South Texas Birding Trip: Hawkwatch (April 2)

Bikes would've been nice for Bentsen

Our flight home left Harlingen's Valley International Airport at 3:40 PM. We did the travel time math and determined that if we set an alarm and got going early, we could drive the hour to the Bentsen-Rio Grande Valley SP Hawk Watch, observe for at least two hours, then come back to our room and shower, and still make our flight in plenty of time.

We planned to catch the 8:30am tram to the Hawk Tower, but, arriving exuberantly nearly an hour early, decided the 1.8 mile walk would do us good. Biking is also a neat way to visit this park and they can be rented at the visitor center.

Our first bird of the morning was a little Black-crested Titmouse seen pecking relentlessly at his reflection on a drinking fountain button.

Cute Black-crested Titmouse pecking at its reflection in a water fountain button

Susan with HawkCount volunteers, Frank and Carolyn, and other observers

The Hawk Tower was fully ramp accessible, to our surprise. The cloudy morning would provide better contrast for viewing the birds, the two volunteers up top explained. Conditions this morning were similar to yesterday so we were hopeful for a repeat performance. But the counts vary in a random fashion, one of the volunteers offered, with high counts being correlated only to his days off!

Broad-winged Hawk

It was surprisingly cool at the top of the tower, from which we could see quite a bit south into Mexico. The volunteers were happy to share their knowledge, both in identifying the raptors and explaining what was happening.

The mission of HawkWatch International includes education, conservation and research, including monitoring migration through many HawkCount migration observation sites in North America and Panama. The Rio Grand Valley sees a great concentration of hawks through its flyway, yet only Bentsen and Santa Ana NWR, a mere 10 miles apart, have hawk count sites.

Observers on the Hawk Tower

The birds would be counted as they came up from Mexico, crossed roughly overhead, then headed north. Early in the morning as the air warmed and created thermals, the hawks would leave their roosts and spiral upward in the thermals, usually in groups called kettles. When the thermals could carry them no higher, they would begin to stream northward in a mostly single file, which also made counting easier.

A "kettle" of Broad-winged Hawks became part of our morning count

It was a coordinated group effort by the two volunteers (both named John) leading the count, other experienced counters who showed up throughout the morning, and a few newbies like ourselves, all using spotting scopes and binoculars to spot rising kettles on the horizon, call them out to the group, then wait for them to stream out and be counted and recorded. Later in the morning the birds we saw had roosted further south so that by the time they reached us, they were already streaming high overhead, acheiving heights of 10,000 feet!

Broad-winged Hawk

It was exciting to see several kettles at once, and we can only imagine the thrill of being there on a record day like the previous one when thousands were counted. By far the largest number of birds of the 9 species we saw during the count were Broad-winged Hawks. Their silhouette is permanently etched on our brains, those broad wings allowing them to travel great distances without flapping. They don't even stop to feed during their migration which can take them as far as 4,000 miles.

It was a respectable showing of over 450 Broad-winged Hawks, but we hope to experience a hawk count with numbers in the thousands some day. It is possible to see these hawks migrate in September in Pennsylvania, and we hope to see that someday. We are fortunate to have a hawk count site not too far from us at Dinosaur Ridge in Morrison, Colorado.

Here is the observation report from the HawkCount website of our morning count at Bentsen.

One other fun thing about the morning was the cloud cover. It not only kept things a little cooler, but at times, the clouds almost totally obscured the sun, allowing you to cautiously look at it directly for a few seconds. Another hawk watcher, Frank, noted that by carefully using this technique with binoculars he could see a sunspot. So Mike tried the same technique to get this photo of the filtered sun and some easily visible sunspots.

Several sunspots were visible on the sun

Taking the tram back to the visitor center was welcome in the mid-day heat plus had the benefit of visiting with fellow birders who highly recommended a trip up to the Falcon Dam. We also visited with some folks about the Gray's Shorebird Festival in Washington and got some great tips which we will be able to use very soon. (-:

With plenty of time to make our flight home, we stopped for a late lunch at Pepe's Mexican Restaurant. We quickly returned our rental car and breezed through checkin and security and were impressed with the convenience of this modern little airport. Good to know since we will undoubtedly be back.

Yummy food at Pepe's Mexican Restaurant in Harlingen

This was an excellent trip and very productive for our life list. We added about 30 new birds: Altamira Oriole, American Golden Plover, Anhinga, Black-bellied Whistling Duck, Black-chinned Hummingbird, Blue-gray Flycatcher, Broad-winged Hawk, Brown-crested Flycatcher, Buff-bellied Hummingbird, Clay-colored Thrush, Common Pauraque, Crimson-collared Grosbeak, Fulvous Whistling Duck, Glossy Ibis, Gray Hawk, Green Heron, Green Jay, Green Kingfisher, Hooded Oriole, Inca Dove, Least Grebe, Least Sandpiper, Louisiana Waterthrush, Northern Beardless Tyrannulet, Olive Sparrow, Pectoral Sandpiper, Plain Chachalaca, Scissor-tailed Flycatcher, Stilt Sandpiper, White-eyed Vireo.

Still, there were birds and area wildlife we were keen to see but didn't -- maybe next time:  Ringed Kingfisher, Aplomado Falcon, Groove-billed Ani, Green Parakeet, Red-crowned Parrot, Zone-tailed Hawk, White-tailed Kite, Kemp's ridley sea turtle and hatchlings, and of course the Ocelot.

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