[All photographs copyright, Gary Nunn 2013] – While watching the very camera friendly Hammond’s Flycatcher at Fort Rosecrans National Cemetery another dull olive-gray Empidonax, agitated and a lot more frazzled looking, suddenly came flying into the scene next to it. Interacting briefly with the Hammond’s, the new flycatcher then moved off to a distant isolated pine tree before finally returning briefly to feed along the fence line. At first I thought it might be another Hammond’s Flycatcher but its longer tailed look, different head shape, and strong looking bill, made me think again. After examining detailed photographs that show its very short primary projection, relatively scruffy looking plumage, strong bill, and mostly absent yellow coloration on the underparts, this does appear to be a Dusky Flycatcher Empidonax oberholseri.

The photographs below show very well the short primary projection characteristic of Dusky Flycatcher. One can compare it to the the rakish, extremely long, primary projection of Hammond’s Flycatcher (for example, see my previous blog post). In addition the pale whitish patch around the lores area is very evident along with the stronger bill and more rounded head shape. This individual has just begun molting with some patchy new and stronger colored plumage (more olive) scattered around on its body. Much of the underpart feathers appear to be worn looking.

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Viewed in ideal lighting conditions the outer edge to the outer tail feather (r6) appears distinctly white in Dusky Flycatcher. The short primary projection and long tail creates the relative impression of about the longest tailed Empidonax there is in my opinion.

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

It is difficult to capture images from below of Empidonax bills and usually the coloration is next to impossible to see. My only advice is keep taking photographs from all angles underneath the bird! The following images show the characteristic narrower spear-shaped bill and extensive darker coloration of the lower mandible of Dusky Flycatcher. It really only has a pale base. The Gray Flycatcher has a fully pale lower mandible with a small dark tip, while the Pacific-slope Flycatcher is wholly pale and in addition of greater width with a spade shaped morphology.

One novel field character which I believe can differentiate Dusky Flycatcher apart from the confusion species, Hammond’s Flycatcher, is the small overhanging hooked tip of the upper mandible. To my eye it looks like the small hook seen on a vireo bill and is noticeable in the close-up head-shot below. Certainly this hooked upper mandible feature is very difficult to see with binoculars! But I feel I can always notice this hooked tip in photographs of birds that I believe are Dusky Flycatchers. Hammond’s Flycatcher has a smaller bill with more closely meeting mandible tips without the hook present on the upper mandible like Dusky Flycatcher. Maybe a “birding photography” strategy here is to “get as close as you can photographs of the bill tip”! I think it could be very useful for differentiating the two species apart. The hooked tip of the upper mandible can also be clearly seen on photographs of a Dusky Flycatcher that I found at Fort Rosecrans National Cemetery earlier this year. In my opinion Dusky Flycatcher is under reported in San Diego County due to the difficulties of identification. Look for the hook!

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

Dusky Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego 20 Oct 2013

[All photographs copyright, Gary Nunn 2013] – I am beginning to think video could be a great aid to teaching Empidonax identification. There is just a look-and-feel of each species in my opinion. I put together some high definition video clips of the Hammond’s Flycatcher Empidonax hammondii found by Sue Smith on 20 October 2013 at Fort Rosecrans National Cemetery, Point Loma, San Diego, California. This flycatcher was very approachable and you can hear the “flaparazzi” in the background. Yes, that noise is Matthew Binns’ Canon 1Dx shooting at a full 12.5 frames per second!

All the field marks appropriate for this species can be seen in the video including, most importantly I think; the extreme long primary extension beyond the tertials (start of the second clip, for example!), the strong yellow wash on the freshly molted plumage of the underparts, the small dark bill, and the light gray throat (tricky to see I agree, but it is actually not white). Digital photography, or videography for that matter, can be extremely helpful but lighting is a very important factor. To observe many of the subtle plumage coloration characteristics of Empidonax species avoid strong sunlight and follow a bird around into more shaded light conditions if possible. Also, obtaining truly representative images of primary extension can be frustratingly difficult. The best documentation photographs require the bird to be at camera height straight ahead of you standing with its side facing you. Photographs taken from above or below, or at an oblique angle, will be inferior and more difficult to interpret.

In addition the following still photographs show more of the field characters of this delightful small Empidonax species. Primary extension beyond the tertials is strikingly long in this species and presents a very good field mark if seen well at close enough range. Digital photography of course makes this much easier to study, but practice really helps when looking for this field mark. To photograph the flycatcher Mathew Binns let me try out his Canon 1Dx and 500 mm II lens and the first two shots below reflect this!

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, California 20 Oct 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, California 20 Oct 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, California 20 Oct 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, California 20 Oct 2013

[All photographs copyright, Gary Nunn 2013] – I have been looking out for migrant flycatchers lately and was pleased to find this characterful Hammond’s Flycatcher Empidonax hammondii frequenting the “wall” area on the east side of Fort Rosecrans National Cemetery. Based on the San Diego Bird Atlas (Unitt, 2004) the Hammond’s Flycatcher can be found on spring migration here generally a few weeks earlier than the similar looking Dusky Flycatcher – the first clue to its identity!

In addition to the date of observation, several important field characters of Hammond’s Flycatcher can be seen in the photographs below which separate it from the closely similar, and rarer, Dusky Flycatcher. The condition of the plumage is very worn, particularly the wing and tail feathers, and these look faded, almost brownish in fact. This worn condition is characteristic of Hammond’s Flycatcher in spring, and contrasts the relatively freshly molted plumage of Dusky Flycatcher at this time of year. In addition the primary projection extends a great length beyond the secondaries, characteristic of Hammond’s versus a short primary projection of Dusky. Finally the bill is narrow at the base and fine shaped, quite weak looking in fact, and dark blackish colored, characteristic of Hammond’s, and unlike Dusky which has a stronger looking, broader based, and usually bicolored bill.

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

I was lucky enough to obtain more photographs of this Hammond’s Flycatcher from different angles under cloudy late afternoon lighting. In fact it was raining lightly some of the time. This flat lighting helps illustrate some other important field characters. The overall grey coloration of the face and plain grey lores, giving it an “emotionless” staring appearance, also separates it from Dusky Flycatcher, which has pale-colored lores and a more aggressive appearance. The underparts are also a cool grey color throughout with perhaps only a hint of yellowish wash at the rear, unlike Dusky which is more yellowish in spring. Also important is the grey throat color, again unlike other species with throats that appear whiter. Really, only the back of this bird has a different color – a green tone – being olive in coloration. And there is, urm, maybe the hint of something in the crown color…

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013

Hammond’s Flycatcher is about the second most likely Empidonax to be encountered in San Diego County, after Pacific-slope Flycatcher. I would say around 95%, or more, of Empidonax flycatchers that I find here on the coast are the latter species. There is always something new to learn or questions to be asked about this difficult to identify genus! Which in fact brings me to my question – maybe it is an artifact of lighting or the feathers are wet, or I am losing my marbles – does the bird shown here have dark reddish coloration in the crown feathers?

Hammond’s Flycatcher – Fort Rosecrans National Cemetery, Point Loma, San Diego, 14 Apr 2013