Monday, January 26, 2015

Checking Out the Gulls on Lake Norman

Yesterday I joined six other local birders for several hours of birding-by-boat at Lake Norman. Our primary goals were to look for a red-throated loon that had been seen recently; and to check out the huge evening gull roost in the Davidson Creek main channel.

Temperatures on land were at 60 F when we embarked at 2:00 PM, but it was soon evident that I would need the three layers of shirts, heavy coat, toboggan, and gloves that I wore.. It was cold out there on the water in a moving boat!

Immediately we began seeing common loons, not a rare sight on the lake in winter. We checked every loon carefully, but no red-throated turned up. A few ring-billed gulls had already started to form some small flocks resting on the water while some Bonaparte’s gull flocks hovered over the water’s surface.

We also started seeing large numbers of horned grebes on the open water. Their habits are similar to loons but they are much smaller. Some years they can be more challenging to find but this is apparently a good year for them here.

We boated around Nantz Cove and were treated to an adult bald eagle circling overhead. A few minutes later an immature bald eagle flew right by. By that time we noted increasing numbers of gulls heading for Davidson Creek so we turned to that direction. When we arrived at the roost site off Torrence Chapel Road there were already several thousand gulls massed up on the water. We carefully scanned the growing flock as more seemed to literally pour down from the sky. A few herring gulls started mixing in with the ring-billeds. Herring gulls make a up tiny percentage of the total gull numbers, but when there are 10,000 gulls it is easy to find a few herrings. It is also easy to pick them out because most are brown immature birds; quite a different look from the ring-billed gulls.

By 5:30 PM the fading light made viewing difficult so we headed in without finding the target loon or any rare gulls. We’ll check the flock again in a month or so. There are just too many birds out there for there not to be something really good. 

Below are some photographic comparisons of the three most common gull species on area reservoirs in the winter:

The ring-billed gull is the most common species. This is the gull you might see flying over any part of the county, sitting in parking lots, or pilfering french fries at fast food restaurants. The bird below is an adult in winter. Note the ring around the bill, gray mantle, white underparts, yellow legs, and yellow eye.

Adult Ring-billed Gull by Taylor Piephoff

Ring-billed gulls take two years to mature, so there are two distinct plumages. This is first-winter bird. Note the bi-colored bill, browner plumage, flesh colored legs, and dark eye.

First Winter Ring-billed Gull by Taylor Piephoff

First-winter herring gulls are easily picked out of the ring-billed gull flocks. Note the overall brown plumage, mostly dark bill, and flesh colored legs. they are also about one third larger than ring-billed gulls.

First-winter Herring Gull by Taylor Piephoff

Adult herring gulls rarely show up in winter at Lake Norman. Compare with the adult ring-billed gull. Note the more massive bill with no circling ring, and flesh colored legs. Unlike ring-billed gulls, herring gulls take four years to mature so there are four distinct plumages. Only two are shown here today. 

Bonaparte's gulls are small, dainty gulls that pick food off the surface of the water. Flocks of Bonaparte's gulls hover over feeding loons in hopes of scavenging some fish scraps. Note the long, thin black bill, and black spot behind the ear of the winter birds. The white leading edge of the wings is also a helpful identification mark.
Adult Bonaparte's Gull by Jeff Lewis