This paper will detail information related to the sighting of a juvenile dark morph Rough-legged Hawk at the Coastal Bend Hawk Watch, Hazel Bazemore County Park, Corpus Christi, Texas, on September 27, 1997.

The Coastal Bend Hawk Watch has existed since the l970s.  It originally was a picket line of observers over many miles.  In fall 1988, the watch initiated a single observation point atop the ridge at Hazel Bazemore County Park.  The watch provides a commanding view west, north, and east for miles.  The view to the south is somewhat obscured by trees related to the l7th tee-box of a golf course.

Since 1988, the watch has grown in popularity and importance.  The watch proved that hundreds of thousands of raptors migrate through the coastal bend of Texas en route to Central and South America.  Raptors occurring in largest numbers are Broad-winged Hawks and Mississippi Kites.  As the watch became manned over additional days and hours, more and more species were detected, including Prairie Falcon and Ferruginous Hawk.  The watch initiated a two-man confirmation rule to document all dark-morph Broad-winged Hawks.

On September 27, 1995, the hawk watch had its first Rough-legged Hawk.  It was a light morph.  Multiple observers identified it among a kettle of Broad-winged Hawks.  It was substantially larger than the adjacent Broad-winged Hawks, had long, narrow wings, and prominent dark carpal patches.  Observers viewed this RL through both l0-x binoculars and 20-x scope.  It was below and to the side of a kettle of Broad-winged Hawks.  The sighting was between 1400 and l500 hours.  Field notes do not relate the size of the kettle but document that the hour experienced 1,520 BWs in that hour.

It also should be remembered that heavy snows fell in the Rockies around September 20-22, 1995.  Indeed, the HMANA Texas Regional Editor flew back from Alaska via Seattle and Memphis and observed snow through the Rockies and Great Plains on the return flight.  This cold weather likely produced the large number of Ferruginous Hawks that the hawk watch recorded around in that time period: l, 1, and 4 on September 17, 20, and 23 respectively.

In 1997, the Coastal Bend Hawk Watch moved from volunteers over a l0-day period to paid observers working a minimum of 8 hours a day from August 15 to November 15.

The sighting of the juvenile dark morph RL occurred on Saturday, September 27, 1997.  Skies were clear blue without clouds.  In mid-afternoon, a monster flight began.

It can only be described as a constant, raging river of hawks.  The flight continued non-stop for at least 25 minutes.  The BWs came from the east and the northeast, which shows that they were coming down the Texas Coast.  The total number of BWs documented in the flight was officially 76,000, although at least two other qualified  observers independently counted 84,000.  Significantly, there were seven dark morph Broad-winged Hawks confirmed in this flight under the two-observer rule.  The dark morph BWs suggest that the flight originated in the northwestern portion of the Canadian province of Alberta.

Initially the streams were to the east of the watch.  The air was heavy, and the hawks were unable to gain great heights.  Triple-decked boiling kettles were common along the stream.  Gradually, the stream drifted to the immediate area of the hawk watch.

The stream began to kettle just above the hawk watch at about l5 degrees off vertical.

Multiple observers simultaneously called out that there was a big dark raptor amongst the kettle.  At least six seasoned hawkwatcher observers saw the raptor.  It was easily viewed at flight level 3 with the standard l0X binoculars used at the watch.

Here is what was observed:

(l)  The binocular field depicted at 10-x about l0-12 BWs in a kettle accompanied by the dark raptor.

(2)  The dark raptor was substantially larger than the BWs.  As the dark raptor circled eight or so times, BWs were both above and below the dark raptor.

(3)  Body was dark.  It lacked a white breast patch or white markings anywhere on its body.

(4)  Underwing coverts were uniformly dark with light primary and secondary flight feathers.  Dark carpal patches were profoundly visible.  The dark carpal patches were visible in two visual modes.  First, in part of the turn, the sun hit directly on the underside of the wing.  Second, in another part of the turn, the sun came through the top and depicted the dark carpal patch even more profoundly.  The hawk lacked white commas in the wing.

(5)  Wings were long and pointed.  The wings did not pinch in at the waist.

(6)  The raptor was not seen from above, even in its turning circles.

