The photo this week is of a sooty tern by Jeff Lemons
Tropical systems are well known for their ability to displace seabirds caught up in the center of rotation. A land-falling storm brings birds, many from tropical open ocean with it, and they stay with it until they can exit as it weakens.
How fast the system moves inland and how long the storm maintains integrity determines what birds, and how many, might appear at a given locale. Seabirds that are strong flyers; gulls, shearwaters, petrels, and jaegers; will usually exit the storm first.
Lighter, more buoyant flyers like terns, will stay with the storm longer. The location of the center of rotation makes a difference too; birds exit on the east side of the center so areas to the east of the center get the birds.
In 1989 Hurricane Hugo was still an organized minimal hurricane or very strong tropical storm when it passed just west of Charlotte. A fast mover, Hugo dumped hundreds of gulls, terns, storm petrels and shorebirds at area reservoirs.
Irma, a slower mover that had spent more time over land before passing to our west on Sept. 12 apparently displaced terns as the most prevalent group of affected birds at our reservoirs. She was also responsible for grounding many migrating shorebirds.
The effects of Irma were far-reaching though. Displaced seabird and grounded shorebird reports came in from coastal beaches, eastern Piedmont reservoirs, and mountain reservoirs and turf farms. She was a significant mover of birds.
A group of local birders birded Lake Norman by boat that day and proved that Irma’s passage had brought some real local rarities our way. A sooty tern provided a first county record for Mecklenburg and a great black-backed gull provided a first photographically documented occurrence for the county.
A large exposed mud bar just off Governor’s Island in Lincoln County was a haven for some locally rare shorebirds forced down by the unsettled weather. That day, six species of shorebird were present; ruddy turnstone, semipalmated plover, buff-breasted sandpiper, sanderling and white-rumped sandpiper were all tallied.
That’s a banner day for birding in the southwestern Piedmont.
It was a bit painful for me to hear that a boatload of birders got to add sooty tern and great black-backed gull to their Mecklenburg County lists. I do not have either of those species on my list. I had work obligations. It will likely take another similar weather phenomenon to bring those birds back to Mecklenburg.
Taylor Piephoff is a naturalist with an interest in the birds and wildlife of the southern Piedmont: PiephoffT@aol.com.