More birds appear on coins of St. Helena|
In an earlier issue of World Coin News I told you about the St. Helena plover or commonly called the wirebird that appears on a 2013 St. Helena coin. In this article I will cover the red-billed tropicbird (Phaethon aethereus), masked booby (Sula dactylatra) and band-rumped storm petrel, also called Madeiran storm petrel (Oceandroma castro), all appearing on St. Helena coins.
St. Helena is associated with two other remote islands (dependencies of St. Helena), Ascension (810 miles northwest) and Tristan da Cunha 1,510 miles south from St. Helena. The three are British Overseas Territories.
The specifications of the four coins are: issued in 2013, 25 shillings, base metal, gold plated, diameter 38.6 mm, portrait of Queen Elizabeth II on the obverse.
Red-billed Tropicbird: Phaethon (Gr. the sun) was the name of the genus given by Linnaeus to the red-billed tropicbird in allusion to its attempt to follow the sun. The species name aethereus is Latin for heavenly and was given to this tropicbird for its ethereal plumage and graceful flight.
Tropicbirds spend most of their lives over ocean waters and come to land only to breed There are only three species of tropicbirds in the world. They are: red-bill, red-tailed (P. rubricauda ) and white-tailed (P. lepturus). Tropicbirds were considered formerly to be in the same large group (Order) as pelicans, boobies, frigatebirds, cormorants, and others, but DNA research has revealed tropicbirds have no close relatives and are now in their own order Phaethontiformes.
The red-billed tropicbird has a very large range occurring in tropical Atlantic, Indian and eastern Pacific Oceans. There are records for California, Florida and one for Arizona. The red-tailed occurs in the Indian Ocean, western and central tropical Pacific. The white-tailed is in most of the tropical waters except in eastern Pacific Ocean.
The red-billed is the largest of the three tropicbirds with a total length of 35 to 41 inches. The head and underparts are white, with faint black lines on the white back, wings with black tips, black stripe through the eyes, crimson bill and wedge-shaped tail with two long central tail feathers (18-20 inches) and a wingspan of 39-43 inches.
Typically the red-billed flies well above the surface of the water and often it soars high in the sky. They feed on fish (especially flying-fish) and squid by plunging into the water but only for a few inches.
There are three geographic varieties (subspecies) of this species. The one on the coin is P. a. aethereus. As stated above tropicbirds have to come to land to breed, and this subspecies nests only on two of the islands: St. Helena and Ascension.
This species is monogamous. Nests are but a scrape under rocks, on ledges, in caves or cavities. A pair engages in complicated highly acrobatic courtship flight before mating. One will fly just above the other one with its wings almost touching the wings of the other one. Both swish their streamer tail feathers and go higher and then plunge down to just above the water surface and then spiral upward again. They will repeat this several times and return to the nest site and mate. The female lays one egg and both incubate it for 42 to 44 days. The young fledges in 12-13 weeks. I was unable to find recent population estimates of breeding pairs of this subspecies, but a 1981 estimate for St. Helena was 86 pairs and 600 pairs on Ascension, but another estimate was 500 pairs (see below).
Masked Booby: There are seven species of boobies all belonging to the genus Sula. Boobies are large sea birds of tropical oceans and rare visitors to North America. The masked booby is the largest. Their name may be from the Spanish word bobo, which means “stupid.” Boobies often plop down on the deck of ships, and seamen in early sailing vessels promptly caught them and had a fine dinner that night.
My wife and I were fishing one day in the Salton Sea, which is a large saltwater lake in the desert of southern California, and as we approached a large wooden structure I saw a large bird sitting staring at our approaching boat. We got to within about 20 feet and I recognized it as a blue-footed booby. This is the only booby I have seen. It never did fly off, and we drifted away.
The red-billed booby is 32-36 inches long and the wing span is 60 inches. It has blue-gray facial skin (the “mask”), white head and neck, white body and trailing edge of wings are black.
Masked boobies were very abundant in early 16th century when St. Helena island was discovered, but it did not take long for humans following settlement in 1659 and their mammalian predators (domestic cats, Norway and black rats) to start killing the boobies and eventually wiped them out on the St. Helena mainland. Then in a 2011 scientific paper researchers reported finding the first instance of masked boobies breeding again on the mainland. (Bolton, M. et al. 2011. Re-colonization and successful breeding of masked boobies Sula dactylatra on mainland St Helena, South Atlantic, in the presence of feral cats Felis catus. Seabird 24: 60-71.) They found one pair with a chick, four pairs were confirmed incubating eggs, and 25 pairs apparently incubating eggs. They monitored the sites up to 2010 and they found moderate fledging success. Now there about 150 birds and about 60 nests. They speculated that are fewer cats or cats are preying on other prey more easily killed. Good news indeed!
Band-rumped Storm-Petrel: This is a small family of 20 species 12 of which are in the genus Oceandroma. Storm-petrels are the smallest of the seabirds. The band-rumped is 7-8 inches long with a wingspan of 17-18 inches and weighs a maximum of less then 2 ounces. They are entirely pelagic coming to land only to breed. The family has a cosmopolitan distribution occurring in all oceans. Regrettably, not much is known about their natural history because they are hard to find and identify at sea and when on land they carry out their courtship and mating in the dark.
Members of the genus Oceandroma are mostly restricted to the northern hemisphere. The band-rumped breeds in eastern Atlantic from Azores down to St. Helena and Ascension islands, in the Pacific off eastern Japan, on Kauai, Hawaii, and on the Galapagos. The species is fairly common on mid-Atlantic Coasts off North Carolina and Virginia. A few records of storm driven individuals inland in the U.S.A. They eat small crustaceans, small fishes and other marine animals. They are colonial nesters in rock crevices, and are strictly nocturnal at breeding sites to avoid being eaten by gulls and skuas. They do not even come to land during a full moon. Females lay a single egg. I discovered that by far most of these three species that are associated in the literature with Ascension Island are not on that island, but are on Boatswain Bird Island, a small island (13 acres) less than 1,000 feet from the eastern coast of Ascension. It is solid white due to the bird droppings. The reason birds nest there is because of rats and cats eating the eggs and birds on Ascension. There are thousands of birds using this tiny cat and rat free island as nesting grounds.
For example, 10 percent (1200 pairs) of the Atlantic’s masked booby population use the island for nesting. About 3,000 band-rump storm-petrels nest there and 500 pairs of red-billed tropicbirds nest also here and nearby cliffs of Ascension. White-tailed tropicbirds (2,200 individuals), red-footed bobbies (about 30) and brown boobies (2,000 birds) also nest here. Every square foot of the island will have a nesting seabird. Not any of the four species of birds on the St. Helena coins are on Tristan da Cunha Island, according to the website Avibase.
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