(7)  Tail was light with a light dusky band at the end.

The overall appearance of the bird is very similar to the black and white drawing of the juvenile dark morph RL on plate 26 of Clark & Wheeler’s Peterson Field Guide HAWKS.  The dark carpal patch was more prominent than the patch displayed on plate 26.  The RL12 photograph of a juvenile dark morph RL on page 112 of Clark & Wheeler’s A Photographic Guide to North American Raptors also is similar, but not as good as the B&W drawing, in my opinion.

The instant unanimous opinion of the multiple observers was that it was an immature dark morph RL.  An attempt to photograph the raptor with a 600 mm lens was unsuccessful as the hawk and its kettle had moved behind the trees by the time the camera and its tripod could be obtained.

So why wasn’t this some other species?

It clearly was not a juvenile White-tailed Hawk.  Two adult White-tailed Hawks are resident in the watch area.  Observers are very familiar with this coastal Texas species.  However, it was not a WTH for several reasons:

    (1)  The wings did not pinch in at the waist like a WTH;

    (2) The dark raptor lacked any white breast patch; and

    (3) The raptor had thinner wings than a WTH.

It was not a dark morph Broad-winged Hawk.

    (1)  The raptor was much larger than the other BWs; and

    (2) It lacked multiple bands in the tail like a dark morph BW.

It was not a dark morph Swainson’s Hawk.  The dark morph Swainson’s Hawk has dark flight feathers.  This raptor had light flight feathers.

It was not a dark morph Ferruginous Hawk.  The raptor lacked the white comma in the carpal area.

It was not a dark morph Red-tailed Hawk or Harlan’s  Red-tailed Hawk.  It lacked any white breast markings that are typical of a Harlan’s.  It did not have a profound dark trailing edge to the flight feathers.

It was not an eagle, as eagles generally have dark flight feathers, plus this raptor was not as big as an eagle.

Hawk Mountain suggested the possibility of a dark morph Short-tailed Hawk.

I must admit that colors are intriguingly similar.  However, the Short-tailed Hawk is only marginally larger than a BW, and this raptor was substantially larger than the BWs in the kettle.  Also, this monster flight had several dark morph BWs and approached from the east and the northeast, and such composition and flight direction suggest the raptor did not come from Florida or Mexico.

Another commentator suggested the bird was a Honey-Buzzard from Europe, as its dark morph has dark carpal patches.  The muse fails.  Unlike the RL at Hazel Bazemore, the Honey-Buzzard has dark secondary flight feathers below.

In the final analysis, the dark carpal patches were profound and specific for a Rough-legged Hawk.

It also is of interest that multiple observers of the Panhandle Bird Club saw a dark morph RL east of Pampa, Texas on September 20, 1997.

Dr. David Mindell reports in 5 Ralph Palmer, Handbook of North American Birds:  Diurnal Raptors (Part 2), at 165 (1988) that, “A few (Rough-legged Hawks) are early travelers both in fall and spring, and migration is protracted and on a broad front.  The birds go farther s. from Tex. to Ariz. than elsewhere.  First winter birds are recognizable from older ones, and there is evidence both from observation and collection that younger Roughlegs tend to travel farther, and males farther than females … Some Roughlegs apparently vacate n. breeding range early, especially in poor lemming years. A few arrive on winter range even before the end of Aug., yet most evidence does not indicate leaving the breeding range until around mid-Sept.—Oct.  Numbers of migrants increase through Sept., and main passage in s. Canada and coterminous U.S. occurs in Oct.”

It also is noted that the web page for Hawk Ridge, MN states that the earliest date that watch has experienced for a RL is September 6, some three weeks before this RL appeared at the Coastal Bend Hawk Watch. If one scans the Internet search engines for Rough-legged Hawk, one will find an entry that details early September arrivals of Rough-legged Hawks for Illinois and Indiana.   Hawk Ridge observers have seen Rough-legged Hawks flying with Broad-winged Hawks.  In his classic monogram, Bent also details a report where Legs have migrated with Wings.

The raptor was unmistakably a juvenile dark morph Rough-legged Hawk that was out of place and out of time.