Birds are familiar and welcomed sights along the Lake Pontchartrain Causeway. Brown pelicans set their large wings and glide amazingly close to motorists on the bridge. And large, frenzied swarms of purple martins appear at each end of the bridge at sundown during certain times of the year. Now some rare birds have also decided to make the Causeway their home, although largely out of sight. Several groups of brown boobies, large brown-and-white, fish-eating sea birds commonly seen farther south in tropical waters, have taken up residence alongside and beneath the Causeway. Bridge General Manager Carlton Dufrechou said about nine...