DFW Urban Wildlife

Denton County – March 20, 2019

Every year when the skies turn cold and gray, Ring-billed Gulls leave their summer breeding grounds in the North American interior and fly away to the south. They migrate en masse, and many find their way into the Dallas/Fort Worth area where they stay to overwinter.

These are not the sea birds that most people think of when they imagine gulls. Ring-billed Gulls are just as likely to frequent the American heartland as the coast. In the metroplex you will find these birds congregating in shopping center parking lots, landfills, and area lakes and ponds.

Dietary generalists, these birds are able to feed on a wide variety of food stuffs. This is the trait that draws them to our urban areas. Ring-billed Gulls thrive in the presence of people. They feed on our scraps and garbage, and take refuge on our man-made lakes and reservoirs.

This small lake in Denton County is a perfect example. Approximately one thousand or so Ring-billed Gulls have gathered at this fortuitous conjunction of parking lots, landfills, and other water features–just the type of urban environment these gulls prefer.

Most of these gulls will soon be heading back to their breeding grounds in the north. We won’t see them again until next autumn when this cycle of nature repeats. For more information about Ring-billed Gulls, visit Wikipedia. Here is a snippet from the article found there…

The ring-billed gull’s breeding habitat is near lakes, rivers, or the coast in Canada and the northern United States. They nest colonially on the ground, often on islands. This bird tends to be faithful to its nesting site, if not its mate, from year to year.

The ring-billed gull is a familiar sight in parking lots of the United States, where it can regularly be found congregating in large numbers. In some areas, it is displacing less aggressive birds such as the common tern.

They are migratory and most move south to the Gulf of Mexico and the Atlantic and Pacific coasts of North America, and the Great Lakes.

This gull is a regular wanderer to western Europe. In Ireland and Great Britain it is no longer classed as a rarity, with several birds regularly wintering in those countries.

Ring-billed gulls forage in flight or pick up objects while swimming, walking or wading. They also steal food from other birds and frequently scavenge. They are omnivorous; their diet may include insects, fish, grain, eggs, earthworms and rodents. These birds are opportunistic and have adapted well to taking food when discarded or even left unattended by people. It is regarded as a pest by many beach-goers because of its willingness to steal unguarded food on crowded beaches. The gull’s natural enemies are rats, foxes, dogs, cats, raccoons, coyotes, eagles, hawks, and owls.

For most of the time I was present at the lake, the group of gulls was peaceful and calm, save for the constant drone of squawks and occasional jockeying for position. In the next moment, the congregation erupted as something unseen spooked the entire flock. A white-feathered explosion rose into the air.

As the congregation began to settle once again, I noticed a few outlier individuals. Occasionally, other gull species will mix in with a mass of Ring-billed Gulls. On this day, it was the distinctive Franklin’s Gull that joined in with the larger congregation at a ratio of one to several hundred.

Franklin’s Gulls pass through Dallas/Fort Worth in the spring and fall during their long migration between North and South America. While here they may drop in temporarily to rest and recharge for the remainder of their journey. This is how Wikipedia describes the Franklin’s Gull…

The Franklin’s Gull breeds in central provinces of Canada and adjacent states of the northern United States. It is a migratory bird, wintering in Argentina, the Caribbean, Chile, and Peru.

The summer adult’s body is white and its back and wings are much darker grey than all other gulls of similar size except the larger laughing gull. The wings have black tips with an adjacent white band. The bill and legs are red. The black hood of the breeding adult is mostly lost in winter.

Young birds are similar to the adult but have less developed hoods and lack the white wing band. They take three years to reach maturity.

Although the bird is uncommon on the coasts of North America, it occurs as a rare vagrant to northwest Europe, south and west Africa, Australia and Japan, with a single record from Eilat, Israel, in 2011 (Smith 2011), and a single record from Larnaca, Cyprus, July 2006.At the beginning of 2017 has been observed also in Southern Romania, southeast Europe.

They are omnivores like most gulls, and they will scavenge as well as seeking suitable small prey. In the spring, on rivers such as the Bow River large groups will float with the current, sipping the emerging insect hatch. The behaviour includes floating through a particular stretch and returning repeatedly to the same section.