Spring is in the air! As we experience warmer temperatures here in sunny Southwest Florida, we are also rapidly approaching breeding season for many animals in our region. If any of you are bird-nerds like me, you may have noticed some changes in the appearance of many of the gulls on our beaches in the past few weeks. These birds are undergoing molting, which is similar to how snakes shed their skin, but for birds this is the annual or bi-annual replacement of feathers.
We have three species of gulls frequenting our beaches at this time of year – herring gulls, ring-billed gulls, and laughing gulls. The laughing gull is one of the most common gulls in our region and is easily recognizable by its vociferous call. You may see this bird frequenting beaches and parking lots, scavenging for a bite to eat and even dive-bombing beachgoers for French fries. What may be a run-of-the-mill seagull to most, this avian friend is an excellent model to examine plumage changes in birds.
Let’s start with a little ornithology jargon. Plumage refers to the arrangement, color, and patterning of bird feathers. Depending on the species, birds have 3 types of plumage – basic, alternate, and juvenile. Basic plumage is the coloration of feathers a bird wears fall through spring, or the non-breeding season. This type of plumage is generally plainer, drab, and muted in coloration. On the contrary, a bird’s alternate plumage is the coloration of feathers that the bird dons during the breeding season, typically spring and summer. This plumage is much more vibrant and usually consists of intensely bright colors and striking patterns. So for an example, some of our gulls on Sanibel are beginning to replace their basic feathers with their alternate plumage, which we call a prealternate molt.
Juvenile laughing gulls almost always stand out from the flock because their very first set of feathers is mostly mottled brown. You can tell if a gull is experiencing its very first winter because it will have begun to replace some of the brown juvenile feathers with solid grey and white flight feathers, which lay across the dorsal and lateral portions of their body at rest. We call this a first-cycle gull.
Adult laughing gulls during the breeding season don a crisp, black hood that fades to a mottled black cap in the winter months and has a bright red-orange bill and legs. The interesting thing about these gulls, and many other members of the family Laridae, is that it may take 2-3 years for them to reach this full adult plumage. After the first year, young adults will have the same characteristics as mature adults, but have black legs and a black bill instead of red.
Throwing all of these different variables into the mix when trying to identify a gull to species is definitely a challenge – but it is a fantastic learning process that allows us to become better birders! I challenge you all to take a closer look at the gulls that inhabit our beautiful beaches and try your hand at a little bird identification!