If you are watching shorebirds in Florida, one of the more common types you are bound to see are terns. Terns are sometimes confused with seagulls due to similar appearance and location. However terns are often described as looking more “athletic” with their slender build, narrow pointed wings and sharp bill. In this article we will talk a little about terns and include photos and descriptions of the five most common terns you will see in Florida.
5 Common Terns in Florida
Terns can be difficult to distinguish because so many of the species look very similar to each other. Another thing that can make tern identification tricky is that adult terns will have slightly different plumage during the breeding season versus the nonbreeding (winter) season. We will point out the most noticeable identifying features for each species in our descriptions below.
Let’s talk terns!
1. Least tern
Scientific name: Sternula antillarum
Length: 8.3 – 9.1 inches
Weight: 1.3 – 1.9 ounces
Wingspan: 18.9 – 20.9 inches
Least terns are the smallest terns in the world. About the size of a large songbird like a mockingbird or blue jay. In their breeding plumage least terns have a slender yellow bill, sometimes with a black tip. They have a solid black cap with white on the forehead. Their back and wings are light gray with black on the outer edge of their primary feathers. Legs are yellow.
During the nonbreeding season, their black cap becomes mottled, especially on the top of the head. Their bill will appear dark rather than bright yellow.
The least tern can be found all along coastal Florida, and even inland areas, during the summer. In the winter you may be able to find them along the southern coast, but many move further south. They nest in colonies along the beach, and often nest near black skimmers and piping plovers. Unfortunately this species has been in decline for many years.
2. Caspian tern
Scientific name: Hydroprogne caspia
Length: 18.5 – 21.3 inches
Weight: 18.7 – 27.6 ounces
Wingspan: 49.6 – 50.4 inches
The adult breeding caspian tern has a reddish-orange bill that is larger and “fatter” than most terns. Usually a black or dusky patch can be seen at the tip of the beak. Their forehead and cap are solid black with a slight crest at the back of the head. Feet and legs are also black or dark.
They are the largest of all terns with a large head, stocky body and thick neck. In flight their tail has a shallow fork, and you can see black on the underside of their primary feathers.
During the nonbreeding season their bill can appear a little lighter in color and loose some of that rich redness. Their black cap will become lighter gray and mottled, with some birds showing a white forehead.
Along the northern and central Florida coasts, Caspian terns can be found all year. Along the southern coasts and inland areas of the state they are more prevalent during the nonbreeding winter months.
3. Royal tern
Scientific name: Thalasseus maximus
Length: 17.7 – 19.7 inches
Weight: 13.8 – 15.2 ounces
Wingspan: 39.4 – 43.4 inches
Overall, royal terns are fairly large in size. Their beak is orange without any black marking. They have a more defined crest than other Florida terns, which appears as shaggy feathers at the back of the head.
Feet and legs are black. During the breeding season the cap is black, and during the nonbreeding season it is mottled. For the royal tern, during the nonbreeding season the black cap can retreat back quite far, to the point where most of the forehead is stark white and the dark feathers remain in a shaggy tuft behind the eye at the back of the head.
In flight you can note their long forked tail.
The royal tern can be found throughout the Florida coastline year-round. They stick closely to saltwater habitats, so it is not very common to find them inland. However, you may catch a few around inland waterbodies during the winter.
4. Sandwich tern
Scientific name: Thalasseus sandvicensis
Length: 13.4 – 17.7 inches
Weight: 6.3 – 10.6 ounces
Wingspan: 33.1 – 35.4 inches
Sandwich terns have a slender shape with dark feet and legs.
Their bill is long, thin, and black with a pale yellow tip. That pale tip can sometimes be quite hard to see from a distance. During the breeding season their cap is black and the crest at the back of their head is quite shaggy. In the nonbreeding season, the black retreated to the black of the head and becomes less shaggy.
Along areas of the northern and central Florida coasts, sandwich terns can be found throughout the year. Along the southern coasts and inland areas of the state they are more prevalent during the nonbreeding winter months.
5. Forster’s tern
Scientific name: Sterna forsteri
Length: 13.0 – 14.2 inches
Weight: 4.6 – 6.7 ounces
Wingspan: 30.7 – 31.5 inches
The forster’s tern is a medium sized tern with a slender build. In flight you can notice their long forked tail. Feet and legs are orange.
During the breeding season they have an orange bill with a black tip, and a black cap (no shaggy crest at the back). In the nonbreeding season their beak turns dark and the forehead, top of the head and nape become mostly white while they retain a large black patch around the eyes. Underparts remain very white throughout.
Forster’s tern is common throughout Florida during the winter. Much of the breeding population moves out of the state during the summer months.
As you can see, terns are fairly similar to each other with many subtle differences. Obviously we can’t list every little difference in this article, but we tried to touch on some of the most obvious things to look out for. Here is a short list of some of the best things to take note of when trying to identify a tern:
- time of year (this can affect likely location and plumage)
- body size
- beak color and if it is solid or has a separate tip color
- leg color
- crest at the back of the head, or lack of one
- in flight, does the tail appear slightly forked or very forked
Hotspots in Florida to see Terns
Really, during the right time of year a tern could turn up at just about any beach in Florida. However these shorebird hotspots would be a good place to start.
- Fort Pierce Inlet State Park
- St. George Island
- St. Vincent National Wildlife Refuge
- Biscayne National Park
- Manatee County
- Amelia Island State Park
- Everglades National Park
- Perdido Key State Park
- Fort George & The Talbot Islands