Life of a Florida Rooftop Nesting Tern

by Lyndsey Christopher, Rooftop Seabird Field Technician
three least terns on a gravel rooftop

After a long and exhausting migratory journey from South America, a female Least Tern arrives in the Florida Panhandle just in time for breeding season. With increasing habitat loss and human disturbance along the beaches, this Least Tern has decided to return to a building with a gravel rooftop where she has nested in previous years. Upon arrival, she is immediately greeted by the calls of all the other Least Terns there to nest on the same rooftop. This is, quite literally, “great to hear:” Least Terns are colonial nesters, encouraging strength in numbers to help deter predators such as crows, gulls, and raptors. 

A nearby male Least Tern has just arrived back with a fish and is calling out to the females in the colony. The female begins chasing the male throughout the sky. Shortly after, they both land. The male offers the fish in hopes of mating. Success!

Now it is time to make a nest. Seabirds do not nest like a typical songbird up in a tree; instead, they make shallow scrapes in the sand or gravel. Both the male and the female make several scrapes, but ultimately the female will decide where to nest. After laying two beautifully speckled eggs, it is now time to incubate and protect. Not as easy as it sounds. With record breaking heat sweeping through the State of Florida, this Least Tern must find a way to keep the eggs cool. Luckily, there is a small retention pond nearby that can be used to cool down and act as a food source. After about 21 days, a small sand-colored fluff ball emerges from an egg. It’s a chick! Shortly after the other egg hatches. This hardworking mother’s job just got much more difficult, but luckily Least Terns have excellent coparenting skills. Time to feed, feed, and feed some more. 

Both parents work together to protect and feed the young chicks. The mother comes back to feed her chicks to find they are already running around only a few days after hatching. She circles the rooftop and calls out with a fish between her bill. The chicks come running, mouths wide open screaming out to be fed!

A view from the ground looking up as birds flock to a rooftop.
Terns approach a rooftop nesting site. Photo: Sydney Walsh/Audubon

While begging for more food, a dark shadow from the sky approaches. It's a crow! Sound the alarm. The chicks instinctually retreat to nearby cover, like an air conditioning unit, while all the parents mob the crow continuously until it gives up its predation attempt and flies off. Whew, that was a close call! The parents continue to fly to and from the nearby pond to feed their little ones, until the sun goes down. 

A new day awaits this Least Tern family. As the chicks continue to develop and become more mobile, they begin to explore the rooftop, at times getting too close to the roof’s edge. Unfortunately, a chick has found its way off the rooftop and onto the pavement. The parent notices immediately and circles the chick on the ground in distress. Not to worry, a volunteer steward conducting a routine fallen chick check spots the little one and contacts Audubon Florida staff for assistance. With the help of a contraption made from a milk carton attached to an extension pole, the chick is safely returned to the rooftop where it can be cared for by its parents.

Only three weeks after hatching, the chicks are starting to flap their wings and slowly get off the ground. With several failed attempts at flying, they are finally lifting off in short bursts. Once these chicks get more comfortable flying, they will move to the nearby pond. The young must now learn to fend for themselves by catching their own fish. 

The fledged chicks may spend another two months with their parents, learning the essential skills needed to survive. They will need to gain the strength needed for the difficult journey ahead back to South America for the fall and winter. 

Against all odds, this remarkable mother has completed yet another successful breeding season — one of many stories unfolding across rooftops and shorelines every summer, reminding us of the delicate balance between nature and the built environment.

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