Thursday, June 25, 2015

One Good Tern...

Three pairs of interior least terns were seen on the nesting platforms near the C and D Pad Roads area at Hagerman National Wildlife Refuge  this month.  Maybe the courtship behavior (offering a minnow) in one of the photos is a sign of good things to come! 

Last week, Rusty Daniel confirmed at least two nests with one egg each that were being incubated.

Thanks to Rusty  and to Gary Hall for checking on the platforms and getting these  photos to share.

Habitat for the Least Tern, as described by Cornell Lab of Ornithology on All About Birds is “Seacoasts, beaches, bays, estuaries, lagoons, lakes and rivers, breeding on sandy or gravelly beaches and banks of rivers or lakes, rarely on flat rooftops of buildings.” You can add to that the  two artificial nesting platforms at Hagerman National Wildlife Refuge, especially designed and built by Refuge employees for the Least Tern. Funding for the project was provided by Jetta Operating Company, Inc and the Nancy Ruth Fund.

The first of two artificial nesting platforms (above) was  completed and put in place the summer of 2013.  A second platform was constructed and was to be "launched" in 2014 but those plans were on hold due to drought - there was no water in the area where the platform was to go! And for the record, the one-legged Terns are in this photo from 2013 are decoys!

Tern decoy carved by Dick Malnory

The Least Tern, the smallest American Tern, is an 8 to 9 inch bird, with a black "crown" on the head, a snowy whiter underside and forehead, grayish back and wings, orange legs, and a yellow bill with a black tip. Males and females are similar in their appearance. The name “Interior” is attached to Least Terns who breed in isolated areas along the Missouri, Mississippi, Ohio, Red, and Rio Grande river systems. They winter in coastal areas of Central and South America.

Interior Least Terns at HNWR, photographed by Eileen Sullivan in June, 2011

The Interior Least Tern is endangered due to loss of habitat, primarily because of changes in river systems and competition from recreational development. Terns arrive at the breeding ground in late spring – early summer and spend several months there. Nesting in small colonies, Terns scratch out a shallow depression in sand or gravel for a nesting spot. The female lays 2 – 3 eggs in 3 – 5 days. Both parents take turns incubating the eggs for about 3 weeks. Chicks hatch one per day and leave the nest a few days after hatching but continue to be fed and cared for by adults.

Terns feed on small fish and aquatic creatures and can be seen hovering and diving for prey, as well as skimming for insects.

Tern in flight, photographed by Mike Chiles

Terns usually return to the same nesting area year after year. Before the launch of Tern Island I and II, the birds chose the rocky surface of the Pad roads for their nursery, completely vulnerable to predators and extreme summer heat; the successful hatch rate was low to none.  

Nesting Tern, photographed  by Jack Chiles in 2011 on one of the Pad roads at HNWR.

Hopefully,  the platforms at the Refuge will provide a safe nursery environment for a successful hatch this year.

In addition to All About Birds, information for this post came from Texas Parks & Wildlife and from US Fish & Wildlife.

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