fine images: http://pewit.blogspot.com/2011/09/american-black-tern-2.html

A ‘black tern’ in France, along the Atlantic coast has generated some interest on Bird ID-F:

http://www.flickr.com/photos/68193144@N05/

Showing some characters of the  American subspecies, surinamensis, it is a tricky bird.  Peter Adriaens, from Belgium, commented on the French bird as follows:

Compared to juvenile niger, juvenile surinamensis generally looks darker and more uniform. In my experience, from a distance it may give a rather skua/jaeger-like impression.

There are a few more identification pointers:

* The pattern of the rump and upper tailcoverts usually differs between the two subspecies. In surinamensis, the feathers have only thin, dull grey tips, creating a rather uniformly grey rump that does not contrast with the tail. In the French bird, the rump feathers and upper tailcoverts have wide, pale grey fringes that go all the way up to the base of each feather, making the rump look paler than the tail.

* The outer web of the outermost tail feather is usually dark grey in surinamensis; it seems to be pale grey in the French bird.

* The upper wingcoverts often look rather dull and uniform in surinamensis, because they (almost) lack pale edges. The pattern is more variegated in the French bird, with distinct pale edges and tips to these feathers.

The underwing may fit some surinamensis, but not the typical ones, I would say. There is still quite a bit of white admixed in the central part of the arm. Also, many juvenile surinamensis show a dusky leading edge to the underwing, which is not prominent here. Mind you, I agree that the pattern of the underwing and flanks looks unusual, but it does not seem convincing enough for surinamensis to me.”

Here is a recent, fairly similar Black Tern (niger) from Belgium (all links refer to one and the same bird):

http://waarnemingen.be/fotonew/1/2554731.jpg

http://waarnemingen.be/fotonew/3/2560393.jpg

http://waarnemingen.be/fotonew/3/2564193.jpg

Here are a couple of pages from my notebook and   of my photos of juvenile American Black Terns from South Carolina in late August as reference.

surinamensis Black Terns, Connecticut showing variation of head pattern

Lighthouse Guided Walk, 8th October – Reminder

Northern Harrier..always great to see powering past the hawkwatch

With fall migration well underway, hawks are taking center stage and there are few better places in New England than Lighthouse Point to catch some hooky-beaks! Throw in some incredible diurnal movements of passerines and warblers and it’s one of THE hot-spots to visit.

My 2-hour visit this past Saturday revealed good numbers of Cooper’s (c.40), Sharp-shinned (50+), Broad-winged Hawk (3), ad. Bald Eagle (1), Northern Harrier (2), Peregrine (1) and several American Kestrels…and a stunning Connecticut Warbler and a scarce White-eyed Vireo, among other things in the woods.

Come join me on our regular walk, and learn some of the finer points of hawk identification and in-flight identification of passerines. Register Online: http://www.sunrisebirding.com/register_julian.html

It’s time to grab your bins and get out with the Sunrise crew!

A 'river' of 1000s of icterids passing over the point - a typical spectacle in October!

Male 'Taiga' Merlin..often ever-present in fall!