Tricolored Herons Courting. Photo by Joel Jackson.
Creep quietly to the edge of a Florida pond or wetland, and you might see a dark shadow at the very corner of your vision. Standing statue-still over the surface, a Tricolored Heron suddenly slashes its head through the reeds, its bill spearing an unsuspecting frog. Gobbling down its meal, the heron spreads its wings and flies to a new hunting location, revealing a flash of its white belly.
“Multicolored Heron” might be a more accurate name for this small wading bird, formerly known as the Louisiana Heron. Their plumage changes in color rather dramatically from the juvenile stage, when they are mostly brown with blue accents, to their adult form: slate gray with mauve tones. They always have a white belly, but during the breeding season (May – July), they become even more vibrant. Tricolored Heron bills and facial skin take on a bright, cobalt blue hue and their dull, yellow legs transform into pink. Why? These coloration infusions are all about attracting a mate.
Tricolored Herons are Florida residents that typically nest in multi-species colonies on small islands in bays and estuaries. They also nest around ponds or lakes, where alligators on patrol deter raccoons and other swimming mammalian predators.
Constructing the stick nest is part of their courtship ritual. The males generally supply the sticks, while the female weaves them into a shallow platform with a central depression. Grasses and soft vegetative matter is added to the nest as a cushion for three to four light blue eggs, which hatch in about 24 days. The chicks are flight-capable after about five weeks but are fed by their attentive parents until they are three to four months old.
Although they seem to be expanding their range northward, Tricolored Herons are listed as a “Threatened” species by the Florida Fish and Wildlife Conservation Commission because their population numbers are in decline across Florida. They are threatened by development, harmful algal blooms, and alteration of the freshwater wetlands where they actively feed, usually alone, on small fish, crayfish, insects, tadpoles, frogs, lizards, and even spiders.
Disturbance at the nesting islands is also a concern, which is why Audubon volunteers monitor colony sites throughout the nesting season as part of Project Colony Watch. Staff with the Coastal Islands Sanctuaries install signs at estuary-island nesting sites that are managed by Audubon Florida to alert boaters and paddlers to steer clear. They also conduct surveys, manage habitat, remove fishing tackle that can entangle adults or young, and monitor the progress of nests.
Mary Keith, President of Tampa Audubon Society and Colony Watcher for the Lake Forest Bird Colony in east Hillsborough County, said, “I love watching the baby birds as they grow up, being fed by their parents. I love the noise – the cacophony – it’s an orchestra of so many different sounds from the adults and chicks. My colony has nine species and over 100 nests, so it’s a huge variety of birds to watch and keep track of.”
In Florida Bay, monitoring data are showing an increase in Tricolored Heron nesting activity. Thanks to the dedicated efforts of Audubon biologists and others to study these small waders, there appear to be more of them in Florida Bay and southern Biscayne Bay now than there were before 2000. Local land managers directly use the survey data from South Florida colonies from the South Florida Wading Bird Report, which is also used as a tool for regional habitat management.
Audubon’s Project ColonyWatch relies on volunteer bird-watchers to adopt and protect local waterbird colonies. By recruiting and training volunteers to become the local "wardens", biologists, and advocates for a nesting colony, we can increase the effectiveness of our colony protection efforts across Florida. Check out the ColonyWatch handbook, or, to get involved, email us at firstname.lastname@example.org.