[obol] Re: Page Springs Nighthawks - a lesson, and a caveat

From: "Paul T. Sullivan" <paultsullivan@xxxxxxxxxxxx>
To: "'Rick Vetter'" <cotingas@xxxxxxxxx>
Date: Sun, 3 Oct 2021 10:24:39 -0700

Rick,

In all our off-line email exchange I wasn’t clear on the source of the photos.
Thanks for clearing that up, with labels of who took each photo and the date.

The 4 photos you shared on OBOL show Common Nighthawks with 5 feathers in the
white bar, and black in the primaries between the white bar and the wrist.  All
4 photos show the TOP of the wing.

I think I clearly saw underwings with buffy spots all the way from the wing-pit
to the white bar, including the primaries, which would argue for Lesser
Nighthawk.  Do you have UNDERWING photos that show this and show the number of
feathers in the white bar?

Paul

From: Rick Vetter [mailto:cotingas@xxxxxxxxx]
Sent: Sunday, October 03, 2021 6:31 AM
To: Paul T. Sullivan <paultsullivan@xxxxxxxxxxxx>
Cc: OBOL <obol@xxxxxxxxxxxxx>; COBOL <COBOL@xxxxxxxxx>; Craig Miller
<gismiller@xxxxxxxxx>; Will Wright <peelerpoo@xxxxxxxxx>; Sheran Wright
<sheran@xxxxxxxxxxxxxxxxx>; Joan Suther <jsuther10@xxxxxxxxx>;
norde4@xxxxxxxxx; Russ Namitz <namitzr@xxxxxxxxxxx>; Tom Crabtree
<tc@xxxxxxxxxx>; jmeredit@xxxxxxxxxxx; Tim Janzen <tjanzen@xxxxxxxxxxx>
Subject: Re: Page Springs Nighthawks - a lesson

Nice summary of the nighthawk birding adventure Paul. Glad your brought it up.

I was with Paul two of those evenings and looked at nighthawks the night before
also with other birders.

We had initial discussions on these

birds off line.

I was leaning towards lesser as others birders were until I found an ebird
article that thoroughly described the difference between these species and
while reading this article with Will Wright, one key character (that is
impossible to see without a good photograph) was noted. The number of primaries
with white marks making up the wing band.

https://ebird.org/camerica/news/id-challenges-the-chordeiles-nighthawks

And we had lots of poor, plenty of fair and a few good photographs to look at.

I carefully cropped the best photos and attached arrows to the primaries with
white wing marks making up the wing band to determine if 4 ( for a lesser) or 5
(for a common nighthawk) were visible. All photos showed 5 primaries with white
marks ! Damn !

Now the question is did we photograph all the birds each night and there were 3
nighthawks on two occasions so it became challenging to keep track of this and
may have been impossible considering how dark it was and loosing track of birds.

I know I photographed two different birds on the last night 9/25 due to my
tracking of the birds and anomalies in wing feathers on certain birds ( visible
in the photo) but we will never know if the third bird was photographed or two
birds were photographed repeatedly.  I would have to carefully check each
photo. ( when the snow arrives and the house project stops )

Will try to attach several photos of several nighthawks during two of the three
evenings with notes on the white marks.

If this represents all the nighthawks we saw, it would indicate common
nighthawk but what did the first observers (Roger Robb) see a week earlier that
started all this excitement.

Tom Crabtree looked at those photos in the same manner I looked at these. The
photos of Roger’s bird are a bit more challenging, but Tom was able to count
them and noted 5.

This would indicate no lesser nighthawks were observed !

Assuming this character is a deciding factor.

At least we learned a lot about the difference between lesser and common
nighthawks and had a great time birding with people from access the state.
The house project is further behind schedule but the distraction was worth it
for a potential state life and county bird.

Attached are a few representative photos I edited ( low res screen shots for
OBOL ) of the nighthawks at Page Springs CG on 9/23 and 9/25. There are more.
Tom gets the award for the best photo. Where is Owen Schmidt when you need him!

Cheers

Rick

Sent from my iPhone

Rick Vetter  cotingas@xxxxxxxxx <mailto:cotingas@xxxxxxxxx>

Phone 541-589-2230


                      “Even the worst handwritten notes are better than the
best memory or technology”

Sergej Postupalsky, eagle researcher

On Oct 3, 2021, at 3:44 AM, Paul T. Sullivan <paultsullivan@xxxxxxxxxxxx
<mailto:paultsullivan@xxxxxxxxxxxx> > wrote:

I’d like to think that with 40 years of experience, top of the line optics,
careful reading of field guides, and careful observation, I could identify a
bird.

I set off for Malheur NWR a week ago and joined several other birders to try to
see the Lesser Nighthawks reported near Page Springs campground.

On Friday, Sept 24, 3 birds appeared in the distance north of us, flew back and
forth in the sunset, eventually came right over us, and disappeared up the
canyon.  Two had wings with rounded tips, broad bases, and amber speckling on
the underside.   The other bird had longer wings with a sharp tip, a narrower
base, and dark wing linings. It was difficult to judge the position of the
white bar.

On Saturday, Sept 25, we had better views, with the birds flying back and forth
right above us.  I got a satisfying view of the position of the white wing bar,
which seemed to be 2/3 of the distance from the wrist to the wingtip.  Lesser
Nighthawk.

Then came the analysis of the photos obtained by 3 of the party and digging in
reference sources to compare Common vs Lesser Nighthawk.

Wingtip:  field guides say Common has pointed wingtips and Lesser has rounded
wingtips with P10 shorter than P9.

Despite what field guides say, a careful research paper from 1985 says that 1/6
of Common Nighthawks have at least one rounded wingtip, with P10 shorter than
P9.

Position of white wing bar: field guides say Common has the bar half way from
the wrist to the wingtip and Lesser has the bar 2/3 of the way from the wrist
to the wingtip.

No argument there, but it is difficult to see and judge on a flying bird in
fading light at dusk.

Number of primary feathers included in the white bar. National Geographic Field
Guide, 3rd edition, shows this if you use a magnifying glass.

Research paper says Common Nighthawk has 5 feathers within the white bar;
Lesser has four.

This is NOT a field mark that can be seen with binoculars on a flying bird.
Lucky photos are needed to catch this.

Buffy spots on the inner portion of the primaries: Sibley’s 2nd edition shows
this on perched and flying birds.  Lesser Nighthawk has this.  Common Nighthawk
lacks this.

This field mark I thought I saw with binoculars on flying birds both Friday and
Saturday evenings.

Width of the base of the wing:  Common Nighthawk is narrow; Lesser Nighthawk is
broad.

I thought I was seeing this.

All the photos obtained show 5 feathers in the white wing bar, indicating that
the birds were Common Nighthawk with rounded wingtips, not Lesser Nighthawks.

So an eyeball view by an experienced old birder with good optics and a careful
reading of the field guide isn’t enough.  It takes a lucky capture of photos by
a high-end camera and digging in research literature to get to the
identification.  I’m out of my league.  :(

Or else, by chance, the only photos that show the number of feathers with the
white bar were all photos of a Common Nighthawk, and none captured a Lesser
Nighthawk.

I d’know.

Paul Sullivan

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Follow-Ups:
- [obol] Re: Page Springs Nighthawks - a lesson, and a caveat
  - From: Andrea Ogston
- [obol] Re: Page Springs Nighthawks - a lesson, and a caveat
  - From: Tim Rodenkirk
- [obol] Re: Page Springs Nighthawks - a lesson, and a caveat
  - From: Rick Vetter

[obol] Re: Page Springs Nighthawks - a lesson, and a caveat

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