Golden Triangle Bird Alert -- April 9, 2010

After a relatively slow period for migrants, good variety but small numbers being the order of most days, Friday turned into a good day in the late afternoon.  Reports from the morning were of very few migrants in the early hours.  A report from the middle of the day had more, while a report from the 3:30 to 6:00 p.m. period showed a good variety and probably the highest numbers of the season so far.  In the late afternoon period, the larger birds came in first, followed by the vireos and then the warblers.

Sixteen species of warbler were recorded: Northern Parula (10 birds), Black-and-white (8), Hooded (7), Prothonotary (5). Palm Warbler (2 Western, 1 Eastern), Tennessee (4), Yellow-throated (3), Blue-winged (2), Northern Waterthrush (2), Black-throated Green (1), Kentucky (1), Worm-easting (1),  Louisiana Waterthrush (1), and Yellow-rumped (40), Orange-crowned (6), and Common Yellowthroat (5).

Red-eyed Vireos were numerous (30), followed by White-eyed (25) and Yellow-throated (11). Summer Tanagers were present (13 males), as were Rose-breasted Grosbeak (1 male), Blue Grosbeak (2 males).  Of the thrushes, Wood Thrush (50) were most numerous with Swainson's (35) not far behind.  Flycatchers were represented by Eastern Wood-Pewee (2) and Great-crested Flycatcher (2).  There were lots of sparrows in the woods of the species that have wintered there (Lincolns', White-crowned, White-throated and Swamp.

The Updates with full details of the days earlier in the week are posted on the web site at www.goldentriangleaudubon.org in the News Items. 

Those who have read the Updates will know that I have been trying to analyze the relationship between the birding and the weather.  Today, I am frankly puzzled.  While the wind at Merida late last night although northerly (NE to be accurate) was modest at 7 m.p.h., the surface wind at the buoy about 300 miles almost due south of Sabine Pass at 9:00 a.m. this morning is reported as NE at over 20 m.p.h.  With northerly winds prevailing over seemingly most of the southern Gulf, apparently at strengths that would cut the groundspeed of the birds from 25-30 m.p.h. to perhaps as low as 5-10 m.p.h., it seems unlikely that the late afternoon migrants today came across from the Yucatan.  Our knowledge of bird endurance is not complete, but there is little proof of migrant landbirds being able to fly for the 48 hours non-stop that would be necessary to fly from the Yucatan to Sabine Pass in the condition prevalent over the last couple of days.  (There is good evidence that Blackpoll Warblers in the fall fly out from New England SE over the Atlantic non-stop to at least the Caribbean Islands if not the northern coast of South America, a trip which must involve non-stop flights of much, much more than the normal Gulf of Mexico crossing, so perhaps we are not giving warblers the credit they deserve for endurance.)

For those wanting to know about tomorrow, let me just give you the raw data.  The wind this evening at Merida is N at 14 m.p.h. (about double what it was yesterday and the day before at the same time), the wind at the buoy about 300 miles S of Sabine Pass is NE at 15 kts (about 19 m.p.h.) and the wind here in SE Texas is SE at 6 m.p.h.  The wind over the northern Gulf is apparently more or less easterly.  There is some cloudiness/disturbed weather on the satellite picture about 100-150 miles south of the Upper Texas Coast. Could this result in a repeat performance tomorrow?  Did most of the birds assembled on the Yucatan arrive here today?  Did the stronger northerly wind on the Yucatan about 8 p.m. this evening dissuade birds from leaving on the crossing?  We'll know tomorrow! (or Sunday?)

With thanks for reports from Jana Whittle, Sherrie Roden and John Haynes.

John A. Whittle