The Lower Rio Grande Valley is famous for
its spring migration: during the peak times of
mid-April to mid-May, if you get a good storm
front coming in from the north (stopping the
migrants in their tracks as they arrive after just
having crossed the Gulf of Mexico), the birding
can be fabulous! Fall birding isn't quite
as predictable (we don't get many storm fronts
coming up from the south, halting the southbound
migrants before they cross the Gulf), but
it can still be exciting!
One thing many people don't realize is that,
for some birds, migration actually starts in midsummer!
The shorebirds that nest in the high
arctic arrive at the breeding grounds, raise their
kids, and start south before the cold weather
sets in, so they can show up here in the Valley
in July, with peak numbers in August (Upland
and Buff-breasted Sandpipers, Wilson's
Phalarope), September (Semipalmated Plover
and Sandpiper, Solitary Sandpiper, Whimbrel,
Red Knot) and continuing well into October
(Baird's and Pectoral Sandpipers). Many target
shorebirds, such as Piping Plover, Long-billed
Curlew, and Stilt Sandpiper, start showing up
in August and then spend the winter with us,
not heading north again until May or June!
The Bayside Flats at South Padre Island (located
just north of the Convention Centre) is
a great place to look for shorebirds as one can
drive right up to them (a higher-clearance vehicle
is recommended, however, as while the
sand is pretty hard packed under the multiple
big "puddles" that congregate between you and
the birds, they can look rather intimidating)!
Back on the mainland, the nearby Port Isabel
Reservoir on Holly Beach Road (just off FM
510) can be another great place to study shorebirds,
depending on the water levels. If you
haven't gotten enough of driving on the beach,
a run down to Boca Chica Beach will allow
for that, depending on the tides and surf (Note:
Non-US citizens will need to show a passport
at the Immigration Check Point), and north of
the Island, at Port Mansfield, you can observe
shorebirds from the comfort of their new sheltered
overlooks.
Any of the myriad small wetlands and resacas
can also be productive; a few of our favorites
include the "SR 100 Resacas" located just west
of the US77/SR100 intersection, the "Rangerville
Resaca" south of Harlingen on Rangerville
Road and just south of Jimenez Road, and
the multiple ponds within Estero Llano Grande
State Park. If the water is low enough, Delta
Lake (off FM 88) and Sugarhouse Pond (off FM
1425 north of SR 107) can also be very good.
For the "grasspipers", one of the best spots is
the Superior Turf Farms (locally known as the
Weaver Road Sod Farms), located just north of
Jimenez Road; great viewing is had right from
Weaver Road!
September is the big push for many land
birds: Hawk migration is probably the most
famous (the big push of Broad-winged Hawks
takes place about that time, with lesser numbers
of Mississippi Kites, and even more rarely
Swallow-tailed Kites), and October is the peak
for Swainson's Hawks and nightjars (seeing
one of the latter is a challenge); Bentsen Rio
Grande State Park holds weekly hawk watches
during September, so this is a great time to
learn raptor ID skills!
Songbirds such as Baltimore Orioles and
Ruby-throated Hummingbirds can also come
through in staggering numbers in September,
along with smaller numbers of the expected
migrant vireos. Almost all the migrant flycatchers
are present in September, as well as
many of our warblers (see below). Some of
our migrants breed just north of the Valley, so
expect Louisiana Waterthrushes and Orchard
Orioles to show up as early as July!
Warblers such as Yellow-throated, Yellow,
Worm-eating, Canada, Wilson's, and Yellowbreasted
Chats start coming through in August,
followed by Northern Parula, American
Redstart, Northern Waterthrush, and Mourning
Warbler in September. Some of the later migrant
warblers, such as Ovenbird and Tennessee,
Hooded, and Magnolia Warblers, won't
pass through until October. As in spring, the
Convention Centre on South Padre Island
(along with the Birding and Nature Center) can
be good places to look for migrant land birds,
but in fall they can show up most anywhere, so
checking out any of our wooded migrant traps
such as Quinta Mazatlan in McAllen, Frontera
Thicket in Weslaco, Santa Ana NWR in Alamo,
or even Edinburg Scenic Wetlands should
be worthwhile.
A great resource for finding out what occurs
when is John Arvin's Birds of the South Texas
Brushlands, a bar-graph checklist available online
at Texas Parks and Wildlife.