09/29/2017 So Many Birds in So Little Time

9/29/2017 – So Many Birds in So Little Time (Karen Benson)

Hazel Bazemore Park has a raised viewing platform overlooking the Nueces River. This gives hawk watchers a broad vista in which to search for migrating raptors. The “peak” is from September 23-30 when over 100,000 raptors might be seen on a single day. Robert Benson photo.

It was a traffic-stopping moment.  At least, we stopped!  We were leaving Wal-Mart in Beeville, when something caught my eye.  We parked and got out to look at the sky.  The white clouds were peppered with black specks.  Lots of them.  I knew what we were seeing.  It was a flight of migrating hawks on their way south for the winter.

With binoculars, we got a better look and attempted to count the birds.  In the rotating column of hawks, called a “kettle”, the birds spiraled upwards on a rising thermal.  We estimated over a thousand individuals in this one kettle.  Then, two more kettles, each larger than the last, came into view.  Between the kettles, thousands more hawks streamed from one thermal to the next.  We were looking at ten thousand birds, maybe more.  This was a huge flight!

Broad-winged Hawks migrate in large flocks. A flock can easily contain a thousand individuals. The birds ride the rising air of a thermal up to the base of a cloud, then glide down until they encounter the next thermal. This way they can travel more than 60 miles a day with only a few wingbeats. Robert Benson photo.

We were beginning to draw a crowd.  A couple of old folks with binoculars staring at the sky is just a little bit weird for Beeville.  People stopped to ask what we were observing, and we pointed out the specks.  The birds at the bottom of the kettles were discernable as soaring hawks, with their wings and tails spread.  Some observers questioned if they might be vultures, but it was easy to see the lowest birds were whitish underneath, with black wingtips and stripes across the tails.

These were Broad-winged Hawks.  Every autumn, nearly all of the Broad-winged Hawks leave their breeding grounds in the eastern half of North America.  For a few short weeks they ride the thermals, gliding from thermal to thermal, ever southward.  The flocks travel about 60 miles a day, going from North America through Central America and on to South America, without ever crossing salt water.  Their “ride”—the rising warm air producing the thermals—only occurs over land, and only during the day.  At night, the hawks stop rest and feed in forested areas.  The whole trip takes them about 70 days.

This map shows HawkWatch International’s monitoring sites in North America. Site Twelve, with the highest average annual count, is our own Hazel Bazemore Park in Corpus Christi. Hawk Watch International map.

The migrating hawks follow ridges and mountain ranges as these produce updrafts.  The rising air gives the birds an appreciated uplift.  Every mile they can achieve by soaring saves them energy they would otherwise have to expend by flapping their wings.  So, they take advantage of every air current they can to speed them on their way.  This fact has led observers to pinpoint a number of locations where the hawks can be seen regularly, especially in the fall.  These locations have become popular hawk-viewing sites.  They are also great places to observe and count the hawks as they pass by.  HawkWatch International and Hawk Count.org are two of the organizations that monitor migrating hawks at several sites across the United States.

When you look at a map, you notice that our continent narrows down into Texas and further narrows in Mexico and Central America.  This means raptors from the entire continent funnel into a slender pathway.  As the corridor shrinks, the birds are concentrated into a smaller space.  So, hawk-watching sites in South Texas and Mexico are especially good places to get a feel for the size of raptor populations in North America.

The Celebration of Flight has something for everyone. Information tables display snakes, skulls, and skins to intrigue young visitors. Hummingbird feeders are alive with hummers and orioles. And, of course, the sky is full of raptors! Robert Benson photo.

One of these sites is Hazel Bazemore Park in Corpus Christi, Texas.  The park is on the high bank of the Nueces River.  A special viewing platform has been built to make it easier to watch for migrating birds.  Every day, from mid-August until mid-November, birdwatchers and official counters scan the skies for hawks.  Some species come through as single individuals (Peregrine Falcons, for instance) while others pass the site in swirling flocks.  On some days, especially if there is a north wind, as many as 100,000 migrating birds can be seen.  On those days, the official counters have their hands full!

But, don’t take my word for it—go to Hazel Bazemore and see for yourself.  They are celebrating the flight of the hawks with identification help, information, and activities.  There is no cost and it is fun for all ages.  How many hawks will you see?