The Caspian Tern is a large tern found across temperate and tropical regions of the world. But how did this striking seabird get its name? In this article, we’ll explore the origins and meaning behind the Caspian Tern’s name.
What is the Caspian Tern?
The Caspian Tern (Hydroprogne caspia) is the largest tern in the world. It has a wingspan of around 1.5 meters and can grow up to 56 centimeters long. Adults have a black cap, white cheeks, and a stout red-orange bill. Their upper body is pale gray, while their underparts are white. In breeding plumage, their cap is jet black and their underparts are finely speckled with gray markings. Juveniles have black bills and a mottled black-and-white cap and body.
Caspian Terns are found across marine and coastal habitats in temperate and tropical regions around the world. They breed in colonies, nesting on bare or sparsely vegetated ground near the coast. Their diet consists mainly of small fish, which they catch by plunge diving into the water. They also opportunistically scavenge dead fish and marine invertebrates.
Range and Habitat
Caspian Terns have an extremely large global range. They are found across marine and coastal areas of Europe, Asia, Africa, Oceania, and the Americas. Their breeding range centers around temperate and tropical coasts. After breeding, they disperse more widely along marine coasts and inland waterways.
They utilize a variety of coastal and inland wetland habitats. Breeding colonies are typically situated on sandy or gravelly beaches, barrier islands, shell banks, salt marshes, lakes, reservoirs, and river systems. Outside of breeding season, they frequent estuaries, tidal flats, offshore waters, lakes, and rivers.
Conservation Status
Due to their large range and population size, Caspian Terns are considered a species of Least Concern by the IUCN Red List. However, in some regions they are threatened by habitat loss, human disturbance of breeding colonies, and pollution. Their sensitivity to disturbance makes protection of breeding sites an important conservation priority.
Origins of “Caspian Tern” Name
The Caspian Tern was scientifically named and described in 1764 by the German naturalist Peter Simon Pallas. Its original scientific name was Sterna caspia. The genus name Sterna refers to “tern”, while the species name caspia indicates that the species inhabited the Caspian Sea region.
Who was Peter Simon Pallas?
Peter Simon Pallas (1741-1811) was a prominent German zoologist and botanist who made major contributions to the study of Russian flora and fauna. He was born in Berlin and studied natural history at the University of Berlin. Between 1767-1774, he led two major expeditions to Russia on behalf of the St. Petersburg Academy of Sciences. It was during these expeditions that he discovered and described numerous new plant and animal species, including the Caspian Tern during his 1770 expedition to the Volga River delta region.
The Caspian Sea Connection
Pallas bestowed the Caspian Tern with both its common name and scientific name in reference to the Caspian Sea. The sea provided important habitat for the terns. Pallas first observed the species along the western and southern shores of the Caspian during his expedition there.
The Caspian Sea is the largest enclosed inland body of water on Earth. It covers around 371,000 square kilometers and borders five countries: Russia, Kazakhstan, Turkmenistan, Iran, and Azerbaijan. This brackish sea provides prime habitat for seabirds like the Caspian Tern, hosting plentiful fish stocks that they feed on.
Other Species Named After the Caspian
Due to the landmark expeditions of naturalists like Pallas, a number of species found in the Caspian Sea region were named after this important geographic site. In addition to the Caspian Tern, these include:
- Caspian seal – Pusa caspica
- Caspian gull – Larus cachinnans
- Caspian red deer – Cervus elaphus maral
- Caspian cobra – Naja oxiana
So the Caspian Tern shares its name origin story with various other unique species found within the Caspian basin. Pallas left an enduring mark on the region’s natural history through the names he bestowed.
Other Common Names
While its scientific name has remained unchanged, the Caspian Tern goes by a variety of common names across different regions and languages. Some examples include:
- Greater crested tern
- Russian tern
- Gabelschnabel-Seeschwalbe (German)
- Sterne caspienne (French)
- Chorlitos patinegros (Spanish)
However, Caspian Tern remains the most widely used common name for this species in English and many other languages.
Taxonomic Changes Over Time
While the Caspian Tern’s original scientific name of Sterna caspia has stood the test of time, the species has been reclassified under a number of different genera over the years. These taxonomic changes reflect evolving perspectives on the evolutionary relationships between terns and other seabirds.
Original Classification
As mentioned, Pallas originally classified the Caspian Tern in the genus Sterna in 1764. Sterna encompasses typical smaller terns such as the Common Tern.
Placement in Hydroprogne
In 1842, the German ornithologist Johann Jakob Kaup reclassified the Caspian Tern in the newly created genus Hydroprogne, meaning “water tern.” This recognized its larger size compared to most other Sterna terns and its affinities with the Gull-billed Tern.
Back to Sterna
Many subsequent scientists reverted the Caspian Tern back to the genus Sterna for over a century. However, its unique size, ecology, and morphology again prompted reclassification.
Current Classification
Today, most taxonomic authorities recognize the Caspian Tern’s distinctiveness and classify it within Hydroprogne, as originally described by Kaup. Molecular evidence also confirms that it diverged evolutionarily from typical Sterna terns around 14 million years ago.
Its current scientific name is thus Hydroprogne caspia. But Pallas’ original Species name honoring the Caspian Sea remains unaltered from his 1764 description.
Etymology and Meaning of “Tern”
In addition to “Caspian,” the second part of the Caspian Tern’s common name – “tern” – also carries meaning. The word tern traces back centuries and stems from various Germanic languages.
Origins
The word “tern” emerged in the early 17th century from the Middle English term “ternen” and even earlier terms in Old Norse and Old English such as “tharna.” It perhaps originated as an imitation of the sharp, creaking sounds made by terns.
Meaning
“Tern” is thought to mean “third” in reference to the belief that terns were a third type of seabird besides gulls and auks (penguin-like birds). The term has long been used to refer collectively to these slender, lightly built seabirds with long pointed wings, forked tails, and stout pointed bills.
Use Over Time
While originally used to refer to seabirds generally, tern became established from the 17th century onward as a name applying specifically to this family of birds. Today there are over 40 tern species worldwide, with the name referring to members of the Laridae family that display the characteristic tern appearance and behavior.
Conclusion
In summary, the Caspian Tern acquired its enduring binomial name from German naturalist Peter Simon Pallas in 1764. Pallas honored the species’ habitat around the Caspian Sea by naming it Sterna caspia. While its genus assignment has changed over time, the Caspian Sea connection has persisted in this large tern’s scientific name for over 250 years and remains a clue to identifying it among the world’s terns.
